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WO2016103734A1 - Reflective mask and method for manufacturing same - Google Patents

Reflective mask and method for manufacturing same Download PDF

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Publication number
WO2016103734A1
WO2016103734A1 PCT/JP2015/006487 JP2015006487W WO2016103734A1 WO 2016103734 A1 WO2016103734 A1 WO 2016103734A1 JP 2015006487 W JP2015006487 W JP 2015006487W WO 2016103734 A1 WO2016103734 A1 WO 2016103734A1
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WO
WIPO (PCT)
Prior art keywords
reflective mask
pattern
manufacturing
light shielding
shielding frame
Prior art date
Application number
PCT/JP2015/006487
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French (fr)
Japanese (ja)
Inventor
慎平 近藤
泰史 西山
福上　典仁
陽 坂田
英樹 古野
Original Assignee
凸版印刷株式会社
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Publication date
Application filed by 凸版印刷株式会社 filed Critical 凸版印刷株式会社
Publication of WO2016103734A1 publication Critical patent/WO2016103734A1/en

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • G03F1/22—Masks or mask blanks for imaging by radiation of 100nm or shorter wavelength, e.g. X-ray masks, extreme ultraviolet [EUV] masks; Preparation thereof
    • G03F1/24—Reflection masks; Preparation thereof
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • G03F1/38—Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • G03F1/38—Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof
    • G03F1/44—Testing or measuring features, e.g. grid patterns, focus monitors, sawtooth scales or notched scales

Definitions

  • the present invention relates to a photomask used when a semiconductor device or the like is manufactured by a lithography technique and a manufacturing method thereof. More specifically, the present invention relates to a reflective photomask applicable to pattern transfer using light having a wavelength in the extreme ultraviolet region as a light source and a method for manufacturing the same.
  • EUV light Extrem ultraviolet light with a wavelength of 13.5 nanometers (nm) is hereinafter referred to as “EUV light”.
  • the refractive index of all materials is close to 1 and the absorption coefficient is large, so that exposure using a transmission optical system using refraction is performed. Can not. Therefore, an exposure apparatus of a reflective optical system using a multilayer mirror in which materials having a large refractive index difference are alternately stacked is used. Specifically, a multilayer film of molybdenum (Mo) and silicon (Si) is mainly used.
  • a region (hereinafter referred to as a light-shielding frame) having a higher light-shielding property of EUV light than a normal absorption layer on the outer periphery of the chip on the mask.
  • Such a shift causes a malfunction due to an overlay error of each layer when a semiconductor device composed of a plurality of layers is sequentially manufactured in a lithography process. Even if it is not a direct device pattern, for example, if a chip alignment mark is arranged, even if alignment adjustment is performed by an exposure apparatus, it will be transferred after being reduced slightly from the design and transferred onto the wafer. This is a factor that degrades the positional accuracy of the image. Further, such a pattern misalignment caused by digging up the multilayer reflective layer occurs not only when the light shielding frame is formed, but also in a reflective mask in which the multilayer reflective layer is dug to form a circuit pattern.
  • the present invention has been made in view of the above problems, and has as its main object to provide a reflective mask in which the pattern position in the vicinity of the digging area does not shift even when the multilayer reflective layer of the reflective mask is digged. It is.
  • An aspect of the manufacturing method of the reflective mask according to the present invention is as follows.
  • the position change amount of the circuit pattern in the vicinity of the digging region formed by the digging is calculated by a prior experiment or a mechanical simulation prior to the digging, and based on the calculation result, before the digging
  • the circuit pattern is formed by correcting the deviation amount in advance.
  • Another aspect of the reflective mask manufacturing method corresponding to claim 3 of the present invention is: 3.
  • the length measurement pattern includes a corrected pattern in the vicinity of the light shielding frame and an uncorrected pattern, the corrected pattern and the uncorrected pattern.
  • the length measurement pattern is formed so that the positional change amount information can be obtained by calculating the difference between the patterns.
  • Another aspect of the reflective mask manufacturing method corresponding to claim 6 of the present invention is: According to a fourth aspect of the present invention, there is provided a reflective mask manufacturing method, wherein the pattern position correcting means corrects a drawing driving position when drawing original design data.
  • Another aspect of the reflective mask manufacturing method corresponding to claim 8 of the present invention is: The reflective mask manufacturing method according to claim 7, wherein the position correction region is divided into a plurality of segments, and correction is performed with a correction amount required for each segment.
  • Another aspect of the reflective mask manufacturing method corresponding to claim 9 of the present invention is: 9. The method of manufacturing a reflective mask according to claim 8, wherein the correction amount applied to each segment is obtained by fitting the position change amount calculated by the experiment or the dynamic simulation by a polynomial approximation formula, and the polynomial approximation formula. The correction amount is calculated using the above.
  • the method of manufacturing a reflective mask according to claim 10 is characterized in that the length of one side measured in the vertical direction from the light shielding frame of each segment is in the range of 1 ⁇ m to 100 ⁇ m.
  • the pattern position correction method is a combination of a correction method by dividing the position correction region into a plurality of segments and a magnification correction.
  • Another aspect of the method for manufacturing a reflective mask corresponding to claim 14 of the present invention is as follows: 7. The method of manufacturing a reflective mask according to claim 6, wherein the circuit pattern is drawn using a correction map created so as to correct the position change amount of the pattern position in the vicinity of the light shielding frame. To do.
  • the reflective mask manufacturing method corresponding to claim 15 of the present invention.
  • the reflective mask manufacturing method corresponding to claim 17 of the present invention.
  • FIG. 1 is a schematic cross-sectional view of a general EUV mask blank.
  • Explanatory drawing which shows the coordinate axis showing the position on a mask board
  • the graph which shows the result of having calculated the deviation
  • the graph which shows the result of having calculated the difference of the deviation
  • Explanatory drawing which shows the enlarged plan view near the light-shielding frame of a reflective mask, and a correction
  • the pattern position in the vicinity of the light shielding frame does not shift even if the light shielding frame is formed by digging the multilayer reflective layer of the reflective mask.
  • a reflective mask is provided.
  • FIG. 1 illustrates a cross section of a general EUV mask blank 100.
  • the EUV mask blank 100 is provided on the substrate 01, the multilayer reflective layer 02 provided on the substrate 01 and reflecting EUV light, the protective layer 03 provided on the multilayer reflective layer 02, and the protective layer 03. And an absorption layer 04 on which a pattern is formed.
  • a conductive film 05 for using an electrostatic chuck is formed on the back side of the substrate surface on which the above layers are formed.
  • an ultra-low thermal expansion glass (low thermal expansion material, hereinafter sometimes abbreviated as LTEM) made of silicon oxide containing titanium oxide is used.
  • LTEM low thermal expansion material
  • the multilayer reflective layer 02 that reflects EUV light a layer in which 40 to 50 pairs of silicon and molybdenum are alternately stacked with a film thickness of about 4 nm and 3 nm when the wavelength of light is 13.5 nm is used.
  • a film for protecting the surface of the multilayer reflective layer 02 is often formed on the surface of the multilayer reflective layer 02, which is referred to as a capping layer or the like.
  • the absorption layer 04 is a substance having a property of absorbing EUV light.
  • a film containing tantalum as a main component is used and may have a multilayer structure for the purpose of increasing the sensitivity of pattern defect inspection.
  • the form of the light shielding frame 21 having a low EUV light reflectivity shown in the embodiment of the present invention is a groove formed by digging from the absorption layer 04 to the multilayer reflective layer 02 of the reflective mask, and this light shielding frame 21 is formed.
  • a reflective mask provided with the light shielding frame 21 having a high light shielding property with respect to the exposure light source wavelength is formed.
  • the multilayer reflective layer has an internal stress in the compression direction.
  • the compressive stress is released at the end face where the multilayer reflective layer is interrupted. Comparing the elastic modulus of the glass used as the LTEM and the multilayer reflective layer, the multilayer reflective layer is several times larger. For this reason, the multilayer reflective layer is deformed in the direction in which the multilayer reflective layer extends toward the outside on the inner side of the light shielding frame and toward the inner side on the outer side of the light shielding frame, and stops where the force that repels the glass due to the deformation is balanced.
  • the amount of change in the position of each circuit pattern due to such deformation is the Poisson's ratio for each of the materials 01 to 05 constituting the reflective mask blank 100 such as LTEM, multilayer reflective layer 02, protective layer 03, and absorbing layer 04.
  • the reflective mask blank 100 such as LTEM, multilayer reflective layer 02, protective layer 03, and absorbing layer 04.
  • physical property values such as Young's modulus
  • the stress of the multilayer reflective layer 02 can be measured from the amount of deflection caused by the stress by measuring the flatness of the surface before and after forming the multilayer reflective layer 02.
  • an equation called a Stoney equation representing the relationship between the radius of curvature and the stress may be applied, or more precisely, it may be obtained by fitting with a result calculated by software for structural analysis.
  • FIG. 2 shows the coordinate axis representing the position on the mask and the light shielding frame 21 formed on the mask with the center of the 6-inch square reflective mask 200 as the origin.
  • FIG. 3 shows the result of calculating the positional deviation (positional change amount) in the X direction for each point on the film surface on the X axis, using the simulation for structural analysis described above.
  • the light shielding frame 21 is formed between a position of 52 mm and a position of 54 mm in the X-axis direction from the center of the substrate and has a width of 2 mm.
  • FIG. 4 is a diagram obtained by subtracting the result of calculating the deviation amount in the X direction in the same manner in the absence of the light shielding frame 21 from the result of FIG. 3, and represents the difference in displacement amount in the X axis direction depending on the presence or absence of the light shielding frame 21.
  • the displacement can be calculated from the structural analysis simulation. Further, the positional change amount of each point in the Y-axis direction can be calculated in the same manner as in the X-axis direction.
  • the pattern position shift due to the formation of the light shielding frame 21 is corrected by using the change amount of the pattern position obtained from the simulation software for structure analysis and the experiment in this way.
  • FIG. 5 is a schematic plan view of the reflective mask 200.
  • the reflective mask 200 includes a light shielding frame 21 and a pattern region 22 having a substantially square outer edge when the upper surface is viewed from the front.
  • FIG. 6 is an enlarged view of the vicinity of one side of the square of the light shielding frame 21, and shows a position correction area 23 for correcting a positional deviation of the pattern.
  • the position correction area 23 is at most 5000 ⁇ m in the vertical direction from the end of the light shielding frame 21.
  • the position correction region 23 is a direction orthogonal to one side of the light shielding frame 21 from a straight line that forms the outer edge of the end of the pattern region 22 that is a boundary position with the light shielding frame 21 when the upper surface of the reflective mask 200 is viewed from the front.
  • This is a frame-like region having a width of 5000 ⁇ m or less as measured toward the center of the reflective mask 200.
  • the upper limit value of 5000 ⁇ m of the width of the position correction region 23 is a viewpoint in which the light shielding frame 21 and the pattern region 22 are efficiently arranged on the mask.
  • the upper limit value of the width can be appropriately set according to the shape and dimensions of the reflective mask to be applied, the desired pattern region 22 and the desired light shielding frame 21.
  • the shape of the light shielding frame 21 may be other than a square, for example, a rectangular shape.
  • the width of the light shielding frame 21 may be formed so that the length is different between the long side and the short side, for example.
  • a plurality of chip patterns can be formed in the pattern region 22 to cope with multi-sided layout.
  • the portion corresponding to the position correction area 23 of the pattern area 22 is determined according to the position change amount calculated by a prior dynamic simulation or experiment.
  • the circuit pattern is drawn using the corrected design data.
  • the reflective mask manufacturing method according to the embodiment of the present invention as a method of performing correction processing on design data and generating corrected design data, first, as shown in FIG.
  • the data of the pattern area 22 in the area 23 can be divided into a plurality of segments 24.
  • FIG. 7 illustrates a state in which the position correction area 23 is divided into a plurality of segments 24 at equal intervals d.
  • the positional deviation is corrected in a state where the segment 24 is divided and the multilayer reflective layer 02 is deformed based on the positional deviation amount of the pattern position obtained from the structural analysis simulation or experiment. Even if it exists, it can do by setting the arrangement position of the segment 24 in the design data after correction so that the pattern position is in a state close to the design value or close to the design value.
  • the correction amount to be applied to the arrangement of each segment 24 is a correction calculated using a polynomial approximate expression by fitting the relationship between the position change amount calculated by experiment or dynamic simulation and the distance between the light shielding frames 21 using a polynomial approximate expression. Use quantity.
  • one point or one side of the pattern data is fixed, and the positional deviation of the pattern position is corrected by correcting the magnification in the correction area. That is, the dimension of the circuit pattern included in the position correction area 23 can be changed.
  • FIG. 8A shows a corner (corner) of the light shielding frame 21 and a position correction region 23 in the vicinity of the corner.
  • a correction target range is fixed at a point 26 fixed in the position correction area 23, and magnification correction is performed, or FIG.
  • FIG. 8C and FIG. 8D there is a method in which the correction target range is fixed at the side 27 to which the correction area is fixed, and magnification correction is performed.
  • the correction factor 1 / (1 + a) can be calculated using a which is a coefficient of x in the linear approximation formula, and this value is set as the correction factor.
  • the present invention does not limit the approximation expression, and may use a second-order or higher-order polynomial or other function, or may divide the position correction region 23 into a plurality of parts. May be obtained.
  • the position correction area 23 is shown having a width of about 0.5 mm from the position of about 51.5 mm to the position of about 52.0 mm from the mask center.
  • the width of the position correction region 23 is not limited to 0.5 mm, and can be set with a value obtained by an empirical rule. The present inventors have found that when the width from the end position of the pattern region 22 is 100 ⁇ m or more and 200 ⁇ m or less, the position correction region 23 overlaps the region most distorted by digging, and the correction effect is great.
  • Processing for dividing such data into a plurality of segments 24, pattern position arrangement, and data magnification correction can be performed by mask data preparation (MDP) software. Further, in the embodiment of the present invention, it is possible to perform correction by performing magnification correction for each segment 24 by combining division of the segment 24 and magnification correction. Since the distortion of the multilayer reflective layer 02 due to the digging increases as it goes from the center of the mask toward the end of the pattern region 22 as shown in FIG. 4, the correction amount applied to each segment 24 is specifically: It is calculated so as to increase in a staircase (step) direction from the center of the mask toward the end.
  • pattern position correction methods include a method for correcting the drawing position when drawing the original design data.
  • the drawing driving position correction method corrects the drawing driving position so that the pattern position becomes as designed when the light shielding frame 21 is formed, based on the positional deviation amount of the pattern position obtained from structural analysis simulation or experiment. There is a way to do it. In other words, the circuit pattern on the design data side is not corrected, but the part corresponding to the position correction region 23 at the drawing driving position is corrected on the drawing apparatus side according to the position change amount calculated by a prior mechanical simulation or experiment. And draw. Specifically, for example, a drawing correction map is created so as to correct the drawing driving position in consideration of the position shift amount (position change amount) obtained by calculation. A circuit pattern can be actually drawn on the surface of the mask blank using this correction map.
  • the length measurement pattern that is formed in the vicinity of the light shielding frame 21 and is formed to obtain information on the amount of change in position includes a corrected pattern and an uncorrected pattern.
  • a method of creating an uncorrected pattern there is a method of drawing before or after drawing a pattern obtained by performing correction processing on an uncorrected pattern.
  • the length measurement pattern can be composed of an uncorrected length measurement pattern 34 a and a corrected length measurement pattern 34 b so that their shapes and dimensions are different from each other.
  • the uncorrected length measurement pattern 34a and the corrected length measurement pattern 34b have a cross shape (plus) when the top surface of the reflective mask 200a is viewed from the front, and are corrected.
  • the length measurement pattern 34b has a shape reduced at a fixed rate with respect to the length measurement pattern 34a without correction.
  • the uncorrected length measurement pattern 34a forms a basic pattern with respect to the corrected length measurement pattern 34b.
  • the uncorrected length measurement pattern 34a and the corrected length measurement pattern 34b As a method of using the uncorrected length measurement pattern 34a and the corrected length measurement pattern 34b, first, an area where the light shielding frame 21 is to be formed (light shielding frame formation scheduled area) on the surface of the reflective mask blank. Two length measurement patterns 34a and 34b are formed in the vicinity of. Then, the respective dimensions of the two length measurement patterns 34a and 34b are measured, and the difference between the dimensions is calculated from the measurement result. Then, after forming the light shielding frame 21 by digging the light shielding frame formation scheduled region, the respective dimensions of the two length measurement patterns 34a and 34b are measured again, and the dimensions of the two length measurement patterns 34a and 34b are measured. Calculate the difference again. By comparing and analyzing the difference in dimension before digging and the difference in dimension after digging, information on the amount of change in position can be obtained.
  • another length measurement pattern 34 c is provided in a region outside the light shielding frame 21, and this length measurement pattern 34 c is combined with the length measurement patterns 34 a and 34 b inside the light shielding frame 21.
  • Information on the position change amount may be obtained.
  • the position of the length measurement pattern 34c outside the light shielding frame 21 is used as a reference position, and the length measurement pattern 34a inside the light shielding frame 21 before and after the duplication of the multilayer reflective layer 02 is made with respect to this length measurement pattern 34c. It is also possible to measure the position and calculate the amount of displacement displaced by digging.
  • the length measurement patterns 34a, 34b, and 34c can be formed in shapes other than a cross shape such as a triangular shape or a rectangular shape as long as they are easily distinguishable from simple line shapes generally used in circuit patterns. .
  • FIG. 11 and 12A show a reflective mask blank 300 prepared in this embodiment.
  • This blank 300 has a 40-layer reflective layer 02 of Mo and Si designed on a substrate 01 so that the reflectance is about 64% with respect to EUV light having a wavelength of 13.5 nm.
  • a Ru protective layer 03 having a thickness of 0.5 nm and an absorption layer 04 made of TaSi having a thickness of 70 nm are sequentially formed thereon.
  • a positive chemically amplified resist 09 (FEP171: FUJIFILM Electronics Materials) is applied to the blank 300 with a film thickness of 300 nm (FIG. 12B), and first patterned by an electron beam drawing machine (JBX9000: JEOL). After drawing the area and the position correction area, and then drawing the length measurement pattern that has not been corrected in the position correction area, the resist 09 part is obtained by PEB and spray development (SFG3000: Sigma Meltech) at 110 ° C. for 10 minutes. A resist pattern was formed on (FIG. 12C).
  • the absorption layer 04 is etched by CF 4 plasma and Cl 2 plasma using a dry etching apparatus (FIG. 12D), and the resist 09 is peeled and washed, thereby measuring the length shown in FIG.
  • a reflective mask 301 having a pattern for use was prepared.
  • a pattern for length measurement a cross pattern having a width of 2 ⁇ m was arranged on the entire mask at an interval of 1 ⁇ m from the end of the light shielding frame 21.
  • a step of forming the light shielding frame 21 was performed on the pattern region 22 of the reflective mask 301 (FIG. 13A) having the above-described length measurement pattern.
  • An i-line resist 39 is applied to the reflective mask 301 with a film thickness of 500 nm (FIG. 13B), and is drawn and developed there by an i-line drawing machine (ALTA: Applied Materials), so that a light shielding frame is formed later.
  • a resist pattern was formed by removing the region 21 (light shielding frame formation scheduled region 21a) to be 21 (FIG. 13C). At this time, the opening width of the resist pattern was 5 mm, and the resist pattern was arranged at a distance of 3 ⁇ m (micrometer) from the main pattern region 22 of 10 cm ⁇ 10 cm in the center of the mask.
  • CHF 3 plasma pressure in the dry etching apparatus 50 mTorr, ICP (inductively coupled plasma) power 500 W, RIE (reactive ion etching) power 2000 W, CHF 3 : flow rate 20 sccm, processing time 6 minutes, These are the same in the following notation), and the absorption layer 04, the protective layer 03, and the multilayer reflective layer 02 at the opening of the resist 39 are penetrated and removed by vertical dry etching (FIG. 13D, ( e)), a shape as shown in FIG. 13 (e) was obtained.
  • ICP inductively coupled plasma
  • RIE reactive ion etching
  • the resist 39 was stripped and washed with a sulfuric stripping solution and ammonia hydrogen peroxide solution to remove the remaining resist 39 by dry etching (FIG. 13 (f)), and a reflective mask 302 was fabricated.
  • the length measurement pattern was measured with a pattern position accuracy measuring machine (LMS-IPRO: KLA-Tencor), and the positional deviation of the pattern position due to the formation of the light shielding frame 21 was calculated from the measurement results before and after the light shielding frame 21 was formed.
  • LMS-IPRO KLA-Tencor
  • the mask data preparation software is used to divide the data of the pattern area 22 in the position correction area 23 near the light shielding frame 21 into a plurality of segments 24, and the data is calculated by the above experiment. Based on the result of the positional deviation of the pattern position due to the formation of 21, data in which the arrangement position of the segment 24 is set so that the pattern position becomes as designed when the light shielding frame 21 is formed was created.
  • a mask after the correction processing is again applied by applying the steps described with reference to FIGS. 12 and 13, forming the measurement pattern, forming the light shielding frame 21, and shielding the light.
  • the length measurement pattern after the frame 21 was formed was measured.
  • FIG. 14B shows the measurement result of the positional deviation amount of the length measurement pattern after the formation of the light shielding frame 21 of the mask after the correction processing.
  • the present invention when the present invention is applied, there is no pattern displacement due to the formation of the light shielding frame 21. was confirmed.
  • the amount of change in position due to the formation of the light shielding frame 21 was confirmed, and it was also confirmed that the correction amount was appropriate.
  • Example 2 For the mask on which the length measurement pattern was drawn in the same manner as in Example 1, the pattern position deviation amount due to the formation of the light shielding frame 21 was calculated from the measurement results before and after the light shielding frame 21 was formed by the pattern position accuracy measuring machine.
  • the structural analysis simulation calculation was performed for the amount of misalignment in the vicinity of the light shielding frame 21.
  • the Young's modulus and Poisson's ratio of the substrate 01 and the layers 02 to 05 formed on the front and back sides thereof were assumed to be initial values estimated from known literature.
  • the above simulation calculation is repeatedly performed by changing the internal stress of the multilayer reflective layer 02, and the physical property value of the material is adjusted as necessary so that the sum of squares of the difference between the measured value of the positional deviation amount and the simulation calculation value is minimized.
  • the stress of the multilayer reflection layer 02 was calculated, and it was derived that the internal stress of the multilayer reflection layer 02 was a compressive stress of 420 MPa.
  • the average deviation amount in the divided segment 24 was calculated and input to the mask data preparation software as a position correction parameter to create drawing data in which the pattern position in the segment 24 was corrected.
  • the positional deviation of the pattern due to the dug of the multilayer reflective layer 02 is a type in which the circuit pattern is formed by dug the multilayer reflective layer 02 up to the substrate 01 inside the pattern region 22 as shown in FIG. This also occurs in the reflective mask 400.
  • the main pattern which is a design circuit, is arranged on the entire mask surface, and the engraved patterns influence each other.
  • the multilayer reflective layer 02 in FIG. 3 shows a more complicated behavior than the case of the light shielding frame 21 in which only the outer periphery of the main pattern is dug.
  • the amount of positional deviation of each position of the main pattern depends on the distance from the edge of the digging portion, that is, the width of the so-called punched portion. In addition, it depends on the width of the remaining portion. This is because when the remaining pattern is formed, since the line width of the remaining portion is thin in the main pattern, the stress is released toward both sides of the remaining pattern.
  • the reflective mask 400 of the type in which the multilayer reflective layer 02 is dug the calculation of the dynamic simulation is complicated, but the necessary physical parameters are the same as in the case of the light shielding frame 21 described above. This is possible using a film thickness of 01 to 05, Young's modulus, Poisson's ratio, and internal stress of the multilayer reflective layer 02.
  • test pattern assuming a main pattern, for example, a test pattern having the same shape as the main pattern is arranged.
  • experiment the required number of times by varying the level of the width of the blank pattern in the test pattern, the width of the blank pattern, the distance between blank patterns, and the distance between blank patterns within the range included in the actual mask. That's fine.
  • Reflective mask 400 formed up to formation: reflective mask d: segment length

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Preparing Plates And Mask In Photomechanical Process (AREA)
  • Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Abstract

Provided are a reflective mask which, even when digging into a multilayer reflection layer of the reflective mask, experiences no shift of pattern position in proximity to the dug area; and a method for manufacturing the reflective mask. This method for manufacturing a reflective mask includes a step for subjecting a reflective mask, in which mask a circuit pattern, or a pattern of a light-shielding frame having low reflectivity of EUV light and situated in at least a portion of an area outside the pattern area where the circuit pattern is arranged, is to be formed by digging into a multilayer reflection layer, to preliminary testing or dynamic simulation prior to digging, to calculate an amount of change of circuit pattern position in proximity to the digging area, and on the basis of the result of the calculation, the amount of shift is corrected in advance prior to digging, and the circuit pattern is formed.

Description

反射型マスク及びその製造方法Reflective mask and method of manufacturing the same
　本発明は、半導体デバイス等をリソグラフィ技術により製造する際に使用するフォトマスクおよびその製造方法に関する。より詳しくは、極端紫外領域の波長の光を光源としてパターン転写を行う際に適用可能な反射型フォトマスクおよびその製造方法に関する。 The present invention relates to a photomask used when a semiconductor device or the like is manufactured by a lithography technique and a manufacturing method thereof. More specifically, the present invention relates to a reflective photomask applicable to pattern transfer using light having a wavelength in the extreme ultraviolet region as a light source and a method for manufacturing the same.
　半導体集積回路は性能及び生産性を向上させるために微細化、高集積化が進んでおり、回路パターンを形成するためのリソグラフィ技術についても、より微細なパターンを高精度に形成するための技術開発が進められている。これに伴い、パターン形成に使用される露光装置の光源についても短波長化が進められ、波長１３．５ナノメートル（ｎｍ）の極端紫外光（Ｅｘｔｒｅｍｅ　Ｕｌｔｒａｖｉｏｌｅｔ光。以下、「ＥＵＶ光」と称する。）を用いたパターン転写のプロセスが開発されている。 Semiconductor integrated circuits are being miniaturized and highly integrated in order to improve performance and productivity, and also with regard to lithography technology for forming circuit patterns, technological development for forming finer patterns with high accuracy Is underway. Along with this, the light source of the exposure apparatus used for pattern formation is also shortened, and extreme ultraviolet light (Extreme Ultraviolet light with a wavelength of 13.5 nanometers (nm) is hereinafter referred to as “EUV light”. ) Has been developed.
　ＥＵＶ光を用いるリソグラフィでは従来の１９３ｎｍ等の深紫外光とは異なり、あらゆる物質の屈折率が１に近い値であり、吸収係数も大きいことから、屈折を用いた透過光学系を用いた露光ができない。そこで、屈折率差の大きい材料を交互に積層した多層膜ミラーを用いた反射光学系の露光装置が用いられている。具体的にはモリブデン（Ｍｏ）とシリコン（Ｓｉ）の多層膜が主に用いられる。 In lithography using EUV light, unlike conventional deep ultraviolet light such as 193 nm, the refractive index of all materials is close to 1 and the absorption coefficient is large, so that exposure using a transmission optical system using refraction is performed. Can not. Therefore, an exposure apparatus of a reflective optical system using a multilayer mirror in which materials having a large refractive index difference are alternately stacked is used. Specifically, a multilayer film of molybdenum (Mo) and silicon (Si) is mainly used.
　マスクについても同様に基板上にモリブデンとシリコンの多層膜を形成した上にＥＵＶ光を高効率で吸収する材料で露光パターンを形成する。たとえば吸収パターンの材料としてはタンタル（Ｔａ）を主成分とするものが典型的に用いられ、多層膜の最上層にはルテニウム（Ｒｕ）などを成分とする保護膜が形成されているものも使用されている。 Similarly for the mask, a multilayer film of molybdenum and silicon is formed on the substrate, and an exposure pattern is formed using a material that absorbs EUV light with high efficiency. For example, as a material of the absorption pattern, a material mainly composed of tantalum (Ta) is typically used, and a material having a protective film composed of ruthenium (Ru) or the like as the uppermost layer of the multilayer film is also used. Has been.
　反射型マスクを用いて半導体基板上に転写回路パターンを形成する際、一枚の半導体基板上には複数の回路パターンのチップが形成される。隣接するチップ間において、チップ外周部が重なる領域が存在する場合がある。これはウエハ１枚あたりに取れるチップを出来るだけ増加したいという生産性向上のために、チップを高密度に配置するためである。この場合、この領域については複数回（最大で４回）に亘り露光（多重露光）されることになる。この転写パターンのチップ外周部はマスク上でも外周部であり、通常、吸収層の部分である。しかしながら、吸収層上でのＥＵＶ光の反射率は、０．５～２％程度あるために、多重露光によりチップ外周部が感光してしまう問題があった。このため、マスク上のチップ外周部に通常の吸収層よりもＥＵＶ光の遮光性の高い領域（以下、遮光枠と呼ぶ）を設ける必要性が出てきた。 When a transfer circuit pattern is formed on a semiconductor substrate using a reflective mask, a plurality of circuit pattern chips are formed on one semiconductor substrate. There may be a region where the outer periphery of the chip overlaps between adjacent chips. This is because the chips are arranged at a high density in order to improve productivity so as to increase as many chips as possible per wafer. In this case, this region is exposed (multiple exposure) a plurality of times (up to four times). The chip outer peripheral portion of this transfer pattern is also the outer peripheral portion on the mask, and is usually the absorption layer portion. However, since the reflectance of EUV light on the absorption layer is about 0.5 to 2%, there has been a problem that the outer periphery of the chip is exposed by multiple exposure. For this reason, it has become necessary to provide a region (hereinafter referred to as a light-shielding frame) having a higher light-shielding property of EUV light than a normal absorption layer on the outer periphery of the chip on the mask.
　このような問題を解決するために、反射型マスクの吸収層から多層反射層までを掘り込んだ溝を形成することで多層反射層の反射率を低下させることにより、露光光源波長に対する遮光性の高い遮光枠を設けた反射型マスクが提案されている（例えば、特許文献１参照）。 In order to solve such a problem, by reducing the reflectance of the multilayer reflective layer by forming a groove dug from the absorption layer of the reflective mask to the multilayer reflective layer, the light shielding property with respect to the wavelength of the exposure light source is reduced. A reflective mask provided with a high light-shielding frame has been proposed (see, for example, Patent Document 1).
特開２００９－２１２２２０号公報JP 2009-212220 A
　しかしながら、この遮光枠を形成する為に多層反射層をエッチングにより除去すると、遮光枠の端部で多層膜の応力が開放されることによって位置ずれが生じる。また、このような変形においては、遮光枠の端部に近くになるにしたがって、その位置ずれ量は大きくなる事が想定できる。このことから、遮光枠内にあって遮光枠端部に近いパターンは基板中心から外側に向かって設計値よりもずれてしまうことになる。 However, if the multilayer reflective layer is removed by etching in order to form the light shielding frame, displacement occurs due to the release of the stress of the multilayer film at the end of the light shielding frame. Moreover, in such a deformation | transformation, it can be assumed that the amount of positional deviation becomes large as it becomes near the edge part of a light-shielding frame. For this reason, the pattern within the light shielding frame and close to the edge of the light shielding frame is shifted from the design value toward the outside from the center of the substrate.
　このようなずれは、複数の層からなる半導体デバイスを順次リソグラフィ工程にて製造する場合に、各層の重ね合わせ誤差による動作不良の原因となってしまう。また、直接デバイスパターンでなくても、たとえばチップアライメントマークを配置してしまうと、露光装置でアライメント調整しても、設計よりやや縮小されて転写されてしまうことになり、ウエハ上に転写される像の位置精度が低下してしまう要因となってしまう。
　またこのような多層反射層を掘り込むことによるパターンの位置ずれは、遮光枠形成時だけでなく、多層反射層を掘り込んで回路パターンを形成する反射型マスクにも同様に発生する。 Such a shift causes a malfunction due to an overlay error of each layer when a semiconductor device composed of a plurality of layers is sequentially manufactured in a lithography process. Even if it is not a direct device pattern, for example, if a chip alignment mark is arranged, even if alignment adjustment is performed by an exposure apparatus, it will be transferred after being reduced slightly from the design and transferred onto the wafer. This is a factor that degrades the positional accuracy of the image.
Further, such a pattern misalignment caused by digging up the multilayer reflective layer occurs not only when the light shielding frame is formed, but also in a reflective mask in which the multilayer reflective layer is dug to form a circuit pattern.
　本発明は上記問題点に鑑みてなされたものであり、反射型マスクの多層反射層を掘り込んでも、掘り込み領域近傍のパターン位置がずれない反射型マスクを提供する事を主目的とするものである。 The present invention has been made in view of the above problems, and has as its main object to provide a reflective mask in which the pattern position in the vicinity of the digging area does not shift even when the multilayer reflective layer of the reflective mask is digged. It is.
　本発明に係る反射型マスクの製造方法のある態様は、
　基板、前記基板表面に形成された多層反射層、前記多層反射層の上に形成された保護層及び前記保護層の上に形成された吸収層を備え、前記吸収層、前記保護層及び前記多層反射層の掘り込みにより、回路パターン、又は前記回路パターンが配置されるパターン領域の外側の少なくとも一部に設けられるＥＵＶ光の反射率の低い遮光枠のパターンが形成される反射型マスクの製造方法において、前記掘り込みにより形成された掘り込み領域近傍の前記回路パターンの位置変化量を、前記掘り込みに先立つ事前の実験もしくは力学シミュレーションで算出し、前記算出の結果を元に、前記掘り込み前に予めずれ量を補正しておき、前記回路パターンを形成することを特徴とする。 An aspect of the manufacturing method of the reflective mask according to the present invention is as follows.
A substrate, a multilayer reflective layer formed on the substrate surface, a protective layer formed on the multilayer reflective layer, and an absorbent layer formed on the protective layer, the absorbent layer, the protective layer, and the multilayer Method of manufacturing a reflective mask in which a pattern of a light shielding frame having a low reflectivity of EUV light provided on at least a part of the outside of a circuit pattern or a pattern region in which the circuit pattern is arranged is formed by digging a reflective layer In the above, the position change amount of the circuit pattern in the vicinity of the digging region formed by the digging is calculated by a prior experiment or a mechanical simulation prior to the digging, and based on the calculation result, before the digging The circuit pattern is formed by correcting the deviation amount in advance.
　また本発明の請求項２に対応する反射型マスクの製造方法の他の態様は、
　請求項１に対応する反射型マスクの製造方法において、前記算出する位置変化量として、前記回路パターンをなす前記掘り込み領域近傍の前記位置変化量を算出することを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 2 of the present invention is:
2. The reflective mask manufacturing method according to claim 1, wherein the position change amount in the vicinity of the digging area forming the circuit pattern is calculated as the position change amount to be calculated.
　また本発明の請求項３に対応する反射型マスクの製造方法の他の態様は、
　請求項２に対応する反射型マスクの製造方法において、前記遮光枠の近傍に測長用パターンを形成し、前記測長用パターンを計測することで前記位置変化量の情報を得ることを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 3 of the present invention is:
3. The reflective mask manufacturing method according to claim 2, wherein a length measurement pattern is formed in the vicinity of the light shielding frame, and the positional change amount information is obtained by measuring the length measurement pattern. To do.
　また本発明の請求項４に対応する反射型マスクの製造方法の他の態様は、
　請求項３に対応する反射型マスクの製造方法において、前記測長用パターンは前記遮光枠の近傍の補正がされたパターンと補正なしのパターンとから成り、前記補正がされたパターン及び前記補正なしのパターンの差分を計算することで前記位置変化量の情報を得ることができるように、前記測長用パターンを形成することを特徴とする。 According to another aspect of the reflective mask manufacturing method corresponding to claim 4 of the present invention,
4. The reflective mask manufacturing method according to claim 3, wherein the length measurement pattern includes a corrected pattern in the vicinity of the light shielding frame and an uncorrected pattern, the corrected pattern and the uncorrected pattern. The length measurement pattern is formed so that the positional change amount information can be obtained by calculating the difference between the patterns.
　また本発明の請求項５に対応する反射型マスクの製造方法の他の態様は、
　請求項２に対応する反射型マスクの製造方法において、前記パターン位置の補正手段は、オリジナルの設計データに対して補正処理を行い、補正された設計データを作ることを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 5 of the present invention is:
The reflective mask manufacturing method according to claim 2 is characterized in that the pattern position correcting means performs correction processing on the original design data to generate corrected design data.
　また本発明の請求項６に対応する反射型マスクの製造方法の他の態様は、
　請求項４に対応する反射型マスクの製造方法において、前記パターン位置の補正手段は、オリジナルの設計データを描画する際に、描画打ち込み位置を補正することを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 6 of the present invention is:
According to a fourth aspect of the present invention, there is provided a reflective mask manufacturing method, wherein the pattern position correcting means corrects a drawing driving position when drawing original design data.
　また本発明の請求項７に対応する反射型マスクの製造方法の他の態様は、
　請求項５又は６に対応する反射型マスクの製造方法において、前記パターン位置の補正を行う領域である位置補正領域は、前記遮光枠の端から大きくとも略５０００μｍ以下であることを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 7 of the present invention is:
7. The method of manufacturing a reflective mask according to claim 5, wherein a position correction area, which is an area for correcting the pattern position, is at most about 5000 μm or less from the end of the light shielding frame.
　また本発明の請求項８に対応する反射型マスクの製造方法の他の態様は、
　請求項７に対応する反射型マスクの製造方法において、前記位置補正領域を複数のセグメントに分割し、前記セグメント毎に必要な補正量にて補正することを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 8 of the present invention is:
The reflective mask manufacturing method according to claim 7, wherein the position correction region is divided into a plurality of segments, and correction is performed with a correction amount required for each segment.
　また本発明の請求項９に対応する反射型マスクの製造方法の他の態様は、
　請求項８に対応する反射型マスクの製造方法において、前記セグメント毎に適用する補正量は、前記実験もしくは前記力学シミュレーションで算出した前記位置変化量に多項近似式でフィッティングを行い、前記多項近似式を用いて算出された補正量であることを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 9 of the present invention is:
9. The method of manufacturing a reflective mask according to claim 8, wherein the correction amount applied to each segment is obtained by fitting the position change amount calculated by the experiment or the dynamic simulation by a polynomial approximation formula, and the polynomial approximation formula. The correction amount is calculated using the above.
　また本発明の請求項１０に対応する反射型マスクの製造方法の他の態様は、
　請求項９に対応する反射型マスクの製造方法において、前記位置補正領域を複数のセグメントに分割する際は、等間隔に前記位置補正領域を分割することを特徴とする。 According to another aspect of the reflective mask manufacturing method of the present invention,
The reflective mask manufacturing method according to claim 9 is characterized in that when the position correction area is divided into a plurality of segments, the position correction area is divided at equal intervals.
　また本発明の請求項１１に対応する反射型マスクの製造方法の他の態様は、
　請求項１０に対応する反射型マスクの製造方法において、前記各セグメントの前記遮光枠から垂直方向に測った１辺の長さは、１μｍから１００μｍの範囲であることを特徴とする。 According to another aspect of the reflective mask manufacturing method corresponding to claim 11 of the present invention,
The method of manufacturing a reflective mask according to claim 10 is characterized in that the length of one side measured in the vertical direction from the light shielding frame of each segment is in the range of 1 μm to 100 μm.
　また本発明の請求項１２に対応する反射型マスクの製造方法の他の態様は、
　請求項１１に対応する反射型マスクの製造方法において、前記パターン位置の補正方法は、前記位置補正領域の１点あるいは１辺を固定し、前記位置補正領域に対し倍率補正を行うことを特徴とする。 Another aspect of the reflective mask manufacturing method corresponding to claim 12 of the present invention is:
12. The method of manufacturing a reflective mask according to claim 11, wherein the pattern position correction method fixes one point or one side of the position correction area and performs magnification correction on the position correction area. To do.
　また本発明の請求項１３に対応する反射型マスクの製造方法の他の態様は、
　請求項７に対応する反射型マスクの製造方法において、前記パターン位置の補正方法は、前記位置補正領域を複数のセグメントに分割して補正を行う方法と倍率補正とを組み合わせた方法であることを特徴とする。 According to another aspect of the reflective mask manufacturing method corresponding to claim 13 of the present invention,
8. The method of manufacturing a reflective mask according to claim 7, wherein the pattern position correction method is a combination of a correction method by dividing the position correction region into a plurality of segments and a magnification correction. Features.
　また本発明の請求項１４に対応する反射型マスクの製造方法の他の態様は、
　請求項６に対応する反射型マスクの製造方法において、前記回路パターンは、前記遮光枠近傍のパターン位置の前記位置変化量を補正するよう作成された補正マップを用いて描画されることを特徴とする。 In addition, another aspect of the method for manufacturing a reflective mask corresponding to claim 14 of the present invention is as follows:
7. The method of manufacturing a reflective mask according to claim 6, wherein the circuit pattern is drawn using a correction map created so as to correct the position change amount of the pattern position in the vicinity of the light shielding frame. To do.
　また本発明の請求項１５に対応する反射型マスクの製造方法の他の態様は、
　請求項２に対応する反射型マスクの製造方法において、前記遮光枠近傍の回路パターンの前記位置変化量を求める前記実験に用いる反射型マスクブランクの多層反射層の持つ応力は、本番に使用する反射型マスクブランクの多層反射層の持つ応力と同程度であることを特徴とする。 According to another aspect of the reflective mask manufacturing method corresponding to claim 15 of the present invention,
3. The method of manufacturing a reflective mask according to claim 2, wherein the stress of the multilayer reflective layer of the reflective mask blank used in the experiment for obtaining the positional change amount of the circuit pattern in the vicinity of the light shielding frame is the reflection used for the production. It is the same level as the stress which the multilayer reflective layer of a type | mold mask blank has.
　また本発明の請求項１６に対応する反射型マスクの製造方法の他の態様は、
　請求項２に対応する反射型マスクの製造方法において、前記遮光枠近傍の回路パターンの前記位置変化量を求める前記実験は、前記遮光枠を形成する前に測長用パターンを形成及び計測し、前記計測後に前記遮光枠を形成し、再度、前記測長用パターンを計測することで、前記位置変化量を求めることを特徴とする。 According to another aspect of the method for manufacturing a reflective mask corresponding to claim 16 of the present invention,
In the reflective mask manufacturing method corresponding to claim 2, the experiment for obtaining the positional change amount of the circuit pattern in the vicinity of the light shielding frame forms and measures a length measurement pattern before forming the light shielding frame, The position change amount is obtained by forming the light shielding frame after the measurement and measuring the length measurement pattern again.
　また本発明の請求項１７に対応する反射型マスクの製造方法の他の態様は、
　請求項１に対応する反射型マスクの製造方法において、前記遮光枠近傍の回路パターンの前記位置変化量を求める前記力学シミュレーションは、前記反射型マスクブランクを構成する各材料のヤング率、ポアソン比及び膜厚と、前記多層反射層の内部応力とを用いて、前記遮光枠形成後のマスク表面の前記位置変化量を見積もることを特徴とする。 According to another aspect of the reflective mask manufacturing method corresponding to claim 17 of the present invention,
2. The method of manufacturing a reflective mask according to claim 1, wherein the dynamic simulation for obtaining the positional change amount of the circuit pattern in the vicinity of the light shielding frame includes the Young's modulus, Poisson's ratio of each material constituting the reflective mask blank, and The positional change amount of the mask surface after the formation of the light shielding frame is estimated using a film thickness and an internal stress of the multilayer reflective layer.
　また本発明の請求項１８に対応する反射型マスクの製造方法の他の態様は、
　請求項１に対応する反射型マスクの製造方法において、前記算出する位置変化量として、前記回路パターンをなす前記掘り込み領域近傍の前記位置変化量を算出することを特徴とする。 According to another aspect of the reflective mask manufacturing method corresponding to claim 18 of the present invention,
2. The reflective mask manufacturing method according to claim 1, wherein the position change amount in the vicinity of the digging area forming the circuit pattern is calculated as the position change amount to be calculated.
　また本発明の請求項１９に対応する反射型マスクの製造方法の他の態様は、
　請求項１に対応する反射型マスクの製造方法において、前記遮光枠をなす前記掘り込み領域近傍の前記位置変化量と、前記回路パターンをなす前記掘り込み領域近傍の前記位置変化量とを、両方算出することを特徴とする。 According to another aspect of the reflective mask manufacturing method corresponding to claim 19 of the present invention,
2. The method of manufacturing a reflective mask according to claim 1, wherein both the position change amount in the vicinity of the digging area forming the light shielding frame and the position change amount in the vicinity of the digging area forming the circuit pattern are both. It is characterized by calculating.
　また本発明の請求項２０に対応する反射型マスクのある態様は、
　請求項１～請求項１９のいずれか一項に対応する反射型マスクの製造方法を用いて作製した反射型マスクである。 An aspect of the reflective mask corresponding to claim 20 of the present invention is as follows:
A reflective mask produced by using a reflective mask manufacturing method corresponding to any one of claims 1 to 19.
　本発明を実施することにより、多層反射層の除去による掘り込み領域を形成する反射型マスクにおいて、掘り込み領域近傍のパターンの位置ずれを制御することが可能となる。 By implementing the present invention, it is possible to control the positional deviation of the pattern in the vicinity of the digging area in the reflective mask that forms the digging area by removing the multilayer reflective layer.
一般的なＥＵＶマスクブランクの概略断面図。1 is a schematic cross-sectional view of a general EUV mask blank. マスク基板上の位置を表す座標軸とマスク上に形成した遮光枠を示す説明図。Explanatory drawing which shows the coordinate axis showing the position on a mask board | substrate, and the light shielding frame formed on the mask. 多層膜の応力によるＸ軸方向のずれ量を計算した結果を示すグラフ。The graph which shows the result of having calculated the deviation | shift amount of the X-axis direction by the stress of a multilayer film. 遮光枠の有無によるＸ軸方向のずれ量の差を計算した結果を示すグラフ。The graph which shows the result of having calculated the difference of the deviation | shift amount of the X-axis direction by the presence or absence of a light-shielding frame. 反射型マスクの概略平面図。The schematic plan view of a reflective mask. 反射型マスクの遮光枠近傍の拡大平面図と補正領域を示す説明図。Explanatory drawing which shows the enlarged plan view near the light-shielding frame of a reflective mask, and a correction | amendment area | region. 遮光枠近傍の補正領域内におけるパターン部のデータを複数のセグメントに分割した図。The figure which divided | segmented the data of the pattern part in the correction area | region of the shading frame vicinity into several segments. 遮光枠近傍の補正領域内におけるパターン部のデータとデータを倍率補正した図。The figure which corrected the magnification of the data and data of the pattern part in the correction area | region of the shading frame vicinity. 補正領域に対して行う倍率補正の倍率算出方法の例を示すグラフ。The graph which shows the example of the magnification calculation method of the magnification correction performed with respect to a correction area | region. 測長用パターンを備えた反射型マスクの概略平面図。The schematic plan view of a reflective mask provided with the pattern for length measurement. 本発明で使用するＥＵＶマスクブランクの概略断面図。The schematic sectional drawing of the EUV mask blank used by this invention. 本発明の実施例の反射型マスクの作製工程（パターン形成まで）を示す概略断面図。The schematic sectional drawing which shows the preparation process (until pattern formation) of the reflective mask of the Example of this invention. 本発明の実施例の反射型マスクの作製工程（遮光枠形成）を示す概略断面図。The schematic sectional drawing which shows the preparation process (shading frame formation) of the reflective mask of the Example of this invention. 本発明の実施例（ａ）と従来のマスク（ｂ）の遮光枠形成による位置ずれ結果を示すグラフ。The graph which shows the position shift result by the light-shielding frame formation of the Example (a) of this invention and the conventional mask (b). 多層反射層を掘り込んで回路パターンが形成された反射型マスクの概略断面図。The schematic sectional drawing of the reflective mask in which the circuit pattern was formed by digging up a multilayer reflective layer.
　以下に、本発明を実施する形態について図面を用いてさらに詳しく具体的に説明する。以下の図１～図１４を用いて説明する反射型マスクの製造方法は、反射型マスクの多層反射層を掘り込んで遮光枠部を形成しても、遮光枠部近傍のパターン位置がずれない反射型マスクを提供するものである。 Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. In the reflective mask manufacturing method described below with reference to FIGS. 1 to 14, the pattern position in the vicinity of the light shielding frame does not shift even if the light shielding frame is formed by digging the multilayer reflective layer of the reflective mask. A reflective mask is provided.
＜反射型ＥＵＶマスクの構造＞
　図１は一般的なＥＵＶマスクブランク１００の断面を図示したものである。ＥＵＶマスクブランク１００は基板０１と、基板０１の上に設けられＥＵＶ光を反射する多層反射層０２と、多層反射層０２の上に設けられた保護層０３と、保護層０３の上に設けられパターンが形成される吸収層０４とを備える。があり、また、上記各層を形成する基板面の裏側には静電チャックを使用するための導電膜０５が形成されている。 <Structure of reflective EUV mask>
FIG. 1 illustrates a cross section of a general EUV mask blank 100. The EUV mask blank 100 is provided on the substrate 01, the multilayer reflective layer 02 provided on the substrate 01 and reflecting EUV light, the protective layer 03 provided on the multilayer reflective layer 02, and the protective layer 03. And an absorption layer 04 on which a pattern is formed. In addition, a conductive film 05 for using an electrostatic chuck is formed on the back side of the substrate surface on which the above layers are formed.
　基板０１としてはたとえば酸化チタンを含む酸化ケイ素からなる超低熱膨張ガラス（LowThermal Expansion Material、以下ＬＴＥＭと略記する場合もある）が用いられる。ＥＵＶ光を反射する多層反射層０２としては、光の波長が１３．５ｎｍの場合、珪素とモリブデンをおおよそ４ｎｍ、３ｎｍの膜厚として交互に４０ないし５０対積層したものが用いられる。多層反射層０２の表面には、多層反射層０２の表面を保護するための膜が形成されていることが多く、キャッピング層などと称している。吸収層０４はＥＵＶ光を吸収する性質の物質であり、たとえばタンタルを主成分とする膜が用いられ、パターン欠陥検査の感度を高める等の目的で多層構造となっている場合もある。 As the substrate 01, for example, an ultra-low thermal expansion glass (low thermal expansion material, hereinafter sometimes abbreviated as LTEM) made of silicon oxide containing titanium oxide is used. As the multilayer reflective layer 02 that reflects EUV light, a layer in which 40 to 50 pairs of silicon and molybdenum are alternately stacked with a film thickness of about 4 nm and 3 nm when the wavelength of light is 13.5 nm is used. A film for protecting the surface of the multilayer reflective layer 02 is often formed on the surface of the multilayer reflective layer 02, which is referred to as a capping layer or the like. The absorption layer 04 is a substance having a property of absorbing EUV light. For example, a film containing tantalum as a main component is used and may have a multilayer structure for the purpose of increasing the sensitivity of pattern defect inspection.
　本発明の実施の形態で示したＥＵＶ光の反射率の低い遮光枠２１の形態は、反射型マスクの吸収層０４から多層反射層０２までを掘り込んだ溝であり、この遮光枠２１を形成することで多層反射層０２の反射率を低下させることにより、露光光源波長に対する遮光性の高い遮光枠２１を設けた反射型マスクが構成される。 The form of the light shielding frame 21 having a low EUV light reflectivity shown in the embodiment of the present invention is a groove formed by digging from the absorption layer 04 to the multilayer reflective layer 02 of the reflective mask, and this light shielding frame 21 is formed. Thus, by reducing the reflectance of the multilayer reflective layer 02, a reflective mask provided with the light shielding frame 21 having a high light shielding property with respect to the exposure light source wavelength is formed.
（位置変化量の算出方法）
　一般に多層反射層は圧縮方向の内部応力を持っている。多層反射層を枠状にエッチング除去すると、多層反射層が途切れる端面のところで圧縮応力が開放される。ＬＴＥＭとして用いられているガラスと多層反射層の弾性係数を比較すると、多層反射層の方が数倍大きい。このため、遮光枠内側においては外側に向かって、遮光枠外側では内側に向かって多層反射層が伸びる方向に変形し、これに伴う変形にガラスが反発する力がつりあうところで止まることになる。 (Position change calculation method)
In general, the multilayer reflective layer has an internal stress in the compression direction. When the multilayer reflective layer is etched away in a frame shape, the compressive stress is released at the end face where the multilayer reflective layer is interrupted. Comparing the elastic modulus of the glass used as the LTEM and the multilayer reflective layer, the multilayer reflective layer is several times larger. For this reason, the multilayer reflective layer is deformed in the direction in which the multilayer reflective layer extends toward the outside on the inner side of the light shielding frame and toward the inner side on the outer side of the light shielding frame, and stops where the force that repels the glass due to the deformation is balanced.
　このような変形による、回路パターンのそれぞれの位置の変化量はＬＴＥＭや多層反射層０２、保護層０３及び吸収層０４等の反射型マスクブランク１００を構成する各材料０１～０５についてのポアソン比やヤング率などの物性値を用いて、構造解析用のシミュレーションソフトウェアで計算することができる。 The amount of change in the position of each circuit pattern due to such deformation is the Poisson's ratio for each of the materials 01 to 05 constituting the reflective mask blank 100 such as LTEM, multilayer reflective layer 02, protective layer 03, and absorbing layer 04. Using physical property values such as Young's modulus, calculation can be performed with simulation software for structural analysis.
　また多層反射層０２の応力については、多層反射層０２を形成する前後の表面の平坦度を計測し、応力によって生じたたわみ量から計測することができる。たとえば、曲率半径と応力の関係を表わすストーニーの式と呼ばれる式を適用しても良いし、より精密には構造解析用のソフトウェアで計算した結果とのフィッティングにより求めてもよい。 The stress of the multilayer reflective layer 02 can be measured from the amount of deflection caused by the stress by measuring the flatness of the surface before and after forming the multilayer reflective layer 02. For example, an equation called a Stoney equation representing the relationship between the radius of curvature and the stress may be applied, or more precisely, it may be obtained by fitting with a result calculated by software for structural analysis.
　図２は６インチ角の反射型マスク２００の中心を原点として、マスク上の位置を表す座標軸とマスク上に形成した遮光枠２１を示している。上記の構造解析用のシミュレーションを用いて、Ｘ軸上の膜表面の各点についてＸ方向の位置ずれ（位置変化量）を計算した結果を図３に示す。ここで遮光枠２１は基板の中心からＸ軸方向に５２ｍｍの位置から５４ｍｍの位置の間に形成され２ｍｍ幅である。 FIG. 2 shows the coordinate axis representing the position on the mask and the light shielding frame 21 formed on the mask with the center of the 6-inch square reflective mask 200 as the origin. FIG. 3 shows the result of calculating the positional deviation (positional change amount) in the X direction for each point on the film surface on the X axis, using the simulation for structural analysis described above. Here, the light shielding frame 21 is formed between a position of 52 mm and a position of 54 mm in the X-axis direction from the center of the substrate and has a width of 2 mm.
　基板中心から端部に向かって直線的に変位量が大きくなっているのは、多層反射層０２及び基板０１の圧縮応力によって基板０１全体が凸状にたわんでいるためである。遮光枠２１が無い状態で同様にＸ方向のずれ量を計算した結果を図３の結果から差引いたものが図４であり、遮光枠２１の有無によるＸ軸方向の変位量の差を表わしている。　すなわち図４中には、基板０１全体のたわみの影響をキャンセルした、各点のより正確な位置変化量が示されている。例えばＸ＝５２ｍｍの、遮光枠２１に面するパターン領域２２の端部をなす位置では、遮光枠２１の形成前後で約６ｎｍの位置変化量が生じたことがわかる。 The reason why the amount of displacement increases linearly from the center of the substrate toward the end is that the entire substrate 01 is bent in a convex shape due to the compressive stress of the multilayer reflective layer 02 and the substrate 01. FIG. 4 is a diagram obtained by subtracting the result of calculating the deviation amount in the X direction in the same manner in the absence of the light shielding frame 21 from the result of FIG. 3, and represents the difference in displacement amount in the X axis direction depending on the presence or absence of the light shielding frame 21. Yes. That is, FIG. 4 shows a more accurate position change amount of each point where the influence of the deflection of the entire substrate 01 is canceled. For example, it can be seen that a position change amount of about 6 nm occurs before and after the formation of the light shielding frame 21 at the position where X = 52 mm and the end of the pattern region 22 facing the light shielding frame 21.
　このように構造解析のシミュレーションから位置ずれの計算は可能である。またＹ軸方向の各点の位置変化量も、Ｘ軸方向の場合と同様に計算可能である。こうした掘り込みに先立つ事前の力学シミュレーション以外の他の方法として、実際に図１に示したマスクブランク１００を用いて、本番用のマスクブランクと同程度の多層反射層の応力を有するテスト用のマスクブランク１００を作成し、このマスクブランク１００の表面を掘り込んで遮光枠２１を形成し、遮光枠２１形成前後のパターン位置を測定する実験により、その遮光枠２１の有無による位置ずれの差を求める事ができる。 In this way, the displacement can be calculated from the structural analysis simulation. Further, the positional change amount of each point in the Y-axis direction can be calculated in the same manner as in the X-axis direction. As a method other than the dynamic simulation prior to the excavation, a test mask having the same multilayer reflective layer stress as the actual mask blank using the mask blank 100 shown in FIG. A blank 100 is created, a light shielding frame 21 is formed by digging the surface of the mask blank 100, and a pattern position before and after the light shielding frame 21 is formed is measured. I can do things.
　本発明は、このようにして構造解析用のシミュレーションソフトウェアや実験から求められたパターン位置の変化量を用いて、遮光枠２１形成によるパターン位置ずれを補正する。 In the present invention, the pattern position shift due to the formation of the light shielding frame 21 is corrected by using the change amount of the pattern position obtained from the simulation software for structure analysis and the experiment in this way.
（パターン位置の補正方法）
　図５は反射型マスク２００の概略平面図であり、反射型マスク２００は、上面を正面から見て略正方形状の外縁を有する遮光枠２１とパターン領域２２を含む。図６は遮光枠２１の正方形の一辺の近傍を拡大した図で、パターンの位置ずれを補正する位置補正領域２３が示されている。この位置補正領域２３は遮光枠２１の端から垂直方向に大きくとも５０００μｍとする。
　すなわち位置補正領域２３は、反射型マスク２００の上面を正面から見て、遮光枠２１との境界位置となるパターン領域２２の端部の外縁をなす直線から、遮光枠２１の一辺に直交する方向で反射型マスク２００の中心側に向かって測って、５０００μｍ以下の幅を有する額縁状の領域である。 (Pattern position correction method)
FIG. 5 is a schematic plan view of the reflective mask 200. The reflective mask 200 includes a light shielding frame 21 and a pattern region 22 having a substantially square outer edge when the upper surface is viewed from the front. FIG. 6 is an enlarged view of the vicinity of one side of the square of the light shielding frame 21, and shows a position correction area 23 for correcting a positional deviation of the pattern. The position correction area 23 is at most 5000 μm in the vertical direction from the end of the light shielding frame 21.
That is, the position correction region 23 is a direction orthogonal to one side of the light shielding frame 21 from a straight line that forms the outer edge of the end of the pattern region 22 that is a boundary position with the light shielding frame 21 when the upper surface of the reflective mask 200 is viewed from the front. This is a frame-like region having a width of 5000 μm or less as measured toward the center of the reflective mask 200.
　本発明の実施の形態に係る６インチ角の反射型マスク２００においては、位置補正領域２３の幅の上限値である５０００μｍは、マスク上に遮光枠２１及びパターン領域２２を効率的に配置する観点から設定されているが、この幅の上限値は適用する反射型マスク、所望のパターン領域２２及び所望の遮光枠２１のそれぞれの形状及び寸法に応じて適宜設定できる。
　尚、遮光枠２１の形状は正方形以外の他の形状、例えば矩形状等でも構成できる。また遮光枠２１の幅は、例えば長辺と短辺で長さが異なるように形成されてもよい。またパターン領域２２の中に複数のチップパターンを形成して多面付けに対応させることもできる。 In the 6-inch square reflective mask 200 according to the embodiment of the present invention, the upper limit value of 5000 μm of the width of the position correction region 23 is a viewpoint in which the light shielding frame 21 and the pattern region 22 are efficiently arranged on the mask. However, the upper limit value of the width can be appropriately set according to the shape and dimensions of the reflective mask to be applied, the desired pattern region 22 and the desired light shielding frame 21.
The shape of the light shielding frame 21 may be other than a square, for example, a rectangular shape. The width of the light shielding frame 21 may be formed so that the length is different between the long side and the short side, for example. In addition, a plurality of chip patterns can be formed in the pattern region 22 to cope with multi-sided layout.
　パターン位置の位置ずれを補正する手段としては、例えば回路パターンのオリジナルの設計データにおける、パターン領域２２の位置補正領域２３に対応する部分を、事前の力学シミュレーションや実験により算出した位置変化量に応じて補正し、補正された設計データを用いて回路パターンを描画する。
　本発明の実施の形態に係る反射型マスクの製造方法における、設計データに対して補正処理を行い、補正された設計データを作る方法として、まず図７に示すように遮光枠２１近傍の位置補正領域２３内におけるパターン領域２２のデータを複数のセグメント２４に分割することができる。 As a means for correcting the positional deviation of the pattern position, for example, in the original design data of the circuit pattern, the portion corresponding to the position correction area 23 of the pattern area 22 is determined according to the position change amount calculated by a prior dynamic simulation or experiment. The circuit pattern is drawn using the corrected design data.
In the reflective mask manufacturing method according to the embodiment of the present invention, as a method of performing correction processing on design data and generating corrected design data, first, as shown in FIG. The data of the pattern area 22 in the area 23 can be divided into a plurality of segments 24.
　位置補正領域２３内のデータを複数のセグメント２４に分割する際は等間隔に位置補正領域２３内のデータを分割し、そのセグメント２４の遮光枠２１から垂直方向の１辺の長さｄは１μｍから１００μｍの範囲で設定する（１μｍ≦ｄ≦１００μｍ）。
　尚、図７中には、位置補正領域２３が、いずれも等間隔ｄで複数のセグメント２４に分割された状態が例示されている。 When the data in the position correction area 23 is divided into a plurality of segments 24, the data in the position correction area 23 is divided at equal intervals, and the length d of one side of the segment 24 in the vertical direction from the light shielding frame 21 is 1 μm. To 100 μm (1 μm ≦ d ≦ 100 μm).
FIG. 7 illustrates a state in which the position correction area 23 is divided into a plurality of segments 24 at equal intervals d.
　位置ずれの補正は、構造解析シミュレーションや実験から求められたパターン位置の位置ずれ量をもとに、分割されたセグメント２４を、遮光枠２１が形成され多層反射層０２の変形が生じた状態であっても、パターン位置が設計値通り、或いは設計値に近づく状態になるように、補正後の設計データにおけるセグメント２４の配置位置を設定する事によってできる。 The positional deviation is corrected in a state where the segment 24 is divided and the multilayer reflective layer 02 is deformed based on the positional deviation amount of the pattern position obtained from the structural analysis simulation or experiment. Even if it exists, it can do by setting the arrangement position of the segment 24 in the design data after correction so that the pattern position is in a state close to the design value or close to the design value.
　各セグメント２４の配置に適用する補正量は、実験もしくは力学シミュレーションで算出した位置変化量と遮光枠２１の距離の関係に多項近似式でフィッティングを行い、その多項近似式を用いて算出された補正量を用いる。 The correction amount to be applied to the arrangement of each segment 24 is a correction calculated using a polynomial approximate expression by fitting the relationship between the position change amount calculated by experiment or dynamic simulation and the distance between the light shielding frames 21 using a polynomial approximate expression. Use quantity.
　セグメント２４の分割以外の別の補正方法としては、パターンデータの１点あるいは１辺を固定し、補正領域に倍率補正を行うことでパターン位置の位置ずれを補正する。すなわち位置補正領域２３の中に含まれる回路パターンの寸法を変化させることができる。 As another correction method other than the division of the segment 24, one point or one side of the pattern data is fixed, and the positional deviation of the pattern position is corrected by correcting the magnification in the correction area. That is, the dimension of the circuit pattern included in the position correction area 23 can be changed.
　図８（ａ）は遮光枠２１の隅部（コーナー）と、この隅部の近傍にある位置補正領域２３を表している。この位置補正領域２３に対して倍率補正を行う方法は、図８（ｂ）に示すように位置補正領域２３の固定する点２６で補正対象範囲を固定し、倍率補正を行う方法、もしくは図８（ｃ）や図８（ｄ）に示すように補正領域の固定する辺２７で補正対象範囲を固定し、倍率補正を行う方法がある。 FIG. 8A shows a corner (corner) of the light shielding frame 21 and a position correction region 23 in the vicinity of the corner. As a method of performing magnification correction on the position correction area 23, as shown in FIG. 8B, a correction target range is fixed at a point 26 fixed in the position correction area 23, and magnification correction is performed, or FIG. As shown in FIG. 8C and FIG. 8D, there is a method in which the correction target range is fixed at the side 27 to which the correction area is fixed, and magnification correction is performed.
　倍率補正を行う際に適用する倍率は、図９に示すように位置補正領域２３の遮光枠２１形成によるパターン位置の位置ずれ量に対して、一次近似式（Ｙ＝ａＸ＋ｂ）にてフィッティングを行い、その一次近似式のｘの係数であるａを用いて、補正倍率＝１／（１＋ａ）から計算する事ができ、この値を補正倍率とする。 As shown in FIG. 9, the magnification applied when the magnification correction is performed is performed by fitting with a linear approximation formula (Y = aX + b) with respect to the positional deviation amount of the pattern position due to the formation of the light shielding frame 21 in the position correction area 23. The correction factor = 1 / (1 + a) can be calculated using a which is a coefficient of x in the linear approximation formula, and this value is set as the correction factor.
　ここでは一次近似式にてフィッティングしているが、本発明は近似式を制限するものではなく、二次以上の多項式やその他の関数を用いてもよいし、位置補正領域２３を分割して複数の一次近似式を求めてもよい。
　また図９中では、位置補正領域２３は、マスク中心から約５１．５ｍｍの位置から約５２．０ｍｍの位置までの間で約０．５ｍｍの幅を有して示されている。しかし位置補正領域２３の幅は０．５ｍｍに限定されることなく、経験則により得られた値で設定することもできる。本発明者らは、パターン領域２２の端部の位置からの幅が１００μｍ以上２００μｍ以下の場合、位置補正領域２３が掘り込みによって最もひずむ領域に重なり、補正の効果が大きいという知見を得た。 Here, fitting is performed using a first-order approximation expression, but the present invention does not limit the approximation expression, and may use a second-order or higher-order polynomial or other function, or may divide the position correction region 23 into a plurality of parts. May be obtained.
In FIG. 9, the position correction area 23 is shown having a width of about 0.5 mm from the position of about 51.5 mm to the position of about 52.0 mm from the mask center. However, the width of the position correction region 23 is not limited to 0.5 mm, and can be set with a value obtained by an empirical rule. The present inventors have found that when the width from the end position of the pattern region 22 is 100 μm or more and 200 μm or less, the position correction region 23 overlaps the region most distorted by digging, and the correction effect is great.
　このようなデータを複数のセグメント２４に分割する処理、パターン位置の配置およびデータの倍率補正は、マスクデータ・プレパレーション（ＭＤＰ）ソフトウェアによって行うことができる。
　また本発明の実施の形態においては、セグメント２４の分割と倍率補正とを組み合わせて、セグメント２４毎に倍率補正を行って補正することができる。掘り込みによる多層反射層０２のひずみは、図４に示したようにマスクの中心からパターン領域２２の端部に向かうに従って大きくなるため、各セグメント２４に適用する補正量は、具体的には、マスクの中心から端部に向かうに従って、階段（ステップ）状に増加するようにそれぞれ算出される。 Processing for dividing such data into a plurality of segments 24, pattern position arrangement, and data magnification correction can be performed by mask data preparation (MDP) software.
Further, in the embodiment of the present invention, it is possible to perform correction by performing magnification correction for each segment 24 by combining division of the segment 24 and magnification correction. Since the distortion of the multilayer reflective layer 02 due to the digging increases as it goes from the center of the mask toward the end of the pattern region 22 as shown in FIG. 4, the correction amount applied to each segment 24 is specifically: It is calculated so as to increase in a staircase (step) direction from the center of the mask toward the end.
　その他のパターン位置の補正方法は、オリジナルの設計データを描画する際に、描画打ち込み位置を補正する方法がある。 Other pattern position correction methods include a method for correcting the drawing position when drawing the original design data.
　描画打ち込み位置の補正方法は、構造解析シミュレーションや実験から求められたパターン位置の位置ずれ量をもとに、遮光枠２１形成時にパターン位置が設計値通りになるように、描画の打ち込み位置を補正する方法がある。すなわち設計データ側の回路パターンに補正を施すのではなく、描画装置側で描画打ち込み位置における位置補正領域２３に対応する部分を、事前の力学シミュレーションや実験により算出した位置変化量に応じて補正して描画を行う。
　具体的には例えば、算出して求められた位置ずれ量（位置変化量）を考慮して、描画打ち込み位置を補正するように、描画用の補正マップを作成する。そしてこの補正マップを用いて、マスクブランクの表面に回路パターンを実際に描画することができる。 The drawing driving position correction method corrects the drawing driving position so that the pattern position becomes as designed when the light shielding frame 21 is formed, based on the positional deviation amount of the pattern position obtained from structural analysis simulation or experiment. There is a way to do it. In other words, the circuit pattern on the design data side is not corrected, but the part corresponding to the position correction region 23 at the drawing driving position is corrected on the drawing apparatus side according to the position change amount calculated by a prior mechanical simulation or experiment. And draw.
Specifically, for example, a drawing correction map is created so as to correct the drawing driving position in consideration of the position shift amount (position change amount) obtained by calculation. A circuit pattern can be actually drawn on the surface of the mask blank using this correction map.
　位置変化量の情報を得る為に形成する、遮光枠２１の近傍に配置する測長用パターンは、補正がされたパターンと補正なしのパターンから成る。補正されていないパターンを作成する方法としては、補正されていないパターンを補正処理したパターンの描画前もしくは後に描画する方法がある。 The length measurement pattern that is formed in the vicinity of the light shielding frame 21 and is formed to obtain information on the amount of change in position includes a corrected pattern and an uncorrected pattern. As a method of creating an uncorrected pattern, there is a method of drawing before or after drawing a pattern obtained by performing correction processing on an uncorrected pattern.
　図１０中に例示するように、測長用パターンは、それぞれの形状や寸法が互いに異なるように、補正なしの測長用パターン３４ａと、補正がされた測長用パターン３４ｂとで構成できる。図１０中では、補正なしの測長用パターン３４ａ及び補正がされた測長用パターン３４ｂは、いずれも反射型マスク２００ａの上面を正面から見て十字（プラス）形状であり、補正がされた測長用パターン３４ｂは、補正なしの測長用パターン３４ａに対して一定の割合で縮小された形状で構成されている。補正なしの測長用パターン３４ａは補正がされた測長用パターン３４ｂに対する基本パターンをなす。 As illustrated in FIG. 10, the length measurement pattern can be composed of an uncorrected length measurement pattern 34 a and a corrected length measurement pattern 34 b so that their shapes and dimensions are different from each other. In FIG. 10, the uncorrected length measurement pattern 34a and the corrected length measurement pattern 34b have a cross shape (plus) when the top surface of the reflective mask 200a is viewed from the front, and are corrected. The length measurement pattern 34b has a shape reduced at a fixed rate with respect to the length measurement pattern 34a without correction. The uncorrected length measurement pattern 34a forms a basic pattern with respect to the corrected length measurement pattern 34b.
　補正なしの測長用パターン３４ａ及び補正がされた測長用パターン３４ｂの使用方法としては、まず反射型マスクブランクの表面上で、遮光枠２１が形成される予定領域（遮光枠形成予定領域）の近傍に、２個の測長用パターン３４ａ，３４ｂを形成する。そして２個の測長用パターン３４ａ，３４ｂのそれぞれの寸法を計測し、計測結果から互いの寸法の差分を算出する。
　そして遮光枠形成予定領域を掘り込んで遮光枠２１を形成した後、２個の測長用パターン３４ａ，３４ｂのそれぞれの寸法を再度計測し、２個の測長用パターン３４ａ，３４ｂの寸法の差分を再度算出する。掘り込み前の寸法の差分と掘り込み後の寸法の差分を比較して解析することにより、位置変化量の情報を得ることができる。 As a method of using the uncorrected length measurement pattern 34a and the corrected length measurement pattern 34b, first, an area where the light shielding frame 21 is to be formed (light shielding frame formation scheduled area) on the surface of the reflective mask blank. Two length measurement patterns 34a and 34b are formed in the vicinity of. Then, the respective dimensions of the two length measurement patterns 34a and 34b are measured, and the difference between the dimensions is calculated from the measurement result.
Then, after forming the light shielding frame 21 by digging the light shielding frame formation scheduled region, the respective dimensions of the two length measurement patterns 34a and 34b are measured again, and the dimensions of the two length measurement patterns 34a and 34b are measured. Calculate the difference again. By comparing and analyzing the difference in dimension before digging and the difference in dimension after digging, information on the amount of change in position can be obtained.
　また図１０に示すように、遮光枠２１の外側の領域に、別の測長用パターン３４ｃを設け、この測長用パターン３４ｃを、遮光枠２１の内側の測長用パターン３４ａ，３４ｂと組み合わせて位置変化量の情報を得てもよい。例えば遮光枠２１の外側の測長用パターン３４ｃの位置を基準位置とし、この測長用パターン３４ｃに対する、遮光枠２１の内側の測長用パターン３４ａの、多層反射層０２の掘り込みの前後の位置をそれぞれ計測し、掘り込みによってずれた変位量を算出することもできる。
　尚、測長用パターン３４ａ，３４ｂ，３４ｃは、回路パターンに一般的に用いられる単純なライン形状と見分け易いような形状であれば、三角形状や矩形状等といった十字形状以外の形状でも構成できる。 As shown in FIG. 10, another length measurement pattern 34 c is provided in a region outside the light shielding frame 21, and this length measurement pattern 34 c is combined with the length measurement patterns 34 a and 34 b inside the light shielding frame 21. Information on the position change amount may be obtained. For example, the position of the length measurement pattern 34c outside the light shielding frame 21 is used as a reference position, and the length measurement pattern 34a inside the light shielding frame 21 before and after the duplication of the multilayer reflective layer 02 is made with respect to this length measurement pattern 34c. It is also possible to measure the position and calculate the amount of displacement displaced by digging.
The length measurement patterns 34a, 34b, and 34c can be formed in shapes other than a cross shape such as a triangular shape or a rectangular shape as long as they are easily distinguishable from simple line shapes generally used in circuit patterns. .
　以上のようにして、遮光枠２１形成による位置ずれが補正された反射型マスク２００，２００ａを得る事ができる。 As described above, it is possible to obtain the reflective masks 200 and 200a in which the displacement due to the formation of the light shielding frame 21 is corrected.
（実施例１）
　以下に本発明の実施例を示す。図１１及び図１２（ａ）は本実施例で用意した反射型マスクブランク３００を示す。このブランク３００は基板０１の上に、波長１３．５ｎｍのＥＵＶ光に対して反射率が６４％程度となるように設計されたＭｏとＳｉの４０ペアの多層反射層０２が、その上に２．５ｎｍ厚のＲｕの保護層０３が、更にその上に７０ｎｍ厚のＴａＳｉからなる吸収層０４が、順次形成されている。  (Example 1)
Examples of the present invention are shown below. 11 and 12A show a reflective mask blank 300 prepared in this embodiment. This blank 300 has a 40-layer reflective layer 02 of Mo and Si designed on a substrate 01 so that the reflectance is about 64% with respect to EUV light having a wavelength of 13.5 nm. A Ru protective layer 03 having a thickness of 0.5 nm and an absorption layer 04 made of TaSi having a thickness of 70 nm are sequentially formed thereon.
　まずは遮光枠２１形成によるパターンの位置ずれを算出する為の条件出しマスクを作製した。 First, a condition mask for calculating the positional deviation of the pattern due to the formation of the light shielding frame 21 was produced.
　本ブランク３００に対し、ポジ型化学増幅レジスト０９（ＦＥＰ１７１：富士フイルムエレクトロニクスマテリアルズ）を３００ｎｍの膜厚で塗布し（図１２（ｂ））、電子線描画機（ＪＢＸ９０００：日本電子）によってまずパターン領域と位置補正領域を描画し、その後補正処理をしていない測長用パターンを位置補正領域内に描画後、１１０℃、１０分のＰＥＢおよびスプレー現像（ＳＦＧ３０００：シグマメルテック）により、レジスト０９部分にレジストパターンを形成した（図１２（ｃ））。 A positive chemically amplified resist 09 (FEP171: FUJIFILM Electronics Materials) is applied to the blank 300 with a film thickness of 300 nm (FIG. 12B), and first patterned by an electron beam drawing machine (JBX9000: JEOL). After drawing the area and the position correction area, and then drawing the length measurement pattern that has not been corrected in the position correction area, the resist 09 part is obtained by PEB and spray development (SFG3000: Sigma Meltech) at 110 ° C. for 10 minutes. A resist pattern was formed on (FIG. 12C).
　次いで、ドライエッチング装置を用いて、ＣＦ４プラズマとＣｌ２プラズマにより、吸収層０４をエッチングし（図１２（ｄ））、レジスト０９を剥離洗浄することで、図１２（ｅ）に示す測長用パターンを有する反射型マスク３０１を作製した。測長用パターンは幅２μｍの十字パターンを遮光枠２１の端から１μｍの間隔でマスク全面に配置した。 Next, the absorption layer 04 is etched by CF 4 plasma and Cl 2 plasma using a dry etching apparatus (FIG. 12D), and the resist 09 is peeled and washed, thereby measuring the length shown in FIG. A reflective mask 301 having a pattern for use was prepared. As a pattern for length measurement, a cross pattern having a width of 2 μm was arranged on the entire mask at an interval of 1 μm from the end of the light shielding frame 21.
　次いで、測長用パターンをパターン位置精度測定機（ＬＭＳ－ＩＰＲＯ：ケーエルエー・テンコール）で測定した。 Next, the length measurement pattern was measured with a pattern position accuracy measuring machine (LMS-IPRO: KLA-Tencor).
　次いで、上述の測長用パターンを有する反射型マスク３０１（図１３（ａ））のパターン領域２２に対して、遮光枠２１を形成する工程を行った。反射型マスク３０１にｉ線レジスト３９を５００ｎｍの膜厚で塗布し（図１３（ｂ））、そこへｉ線描画機（ＡＬＴＡ：アプライドマテリアルズ）により描画、現像を行うことにより、後に遮光枠２１となる領域（遮光枠形成予定領域２１ａ）を抜いたレジストパターンを形成した（図１３（ｃ））。このときレジストパターンの開口幅は５ｍｍとし、マスク中心部の１０ｃｍ×１０ｃｍのメインパターン領域２２から３μｍ（マイクロメートル）の距離に配置した。 Next, a step of forming the light shielding frame 21 was performed on the pattern region 22 of the reflective mask 301 (FIG. 13A) having the above-described length measurement pattern. An i-line resist 39 is applied to the reflective mask 301 with a film thickness of 500 nm (FIG. 13B), and is drawn and developed there by an i-line drawing machine (ALTA: Applied Materials), so that a light shielding frame is formed later. A resist pattern was formed by removing the region 21 (light shielding frame formation scheduled region 21a) to be 21 (FIG. 13C). At this time, the opening width of the resist pattern was 5 mm, and the resist pattern was arranged at a distance of 3 μm (micrometer) from the main pattern region 22 of 10 cm × 10 cm in the center of the mask.
　次いで、ドライエッチング装置を用いてＣＨＦ３プラズマ（ドライエッチング装置内の圧力５０ｍＴｏｒｒ、ＩＣＰ（誘導結合プラズマ）パワー５００Ｗ、ＲＩＥ（反応性イオンエッチング）パワー２０００Ｗ、ＣＨＦ３：流量２０ｓｃｃｍ、処理時間６分、これらは、以下の表記で同じ。）により、上記レジスト３９の開口部の吸収層０４と保護層０３と多層反射層０２とを垂直性ドライエッチングで貫通・除去し（図１３（ｄ）、（ｅ））、図１３（ｅ）に示すような形状を得た。 Next, using a dry etching apparatus, CHF 3 plasma (pressure in the dry etching apparatus 50 mTorr, ICP (inductively coupled plasma) power 500 W, RIE (reactive ion etching) power 2000 W, CHF 3 : flow rate 20 sccm, processing time 6 minutes, These are the same in the following notation), and the absorption layer 04, the protective layer 03, and the multilayer reflective layer 02 at the opening of the resist 39 are penetrated and removed by vertical dry etching (FIG. 13D, ( e)), a shape as shown in FIG. 13 (e) was obtained.
　次いで、硫酸系の剥離液とアンモニア過酸化水素水により、レジスト３９剥離・洗浄を実施し、ドライエッチングで残ったレジスト３９を除去し（図１３（ｆ））、反射型マスク３０２を作製した。 Next, the resist 39 was stripped and washed with a sulfuric stripping solution and ammonia hydrogen peroxide solution to remove the remaining resist 39 by dry etching (FIG. 13 (f)), and a reflective mask 302 was fabricated.
　最後に、測長用パターンをパターン位置精度測定機（ＬＭＳ－ＩＰＲＯ：ケーエルエー・テンコール）で測定し、遮光枠２１形成前後の測定結果から遮光枠２１形成によるパターン位置の位置ずれを算出した。 Finally, the length measurement pattern was measured with a pattern position accuracy measuring machine (LMS-IPRO: KLA-Tencor), and the positional deviation of the pattern position due to the formation of the light shielding frame 21 was calculated from the measurement results before and after the light shielding frame 21 was formed.
　次いで、マスクデータ・プレパレーション・ソフトウェアを用いて、遮光枠２１近傍の位置補正領域２３内におけるパターン領域２２のデータを複数のセグメント２４に分割し、そのデータを上記の実験により算出された遮光枠２１形成によるパターン位置の位置ずれ結果をもとに、遮光枠２１形成時にパターン位置が設計値通りになるように、セグメント２４の配置位置を設定したデータを作成した。 Next, the mask data preparation software is used to divide the data of the pattern area 22 in the position correction area 23 near the light shielding frame 21 into a plurality of segments 24, and the data is calculated by the above experiment. Based on the result of the positional deviation of the pattern position due to the formation of 21, data in which the arrangement position of the segment 24 is set so that the pattern position becomes as designed when the light shielding frame 21 is formed was created.
　次いで、補正処理を行ったデータを用いて、再度補正処理後のマスクを図１２、図１３で説明した工程を適用して作製を行い、測長用パターンの形成、遮光枠２１の形成、遮光枠２１形成後の測長用パターンの測定を行った。 Next, using the data subjected to the correction processing, a mask after the correction processing is again applied by applying the steps described with reference to FIGS. 12 and 13, forming the measurement pattern, forming the light shielding frame 21, and shielding the light. The length measurement pattern after the frame 21 was formed was measured.
　最後に条件出しマスク３０２の遮光枠２１形成による測長用パターンの位置ずれ量の測定結果を図１４（ａ）に従来のマスクとして示す。また補正処理後のマスクの遮光枠２１形成後の測長用パターンの位置ずれ量の測定結果を図１４（ｂ）に示す。従来のマスクでは遮光枠２１端部（Ｘ＝０付近）では６．０ｎｍ程度の位置ずれが生じていたが、本発明を適用すると改善されて、遮光枠２１形成によるパターンの位置ずれがないことが確認された。また、遮光枠２１の近傍に配置した測長用パターンを計測する事で遮光枠２１形成による位置変化量を確認し、補正量が適切であることも確認された。 Finally, the measurement result of the positional deviation amount of the length measurement pattern by forming the light shielding frame 21 of the condition mask 302 is shown as a conventional mask in FIG. Further, FIG. 14B shows the measurement result of the positional deviation amount of the length measurement pattern after the formation of the light shielding frame 21 of the mask after the correction processing. In the conventional mask, a position shift of about 6.0 nm occurs at the end of the light shielding frame 21 (around X = 0). However, when the present invention is applied, there is no pattern displacement due to the formation of the light shielding frame 21. Was confirmed. Further, by measuring a length measurement pattern arranged in the vicinity of the light shielding frame 21, the amount of change in position due to the formation of the light shielding frame 21 was confirmed, and it was also confirmed that the correction amount was appropriate.
（実施例２）
　前記実施例１と同様に測長用パターンを描画したマスクについて、パターン位置精度測定機で遮光枠２１形成前後の測定結果から遮光枠２１形成によるパターン位置のずれ量を算出した。 (Example 2)
For the mask on which the length measurement pattern was drawn in the same manner as in Example 1, the pattern position deviation amount due to the formation of the light shielding frame 21 was calculated from the measurement results before and after the light shielding frame 21 was formed by the pattern position accuracy measuring machine.
　遮光枠２１近傍の位置ずれ量について構造解析シミュレーション計算を行った。この計算に必要なパラメータとして、基板０１およびその表裏に形成した各層０２～０５のヤング率およびポアソン比は公知の文献より推定した値を初期値とした。 The structural analysis simulation calculation was performed for the amount of misalignment in the vicinity of the light shielding frame 21. As parameters necessary for this calculation, the Young's modulus and Poisson's ratio of the substrate 01 and the layers 02 to 05 formed on the front and back sides thereof were assumed to be initial values estimated from known literature.
　上記シミュレーション計算を多層反射層０２の内部応力を変えて繰り返し計算し、必要に応じて材料の物性値を調整し、位置ずれ量の計測値とシミュレーション計算値の差の二乗和が最小になるような多層反射層０２の応力を算出し、多層反射層０２の内部応力は４２０ＭＰａの圧縮応力であることを導出した。 The above simulation calculation is repeatedly performed by changing the internal stress of the multilayer reflective layer 02, and the physical property value of the material is adjusted as necessary so that the sum of squares of the difference between the measured value of the positional deviation amount and the simulation calculation value is minimized. The stress of the multilayer reflection layer 02 was calculated, and it was derived that the internal stress of the multilayer reflection layer 02 was a compressive stress of 420 MPa.
　ついで上記分割セグメント２４内の平均ずれ量を算出し、マスクデータ・プレパレーション・ソフトウェアに位置補正パラメータとして入力し、セグメント２４内のパターン位置を補正した描画データを作成した。 Next, the average deviation amount in the divided segment 24 was calculated and input to the mask data preparation software as a position correction parameter to create drawing data in which the pattern position in the segment 24 was corrected.
　ついで、上記補正した描画データを用いてマスクの作製を行なった。 Next, a mask was manufactured using the corrected drawing data.
　一方、上記シミュレーション計算を用いることによってパターン位置精度測定機で基板を三点支持する場合の自重によるたわみに起因する見かけの位置ずれ量も計算することができる。この計算結果を用いて、上記補正した描画データを用いて作成したマスクのパターン位置精度を計測したところ、遮光枠２１を形成したことによる位置ずれが補正されて設計値との位置ずれ量が小さいマスクが作製できていることを確認した。 On the other hand, by using the above simulation calculation, it is possible to calculate the apparent positional deviation amount due to the deflection due to its own weight when the pattern position accuracy measuring machine supports the substrate at three points. Using this calculation result, the pattern position accuracy of the mask created using the corrected drawing data was measured. As a result, the positional deviation due to the formation of the light shielding frame 21 was corrected and the positional deviation amount from the design value was small. It was confirmed that the mask was fabricated.
＜その他の実施の形態＞
　このような多層反射層０２を掘り込むことによるパターンの位置ずれは、図１５に示すようなパターン領域２２の内側で、多層反射層０２を基板０１まで掘り込んで回路パターンが形成されたタイプの反射型マスク４００にも、同様に発生する。しかしながら、図１３（ｆ）に示した反射型マスク３０２と異なり、設計回路であるメインパターンはマスク全面に配置されており、また掘り込まれたパターン同士が互いに影響し合うため、反射型マスク４００における多層反射層０２は、メインパターン外周部のみを掘り込んだ遮光枠２１の場合と比べて複雑な挙動を示す。 <Other embodiments>
The positional deviation of the pattern due to the dug of the multilayer reflective layer 02 is a type in which the circuit pattern is formed by dug the multilayer reflective layer 02 up to the substrate 01 inside the pattern region 22 as shown in FIG. This also occurs in the reflective mask 400. However, unlike the reflective mask 302 shown in FIG. 13 (f), the main pattern, which is a design circuit, is arranged on the entire mask surface, and the engraved patterns influence each other. The multilayer reflective layer 02 in FIG. 3 shows a more complicated behavior than the case of the light shielding frame 21 in which only the outer periphery of the main pattern is dug.
　具体的には、実施例１に係る遮光枠２１の場合と同様に、メインパターンのそれぞれの位置の位置ずれ量は掘り込み部分のエッジからの距離、いわゆる抜き部の幅に依存するが、これに加えて、残し部の幅にも依存する。なぜなら、残しパターンを形成した場合、メインパターンでは残し部の線幅が細いため、残しパターンの両側に向かって応力が開放されるためである。
　このように、多層反射層０２を掘り込んだタイプの反射型マスク４００の場合、力学シミュレーションの計算は複雑にはなるが、必要な物理パラメータは、上述した遮光枠２１の場合と同様に、各層０１～０５の膜厚、ヤング率、ポアソン比、および多層反射層０２の内部応力を用いて可能である。 Specifically, as in the case of the light shielding frame 21 according to the first embodiment, the amount of positional deviation of each position of the main pattern depends on the distance from the edge of the digging portion, that is, the width of the so-called punched portion. In addition, it depends on the width of the remaining portion. This is because when the remaining pattern is formed, since the line width of the remaining portion is thin in the main pattern, the stress is released toward both sides of the remaining pattern.
Thus, in the case of the reflective mask 400 of the type in which the multilayer reflective layer 02 is dug, the calculation of the dynamic simulation is complicated, but the necessary physical parameters are the same as in the case of the light shielding frame 21 described above. This is possible using a film thickness of 01 to 05, Young's modulus, Poisson's ratio, and internal stress of the multilayer reflective layer 02.
　事前に実験する方法としては、メインパターンを想定したテストパターン、例えばメインパターンと同じ形状のテストパターン等を配置して行う。この場合、テストパターン等における抜きパターンの線幅、残しパターンの線幅、抜きパターン間の距離、残しパターン間の距離を、実際のマスクに含まれる範囲で水準を振って、必要な回数実験すればよい。 As a method for conducting an experiment in advance, a test pattern assuming a main pattern, for example, a test pattern having the same shape as the main pattern is arranged. In this case, experiment the required number of times by varying the level of the width of the blank pattern in the test pattern, the width of the blank pattern, the distance between blank patterns, and the distance between blank patterns within the range included in the actual mask. That's fine.
　本発明を実施することにより、多層反射層の掘り込みによって遮光枠部や回路パターンを形成する反射型マスクおいて、掘り込み領域近傍のパターンの位置ずれを制御することが可能となる。 By implementing the present invention, it is possible to control the positional deviation of the pattern in the vicinity of the digging region in the reflective mask that forms the light shielding frame and the circuit pattern by digging the multilayer reflective layer.
０１・・・基板
０２・・・多層反射層
０３・・・保護層
０４・・・吸収層
０５・・・裏面導電膜
０９・・・レジスト
２１・・・遮光枠
２１ａ・・・遮光枠形成予定領域
２２・・・パターン領域
２３・・・位置補正領域
２４・・・分割されたパターンデータのセグメント
２５・・・倍率補正された補正領域
２６・・・データに倍率補正する際に固定する点
２７・・・データに倍率補正する際に固定する辺
３９・・・レジスト
１００・・・ＥＵＶマスクブランク（反射型マスクブランク）
２００・・・反射型マスク
２００ａ・・・反射型マスク
３００・・・本発明で使用するＥＵＶマスクブランク
３０１・・・本発明でパターン形成まで行った反射型マスク
３０２・・・本発明で遮光枠形成まで行った反射型マスク
４００・・・反射型マスク
ｄ・・・セグメントの長さ 01 ... Substrate 02 ... Multilayer reflective layer 03 ... Protective layer 04 ... Absorbing layer 05 ... Back conductive film 09 ... Resist 21 ... Light shielding frame 21a ... Light shielding frame formation schedule Area 22 ... Pattern area 23 ... Position correction area 24 ... Segment 25 of the divided pattern data ... Correction area 26 after magnification correction ... Point 27 to be fixed when magnification correction is performed on the data ... Side 39 fixed when correcting magnification in data ... Resist 100 ... EUV mask blank (reflection mask blank)
200... Reflective mask 200 a... Reflective mask 300... EUV mask blank 301 used in the present invention... Reflective mask 302 subjected to pattern formation in the present invention. Reflective mask 400 formed up to formation: reflective mask d: segment length

Claims (20)

  1. 　基板、前記基板表面に形成された多層反射層、前記多層反射層の上に形成された保護層及び前記保護層の上に形成された吸収層を備え、前記吸収層、前記保護層及び前記多層反射層の掘り込みにより、回路パターン、又は前記回路パターンが配置されるパターン領域の外側の少なくとも一部に設けられるＥＵＶ光の反射率の低い遮光枠のパターンが形成される反射型マスクの製造方法において、
    　前記掘り込みにより形成された掘り込み領域近傍の前記回路パターンの位置変化量を、前記掘り込みに先立つ事前の実験もしくは力学シミュレーションで算出し、前記算出の結果を元に、前記掘り込み前に予めずれ量を補正しておき、前記回路パターンを形成することを特徴とする反射型マスクの製造方法。     A substrate, a multilayer reflective layer formed on the substrate surface, a protective layer formed on the multilayer reflective layer, and an absorbent layer formed on the protective layer, the absorbent layer, the protective layer, and the multilayer Method of manufacturing a reflective mask in which a pattern of a light shielding frame having a low reflectivity of EUV light provided on at least a part of the outside of a circuit pattern or a pattern region in which the circuit pattern is arranged is formed by digging a reflective layer In
    The amount of change in the position of the circuit pattern in the vicinity of the digging region formed by the digging is calculated by a prior experiment or dynamic simulation prior to the digging, and based on the calculation result, before the digging. A method for manufacturing a reflective mask, wherein the circuit pattern is formed by correcting a deviation amount.
  2. 　請求項１に記載の反射型マスクの製造方法において、前記算出する位置変化量として、前記回路パターンをなす前記掘り込み領域近傍の前記位置変化量を算出することを特徴とする反射型マスクの製造方法。 2. The method of manufacturing a reflective mask according to claim 1, wherein the position change amount in the vicinity of the digging area forming the circuit pattern is calculated as the position change amount to be calculated. Method.
  3. 　請求項２に記載の反射型マスクの製造方法において、前記遮光枠の近傍に測長用パターンを形成し、前記測長用パターンを計測することで前記位置変化量の情報を得ることを特徴とする反射型マスクの製造方法。 3. The method of manufacturing a reflective mask according to claim 2, wherein a length measurement pattern is formed in the vicinity of the light shielding frame, and the positional change amount information is obtained by measuring the length measurement pattern. A reflective mask manufacturing method.
  4. 　請求項３に記載の反射型マスクの製造方法において、前記測長用パターンは前記遮光枠の近傍の補正がされたパターンと補正なしのパターンとから成り、前記補正がされたパターン及び前記補正なしのパターンの差分を計算することで前記位置変化量の情報を得ることができるように、前記測長用パターンを形成することを特徴とする反射型マスクの製造方法。 4. The reflective mask manufacturing method according to claim 3, wherein the length measurement pattern includes a corrected pattern in the vicinity of the light shielding frame and an uncorrected pattern, the corrected pattern and the uncorrected pattern. A method for manufacturing a reflective mask, wherein the length measurement pattern is formed so that the positional change information can be obtained by calculating a difference between the patterns.
  5. 　請求項２に記載の反射型マスクの製造方法において、前記パターン位置の補正手段は、オリジナルの設計データに対して補正処理を行い、補正された設計データを作ることを特徴とする反射型マスクの製造方法。 3. The method of manufacturing a reflective mask according to claim 2, wherein the pattern position correcting means performs correction processing on the original design data to generate corrected design data. Production method.
  6. 　請求項４に記載の反射型マスクの製造方法において、前記パターン位置の補正手段は、オリジナルの設計データを描画する際に、描画打ち込み位置を補正することを特徴とする反射型マスクの製造方法。 5. The method for manufacturing a reflective mask according to claim 4, wherein the pattern position correcting means corrects the drawing driving position when drawing the original design data.
  7. 　請求項５又は６に記載の反射型マスクの製造方法において、前記パターン位置の補正を行う領域である位置補正領域は、前記遮光枠の端から大きくとも略５０００μｍ以下であることを特徴とする反射型マスクの製造方法。 7. The reflection mask manufacturing method according to claim 5, wherein a position correction region, which is a region for correcting the pattern position, is at most about 5000 μm or less from an end of the light shielding frame. Mold mask manufacturing method.
  8. 　請求項７に記載の反射型マスクの製造方法において、前記位置補正領域を複数のセグメントに分割し、前記セグメント毎に必要な補正量にて補正することを特徴とする反射型マスクの製造方法。 8. The method of manufacturing a reflective mask according to claim 7, wherein the position correction region is divided into a plurality of segments, and correction is performed with a correction amount required for each of the segments.
  9. 　請求項８に記載の反射型マスクの製造方法において、前記セグメント毎に適用する補正量は、前記実験もしくは前記力学シミュレーションで算出した前記位置変化量に多項近似式でフィッティングを行い、前記多項近似式を用いて算出された補正量であることを特徴とする反射型マスクの製造方法。 9. The method of manufacturing a reflective mask according to claim 8, wherein the correction amount to be applied for each segment is obtained by fitting the position change amount calculated by the experiment or the dynamic simulation by a polynomial approximation formula, and the polynomial approximation formula. A method of manufacturing a reflective mask, characterized in that the correction amount is calculated using
  10. 　請求項９に記載の反射型マスクの製造方法において、前記位置補正領域を複数のセグメントに分割する際は、等間隔に前記位置補正領域を分割することを特徴とする反射型マスクの製造方法。 10. The method of manufacturing a reflective mask according to claim 9, wherein when the position correction area is divided into a plurality of segments, the position correction area is divided at equal intervals.
  11. 　請求項１０に記載の反射型マスクの製造方法において、前記各セグメントの前記遮光枠から垂直方向に測った１辺の長さは、１μｍから１００μｍの範囲であることを特徴とする反射型マスクの製造方法。 11. The method of manufacturing a reflective mask according to claim 10, wherein the length of one side of each segment measured in the vertical direction from the light shielding frame is in the range of 1 μm to 100 μm. Production method.
  12. 　請求項１１に記載の反射型マスクの製造方法において、前記パターン位置の補正方法は、前記位置補正領域の１点あるいは１辺を固定し、前記位置補正領域に対し倍率補正を行うことを特徴とする反射型マスクの製造方法。 12. The method of manufacturing a reflective mask according to claim 11, wherein the pattern position correction method fixes one point or one side of the position correction area and performs magnification correction on the position correction area. A reflective mask manufacturing method.
  13. 　請求項７に記載の反射型マスクの製造方法において、前記パターン位置の補正方法は、前記位置補正領域を複数のセグメントに分割して補正を行う方法と倍率補正とを組み合わせた方法であることを特徴とする反射型マスクの製造方法。 8. The method of manufacturing a reflective mask according to claim 7, wherein the pattern position correction method is a combination of a correction method by dividing the position correction region into a plurality of segments and a magnification correction. A method for producing a reflective mask.
  14. 　請求項６に記載の反射型マスクの製造方法において、前記回路パターンは、前記遮光枠近傍のパターン位置の前記位置変化量を補正するよう作成された補正マップを用いて描画されることを特徴とする反射型マスクの製造方法。 7. The method of manufacturing a reflective mask according to claim 6, wherein the circuit pattern is drawn using a correction map created so as to correct the position change amount of the pattern position in the vicinity of the light shielding frame. A reflective mask manufacturing method.
  15. 　請求項２に記載の反射型マスクの製造方法において、前記遮光枠近傍の回路パターンの前記位置変化量を求める前記実験に用いる反射型マスクブランクの多層反射層の持つ応力は、本番に使用する反射型マスクブランクの多層反射層の持つ応力と同程度であることを特徴とする反射型マスクの製造方法。 3. The method of manufacturing a reflective mask according to claim 2, wherein the stress of the multilayer reflective layer of the reflective mask blank used in the experiment for obtaining the positional change amount of the circuit pattern in the vicinity of the light shielding frame is the reflection used for the production. A method for producing a reflective mask, characterized in that the stress is about the same as that of the multilayer reflective layer of the mask blank.
  16. 　請求項２に記載の反射型マスクの製造方法において、前記遮光枠近傍の回路パターンの前記位置変化量を求める前記実験は、前記遮光枠を形成する前に測長用パターンを形成及び計測し、前記計測後に前記遮光枠を形成し、再度、前記測長用パターンを計測することで、前記位置変化量を求めることを特徴とする反射型マスクの製造方法。 3. The method of manufacturing a reflective mask according to claim 2, wherein the experiment for obtaining the positional change amount of the circuit pattern in the vicinity of the light shielding frame forms and measures a length measurement pattern before forming the light shielding frame, A method of manufacturing a reflective mask, wherein the light shielding frame is formed after the measurement, and the position change amount is obtained by measuring the length measurement pattern again.
  17. 　請求項１に記載の反射型マスクの製造方法において、前記遮光枠近傍の回路パターンの前記位置変化量を求める前記力学シミュレーションは、前記反射型マスクブランクを構成する各材料のヤング率、ポアソン比及び膜厚と、前記多層反射層の内部応力とを用いて、前記遮光枠形成後のマスク表面の前記位置変化量を見積もることを特徴とする反射型マスクの製造方法。 2. The manufacturing method of a reflective mask according to claim 1, wherein the dynamic simulation for obtaining the positional change amount of the circuit pattern in the vicinity of the light shielding frame includes a Young's modulus, a Poisson's ratio of each material constituting the reflective mask blank, and A method of manufacturing a reflective mask, wherein the amount of change in the position of the mask surface after the formation of the light shielding frame is estimated using a film thickness and an internal stress of the multilayer reflective layer.
  18. 　請求項１に記載の反射型マスクの製造方法において、前記算出する位置変化量として、前記回路パターンをなす前記掘り込み領域近傍の前記位置変化量を算出することを特徴とする反射型マスクの製造方法。 2. The method of manufacturing a reflective mask according to claim 1, wherein the position change amount in the vicinity of the digging area forming the circuit pattern is calculated as the position change amount to be calculated. Method.
  19. 　請求項１に記載の反射型マスクの製造方法において、前記遮光枠をなす前記掘り込み領域近傍の前記位置変化量と、前記回路パターンをなす前記掘り込み領域近傍の前記位置変化量とを、両方算出することを特徴とする反射型マスクの製造方法。 2. The method of manufacturing a reflective mask according to claim 1, wherein both the position change amount in the vicinity of the digging region forming the light shielding frame and the position change amount in the vicinity of the digging region forming the circuit pattern are both. A method of manufacturing a reflective mask, characterized by: calculating.
  20. 　請求項１～請求項１９のいずれか一項に記載の反射型マスクの製造方法を用いて作製した反射型マスク。 A reflective mask produced by using the reflective mask manufacturing method according to any one of claims 1 to 19.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010008921A (en) * 2008-06-30 2010-01-14 Toshiba Corp Method of creating mask pattern data and method for manufacturing mask
JP2014075484A (en) * 2012-10-04 2014-04-24 Toppan Printing Co Ltd Reflective photomask
JP2014183075A (en) * 2013-03-18 2014-09-29 Toppan Printing Co Ltd Reflective mask, and method of manufacturing the same
JP2014232844A (en) * 2013-05-30 2014-12-11 凸版印刷株式会社 Method for manufacturing reflective mask

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010008921A (en) * 2008-06-30 2010-01-14 Toshiba Corp Method of creating mask pattern data and method for manufacturing mask
JP2014075484A (en) * 2012-10-04 2014-04-24 Toppan Printing Co Ltd Reflective photomask
JP2014183075A (en) * 2013-03-18 2014-09-29 Toppan Printing Co Ltd Reflective mask, and method of manufacturing the same
JP2014232844A (en) * 2013-05-30 2014-12-11 凸版印刷株式会社 Method for manufacturing reflective mask

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