JP6174862B2 - Charged particle beam drawing method and charged particle beam drawing apparatus - Google Patents

Description

  The present invention relates to a charged particle beam drawing method and a charged particle beam drawing apparatus, and more particularly to a method of using a deflection region of a deflector in an electron beam drawing apparatus.

  Lithography technology, which is responsible for the progress of miniaturization of semiconductor devices, is an extremely important process for generating a pattern among semiconductor manufacturing processes. In recent years, with the high integration of LSI, circuit line widths required for semiconductor devices have been reduced year by year. In order to form a desired circuit pattern on these semiconductor devices, a highly accurate original pattern (also referred to as a reticle or a mask) is required. Here, an electron beam (EB) drawing technique has an essentially excellent resolution, and is used to produce a high-precision original pattern.

FIG. 7 is a conceptual diagram for explaining the operation of the variable shaped electron beam drawing apparatus.
The variable shaping type electron beam drawing apparatus operates as follows. In the first aperture 410, a rectangular opening 411 for forming the electron beam 330 is formed. Further, the second aperture 420 is formed with a variable shaping opening 421 for shaping the electron beam 330 having passed through the opening 411 of the first aperture 410 into a desired rectangular shape. The electron beam 330 irradiated from the charged particle source 430 and passed through the opening 411 of the first aperture 410 is deflected by the deflector, passes through a part of the variable shaping opening 421 of the second aperture 420, and passes through a predetermined range. The sample 340 mounted on a stage that continuously moves in one direction (for example, the X direction) is irradiated. That is, the drawing area of the sample 340 mounted on the stage in which the rectangular shape that can pass through both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is continuously moved in the X direction. Drawn on. A method of creating an arbitrary shape by passing both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is referred to as a variable shaping method (VSB method).

  With recent miniaturization of patterns, improvement in drawing accuracy is required. One of the obstruction factors at that time is beam drift (see, for example, Patent Document 1). Therefore, the drawing apparatus corrects beam drift and the like. Causes of beam drift include contamination of a deflector used in the drawing apparatus, charge-up, and the like. In order to reduce such beam drift, regular maintenance of the deflected deflector is necessary.

JP 2007-043083 A

  Maintenance of the deflector is performed when the beam drift amount exceeds an allowable value. In order to maintain the drawing accuracy with high accuracy, it is important not to cause the deflection of the deflector to such an extent that the beam drift is caused, or to extend the period until the deflector is caused to such an extent.

  Therefore, the present invention provides a technique for overcoming the above-described problems and not causing contamination of the deflector to the extent that causes beam drift, or extending the period until the contamination of the deflector occurs to such an extent. For the purpose.

The charged particle beam drawing method of one embodiment of the present invention includes:
A step of setting a deflection width region to be used for the drawing process within the deflectable region of the deflectable region of the deflector for deflecting the charged particle beam in the deflectable region;
Charged particles using the deflector while moving the position of the deflection width area within the deflectable area at the timing when the predetermined measurement value correlated with the amount of contamination adhering to the deflector exceeds the threshold value Drawing a pattern on the sample by deflecting the beam;
It is provided with.
In other words, the charged particle beam writing method of one embodiment of the present invention is
A step of setting a deflection width region to be used for the drawing process within the deflectable region of the deflectable region of the deflector for deflecting the charged particle beam in the deflectable region;
A pattern is drawn on the sample by deflecting the charged particle beam using a deflector while moving the position of the deflection width region within the deflectable region at the timing when the predetermined measurement value exceeds the threshold value. And a process of
With
As the predetermined measurement value, any one of the number of shots of the charged particle beam, the drawing time after starting the drawing process, and the drawn total irradiation amount is used.

  Further, when the number of shots of the charged particle beam is used as the predetermined measurement value and the number of shots of the charged particle beam exceeds a threshold value, the position of the deflection width region is moved within the deflectable region. Is preferred.

  In addition, when the drawing time after starting the drawing process is used as the predetermined measurement value and the drawing time exceeds a threshold value, it is preferable to move the position of the deflection width region within the deflectable region. .

The drawing area of the sample is virtually divided into a plurality of strip- shaped stripe areas,
It is preferable to move the position of the deflection width area within the deflectable area in units of stripe areas.

A charged particle beam drawing apparatus according to one embodiment of the present invention includes:
Of the width of the deflectable area of the deflector that deflects the charged particle beam, a setting unit that sets the area of the deflection width used when performing the drawing process in the deflectable area;
A measurement unit for measuring the number of shots of a charged particle beam;
A determination unit that determines whether the measured number of shots exceeds a threshold;
A movement processing unit that moves the position of the deflection width region within the deflectable region when the number of shots exceeds a threshold;
A drawing unit for drawing a pattern on a sample by deflecting a charged particle beam within a deflection width region at a set position using a deflector;
It is provided with.

  According to one embodiment of the present invention, contamination of a deflector or the like is not caused to an extent that causes beam drift, or a period until the deflector is contaminated or the like can be extended to such an extent.

1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to Embodiment 1. FIG. FIG. 3 is a conceptual diagram for explaining each region in the first embodiment. 6 is a diagram illustrating an example of a deflectable region and a deflection frame in the first embodiment. FIG. FIG. 4 is a flowchart showing main steps of the drawing method according to Embodiment 1. 6 is a diagram illustrating an example of a deflection frame moving method according to Embodiment 1. FIG. 6 is a diagram illustrating another example of a deflection frame moving method according to Embodiment 1. FIG. It is a conceptual diagram for demonstrating operation | movement of a variable shaping type | mold electron beam drawing apparatus.

  Hereinafter, in the embodiment, a configuration using an electron beam will be described as an example of a charged particle beam. However, the charged particle beam is not limited to an electron beam, and a beam using charged particles such as an ion beam may be used. Further, a variable shaping type drawing apparatus will be described as an example of the charged particle beam apparatus.

Embodiment 1 FIG.
FIG. 1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to the first embodiment. In FIG. 1, the drawing apparatus 100 includes a drawing unit 150 and a control unit 160. The drawing apparatus 100 is an example of a charged particle beam drawing apparatus. In particular, it is an example of a variable shaping type drawing apparatus. The drawing unit 150 includes an electron column 102 and a drawing chamber 103. In the electron column 102, there are an electron gun 201, an illumination lens 202, a blanking deflector 212, a blanking aperture 214, a first aperture 203, a projection lens 204, a deflector 205, a second aperture 206, and an objective lens 207. A main deflector 208 and a sub deflector 209 are arranged. An XY stage 105 is disposed in the drawing chamber 103. On the XY stage 105, a sample 101 such as a mask to be drawn at the time of drawing is arranged. The sample 101 includes an exposure mask for manufacturing a semiconductor device. Further, the sample 101 includes mask blanks to which a resist is applied and nothing is drawn yet.

  The control unit 160 includes a control computer 110, a memory 111, a deflection control circuit 120, DAC (digital / analog converter) amplifiers 130 and 132, and storage devices 140, 142, and 144 such as a magnetic disk device. The control computer 110, the memory 111, the deflection control circuit 120, and the storage devices 140, 142, and 144 are connected via a bus (not shown).

  In the control computer 110, a drawing data processing unit 60, a drawing control unit 62, and a deflection width setting unit 64 are arranged. Functions such as the drawing data processing unit 60, the drawing control unit 62, and the deflection width setting unit 64 may be configured by hardware such as an electric circuit, or may be configured by software such as a program that executes these functions. Good. Alternatively, it may be configured by a combination of hardware and software. Information input / output to / from the drawing data processing unit 60, the drawing control unit 62, and the deflection width setting unit 64 and information being calculated are stored in the memory 111 each time.

  In the deflection control circuit 120, a deflection control unit 70, a setting unit 72, a measurement unit 74, a determination unit 76, and a movement processing unit 78 are arranged. Functions such as the deflection control unit 70, the setting unit 72, the measurement unit 74, the determination unit 76, and the movement processing unit 78 may be configured by hardware such as an electric circuit, or software such as a program for executing these functions. It may be constituted by. Alternatively, it may be configured by a combination of hardware and software. Information input / output to / from the deflection control unit 70, setting unit 72, measurement unit 74, determination unit 76, and movement processing unit 78 and information being calculated are stored in a memory (not shown) each time.

  Here, FIG. 1 shows a configuration necessary for explaining the first embodiment. The drawing apparatus 100 may normally have other necessary configurations. For example, the main deflector 208 and the sub-deflector 209, which are the main and sub two-stage multi-stage deflectors, are used for position deflection, but the position deflection is performed by one stage deflector or three or more stages of multi-stage deflectors. It may be the case. Further, the drawing apparatus 100 may be connected to an input device such as a mouse and a keyboard, a monitor device, an external interface circuit, and the like.

  FIG. 2 is a conceptual diagram for explaining each region in the first embodiment. In FIG. 2, the drawing area 10 of the sample 101 is virtually divided into a plurality of strip-shaped stripe areas 20 having a width that can be deflected in the y direction of the main deflector 208. Within each stripe region 20, the main deflector 208 is within a rectangular main deflectable region 22 (an example of a deflectable region) surrounded by an x-direction deflectable width that is approximately the same width as the y-direction deflectable width. The electron beam can be deflected. Each stripe region 20 is virtually divided into a plurality of subfields (SF) 30 (small regions) that are the deflectable size of the sub deflector 209. Then, shot figures 52, 54, and 56 are drawn at each shot position of each SF30.

  A digital signal for blanking control is output from the deflection control unit 70 to a DAC amplifier for blanking control (not shown). In the DAC amplifier for blanking control, the digital signal is converted into an analog signal, amplified, and then applied to the blanking deflector 212 as a deflection voltage. The electron beam 200 is deflected by the deflection voltage, and the irradiation time (irradiation amount) of each shot is controlled.

  A digital signal for main deflection control is output from the deflection control unit 70 to the DAC amplifier 132. The DAC amplifier 132 converts the digital signal into an analog signal, amplifies it, and applies it to the main deflector 208 as a deflection voltage. The electron beam 200 is deflected by the deflection voltage, and the beam of each shot is deflected to the reference position of the target SF 30 which is virtually divided into a mesh shape.

  A digital signal for sub-deflection control is output from the deflection control unit 70 to the DAC amplifier 130. The DAC amplifier 130 converts the digital signal into an analog signal, amplifies it, and applies it to the sub deflector 209 as a deflection voltage. The electron beam 200 is deflected by the deflection voltage, and the beam of each shot is deflected to each shot position in the target SF 30.

  In the drawing apparatus 100, drawing processing is performed for each stripe region 20 using a multistage deflector having a plurality of stages. Here, as an example, a two-stage deflector such as a main deflector 208 and a sub deflector 209 is used. While the XY stage 105 continuously moves in the −x direction, for example, the drawing is advanced in the x direction with respect to the first stripe region 20. Then, after the drawing of the first stripe region 20 is finished, the drawing of the second stripe region 20 proceeds in the same manner or in the reverse direction. Thereafter, similarly, drawing of the third and subsequent stripe regions 20 proceeds in order.

  As the XY stage 105 moves, the position of the main deflectable region 22 apparently moves on the stripe region 20 in order. For example, as described above, when drawing proceeds in the x direction, the position of the main deflectable region 22 also moves on the stripe region 20 in the x direction. Then, the main deflector 208 deflects the electron beam 200 to the reference position A of the SF 30 to be drawn in the main deflectable region 22. At that time, the electron beam 200 is continuously deflected to the reference position A of the SF 30 to be drawn in the main deflectable region 22 so as to follow the movement of the XY stage 105. While the main deflector 208 continues to deflect the electron beam 200 to the reference position A of the SF 30 to be drawn, the sub deflector 209 applies each of the beams irradiated into the SF 30 from the reference position A of each SF 30. The electron beam 200 is deflected to the shot position. As described above, the main deflector 208 and the sub deflector 209 have deflection areas having different sizes. The SF 30 is a minimum deflection area among the deflection areas of the multi-stage deflector. When the drawing in the SF 30 that has been the drawing target is completed, the main deflector 208 moves the deflection target to the reference position A of the next SF 30. Thereafter, the graphic pattern in each SF 30 is sequentially drawn by the same operation.

FIG. 3 is a diagram illustrating an example of a deflectable region and a deflection frame in the first embodiment. FIG. 3 shows the main deflectable region 22 of the main deflector 208, for example. In the conventional drawing process, when drawing the target stripe region 20, if the drawing target SF30 enters the main deflectable region 22 as the XY stage 105 moves in the -x direction, for example, the previous SF30 is drawn. If drawing on the drawing object is finished, drawing on the drawing object SF30 is started immediately. Therefore, in the conventional drawing process, the deflection area in which the main deflector 208 is deflected in the actual drawing process in the main deflectable area 22 in FIG. 3 is, for example, an area having a width L ₁ from the right end in the x direction. (In FIG. 3, it is only within the deflection frame 24a). Width _{L 1} is only for example, about 1/5 of the x-direction deflectable width _{L 0} of the main deflection region 22. Therefore, the main deflector 208 is made of such right end to repeated deflection in the region of about the width L _1. On the other hand, when drawing is performed while the XY stage 105 moves in the x direction, for example, the deflection area of the main deflectable area 22 in which the main deflector 208 is deflected in the actual drawing process is in the −x direction. only from the left end within the width L ₁ of about region (not shown).

  Empirically, there are a plurality of attachment points of contamination (hereinafter referred to as contamination) of the main deflector 208 when a forward (FWD) / forward (FWD) operation in which drawing processing of all stripe regions 20 is advanced in the x direction is performed. A similar tendency is shown in the drawing apparatus. Further, the adherence location of the main deflector 208 in the case of performing the backward (BWD) / backward (BWD) operation in which the drawing processing of all the stripe regions 20 is advanced in the −x direction is similar in a plurality of drawing apparatuses. Show the trend. Further, when the forward (FWD) / backward (BWD) operation in which the drawing process of each stripe region 20 is alternately performed in the x direction and the −x direction is performed, a plurality of drawing positions of the contamination of the main deflector 208 are provided. A similar trend is shown in the device. Similarly, the tendency of beam drift deterioration when performing forward (FWD) / forward (FWD) operations is similar in a plurality of drawing apparatuses. Similarly, the tendency of beam drift degradation in the backward (BWD) / backward (BWD) operation is similar in a plurality of drawing apparatuses. Similarly, the tendency of beam drift degradation when performing forward (FWD) / backward (BWD) operations is similar in a plurality of drawing apparatuses.

  More specifically, depending on the position of the deflection area where the main deflector 208 is deflected in the actual drawing process, the contamination spot that adheres to the main deflector 208 is locally biased to a part of the main deflector 208. End up. For this reason, although contamination such as contamination is hardly observed in other portions of the main deflector 208, contamination on such unevenly distributed attachment portions is concentrated. As a result, the beam drift is caused by an increase in contamination of the unevenly attached adhesion portions. Therefore, in the first embodiment, the contaminated portion of the main deflector 208 is not unevenly distributed at a local position. Therefore, in the first embodiment, the position of the deflection frame 24 in FIG. 3 is initially set to the right end of the main deflectable region 22 (indicated by the deflection frame 24a in FIG. 3), and in the middle of the drawing process, When a predetermined threshold value to be described later is exceeded, it is moved to another position (in FIG. 3, for example, indicated by a deflection frame 24b from the center left). As a result, it is possible to sequentially change the adhesion location of the main deflector 208 such as contamination. As a result, it is possible to avoid local concentration of contamination and the like. As a result, it is possible to extend the period until beam drift caused by contamination of the main deflector 208 occurs.

  FIG. 4 is a flowchart showing main steps of the drawing method according to the first embodiment. 4, in the drawing method according to the first embodiment, the deflection width setting step (S102), the deflection frame setting step (S104), the drawing step (S106), the determination step (S108), and the determination step (S110). Then, a series of steps of a determination step (S112), a deflection frame moving step (S114), and a log output step (S116) are performed.

As the deflection width setting step (S102), the deflection width setting unit 64 includes a deflection area width L ₁ (in the example of FIG. 3) used by the main deflector 208 for deflection in the actual drawing process. , X direction width). For the y direction, the y-direction deflectable width of the main deflectable region 22 is used as it is. Such a width is preferably set based on past results or the like. In the first embodiment, for each layout drawn in the past, the width of the deflection area (width in the x direction) actually used for deflection by the main deflector 208 is stored in the storage device 144 as log information. Deflection width setting unit 64 reads the log information from the storage device 144, the average value of the width of the deflection space used for deflection, median, or to set the maximum value as the width L _1. Alternatively, if there is a width of the deflection area used when drawing with the same drawing data as the drawing data of the layout to be drawn in the past, it is preferable to set the value.

As a deflecting frame setting step (S104), setting unit 72, used to draw processing in the x-direction deflectable width L ₀ of the main deflection region 22 of the main deflector 208 deflects the electron beam 200 (an example of a deflector) deflecting frame 24 to the (region of deflection width L ₁₎ is set in the main deflection region 22. Deflecting frame 24 is set in the rectangular area x-direction width of the y-direction width is y-direction deflectable width of the main deflectable region 22 in deflection width L _1. Here, as shown in FIG. 3, the initial position is set, for example, at the right end of the main deflectable region 22.

  In the drawing step (S106), the drawing unit 150 draws a pattern on the sample 101 by deflecting the electron beam 200 within the deflection frame 24 at a set position using the main deflector 208 or the like. Specifically, it operates as follows. First, the drawing data processing unit 60 reads the drawing data from the storage device 140 and performs a plurality of stages of data conversion processing to generate shot data unique to the drawing apparatus 100. For example, the drawing data has a file structure for each frame area obtained by virtually dividing the chip area of the drawing target chip on a strip. Then, the drawing data processing unit 60 sequentially reads the data file for each frame area and generates shot data. In addition, a plurality of graphic patterns are arranged on the chip, but the drawing apparatus 100 has a limited size that can be formed by one beam shot. Therefore, in the data conversion process, each figure pattern is divided into shot figures that can be formed by one beam shot. Then, the figure type, size, position, etc. of each shot figure are generated as shot data. In addition, an irradiation amount (irradiation time) is defined as shot data. Shot data is sequentially stored in the storage device 142.

  The drawing control unit 62 controls the deflection control circuit 120 and other control circuits (not shown) to cause the drawing unit 150 to perform a drawing operation. In the deflection control circuit 120, the deflection control unit 70 reads shot data from the storage device 142, and generates main deflection data and sub deflection data for each shot figure in accordance with irradiation position data defined in the shot data. The main deflection data is output to the DAC amplifier 132. The sub deflection data is output to the DAC amplifier 130. Further, the deflection control unit 70 generates blanking data for each shot figure in accordance with the irradiation time defined in the shot data, and outputs the blanking data to a blanking DAC amplifier (not shown). Further, the deflection control unit 70 generates shaping data according to the figure type and figure size defined in the shot data, and outputs them to a beam shaping DAC amplifier (not shown). Then, based on signals from each DAC amplifier controlled by the deflection control circuit 120 and control information from other control circuits (not shown), the drawing unit 150 uses the electron beam 200 to apply the graphic pattern to the sample 100. draw. Specifically, it operates as follows.

  The electron beam 200 emitted from the electron gun 201 (emission unit) is turned on by a blanking deflector 212 controlled by a deflection signal from a blanking DAC amplifier when passing through the blanking deflector 212. In this state, the beam is controlled to pass through the blanking aperture 214, and in the beam OFF state, the entire beam is deflected so as to be shielded by the blanking aperture 214. The electron beam 200 that has passed through the blanking aperture 214 until the beam is turned off after the beam is turned off becomes one shot of the electron beam. The blanking deflector 212 controls the direction of the passing electron beam 200 to alternately generate a beam ON state and a beam OFF state. For example, the voltage may be applied to the blanking deflector 212 when the beam is OFF, without applying a voltage when the beam is ON. The irradiation amount per shot of the electron beam 200 irradiated on the sample 101 is adjusted at the irradiation time t of each shot.

  The electron beam 200 of each shot generated by passing through the blanking deflector 212 and the blanking aperture 214 as described above illuminates the entire first shaping aperture 203 having a rectangular hole by the illumination lens 202. Here, the electron beam 200 is first shaped into a rectangle. Then, the electron beam 200 of the first aperture image that has passed through the first shaping aperture 203 is projected onto the second shaping aperture 206 by the projection lens 204. The deflector 205 controls the deflection of the first aperture image on the second shaping aperture 206 and can change the beam shape and dimensions (variable shaping is performed). Such variable shaping is performed for each shot, and is usually shaped into different beam shapes and dimensions for each shot. Then, the electron beam 200 of the second aperture image that has passed through the second shaping aperture 206 is focused by the objective lens 207, deflected by the main deflector 208 and the sub deflector 209, and continuously moved. The desired position of the sample 101 arranged at 105 is irradiated. FIG. 1 shows a case in which multi-stage deflection of main and sub two stages is used for position deflection. In such a case, the main deflector 208 deflects the electron beam 200 of the corresponding shot while following the stage movement to the reference position of the SF 30, and the sub deflector 209 deflects the beam of the corresponding shot applied to each irradiation position in the SF. do it. By repeating such an operation and connecting the shot figures of the respective shots, a figure pattern defined in the drawing data is drawn.

  The drawing process is performed in units of 20 stripe regions. Further, during the drawing step (S106), the measuring unit 74 measures the number of shots of the shot figure (an example of a predetermined measurement value). Alternatively, the measurement unit 74 is preferably capable of measuring a drawing time T (another example of a predetermined measurement value) after starting the drawing process. Or the measurement part 74 is suitable also if it measures the drawn total irradiation amount. The total irradiation amount may be calculated by accumulating the product of the area S of the shot figure, the current density J, and the irradiation time t.

  As a determination step (S108), the drawing control unit 62 determines whether or not drawing of the target stripe region 20 has been completed. If the drawing of the target stripe region 20 has not been completed, the drawing process (S106) is continued until the drawing of the target stripe region 20 is completed. When the drawing of the target stripe region 20 is completed, the process proceeds to the next determination step (S110).

  As a determination step (S110), the drawing control unit 62 determines whether drawing of all the stripe regions 20 has been completed. In other words, it is determined whether or not the drawing process has been completed. If the drawing process has not ended, the process proceeds to the determination step (S112). When the drawing process is completed, the process proceeds to the log output step (S116).

  As a determination step (S112), the determination unit 76 determines whether or not the number of shots of the electron beam 200 exceeds a threshold value (shot number threshold value). If the number of shots of the electron beam 200 does not exceed the threshold value, the process returns to the drawing step (S106). Then, until the number of shots of the electron beam 200 exceeds the threshold value, the drawing process (S106) to the determination process (S112) are sequentially repeated for the next stripe region 20. When the number of shots of the electron beam 200 exceeds the threshold value, the process proceeds to the deflection frame moving step (S114). When returning to the drawing step (S106), the measurement unit 74 once resets the measured number of shots and starts measurement again.

  Alternatively, when the measurement unit 74 measures the drawing time T after starting the drawing process, as a determination step (S112), the determination unit 76 sets the drawing time T to a threshold value (drawing time) after starting the drawing process. Threshold) is exceeded. If the drawing time T does not exceed the threshold value, the process returns to the drawing step (S106). Then, the drawing process (S106) to the determination process (S112) are sequentially repeated for the next stripe region 20 until the drawing time T exceeds the threshold value. When the drawing time T exceeds the threshold value, the process proceeds to the deflection frame moving step (S114). When returning to the drawing step (S106), the measuring unit 74 once resets the measured drawing time and starts measuring again.

  Alternatively, when the measurement unit 74 measures the total dose, as a determination step (S112), the determination unit 76 determines whether the total dose exceeds a threshold (total dose threshold). . Then, when the total irradiation amount does not exceed the threshold value, the process returns to the drawing step (S106). Then, the drawing process (S106) to the determination process (S112) are sequentially repeated for the next stripe region 20 until the total irradiation amount exceeds the threshold value. When the total irradiation amount exceeds the threshold value, the process proceeds to the deflection frame moving step (S114). When returning to the drawing step (S106), the measurement unit 74 once resets the measured total irradiation amount and starts measurement again.

  In the deflection frame moving step (S114), the movement processing unit 78 moves the position of the deflection frame 24 within the main deflectable region 22. Then, returning to the drawing step (S106), the drawing step (S106) to the deflection frame moving step (S114) are repeated.

  As described above, in the first embodiment, when the number of shots of the electron beam 200 exceeds the threshold value, the position of the deflection frame 24 is moved within the main deflectable region 22. Alternatively, the position of the deflection frame 24 is moved within the main deflectable region 22 when the drawing time T after starting the drawing process exceeds a threshold value. When the position of the deflection frame 24 is moved, it is preferable to move the deflection frame 24 in units of the stripe region 20. As a result, it is possible to avoid the risk of the stagnation of the drawing operation caused by moving the position of the deflection frame 24 in the middle of the same stripe region 20. Even if the position of the deflection frame 24 is moved in the middle of the same stripe region 20 or the position of the deflection frame 24 is moved between the stripe regions 20, there is a large difference in the situation of the contamination attachment location of the main deflector 208. Does not occur. As described above, in the first embodiment, a pattern is drawn on the sample 101 by deflecting the electron beam using the main deflector 208 or the like while moving the position of the deflection frame 24 within the main deflectable region 22. .

  As the log output step (S116), the drawing control unit 62 stores the data subjected to the drawing process in the storage device 144 as log information. As described above, the log information includes the width of the deflection area (width in the x direction) used by the main deflector 208 for deflection.

FIG. 5 is a diagram illustrating an example of a deflection frame moving method according to the first embodiment. Movement processing section 78, the aforementioned threshold value in deflection width L ₁ determines whether less than a predetermined threshold value. The deflection width L ₁ is equal to or less than the threshold value, it is divided as follows. First, a threshold value for the number of divisions is set in advance. Then, using the x-direction deflectable width L ₀ of the main deflectable region 22, the deflection width L ₁ is expressed by the following formula L ₀ / n ≧ L ₁ > L ₀ / (n + 1).
And a natural number n such that n ≧ “threshold number of division” is satisfied. For example, the threshold for the number of divisions is 4. L ₀ is set to 100 μm. If L ₁ is 18 μm, n = 5 is
100/5 ≧ 18> 100 / (5 + 1) is satisfied. Furthermore, since n = 5 satisfies n> 4 (threshold value), it is divided into five. Therefore, when performing such division, it is preferable that L ₁ is set to 20 μm when setting the deflection width L ₁ in the deflection width setting step (S102). In addition, when there is no division number that satisfies the above-described conditions, a moving method described later may be performed.
Then, as shown in FIG. 5, for example, the movement processing unit 78 a, b, c, d, e... From the right end of the main deflectable region 22 and the direction opposite to the drawing direction (−x direction). The deflection frame 24 is sequentially moved toward (to a deflection frame different from the previous deflection frame). Alternatively, the deflection frame 24 may be sequentially moved from the left end of the main deflectable region 22 in the same direction (x direction) as e, d, c, b, a. Alternatively, the deflection frame 24 may be sequentially moved at random.

FIG. 6 is a diagram illustrating another example of the deflection frame moving method according to the first embodiment. When deflection width L ₁ is not less than the threshold value, the movement control section 78, as shown in FIG. 6, as the deflection frame 24 overlaps a portion to each other, to move the deflecting frame 24 in order. For example, the deflection frame 24 is sequentially moved from the right end of the main deflectable region 22 in the direction opposite to the drawing direction (−x direction) from a, b. Alternatively, the deflection frame 24 may be sequentially moved from the left end portion of the main deflectable area 22 in the same direction (x direction) as the drawing direction so as to partially overlap. Alternatively, the deflection frames 24 may be moved in order so that the deflection frames 24 partially overlap each other. When deflection width L ₁ is large, by performing such an operation, can be made as the number of times of movement of the deflecting frame 24 is not reduced. As a result, the contaminated portion can be prevented from being biased to a local position.

  As described above, according to the first embodiment, the contamination of the deflector is not caused to such an extent that the beam drift is caused, or the period until the deflector is caused to such an extent can be extended. As a result, the drawing accuracy can be maintained with high accuracy. Moreover, since the maintenance period of the main deflector can be lengthened, the operating rate of the apparatus can be improved.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In the above-described example, the case where the main deflection deflection frame 24 is moved is shown for the two-stage deflection of the main and sub stages. However, the present invention is not limited to this. Even in the case of three or more stages of deflection, it can be similarly applied except for the minimum deflection region.

  In addition, although descriptions are omitted for parts and the like that are not directly required for the description of the present invention, such as a device configuration and a control method, a required device configuration and a control method can be appropriately selected and used. For example, although the description of the control unit configuration for controlling the drawing apparatus 100 is omitted, it goes without saying that the required control unit configuration is appropriately selected and used.

  In addition, all charged particle beam writing methods and charged particle beam writing apparatuses that include elements of the present invention and whose design can be appropriately changed by those skilled in the art are included in the scope of the present invention.

10 Drawing Area 20 Stripe Area 22 Main Deflection Area 24 Deflection Frame 30 SF
52, 54, 56 Shot figure 60 Drawing data processing unit 62 Drawing control unit 64 Deflection width setting unit 70 Deflection control unit 72 Setting unit 74 Measuring unit 76 Determination unit 78 Movement processing unit 100 Drawing apparatus 101, 340 Sample 102 Electronic lens tube 103 Drawing chamber 105 XY stage 110 Control computer 111 Memory 120 Deflection control circuit 130, 132 DAC amplifier 140, 142, 144 Storage device 150 Drawing unit 160 Control unit 200 Electron beam 201 Electron gun 202 Illumination lens 203, 410 First aperture 204 Projection Lens 205 Deflectors 206 and 420 Second aperture 207 Objective lens 208 Main deflector 209 Sub deflector 212 Blanking deflector 214 Blanking aperture 330 Electron beam 411 Opening 421 Variable shaping opening 430 Charged particle source

Claims (6)

A step of setting, within the deflectable region, a deflection width region to be used for the drawing process among the deflectable region widths of the deflector for deflecting the charged particle beam;
The deflector is moved while moving the position of the deflection width region within the deflectable region at a timing when a predetermined measurement value correlated with the amount of contamination adhering to the deflector exceeds a threshold value. Drawing a pattern on the sample by using and deflecting the charged particle beam;
A charged particle beam drawing method comprising: A step of setting, within the deflectable region, a deflection width region to be used for the drawing process among the deflectable region widths of the deflector for deflecting the charged particle beam;
By deflecting a charged particle beam using the deflector while moving the position of the deflection width region within the deflectable region at a timing when a predetermined measurement value exceeds a threshold value, Drawing a pattern;
With
Any one of the number of shots of the charged particle beam, the drawing time after the drawing process is started, and the drawn total irradiation amount is used as the predetermined measurement value. The number of shots of the charged particle beam is used as the predetermined measurement value,
3. The charged particle beam drawing method according to claim 1, wherein when the number of shots of the charged particle beam exceeds a threshold value, the position of the deflection width region is moved within the deflectable region. . The drawing time after starting the drawing process is used as the predetermined measurement value,
3. The charged particle beam writing method according to claim 1, wherein when the writing time exceeds a threshold value, the position of the deflection width region is moved in the deflectable region. The drawing area of the sample is virtually divided into a plurality of strip-shaped stripe areas,
Claim 1-4 charged particle beam writing method of any characterized in that moving the location of the region of the deflection width by the deflectable region in the stripe region units. Of the width of the deflectable area of the deflector that deflects the charged particle beam, a setting unit that sets the area of the deflection width used when performing the drawing process in the deflectable area;
A measurement unit for measuring the number of shots of the charged particle beam;
A determination unit that determines whether the measured number of shots exceeds a threshold;
A movement processing unit that moves the position of the deflection width region within the deflectable region when the number of shots exceeds a threshold;
A drawing unit that draws a pattern on a sample by deflecting a charged particle beam within the deflection width region at a set position using the deflector;
A charged particle beam drawing apparatus comprising:

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