JP5398318B2 - Exposure apparatus and method for manufacturing electronic device - Google Patents

Description

  The present invention relates to an exposure apparatus and an electronic device manufacturing method.

  In the manufacture of electronic devices such as semiconductor devices and flat panel displays, a thin film layer is laminated on a substrate and processed into a desired shape to form a circuit pattern. When the laminated thin film layer is processed into a desired shape, a circuit pattern is formed by repeating the photolithography process and the etching process. In this case, generally, in a photolithography process, a photosensitive material called a resist is laminated on a thin film layer to form a resist film, and this resist film is selectively exposed and developed to form a resist mask. I have to. In the etching process, the circuit pattern is formed by dry etching the thin film layer using a resist mask.

  Here, if an error occurs between the dimension of the designed circuit pattern and the dimension of the actually formed circuit pattern, there is a risk that the device characteristics may vary or the product yield may be reduced. As a factor causing such a dimensional error, a light interference effect at the time of exposure, a so-called optical proximity effect is known, and a pattern size of a resist mask formed by performing a light intensity simulation or the like is corrected. .

  However, such a dimensional error can occur not only during exposure (photolithography process) but also in the etching process. For example, there are cases where the etching characteristics change due to fluctuations in plasma characteristics such as plasma distribution in the etching process, resulting in excessive etching or insufficient etching. Therefore, a technique for correcting the pattern dimension of a reticle (mask) used when performing exposure in a photolithography process in consideration of a dimensional error in the etching process (hereinafter referred to as a processing conversion difference) has been proposed (patent). Reference 1).

  However, the etching characteristics may change over time due to changes in plasma characteristics and the like. Therefore, if the processing pattern difference is reduced by correcting the pattern size of the reticle, it is necessary to select and replace a reticle having an appropriate pattern size, and there is a possibility that quick response cannot be achieved. In addition, a large number of reticles may be required according to the amount of variation in etching characteristics, or proper correction may not be possible.

JP 2003-15272 A

  The present invention provides an exposure apparatus and an electronic device manufacturing method capable of quickly reducing a processing conversion difference even when etching characteristics vary.

According to one aspect of the present invention, the illumination optical system includes a light source, an illumination stop portion and a shielding plate provided on an emission side of the light source, and emits a light beam toward a pattern area of the reticle. a projection optical system for projecting an image of a pattern light beam is irradiated on the exposed surface of the substrate, the shape of the illumination provided before Symbol illumination optical system coherence factor, and the illumination optical system at least one, the resist mask The pattern size of the resist mask from the correction information storage unit that stores the relationship with the pattern dimension as correction information of the pattern dimension of the resist mask, the inspection information of the circuit pattern formed on the substrate, and the correction information determined as at least one of the correction condition in the form of pre-Symbol illumination optical system coherence factor, and illumination the provided illumination optical system for correcting the A correction condition calculating unit, based on the correction condition, the illumination diaphragm unit for controlling the coherence factor of the illumination optical system by changing the numerical aperture of the illumination optical system, and the for changing the shape of the illumination controlling at least one of the position of the shielding plate, the resist and the optical system controller for the pattern dimension Ru changing the mask, the exposure apparatus characterized by having a are provided.

Further, according to another aspect of the present invention, the shape of the step and the illumination provided before Symbol illumination optical system coherence factor, and the illumination optical system for collecting inspection information of a circuit pattern formed on the substrate A step of collecting the relationship between at least one of the resist mask pattern dimension and the resist mask pattern dimension as correction information of the resist mask pattern dimension, a step of determining a circuit pattern state based on the inspection information, and the correction information and selects the appropriate, determined as at least one of the correction condition in the form of illumination provided before Symbol illumination optical system coherence factor, and the illumination optical system for correcting the pattern size of the resist mask step , in order to change the pattern size of the resist mask, based on the correction condition, changes the numerical aperture of the illumination optical system It was a step that controls at least one of the positions of the illumination optical system illuminating aperture portion provided in the illumination optical system that controls the coherence factor, and shield plate for changing the shape of the illumination, reticle And a step of performing exposure by projecting an image of a pattern irradiated with the light beam onto an exposure surface of the substrate. Is provided.

  According to the present invention, there are provided an exposure apparatus and an electronic device manufacturing method capable of quickly reducing a processing conversion difference even when etching characteristics fluctuate.

It is a schematic diagram for illustrating the exposure apparatus which concerns on this Embodiment. It is a schematic diagram for illustrating an illumination stop part. It is a schematic graph for demonstrating a process conversion difference and its in-plane distribution. It is a schematic graph for demonstrating the case where coherence factor (sigma) is changed. It is a schematic diagram for illustrating the shape of illumination. It is a schematic graph for demonstrating the process conversion difference after correction | amendment, and its in-plane distribution. It is a schematic diagram for illustrating the illumination stop part which concerns on other embodiment. It is a schematic diagram for illustrating an illumination stop part. It is a flowchart for illustrating the procedure of exposure.

Hereinafter, embodiments of the present invention will be illustrated with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.
FIG. 1 is a schematic view for illustrating an exposure apparatus according to the present embodiment.
As shown in FIG. 1, the exposure apparatus 1 is provided with an illumination optical system 2, a reticle stage 7, a projection optical system 8, a substrate stage 10, a correction condition calculation unit 11, a correction information storage unit 12, and an optical system control unit 13. It has been.

The illumination optical system 2 that emits a light beam toward the pattern area of the reticle R is provided with a light source 3, a fly-eye lens 4, an illumination diaphragm unit 5, and a condenser lens 6.
The light source 3 can emit far ultraviolet rays such as a laser light source. For example, a KrF excimer laser light source having a wavelength of 248 nm, an ArF excimer laser light source having a wavelength of 193 nm, an F ₂ laser light source having a wavelength of 157 nm, a YAG laser, a solid-state laser (for example, a semiconductor laser), or the like can be used.
A fly-eye lens 4 is provided on the emission side of the light source 3. The fly-eye lens 4 is configured to integrate a plurality of small lenses in a matrix. The light beam emitted from the light source 3 passes through the fly-eye lens 4 so that the light intensity distribution in the beam cross section is uniform.

An illumination stop 5 is provided at the focal position on the exit side of the fly-eye lens 4. The illumination diaphragm unit 5 changes the dimension of the light beam cross section.
FIG. 2 is a schematic diagram for illustrating the illumination stop section 5. 2A is a schematic cross-sectional view for illustrating the illumination stop section 5, and FIG. 2B is a view taken along the line AA in FIG. 2A. As shown in FIG. 2, the illumination stop portion 5 is provided with a light shielding portion 5 a and a transmission portion 5 b. The light shielding portion 5a is formed of an opaque material such as metal and shields a part of the light beam emitted from the fly-eye lens 4. The light shielding portion 5a is configured by overlapping a plurality of plate-like bodies 5c with each other. Each plate-like body 5c is configured to be able to rotate around the support portion 5d. An elongated hole 5e is provided on the side opposite to the side where the support portion 5d is provided. A movable pin 5f is inserted into the elongated hole 5e. Further, depending on the position of the movable pin 5f, each plate-like body 5c is rotated about the support portion 5d. And the opening dimension (diameter dimension) of the permeation | transmission part 5b changes as each plate-shaped body 5c rotates. In addition, a drive unit (not shown) for changing the position of the movable pin 5f is provided, and the drive unit (not shown) and the optical system control unit 13 are electrically connected. It should be noted that the dimensions, shape, number, arrangement position, and the like of the plate-like body 5c, the support portion 5d, the long hole 5e, and the movable pin 5f are not limited to those illustrated, but can be changed as appropriate.
In the illumination diaphragm unit 5 having such a configuration, a driving unit (not shown) is driven based on an electric signal from the optical system control unit 13, and each plate-like body 5c is rotated to move the aperture size ( diameter), and is capable of changing the numerical aperture NA _L of the illumination optical system 2 thus.

Here, the numerical aperture of the illumination optical system 2 NA _L, coherence factor σ and the numerical aperture of the projection optical system 8 and NA _P is represented by the following formula (1).

σ = NA _L / NA _P (1)

In general, the resolution can be improved by increasing the numerical aperture. Further, if the coherence factor σ is reduced, the coherency is improved, so that the edge of the pattern can be emphasized. Further, when the coherence factor σ is changed, the illuminance distribution on the pupil plane of the projection optical system 8 can be changed. Therefore, the imaging characteristics of the pattern can be controlled by changing the numerical aperture and the coherence factor σ.
The control of the coherence factor σ will be described later.

A condenser lens 6 is provided on the exit side of the illumination stop 5. The condenser lens 6 converts the incident light beam into a substantially parallel light beam.
On the exit side of the condenser lens 6 (illumination optical system 2), a reticle stage 7 for holding a reticle (mask) R is provided. The reticle R held on the reticle stage 7 and the illumination stop 5 are disposed at optically conjugate positions.
The reticle R can have, for example, a transparent substrate and a pattern formed in a pattern region on the surface of the transparent substrate. The transparent substrate is made of a material that transmits the irradiated light beam. The transparent substrate can be formed from, for example, quartz glass. The pattern is formed of a material that blocks or attenuates the irradiated light beam. The pattern can be formed from, for example, chromium (Cr) or molybdenum silicide (MoSi).

A projection optical system 8 is provided on the exit side of the reticle stage 7. The projection optical system 8 transfers the pattern formed in the pattern area of the reticle R onto the exposure surface (on the resist film) of the substrate W at a predetermined magnification. That is, the projection optical system 8 projects an image of the pattern irradiated with the light beam onto the exposure surface of the substrate W. The projection optical system 8 is provided with an aperture stop 9. The aperture stop section 9 is provided on the pupil plane of the projection optical system 8, and the aperture stop section 9 and the illumination stop section 5 are in an optically conjugate position. Also, so that it is possible to change the opening size of the aperture stop unit 9 (diameter) to be able to change the numerical aperture NA _P. The aperture stop 9 can have the same configuration as the illumination stop 5 illustrated in FIG. Therefore, the drive unit (not shown) is driven based on the electrical signal from the optical system control unit 13 and the plate-shaped body is rotated to move, so that the aperture size (diameter size) of the transmission unit, and hence the numerical aperture of the projection optical system 8 is obtained. and it is capable of changing the NA _P.

  A substrate stage 10 is provided on the exit side of the projection optical system 8. The surface of the substrate stage 10 on which the substrate W is placed (mounting surface) is provided with a holding means (not shown) (for example, an electrostatic chuck), so that the placed substrate W can be held. ing. In addition, the position of the substrate W placed in a two-dimensional plane (horizontal plane) substantially perpendicular to the optical axis of the projection optical system 8 can be moved. That is, the substrate stage 10 has a function as a so-called XY table. It is also possible to enable movement in a direction substantially parallel to the optical axis of the projection optical system 8. The substrate stage 10 is provided with coordinate measuring means (not shown) so that position information of the substrate W placed thereon can be detected.

  A correction information storage unit 12 and an optical system control unit 13 are electrically connected to the correction condition calculation unit 11 so that information can be transferred. The correction condition calculation unit 11 is electrically connected to an inspection apparatus 100 provided outside the exposure apparatus 1 so that inspection information can be transferred. The inspection apparatus 100 collects inspection information of circuit patterns formed on the substrate W by etching. In this case, the inspection information of the circuit pattern can include at least one of the processing conversion difference and the in-plane distribution of the processing conversion difference.

  The optical system control unit 13 changes the numerical aperture and the coherence factor σ which are optical conditions in exposure by changing the aperture size (diameter size) of the illumination stop unit 5 and the aperture stop unit 9. That is, the optical system control unit 13 changes the optical conditions in exposure based on correction conditions described later.

Here, the correction of the resist mask pattern dimension in consideration of the processing conversion difference will be illustrated before further illustrating the correction condition calculation unit 11 and the like.
If an error occurs between the designed circuit pattern dimension and the actually formed circuit pattern dimension, the device characteristics may vary and the product yield may decrease. Such a dimensional error may occur not only at the time of exposure (for example, optical proximity effect) but also in an etching process which is a subsequent process. For example, there are cases where the etching characteristics change due to fluctuations in plasma characteristics such as plasma distribution in the etching process, resulting in excessive etching or insufficient etching.

  Further, in-plane distribution may occur in the processing conversion difference (dimensional error in the etching process). For example, the etching rate may vary depending on the position on the substrate W due to variations in plasma distribution and the like. Therefore, an in-plane distribution may occur in the processing conversion difference.

  FIG. 3 is a schematic graph for illustrating the processing conversion difference and its in-plane distribution. The horizontal axis represents the pitch width dimension of the circuit pattern, and the pitch width dimension increases toward the right side. The vertical axis represents the machining conversion difference, and the machining conversion difference increases as it goes upward. In the figure, S1 is near the periphery of the substrate W, S2 is near the center of the substrate W, and S3 is a region between S1 and S2.

  As shown in FIG. 3, the plasma product (for example, ions, neutral active species, electrons, etc.) can be introduced more easily as the pitch width dimension of the circuit pattern becomes larger, so that it is more susceptible to plasma characteristics such as plasma distribution. Become. Therefore, the processing conversion difference tends to increase as the pitch width dimension of the circuit pattern increases. Further, the vicinity of the periphery is more susceptible to the influence of the processing atmosphere than the vicinity of the center of the substrate W. For example, the plasma product flow tends to be slower and more stable near the center. Therefore, even if the pitch width dimension of the circuit pattern is the same, the processing conversion difference tends to increase as the peripheral edge of the substrate W is reached. That is, as shown in FIG. 3, the processing conversion difference in the vicinity S1 of the periphery of the substrate W becomes the largest. Further, the processing conversion difference near the center S2 of the substrate W is the smallest, and the region S3 is a value between the vicinity S1 of the periphery of the substrate W and the vicinity S2 of the center of the substrate W. Thus, in-plane distribution may occur in the processing conversion difference.

  Further, the processing conversion difference can be affected by the process conditions and the characteristics of the etching apparatus. That is, the processing conversion difference can be influenced by the contents of process conditions (for example, process gas component ratio, pressure, applied power, etc.) and the type of etching apparatus (for example, difference in plasma generation method, model, etc.). .

  In addition, the processing conversion difference may vary depending on the usage status of the etching apparatus. For example, the processing conversion difference may change depending on the amount of deposits in the processing container of the etching apparatus. That is, the processing conversion difference may change over time depending on the usage status of the etching apparatus.

In this case, it is considered that the dimensional error during exposure is mainly due to the light interference effect, so-called optical proximity effect. The optical proximity effect means that when the dimension (space width dimension) between adjacent lines on the reticle R is different, the line width dimension after exposure is the same on the reticle R even if the line width dimension is the same. This is a phenomenon in which (line width dimension in a resist mask) changes.
In the case of the dimensional error due to the optical proximity effect, it is considered that the in-plane distribution and the change with time are small. Therefore, the dimensional error at the time of exposure can be uniquely obtained by performing a light intensity simulation in advance. Therefore, the reticle R in which the pattern dimension is corrected in consideration of the dimension error during exposure can be created.

  On the other hand, as described above, in the case of processing conversion differences, in-plane distribution and changes with time can occur. For this reason, if the reticle R considering the processing conversion difference is to be created, a very large number of reticles R must be created. Further, it is necessary to select and replace the reticle R having an appropriate pattern dimension, and there is a possibility that quick response cannot be achieved. Moreover, there is a possibility that proper correction cannot be performed. Therefore, it is preferable that the resist mask pattern dimensions can be corrected in consideration of the processing conversion difference without exchanging the reticle R.

Here, according to the knowledge obtained by the present inventor, the pattern dimension of the resist mask can be corrected by changing the optical conditions in the exposure. For example, the pattern size of the resist mask can be corrected by changing the numerical aperture NA _L , the numerical aperture NA _P , the coherence factor σ, and the like.
FIG. 4 is a schematic graph for illustrating the case where the coherence factor σ is changed. The horizontal axis represents the pitch width dimension of the circuit pattern, and the pitch width dimension increases toward the right side. The vertical axis represents the pattern dimension of the resist mask to be formed, and represents that the pattern dimension of the resist mask to be formed becomes larger toward the upper side. In the figure, σ is a case where the coherence factor σ is a reference value, σ ₋₂ is a value 2% less than the reference value, and σ ₊₂ is a value 2% larger than the reference value.
The pattern dimensions of the resist mask include a line width dimension, a space width dimension, and a pitch width dimension, and the same tendency is shown for any of them. Therefore, the vertical axis may be a resist mask pattern dimension, a resist mask line width dimension, a resist mask space width dimension, a resist mask pitch width dimension, or the like.
The resist mask pattern dimensions include a line width dimension, a space width dimension, and a pitch width dimension, and these are referred to as a resist mask pattern dimension.

As shown in FIG. 4, the pattern dimension of the resist mask can be changed by changing the coherence factor σ. That is, the pattern dimension of the resist mask can be corrected by controlling the coherence factor σ. Further, as shown in the aforementioned equation (1), the numerical aperture NA _L, since if by changing the numerical aperture NA _P coherence factor σ is changing, controlling the numerical aperture NA _L, the numerical aperture NA _P In this way, the pattern dimension of the resist mask can be corrected.

The pattern size of the resist mask can also be changed by changing the illumination shape.
FIG. 5 is a schematic diagram for illustrating the shape of illumination. FIG. 5 shows an example of quasar illumination.
As shown in FIG. 5, the illumination 30 which is quasar illumination is provided with four poles 30a. The pole 30a has a shape surrounded by two radii of an annulus and two arcs therebetween. Moreover, each pole 30a has substantially the same shape, and is arrange | positioned at equal intervals on the concentric circle. The radius dimension of the outer circle of the ring is L1, and the radius dimension of the inner circle is L2. The angle between the two radii of the ring is θ.

When changing the pattern size of the resist mask by changing the shape of illumination, for example, the luminance ratio (ratio of luminance in the vertical and horizontal directions) may be changed. In this case, the luminance ratio can be changed by changing the size of the pole 30a. Further, the size of the pole 30a can be changed by changing the radial dimensions L1, L2 and the angle θ. Therefore, the pattern size of the resist mask can be corrected by changing the shape of illumination by controlling the radial dimensions L1, L2, the angle θ, and the like.
The pattern size of the resist mask can also be corrected by changing light intensity, phase difference, and the like. For example, the intensity of light can be changed by controlling the voltage applied to the light source 3.

Next, returning to FIG. 1, the correction condition calculation unit 11 and the like will be further illustrated.
The correction information storage unit 12 stores correction information related to the resist mask pattern dimensions obtained based on simulations and experiments. That is, the correction information storage unit 12 stores the relationship between the optical conditions in exposure and the pattern size of the resist mask as correction information of the pattern size of the resist mask.

For example, the relationship between the coherence factor σ illustrated in FIG. 4 and the pattern size of the resist mask is obtained in advance by simulation or experiment, and the information is stored as correction information. Note that the correction information is not limited to information related to the coherence factor σ, but may be related to other optical conditions in exposure. For example, the numerical aperture NA _L , the numerical aperture NA _P , the illumination shape, the light intensity, the phase difference, and the like described above can be used. That is, the optical conditions in the exposure are the numerical aperture NA _L of the illumination optical system 2, the numerical aperture NA _P of the projection optical system 8, the coherence factor σ, the shape of the illumination provided in the illumination optical system 2, the light intensity, It may be at least one selected from the group consisting of phase differences.

The inspection apparatus 100 provided outside the exposure apparatus 1 performs a dimensional inspection of the circuit pattern formed on the substrate W and provides inspection information to the correction condition calculation unit 11.
Examples of the circuit pattern dimension inspection method include so-called electronic inspection and optical inspection. In this case, examples of the electronic inspection include a scanning electron microscope (SEM), a transmission electron microscope (TEM), a scanning transmission electron microscope (STEM), an interatomic An inspection using a force microscope (AFM) or the like can be exemplified. Further, examples of the optical inspection include inspection using a scatterometry method (Scatterometory), an optical microscope, and the like.
However, it is not limited to the illustrated inspection method, and can be changed as appropriate.
The inspection information provided to the correction condition calculation unit 11 is stored in a storage unit (not shown) provided in the correction condition calculation unit 11. This inspection information includes circuit pattern dimension information (including information converted into processing conversion difference information) and in-plane distribution information. Note that the inspection information may be provided sequentially or may be provided periodically. Further, it may be provided in response to a request from the correction condition calculation unit 11. That is, the circuit pattern inspection information can be collected and provided sequentially or as necessary. In addition, inspection information may be provided to the correction condition calculation unit 11 via a storage unit (not shown). For example, the inspection information from the inspection apparatus 100 can be stored in a storage unit (not shown) and can be appropriately provided in response to a request from the correction condition calculation unit 11.

  The correction condition calculation unit 11 determines the state of the circuit pattern (the degree of processing conversion difference, the degree of in-plane distribution, etc.) based on the provided inspection information, and it is determined that correction of the pattern dimension of the resist mask is necessary. In such a case, an appropriate one is selected from the correction information stored in the correction information storage unit 12, and a correction condition (for example, a correction value or a function expression related to correction) is calculated. That is, the correction condition calculation unit 11 obtains an optical condition for correcting the pattern dimension of the resist mask as the correction condition from the inspection information of the circuit pattern formed on the substrate W and the correction information. Then, the optical conditions in the exposure are changed so that the resist mask pattern has an appropriate dimension based on the obtained correction conditions.

In the present embodiment, the correction condition obtained by the correction condition calculation unit 11 is provided to the optical system control unit 13. The optical system control unit 13 controls the illumination stop unit 5 and the aperture stop unit 9 based on the provided correction conditions to change the numerical aperture (numerical aperture NA _L , numerical aperture NA _P ) and the coherence factor σ. That is, the optical system control unit 13 changes the optical condition based on the correction condition. Therefore, the resist mask pattern dimension is corrected to an appropriate value. Incidentally, the numerical aperture NA _L, may be changed at least one of the numerical aperture NA _P. In this case, it is possible numerical aperture NA _L, be allowed to at least change either the numerical aperture NA _P to change the coherence factor sigma.

  In the exposure apparatus 1 illustrated in FIG. 1, the illumination diaphragm 5 and the aperture diaphragm 9 are controlled by the optical system controller 13, but the present invention is not limited to this. You may make it change the thing regarding other optical conditions, such as the shape of illumination mentioned above, the intensity | strength of light, and a phase difference. In this case, for example, when changing the shape of the illumination, the shape of the illumination is changed by controlling the position of a shielding plate (not shown) based on the correction condition obtained by the correction condition calculation unit 11. be able to. Further, when the light intensity is changed, the light intensity can be changed by controlling the voltage applied to the light source 3 based on the correction condition obtained by the correction condition calculation unit 11.

FIG. 6 is a schematic graph for illustrating the processed conversion difference and its in-plane distribution after correction. The horizontal axis represents the pitch width dimension of the circuit pattern, and the pitch width dimension increases toward the right side. The vertical axis represents the machining conversion difference, and the machining conversion difference increases as it goes upward. Also, S11, S21, and S31 in the figure are corrections of S1, S2, and S3 in FIG. 3, respectively.
As shown in FIG. 6, the optical conditions (for example, numerical aperture (numerical aperture NA _L , numerical aperture NA _P ), coherence factor σ, illumination shape, light intensity, phase difference, etc.) are changed. For example, the in-plane distribution of the processing conversion difference can be made uniform. Moreover, the processing conversion difference can also be reduced.

Next, the operation of the exposure apparatus 1 will be illustrated.
First, a predetermined reticle R is held on the reticle stage 7. Then, a substrate W (for example, a wafer or a glass substrate) is carried in by a transfer means (not shown), and is placed and held on the placement surface of the substrate stage 10.
Next, inspection information of the substrate W that has been exposed and etched is provided to the correction condition calculation unit 11. The provided inspection information includes circuit pattern dimension information (including information converted into processing conversion differences) and in-plane distribution information.

  On the other hand, correction information relating to the pattern size of the resist mask obtained based on simulations and experiments is stored in the correction information storage unit 12. The stored correction information may be related to the relationship between the optical conditions such as the coherence factor σ and the pattern size of the resist mask.

  The correction condition calculation unit 11 determines the state of the circuit pattern (the degree of processing conversion difference, the degree of in-plane distribution, etc.) based on the provided inspection information, and it is determined that correction of the pattern dimension of the resist mask is necessary. In such a case, an appropriate one is selected from the correction information stored in the correction information storage unit 12, and a correction condition (for example, a correction value or a function expression related to correction) is calculated.

The calculated correction condition is provided to the optical system control unit 13. Then, based on the provided correction conditions, the optical conditions in the exposure are changed so that the pattern dimension of the resist mask becomes an appropriate value. For example, the optical system control unit 13 controls the illumination diaphragm unit 5 and the aperture diaphragm unit 9 to change the numerical aperture (numerical aperture NA _L , numerical aperture NA _P ) and the coherence factor σ. In this case, at least one of the illumination stop 5 and the aperture stop 9 may be controlled. In addition, other optical conditions such as illumination shape, light intensity, and phase difference can be changed.

  Next, a light beam is emitted from the light source 3 and transmitted through the fly-eye lens 4 so that the light intensity distribution in the light beam cross section becomes uniform. Then, the cross section of the light beam is made to have a predetermined dimension by passing through the illumination stop portion 5. The light beam that has passed through the illumination stop 5 is converted into a substantially parallel light beam by passing through the condenser lens 6, and is applied to the pattern region of the reticle R held on the reticle stage 7.

  The light beam that has passed through the reticle R enters the projection optical system 8, and the pattern formed in the pattern area of the reticle R by the projection optical system 8 is transferred onto the exposure surface (on the resist film) of the substrate W at a predetermined magnification. At this time, the cross section of the light beam is set to a predetermined size by transmitting through the aperture stop 9 provided on the pupil plane of the projection optical system 8.

Then, the position of the substrate W is changed by the substrate stage 10 to transfer the pattern to a plurality of positions on the exposure surface of the substrate W.
The substrate W on which the pattern transfer has been completed is carried out by a conveying means (not shown). Thereafter, if necessary, the above-described procedure is repeated to transfer the pattern onto the exposed surface of the substrate W.

  As illustrated above, according to the present embodiment, a correction condition (for example, a correction value or a function expression related to correction) is determined based on the inspection information provided from the inspection apparatus 100, and based on this correction condition. By changing the optical conditions in the exposure, the resist mask pattern has an appropriate dimension. That is, instead of correcting the pattern dimension of the reticle R in order to reduce the processing conversion difference or make the in-plane distribution uniform, the optical condition in exposure is changed. Therefore, even when the etching characteristics change over time due to changes in plasma characteristics and the like, it is possible to quickly and easily reduce the processing conversion difference and make the in-plane distribution uniform.

FIG. 7 is a schematic diagram for illustrating an illumination stop 15 according to another embodiment. 7A is a schematic cross-sectional view for illustrating the illumination stop section 15, and FIG. 7B is a view taken along the line BB in FIG. 7A.
As shown in FIG. 7, the illumination stop unit 15 is provided with a light shielding unit 15 a and transmission units 15 b to 15 e. The outer diameter dimensions (diameter dimensions) of the transmission parts 15b to 15e are different from each other. In addition, the illumination diaphragm unit 15 is provided with a drive unit 18 for rotating the light shielding unit 15a. The drive unit 18 and the optical system control unit 13 are electrically connected.
Further, the transmission parts 15 b to 15 e are provided on concentric circles centering on the rotation center of the illumination stop part 15. Note that the outer diameter dimensions (diameter dimensions), the number, the arrangement position, and the like of the transmission portions 15b to 15e are not limited to those illustrated, but can be changed as appropriate.

  The light shielding portion 15a is formed of an opaque body such as metal, and shields a part of the light beam emitted from the fly-eye lens 4. The transmission parts 15 b to 15 e transmit the light beam emitted from the fly-eye lens 4. The transmission parts 15b to 15e can be made of a transparent body such as glass, or can be holes.

In the illumination stop section 15 according to the present embodiment, the drive section 18 is driven based on an electrical signal from the optical system control section 13. Then, the light-transmitting portions 15b to 15e can be selected by rotating the light shielding portion 15a by the driving portion 18. Therefore, it is possible to change the numerical aperture NA _L of the illumination optical system 2 by selecting the transmission unit 15b~15e appropriate.
According to the present embodiment, it is possible to reduce the number of sliding portions, and thus it is possible to suppress the generation of particles.

FIG. 8 is a schematic diagram for illustrating the illumination diaphragm unit 25. FIG. 8A is a schematic cross-sectional view for illustrating the illumination stop 25, and FIG. 8B is a CC arrow view in FIG. 8A.
As shown in FIG. 8, the illumination stop section 25 is provided with a light shielding section 25a, a transmission section 25b, and a polarization section 25c. The light shielding portion 25a is formed of an opaque material such as metal, and shields a part of the light beam emitted from the fly-eye lens 4. The transmission part 25 b transmits the light beam emitted from the fly-eye lens 4. The transmission part 25b can be a transparent body such as glass, or can be a hole.
The polarization unit 25c is provided with a drive unit (not shown). In addition, a drive unit (not shown) and the optical system control unit 13 are electrically connected. Then, by driving a drive unit (not shown) based on an electrical signal from the optical system control unit 13, the light transmitting state and the light blocking state are switched. As such a thing, what switches a translucent state and a light-shielding state can be illustrated, for example using the property of the liquid crystal that a molecular arrangement direction changes by applying a voltage. And, so that it is possible to change the numerical aperture NA _L of the illumination optical system 2 by switching the light-shielding state and light-transmitting state of polarization section 25c. In addition, the magnitude | size, the number, etc. of the polarizing part 25c are not necessarily limited to what was illustrated, and can be changed suitably. For example, a plurality of polarizing portions can be provided concentrically.
According to the present embodiment, since the sliding portion can be eliminated, the generation of particles can be suppressed. In addition, quick switching can be performed.
A configuration similar to that of the illumination diaphragm unit 15 and the illumination diaphragm unit 25 can be used for the aperture diaphragm unit provided in the projection optical system 8.

Next, an example of a method for manufacturing an electronic device according to this embodiment will be described.
As an example of the method for manufacturing an electronic device according to this embodiment, a method for manufacturing a semiconductor device can be illustrated.
Here, the manufacture of the semiconductor device is a process of forming a circuit pattern on the substrate (wafer) surface by film formation, resist coating, exposure, development, etching, resist removal, etc., circuit pattern inspection process, cleaning process, heat treatment process, This is performed by repeating a plurality of steps such as an impurity introduction step, a diffusion step, and a planarization step. In this case, since techniques other than exposure can be applied to known processes in each step, their descriptions are omitted.

  In addition, although manufacture of the semiconductor device was illustrated as an example, it is not necessarily limited to this. The present invention can be widely applied to the manufacture of electronic devices having an exposure process. For example, the present invention can be applied to the production of flat panel displays such as liquid crystal displays, plasma displays, organic EL displays, and surface conduction electron-emitting device displays (SEDs). Even in this case, since the techniques other than the exposure can be applied to known techniques in each electronic device, the description thereof is omitted.

FIG. 9 is a flowchart for illustrating an exposure procedure.
Inspection information of the substrate W that has been exposed and etched is collected (step S1a). Inspection information can be collected using an inspection device or the like. The inspection information includes circuit pattern dimension information (including information converted into processing conversion differences) and in-plane distribution information.
Also, correction information relating to the relationship between the optical conditions in exposure and the pattern size of the resist mask is collected (step S1b). The correction information is obtained and collected in advance by simulation or experiment. Examples of the optical conditions include numerical aperture NA _L of the illumination optical system, numerical aperture NA _P of the projection optical system, coherence factor σ, illumination shape, light intensity, phase difference, and the like.

Next, the state of the circuit pattern is determined based on the collected inspection information (step S2). For example, the quality of the processing conversion difference or the in-plane distribution is determined based on a predetermined threshold value.
As a result of determining the state of the circuit pattern, if correction of the pattern size of the resist mask is required, an appropriate one is selected from the collected correction information and a correction condition (for example, a correction value or a function related to correction) is selected. Equation (etc.) is obtained (step S3).
If correction of the pattern size of the resist mask is not necessary, exposure (step S5) described later is performed.

Next, the optical conditions for exposure are changed based on the obtained correction conditions (step S4).
Next, the light beam is emitted from the light source, and the light beam is incident on the exposure surface (on the resist film) of the substrate W through the reticle R to perform exposure (step S5).

  That is, the method for manufacturing an electronic device according to the present embodiment collects inspection information on circuit patterns formed on a substrate (for example, step S1a), optical conditions in exposure, and pattern dimensions of a resist mask. And the process of collecting the relationship as correction information of the pattern size of the resist mask (for example, step S1b), the process of determining the state of the circuit pattern based on the inspection information (for example, step S2), and the correction information A process for selecting an appropriate one and obtaining an optical condition for correcting the pattern dimension of the resist mask as a correction condition (for example, step S3), and a process for changing the optical condition based on the correction condition (for example, , Step S4), and a light beam is emitted toward the pattern area of the reticle, and an image of the pattern irradiated with the light beam is used as a basis. Step of performing exposure by bringing projected on the exposure surface (e.g., step S5) is provided with a, a.

In this case, in the process of changing the optical conditions, the numerical aperture of the illumination optical system, the numerical aperture of the projection optical system, the coherence factor, the shape of the illumination provided in the illumination optical system, the light intensity, and the phase difference are included. At least one selected from the group can be changed.
In the step of collecting circuit pattern inspection information, at least one of the processing conversion difference and the in-plane distribution of the processing conversion difference can be collected.
Further, the circuit pattern inspection information can be collected sequentially or as necessary.

  According to the present embodiment, a correction condition (for example, a correction value or a function expression related to correction) is obtained based on inspection information collected by an inspection apparatus or the like, and an optical condition in exposure is determined based on the correction condition. By changing the pattern, the resist mask pattern has an appropriate dimension. That is, instead of correcting the pattern dimension of the reticle R in order to reduce the processing conversion difference or make the in-plane distribution uniform, the optical condition in exposure is changed. Therefore, even when the etching characteristics change over time due to changes in plasma characteristics and the like, it is possible to quickly and easily reduce the processing conversion difference and make the in-plane distribution uniform.

Heretofore, the present embodiment has been illustrated. However, the present invention is not limited to these descriptions.
As long as the features of the present invention are provided, those skilled in the art appropriately modified the design of the above-described embodiments are also included in the scope of the present invention.
For example, the shape, dimensions, material, arrangement, and the like of each element included in the exposure apparatus 1 are not limited to those illustrated, but can be changed as appropriate.
Moreover, each element with which each embodiment mentioned above is combined can be combined as much as possible, and what combined these is also included in the scope of the present invention as long as the characteristics of the present invention are included.

DESCRIPTION OF SYMBOLS 1 Exposure apparatus, 2 Illumination optical system, 3 Light source, 4 Fly eye lens, 5 Illumination diaphragm part, 5a Light-shielding part, 5b Transmission part, 6 Condenser lens, 7 Reticle stage, 8 Projection optical system, 9 Aperture diaphragm part, 10 Substrate stage, 11 correction condition calculating unit, 12 correction information storage unit, 13 an optical system control unit, 100 inspecting apparatus, NA _L aperture, NA _P NA, sigma coherence factor, R reticle, W substrate

Claims (6)

An illumination optical system that includes a light source, an illumination stop portion and a shielding plate provided on an emission side of the light source, and emits a light beam toward a pattern region of the reticle;
A projection optical system that projects an image of the pattern irradiated with the light beam onto an exposure surface of the substrate;
Correction information stored coherence factor before Symbol illumination optical system, and at least one of shape of the illumination provided in the illumination optical system, and the pattern size of the resist mask, the relationship as correction information pattern size of the resist mask A storage unit;
And examination information of the circuit pattern formed on the substrate, wherein the correction information and from the resist mask coherence factor before Symbol illumination optical system for correcting the pattern size, and illumination the provided illumination optical system a correction condition calculating unit for obtaining at least one as a correction condition of shape,
Based on the correction condition, at least one of the positions of the illumination diaphragm unit for controlling the coherence factor of the illumination optical system by changing the numerical aperture of the illumination optical system , and the shielding plate for changing the shape of the illumination one control, an optical system controller for Ru changing the pattern size of the resist mask,
An exposure apparatus comprising:   2. The exposure apparatus according to claim 1, wherein the inspection information of the circuit pattern includes at least one of a processing conversion difference and an in-plane distribution of the processing conversion difference.   3. The exposure apparatus according to claim 1, wherein the inspection information of the circuit pattern is collected sequentially or as necessary. Collecting inspection information of circuit patterns formed on the substrate;
Coherence factor before Symbol illumination optical system, and at least one of shape of the illumination provided in the illumination optical system, and acquiring the pattern size of the resist mask, the relationship as correction information pattern size of the resist mask ,
Determining the state of the circuit pattern based on the inspection information;
Wherein selects the appropriate from the correction information, at least one correction condition of shape before Symbol illumination optical system coherence factor, and illumination the provided illumination optical system for correcting the pattern size of the resist mask As a process
Illumination stop provided in the illumination optical system for controlling the coherence factor of the illumination optical system by changing the numerical aperture of the illumination optical system based on the correction condition in order to change the pattern dimension of the resist mask parts and steps that control, and at least one of the position of the shield plate for changing the shape of the illumination,
A step of performing exposure by emitting a light beam toward a pattern area of a reticle and projecting an image of the pattern irradiated with the light beam onto an exposure surface of the substrate;
An electronic device manufacturing method comprising:   5. The method of manufacturing an electronic device according to claim 4, wherein in the step of collecting the inspection information of the circuit pattern, at least one of a processing conversion difference and an in-plane distribution of the processing conversion difference is collected.   6. The method of manufacturing an electronic device according to claim 4, wherein the inspection information of the circuit pattern is collected sequentially or as necessary.

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