JP2008250141A - Exposure method of exposure apparatus, and exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a wiring pattern having a desired line width without measuring a film thickness distribution of a resist. <P>SOLUTION: When the resist applied onto a substrate having a thin film formed thereon is scanned and exposed by an exposure device 80 controlled to be turned on/off by image data and then a thin film pattern having a desired line width is formed by development and etching, a temperature of the substrate F at the time of prebaking is measured by a baking temperature measuring instrument 102, and a resist sensitivity to the measured temperature of the substrate is calculated in accordance with a relation between substrate temperatures at the time of prebaking and resist sensitivities, and a line width correction amount after etching for the calculated resist sensitivity is determined in accordance with a preliminarily obtained relation between exposures for line widths after etching and resist sensitivities, and a set exposure of the exposure device 80 for the desired line width is corrected by the determined line width correction amount. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the present invention, a thin film-formed substrate coated with a resist is pre-baked, and the pre-baked substrate is subjected to scanning exposure with an exposure machine controlled on and off by image data, and then developed, post-baked, further etched, and then left. An exposure method and an exposure apparatus in an exposure apparatus for forming a pattern having a desired line width on a substrate by using a thin film of the portion formed.

In the manufacturing process of the TFT array of FPD, for example, LCD, as shown in FIG. 20, cleaning (including glass substrate cleaning and substrate cleaning during photolithography process) → film formation (gate metal sputtering, gate insulating film) / A-Si film / N ⁺ type a-Si film CVD, source / drain electrode sputtering, protective film CVD, transparent electrode sputtering) → photolithography (gate electrode / wiring, island, source / drain electrode, protective film, transparent electrode) ) → etching (etching during photolithography process, channel etching) is repeated several times (see Non-Patent Document 1).

  Here, as shown in FIGS. 20 and 21, the photolithography process for forming the circuit pattern is a substrate on which the underlying thin film 2 to be patterned is formed (wafer for a semiconductor, for a FPD). After the glass substrate 1 is cleaned (cleaning process), a resist (photoresist) 3 is applied (resist coating process), prebaked, dried, and solidified (prebaking process). Here, the substrate 1 on which the photoresist 3 is applied and prebaked is referred to as a substrate (resist-coated thin film forming substrate) F.

  Next, the substrate F is exposed to a two-dimensional pattern shape on the resist 3 by an exposure machine to form a latent image on the resist 3 (exposure process).

  Next, the exposed portion is melted with a developer, and the resist 3 is patterned (development process). This is hardened by post-baking to improve the adhesion between the resist 3 and the substrate 1 (post-baking step), and a resist pattern serving as an etching mask is formed (providing etching resistance).

  Next, the thin film 2 which is a base film is melt | dissolved (wet etching) by an etching process, or the thin film 2 is patterned by etching (dry etching) with plasma (etching process).

  Thereafter, the resist 3 is peeled off to obtain a substrate (pattern forming substrate) Fa on which a pattern is formed.

  It should be noted that the line width (thin film pattern) of the thin film 2 does not change even if the resist 3 is stripped with respect to the line width (thin film pattern) of the thin film 2 after the etching process. That is, the line width of the thin film 2 is determined after the etching process.

  By the way, when exposing a two-dimensional pattern shape to a resist with an exposure machine, there is a problem that the line width of the pattern does not become the set line width (desired line width) if the resist film thickness varies. (Patent Document 1).

  In order to solve this problem, in the technique according to Patent Document 1, a mask pattern is projected onto a substrate coated with a resist by a projection optical system, and the mask and the substrate are sequentially scanned to form a pattern. In the apparatus, the exposure amount setting means obtains an appropriate exposure amount f (x) according to the resist film thickness distribution on the substrate, and the exposure amount control means at each position x satisfies the exposure amount f (x). It is disclosed that the illuminance L (x) can be adjusted to correct the resolution failure and the line width.

  However, in this technique, since the exposure amount is adjusted for each shot, the line width at the shot connecting portion varies. Further, expensive mask replacement is required for correction other than the exposure amount and line width correction on the input image data.

  As an exposure machine that does not use an expensive mask, an exposure apparatus (digital exposure apparatus) that performs scanning exposure using a spatial light modulation element such as a digital micromirror device (DMD) has been proposed (see Patent Document 2). . The DMD has a large number of micromirrors arranged in a lattice on an SRAM cell (memory cell) in a swingable state. The surface of each micromirror has a high reflectivity such as aluminum. Material is deposited. When a digital signal according to the image data is written to the SRAM cell, each micromirror is tilted in a predetermined direction according to the signal, and the light beam is controlled to be turned on / off according to the tilted state and guided to the resist, and the wiring pattern is exposed. To be recorded.

  In the above-mentioned Patent Document 1, it is described that the line width is corrected by determining an appropriate exposure amount in accordance with the resist film thickness distribution, but the baking process (pre-baking process and post-baking process) is a final pattern. Nothing is disclosed about the point that affects the line width.

  In the baking process, it is required that the temperature irregularity in the substrate at the time of baking in the baking apparatus is within about ± 3 ° C. (Non-patent Document 1).

  As a technique for reducing the temperature unevenness and the temperature unevenness, a technique for setting the air introduction path opening length constant to make the amount of air introduced into the baking furnace uniform has been proposed (Patent Document 3).

  In this Patent Document 3, the hot plate is used to put a substrate support pin on the hot plate or to remove a substrate support pin for peeling the substrate after baking from the hot plate from the surface of the mounting surface of the hot plate. A baking furnace is disclosed in which a vertical through hole is formed, and the substrate support pin is movable in a horizontal direction in a state where the substrate support pin passes through the through hole, and the substrate support pin and the through hole are disclosed. There is also described a technique for avoiding generation of particles in the baking furnace due to excessive contact with holes.

  In order to suppress temperature unevenness during baking due to substrate deflection, the substrate is held by the rough glass surface formed on the surface of the hot plate, instead of holding the substrate by pins. A technique for keeping the distance between the hot plate and the substrate equal is disclosed (Patent Document 4).

JP-A-7-29810 Japanese Patent Laying-Open No. 2005-266779 JP-A-8-313855 JP 2000-77318 A Semiconductor / Liquid Crystal Display Photolithography Technology Handbook, published by Realize Science Center / Realize AT Co., Ltd., published on January 31, 2006, P448

  In order to suppress temperature unevenness on the substrate during baking, it is necessary to consider the arrangement of the heat generating portions in the hot plate.

  However, if the temperature unevenness is to be reduced, the structure of the baking apparatus becomes complicated and expensive.

  The present invention has been made in consideration of such problems, and an object thereof is to provide an exposure method and an exposure apparatus in an exposure apparatus that can form a wiring pattern having a desired line width.

  The exposure method in the exposure apparatus according to the present invention pre-bakes a thin film-formed substrate coated with a resist, scans and exposes the pre-baked substrate with an exposure machine controlled on and off by image data, and then develops and post-bakes, Further, the exposure method in the exposure apparatus that forms a pattern with a desired line width on the substrate with the remaining thin film by performing etching has the following features (1) to (3).

  (1) A resist for calculating a resist sensitivity with respect to the measured temperature of the substrate from a temperature measurement step for measuring the temperature of the substrate during pre-baking and a relationship between the substrate temperature during pre-baking and the resist sensitivity obtained in advance. A line for determining a line width correction amount after development or after etching with respect to the calculated resist sensitivity, based on the relationship between the sensitivity calculation step and the exposure amount obtained in advance with respect to the line width after development or after etching and the resist sensitivity. A width correction amount determining step; and an exposure amount correcting step of correcting a set exposure amount of the exposure device to obtain the desired line width based on the determined line width correction amount.

  (2) A temperature measuring step for measuring the temperature of the substrate during post-baking, and a previously determined relationship between the substrate temperature during post-baking and the resist taper angle, the resist taper angle with respect to the measured substrate temperature From the relationship between the resist taper angle and the resist line width with respect to the line width after etching, the resist taper angle calculation step for calculating A step of determining a line width correction amount to be determined; and an exposure amount correction step of correcting a set exposure amount of the exposure apparatus to obtain the desired line width based on the determined line width correction amount. .

  (3) In the invention having the above feature (1) or (2), the set exposure amount of the exposure device can be corrected by the image data or the exposure amount of the exposure device.

  The exposure apparatus according to the present invention pre-bakes a thin film-formed substrate coated with a resist, scans and exposes the pre-baked substrate with an exposure machine controlled on and off according to image data, and then develops, post-bakes, and further etches the substrate. An exposure apparatus that performs a pattern with a desired line width on the substrate by using the remaining thin film has the following characteristics (4) to (6).

  (4) A temperature measuring device that measures the temperature of the substrate during pre-baking, and a resist that calculates the resist sensitivity with respect to the measured temperature of the substrate from the relationship between the substrate temperature during pre-baking and the resist sensitivity that has been obtained in advance. A line for determining a line width correction amount after development or after etching with respect to the calculated resist sensitivity, based on the relationship between the sensitivity calculation means and the exposure amount obtained in advance with respect to the line width after development or after etching and the resist sensitivity. A width correction amount determination unit; and an exposure amount correction unit that corrects a set exposure amount of the exposure device to obtain the desired line width based on the determined line width correction amount.

  (5) A temperature measuring device for measuring the temperature of the substrate during post-baking, and a previously determined relationship between the substrate temperature during post-baking and the resist taper angle, the resist taper angle with respect to the measured substrate temperature From the relationship between the resist taper angle and the resist line width obtained in advance and the resist taper angle and the resist line width with respect to the line width after etching, a line width correction amount after etching with respect to the calculated resist taper angle is calculated. A line width correction amount determining unit to be determined; and an exposure amount correcting unit for correcting a set exposure amount of the exposure apparatus to obtain the desired line width based on the determined line width correction amount. .

  (6) In the invention having the above feature (4) or (5), the set exposure amount of the exposure device can be corrected by the image data or the exposure amount of the exposure device.

  As an exposure apparatus, an exposure apparatus that performs scanning exposure using an optical deflector can be used in addition to an exposure apparatus (digital exposure apparatus) that performs scanning exposure using a spatial light modulator such as DMD. When an optical deflector is used, in the exposure amount correction step, the intensity of the light beam deflected by the optical deflector is corrected according to the location on the substrate. As the optical deflector, a rotating polygon mirror or a galvanometer mirror can be adopted.

  According to the present invention, a wiring pattern having a desired line width can be formed on a substrate by measuring the pre-bake temperature or the post-bake temperature.

  First, an example of an exposure apparatus that does not require an expensive mask for exposure will be described. FIG. 1 shows an exposure apparatus 10 to which an exposure method and an exposure apparatus according to an embodiment of the present invention are applied.

  The exposure apparatus 10 includes a surface plate 14 supported by a plurality of legs 12, and an exposure stage 18 is installed on the surface plate 14 through two guide rails 16 so as to be reciprocally movable in the direction of the arrow. The On the exposure stage 18, a rectangular substrate (resist-coated thin film forming substrate) F obtained by applying the resist 3 to the substrate 1 on which the thin film 2 is formed and prebaking as shown in FIG.

  A gate-shaped column 20 is installed at the center of the surface plate 14 so as to straddle the guide rail 16. CCD cameras 22a and 22b for detecting the mounting position of the substrate F with respect to the exposure stage 18 are fixed to one side of the column 20, and an image is exposed to the substrate F on the other side of the column 20. A scanner 26 in which a plurality of exposure heads 24a to 24j to be recorded are positioned and held is fixed. The exposure heads 24a to 24j are arranged in a staggered pattern in two rows in a direction orthogonal to the scanning direction of the substrate F (the moving direction of the exposure stage 18). Strobes 64a and 64b are attached to the CCD cameras 22a and 22b via rod lenses 62a and 62b. The strobes 64a and 64b irradiate the imaging areas of the CCD cameras 22a and 22b with illumination light composed of infrared light that does not expose the substrate F.

  A guide table 66 extending in a direction orthogonal to the moving direction of the exposure stage 18 is attached to the end of the surface plate 14, and the light beams output from the exposure heads 24a to 24j are mounted on the guide table 66. A photosensor 68 for detecting the exposure amount of the (laser beam) L is disposed so as to be movable in the arrow x direction.

  FIG. 2 shows the configuration of each of the exposure heads 24a to 24j. For example, light beams L output from a plurality of semiconductor lasers constituting the light source units 28 a to 28 j are combined and introduced into the exposure heads 24 a to 24 j through the optical fiber 30. A rod lens 32, a reflection mirror 34, and a digital micro mirror device (DMD) 36 are arranged in order at the exit end of the optical fiber 30 into which the light beam L is introduced.

  As shown in FIG. 3, the DMD 36 includes a large number of micromirrors 40 (exposure recording elements) arranged in a lattice on an SRAM cell (memory cell) 38 in a swingable state. A material having high reflectivity such as aluminum is deposited on the surface of the micromirror 40. When a digital signal according to the drawing data is written from the DMD controller 42 to the SRAM cell, each micromirror 40 is tilted in a predetermined direction according to the signal, and the on / off state of the light beam L is realized according to the tilted state.

  In the emission direction of the light beam L reflected by the DMD 36 whose on / off state is controlled, a large number of lenses are arranged in correspondence with the first imaging optical lenses 44 and 46 that are the magnifying optical system and the micromirrors 40 of the DMD 36. The provided microlens array 48 and second imaging optical lenses 50 and 52 which are zoom optical systems are sequentially arranged. Before and after the microlens array 48, microaperture arrays 54 and 56 for removing stray light and adjusting the light beam L to a predetermined diameter are disposed.

  As shown in FIGS. 4 and 5, the DMD 36 constituting the exposure heads 24 a to 24 j is set in a state inclined at a predetermined angle with respect to the moving direction of the exposure heads 24 a to 24 j in order to achieve high resolution. That is, by inclining the DMD 36 with respect to the scanning direction of the substrate F (arrow y direction), a direction (arrow x direction) orthogonal to the scanning direction of the substrate F with respect to the interval m with respect to the arrangement direction of the micromirrors 40 constituting the DMD 36. ) Can be narrowed and the resolution can be set high. In practice, one pixel constituting the image data is exposed and formed by a plurality of micromirrors 40.

  As shown in FIG. 5, a plurality of micromirrors 40 are arranged on the same scanning line 57 in the scanning direction (arrow y direction), and the substrate F is substantially the same by the plurality of micromirrors 40. The image is subjected to multiple exposure by the light beam L guided to the position. Thereby, the unevenness of the exposure amount between the micromirrors 40 is averaged. In addition, the exposure areas 58a to 58j by the exposure heads 24a to 24j are set so as to overlap in the direction of the arrow x so that there is no joint between the exposure heads 24a to 24j.

  Here, the exposure amount of the light beam L guided to the substrate F through each micromirror 40 constituting the DMD 36 is, for example, in the direction of the arrow x, which is the arrangement direction of the exposure heads 24a to 24j, as shown in FIG. Each DMD 36 has locality due to the reflectivity, optical system, and the like. In such a state of locality, as shown in FIG. 7, when the image is exposed and recorded on the substrate F using the light beam L with a small combined exposure amount reflected by the plurality of micromirrors 40, and the combined exposure amount In the case where an image is exposed and recorded on the substrate F using a light beam L having a large amount of light, if the threshold value at which the substrate F, which is a photosensitive material, is exposed to a predetermined state is th, the widths W1 and W2 of the image in the arrow x direction are A different problem will occur. In addition, as shown in FIG. 21, in the case where each of the development process, the etching process, and the peeling process is further performed on the exposed substrate F, in addition to the influence of the locality of the exposure amount of the light beam L, the resist Variation in line width (image width) due to uneven coating, development unevenness, etching unevenness, peeling unevenness, etc. occurs.

  Therefore, in consideration of the above variation factors, the number of micromirrors 40 used for forming one pixel on the substrate F is set and controlled using mask data, so that the substrate F can be formed as shown in FIG. The line width W1 in the direction of the arrow x of the pattern formed in consideration of the final peeling process can be controlled to be constant (desired line width) regardless of the position.

  FIG. 9 is a block diagram of a control circuit 90 related to the exposure apparatus 10 having a function for performing such control.

  In FIG. 9, the control circuit 90 stores image data input unit 70 for inputting image data to be exposed and recorded on the substrate F (raster data in which pixels are arranged vertically and horizontally as an image), and the input two-dimensional image data. A frame memory 72, a resolution converter 74 for converting the image data stored in the frame memory 72 into a high resolution according to the size and arrangement of the micromirrors 40 of the DMD 36 constituting the exposure heads 24a to 24j, and resolution conversion The assigned image data is assigned to each micromirror 40 and output data (also referred to as mirror data or frame data. Each ON / OFF state of the plurality of micromirrors 40 that expose each pixel corresponding to the position is defined at the same timing. Data) and an output data calculation unit 76, and the output data is mask data (same type). The output data correction unit 78 corrects the data according to the corrected output data, and controls the DMD 36 according to the corrected output data. A DMD controller 42 (exposure recording element control means) that performs exposure, and exposure heads 24a to 24j that expose and record desired images on the substrate F using the DMD 36 controlled by the DMD controller 42. The light source units 28a to 28j and the exposure heads 24a to 24j constitute an exposure machine 80.

  Connected to the output data correction unit 78 is a mask data memory (DMD mask data memory) 82 (mask data storage means) for storing mask data. The mask data is data that designates the micromirror 40 that is always turned off during exposure scanning, and is set in a mask data setting unit (DMD mask data setting unit) 86.

  The mask data setting unit 86 determines the micromirror 40 to be masked according to the two-dimensional line width correction amount ΔL (x, y) calculated by the line width correction amount calculation unit 110.

  In the line width correction amount calculation unit 110, the line width correction amount is based on the pre-bake temperature distribution t1 (x, y) or the post-bake temperature distribution t2 (x, y) measured by the bake temperature measuring device 102 (102a or 102b). ΔL (x, y) is calculated.

  In the exposure apparatus 10 having the control circuit 90 of FIG. 9, by masking a part of the micromirrors 40, the integrated exposure amount accumulated in the resist 3 can be adjusted to correct the finished line width. However, the present invention is not limited to this, and an image data correction calculation unit 100 is provided as in the control circuit 90A shown in FIG. 10, and the finished line width can be corrected by correcting the image data by the image data correction calculation unit 100. it can. In the control circuit 90A shown in FIG. 10, components corresponding to those shown in FIG.

  In the image data correction calculation unit 100, image data is enlarged or reduced according to the two-dimensional line width correction amount ΔL (x, y) calculated by the line width correction amount calculation unit 120 and corrected in the frame memory 72. The processed image data is stored.

  As described above, the exposure apparatus 10 masks a part of the micromirror 40 to adjust the integral exposure amount accumulated in the resist 3 to correct the finished line width, or correct the image data to finish the image. The line width can be corrected.

  In practice, the line width correction amount calculation unit 120 uses the line width correction amount ΔL (based on the pre-bake temperature distribution t1 (x, y) or the post-bake temperature distribution t2 (x, y) measured by the bake temperature measuring device 102. x, y) is calculated.

  More specifically, each of the line width correction amount calculation units 110 and 120 is configured as a prebake corresponding line width correction amount calculation unit 130 shown in FIG. 11 or a post bake corresponding line width correction amount calculation unit 140 shown in FIG. .

As shown in FIG. 11, the prebake-corresponding line width correction amount calculation unit 130 includes a two-dimensional prebake temperature distribution data memory 132 that stores a two-dimensional prebake temperature distribution t1 (x, y) supplied from the bake temperature measuring device 102. From the relational expression sensitivity E0 = f (t1) between the resist sensitivity E0 [mJ / cm ² ] and the prebaking temperature t1 obtained by experiments in advance, and the measured prebaking temperature distribution t1 (x, y), the resist sensitivity distribution The line width after development / etching from the resist sensitivity distribution calculating unit 134 for calculating E0 (x, y) and the relational expression L = h (E / E0) between the resist line width L and the exposure amount E obtained experimentally The post-etching line width distribution / correction amount calculation unit 136 calculates a distribution L (x, y) and calculates a line width correction amount ΔL (x, y).

  On the other hand, as shown in FIG. 12, the post-bake correspondence line width correction amount calculation unit 140 stores the two-dimensional post-bake temperature distribution data storing the post-bake temperature distribution t2 (x, y) supplied from the bake temperature measuring device 102. From the memory 142, the relational expression θ = g (t) between the post-bake temperature t2 and the taper angle θ obtained by experiments in advance and the measured post-bake temperature distribution t2 (x, y), the taper angle distribution θ (x , Y), and a relational expression L = h (θ, L) between the taper angle θ, the resist line width L, and the line width after development / etching. The post-etching line width distribution / correction amount calculation unit 146 calculates a width distribution L (x, y) and calculates a line width correction amount ΔL (x, y).

  FIG. 13 shows a schematic diagram of a bake temperature measuring device 102a arranged in the heating device for the substrate F. FIG. The bake temperature measuring device 102a has a hot plate 152a for uniformly heating the substrate F that has been positioned and placed, and a thermocouple 154 that is a two-dimensional thermometer measuring unit on or inside the hot plate 152a. Is provided. Temperatures measured by the thermocouple 154 are supplied to the line width correction amount calculation units 110 and 120 as bake temperature distributions t1 (x, y) and t2 (x, y), respectively.

  FIG. 14 shows a schematic diagram of another example of the baking temperature measuring device 102b arranged in the heating apparatus for the substrate F. FIG. The bake temperature measuring device 102b has a hot plate 152b for uniformly heating the substrate F that is positioned and placed, and an infrared temperature that two-dimensionally measures the surface temperature of the substrate F placed on the hot plate 152b. A measuring device 156 is provided. Temperatures measured by the infrared temperature measuring device 156 are supplied to the line width correction amount calculation units 110 and 120 as bake temperature distributions t1 (x, y) and t2 (x, y), respectively.

  A specific embodiment of the present invention using the exposure apparatus 10 configured and operating as described above will be described.

[Example 1] (Correction for pre-baking)
First, the thin film forming substrate F coated with the resist 3 is pre-baked by a baking apparatus, and at the time of this pre-baking, the two-dimensional surface direction of the thin film forming substrate F is measured by the baking temperature measuring device 102 {102a and / or 102b}. The prebake temperature t 1 (x, y) is measured and stored in the two-dimensional prebake temperature distribution data memory 132.

Next, in the resist sensitivity distribution calculation unit 134, the pre-baking temperature distribution measured in advance with respect to the relational expression E0 = f (t1) between the resist sensitivity E0 [mJ / cm ² ] and the pre-baking temperature t1 obtained by experiment. Substituting t1 (x, y), the resist sensitivity distribution E0 (x, y) is calculated.

FIG. 16 shows a table of measured values of resist sensitivity E0 [mJ / cm ² ] and pre-baking temperature t1 [° C.] for a resist (RG-300: AZ Electronic Materials: film thickness 1.6 [μm]), FIG. 17 shows the characteristic of the relational expression (empirical expression) f (t1) in which the values in the table are plotted.

  Next, in the post-etching line width distribution / correction amount calculation unit 136, the resist sensitivity distribution E0 (x, y) is expressed by a relational expression L = h (E / E0) between the resist line width L and the exposure amount E obtained experimentally. Is substituted, the line width distribution L (x, y) after development / etching is calculated, and the line width correction amount ΔL (x, y) with respect to the set line width (target line width, line width based on image data) is calculated. .

  The image data correction calculation unit 100 corrects the image data by this line width correction amount ΔL (x, y), or corrects the DMD mask data, and the exposure apparatus 10 exposes the substrate F, so that a desired value is obtained after the etching. The substrate Fa on which the pattern of the thin film 2 having a line width is formed can be manufactured.

  As described above, according to the first embodiment, the thin film forming substrate F coated with the resist 3 is pre-baked, and the pre-baked substrate F is scanned and exposed by the exposure device 80 controlled to be turned on / off by image data, and then developed. In the exposure apparatus 10 that forms a pattern with a desired line width on the substrate Fa by the remaining thin film by post-baking and further etching, the baking temperature measuring devices 102a and 102b are used to pre-bake the substrate F. The temperature t1 (x, y) is measured, and the resist sensitivity distribution calculating unit (resist sensitivity calculating means) 134 measures the relationship from the relationship f (t1) between the substrate temperature t1 and the resist sensitivity at the time of pre-baking. The resist sensitivity with respect to the temperature t1 (x, y) of the substrate F is calculated. Further, the post-etching line width distribution / correction amount calculation unit (line width correction amount determining means) 136 obtains the relationship between the exposure amount E and the resist sensitivity E0 with respect to the post-etching line width L, L = h ( E / E0), the post-etching line width correction amount ΔL (x, y) for the calculated resist sensitivity E0 is determined.

  Setting exposure of the exposure device 80 to obtain the desired line width based on the line width correction amount ΔL (x, y) determined by the DMD mask data setting unit 86 or the image data correction calculation unit 100 as exposure amount correction means. The amount is corrected.

  Therefore, by measuring the baking temperature of the substrate F during pre-baking and correcting the set exposure amount, the substrate Fa having a pattern with a desired line width can be manufactured.

  Note that the post-etching line width distribution / correction amount calculation unit (line width correction amount determining means) 136 obtains the relationship between the exposure amount E and the resist sensitivity E0 with respect to the post-etching line width L, L = h ( E / E0) is used to determine the post-etching line width correction amount ΔL (x, y) for the calculated resist sensitivity E0. However, the present invention is not limited to this, and the post-development line width obtained in advance. From the relationship L ′ = h ′ (E / E0) between the exposure amount E and the resist sensitivity E0 with respect to L ′, the post-development line width correction amount ΔL ′ (x, y) with respect to the calculated resist sensitivity E0 is determined. May be.

[Example 2] (Correction for post-baking)
First, when the thin film forming substrate Fpost on which the resist 3 is exposed and developed by the baking apparatus is post-baked, the two-dimensional surface direction post-baking of the thin film forming substrate F is performed by the baking temperature measuring device 102 {102a and / or 102b}. The temperature t 2 (x, y) is measured and stored in the two-dimensional post-bake temperature distribution data memory 142.

  Next, in the two-dimensional taper angle distribution calculation unit 144, a post-bake temperature distribution t2 (preliminarily measured with respect to a relational expression θ = g (t2) between the taper angle θ and the post-bake temperature t2 obtained by experiment. Substituting x, y), the resist taper angle distribution θ (x, y) is calculated.

  FIG. 17 shows a taper angle θ [deg] with respect to a resist (TFR-60000 Tokyo Ohka Kogyo Co., Ltd .: film thickness 2.2 [μm]) and a post-bake temperature t2 [° C.] (post-bake time was 130 seconds). FIG. 18 shows the characteristics of the relational expression (empirical formula) g (t2) in which the values in the table are plotted.

  Next, in the post-etching line width distribution / correction amount calculation unit 146, a relational expression L = h (θ, θ, L) of the set line width (corresponding to the resist line width) Ls obtained experimentally and the post-etching / etching line width L. The calculated taper angle θ and the set line width Ls are substituted into Ls) to calculate the line width distribution L (x, y) after development and etching, and the set line width Ls (target line width, line width based on image data) ) To calculate the line width correction amount ΔL (x, y).

  The image data correction calculation unit 100 corrects the image data by this line width correction amount ΔL (x, y), or corrects the DMD mask data, and the exposure apparatus 10 exposes the substrate F, so that a desired value is obtained after the etching. The substrate Fa on which the pattern of the thin film 2 having a line width is formed can be manufactured.

  In the etching process, the pattern formed by etching on the thin film 2 has a line width 2 of the thin film because the etching particles are scraped off the unnecessary thin film 2 on the substrate 1 while the resist 3 is affected by the etching. Is affected not only by the line width of the resist 3 but also by the profile (residual film amount, taper angle) of the resist 3.

  FIG. 19A is a schematic cross-sectional view of a resist profile when the taper angle θ of the resist 3 before the etching process is large (right side) and small (left side).

  FIG. 19B is a schematic cross-sectional view after dry etching. It can be seen that when the taper angle θ is large, the line width L1 of the resist 3 and the line width L2 of the thin film 2 formed by etching are substantially equal (L2≈L1). On the other hand. It can be seen that when the taper angle θ is small, the line width L3 of the thin film 2 formed by etching is narrower than the line width L1 of the resist 2 (L3 <L1), and the wiring pattern is formed thin.

  As described above, according to the second embodiment described above, the thin film forming substrate F coated with the resist 3 is pre-baked, and the pre-baked substrate F is scanned and exposed by the exposure machine 80 that is controlled to be turned on / off by image data. Development, post-baking, and further etching are performed, and in the exposure apparatus 10 that forms a desired line width pattern on the substrate Fa with the remaining thin film, the baking temperature measuring devices 102a and 102b are used for post-baking. The temperature t2 (x, y) of the substrate Fpost is measured, and the two-dimensional taper angle distribution calculation unit (resist taper angle calculation means) 144 obtains in advance the substrate temperature t2 and resist taper angle θ during post-baking. From the relationship g (t2), the resist taper angle θ with respect to the measured temperature T2 (x, y) of the substrate F is calculated. Further, the post-etching line width distribution / correction amount calculation unit (line width correction amount determining means) 146 obtains the relationship between the resist taper angle θ with respect to the post-etching line width L and the resist line width L, L = From h (θ, L), a line width correction amount ΔL (x, y) after etching with respect to the calculated resist taper angle θ is determined.

  Setting exposure of the exposure device 80 to obtain the desired line width based on the line width correction amount ΔL (x, y) determined by the DMD mask data setting unit 86 or the image data correction calculation unit 100 as exposure amount correction means. Correct the amount.

  For this reason, the substrate Fa having a desired line width pattern can be manufactured by measuring the baking temperature of the substrate F during post-baking and correcting the set exposure amount.

  In the first and second embodiments described above, it is also possible to have means for acquiring substrate temperature distribution data for each substrate in the manufacturing process, and to correct the line width for each substrate.

  In the first and second embodiments, when there are a plurality of baking apparatuses in the manufacturing process, there is a means for acquiring baking temperature distribution data t1 (x, y) and t2 (x, y) for each baking apparatus. It is also possible to correct the line width for each baking apparatus.

  Further, in the first and second embodiments described above, there is a means for obtaining the baking temperature unevenness tj (x, y) caused by the difference in substrate thermal conductivity for each TFT layer layer in the manufacturing process, and for each TFT layer layer. It is also possible to correct the line width.

  Furthermore, in the first and second embodiments, when different resists are used in the manufacturing process, the relational expression E0 = f (f) between the pre-baking temperature t1 and the resist sensitivity for each resist, the post-baking temperature t2, and the taper angle. It is also possible to correct the line width from the θ relational expression θ = g (t) and the relational expression L = h (E / E0) between the line width L and the exposure amount E.

  As described above, according to the embodiment described above, the following effects are achieved.

(1) The yield can be improved by reducing the variation in the pattern line width by performing the exposure in which the line width variation due to the baking temperature is predicted in advance.

(2) The yield can be improved by predicting the line width variation due to the temperature unevenness unique to the plurality of baking apparatuses in advance, thereby reducing the pattern line width variation caused by the temperature unevenness regardless of the baking apparatus.

(3) By predicting the line width variation due to the substrate temperature unevenness caused by the difference in substrate thermal conductivity for each layer of TFT, the yield can be improved by reducing the variation in the pattern line width.

(4) Yield can be improved by reducing variation in pattern line width by predicting line width fluctuation due to fluctuations in sensitivity and taper angle with respect to baking temperatures peculiar to various resists.

(5) The conditions required in the baking process or each step can be relaxed, and the cost can be reduced.

  As described above, according to the present invention, a wiring pattern having a desired line width can be formed without measuring the film thickness distribution of the resist.

  The present invention is not limited to the above-described embodiment. For example, the light beam L applied to the resist-coated thin film forming substrate F is not an exposure apparatus 10 using the DMD 36 but light such as a rotary polygon mirror or a galvanometer mirror. When assuming an exposure device (optical scanning digital exposure system) using a deflector, exposure amount correction for correcting a set exposure amount of the exposure device to obtain a desired line width based on the determined line width correction amount. In the step, intensity modulation of the light source is performed, and the intensity (exposure intensity) of the light beam deflected by the optical deflector is changed depending on the location on the resist-coated thin film forming substrate F so as to obtain an exposure amount distribution with an appropriate exposure amount. The same effect can be obtained.

1 is an external perspective view of an exposure apparatus according to an embodiment of the present invention. It is a schematic block diagram of the exposure head in the exposure apparatus of the example in FIG. It is explanatory drawing of DMD which comprises the exposure head shown in FIG. It is explanatory drawing of the exposure recording state by the exposure head shown in FIG. It is explanatory drawing of DMD which comprises the exposure head shown in FIG. 2, and the mask data set to it. FIG. 6 is an explanatory diagram of a relationship between a recording position and a light amount locality. It is explanatory drawing of the line | wire width recorded when not correcting light quantity locality shown in FIG. It is explanatory drawing of the line | wire width recorded when the light quantity locality shown in FIG. 6 was correct | amended. It is a control circuit block diagram which concerns on the exposure apparatus which concerns on this embodiment. It is another control circuit block diagram of the exposure apparatus which concerns on this embodiment. FIG. 11 is a detailed block diagram of a line width correction amount calculation unit (a pre-bake-corresponding line width correction amount calculation unit) in FIGS. 9 and 10. FIG. 11 is a detailed block diagram of a line width correction amount calculation unit (post bake correspondence line width correction amount calculation unit) in FIGS. 9 and 10. It is a schematic diagram of a bake temperature measuring device. It is a schematic diagram of another bake temperature measuring device. It is a table | surface of the experimental data of prebaking temperature and resist sensitivity. FIG. 6 is an explanatory diagram of the relationship between pre-baking temperature and resist sensitivity. It is a table | surface of the experimental data of a post-baking temperature and a taper angle. It is explanatory drawing of the relationship between post-baking temperature and a taper angle. 19A is a schematic cross-sectional view of a resist profile when the taper angle of the resist is large and small, and FIG. 19B is a schematic cross-sectional view after dry etching. It is a flowchart of a general TFT array process. It is explanatory drawing of the circuit manufacturing process in a semiconductor or FPD.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Exposure apparatus 18 ... Exposure stage 24a-24j ... Exposure head 36 ... DMD
DESCRIPTION OF SYMBOLS 40 ... Micromirror 78 ... Output data correction part 80 ... Exposure machine 100 ... Image data correction calculating part 90, 90A ... Control circuit 102 (102a, 102b) ... Bake temperature measuring device 120 ... Line width correction amount calculating part 130 ... Pre-baking correspondence Line width correction amount calculation unit 140... Post bake compatible line width correction amount calculation unit

Claims (6)

After pre-baking the thin film forming substrate coated with the resist, the pre-baked substrate is scanned and exposed with an exposure machine controlled on and off by image data, then developed, post-baked, and further etched, and the remaining portion In an exposure method in an exposure apparatus that forms a pattern with a desired line width on a substrate with a thin film,
A temperature measuring step for measuring the temperature of the substrate during pre-baking;
A resist sensitivity calculation step for calculating a resist sensitivity with respect to the measured temperature of the substrate from a relationship between the substrate temperature and the resist sensitivity at the time of pre-baking, which has been obtained in advance,
A line width correction amount determining step for determining a post-development or post-etching line width correction amount with respect to the calculated resist sensitivity based on a relationship between the exposure amount and the resist sensitivity with respect to the post-development or post-etching line width. When,
An exposure amount correction step of correcting a set exposure amount of the exposure device to obtain the desired line width according to the determined line width correction amount;
An exposure method for use in an exposure apparatus. After pre-baking the thin film forming substrate coated with the resist, the pre-baked substrate is scanned and exposed with an exposure machine controlled on and off by image data, then developed, post-baked, and further etched, and the remaining portion In an exposure method in an exposure apparatus that forms a pattern with a desired line width on a substrate with a thin film,
A temperature measuring step for measuring the temperature of the substrate during post-baking;
A resist taper angle calculation step for calculating a resist taper angle with respect to the measured temperature of the substrate from the relationship between the substrate temperature and the resist taper angle during post-baking that has been obtained in advance.
A line width correction amount determining step for determining a post-etching line width correction amount with respect to the calculated resist taper angle from a relationship between the resist taper angle and the resist line width with respect to the line width after etching, which has been obtained in advance,
An exposure amount correction step of correcting a set exposure amount of the exposure device to obtain the desired line width according to the determined line width correction amount;
An exposure method for use in an exposure apparatus. In the exposure method in the exposure apparatus of Claim 1 or 2,
The exposure method in the exposure apparatus, wherein the exposure amount set by the exposure device is corrected by the image data or the exposure amount of the exposure device. After pre-baking the thin film forming substrate coated with the resist, the pre-baked substrate is scanned and exposed with an exposure machine controlled on and off by image data, then developed, post-baked, and further etched, and the remaining portion In an exposure apparatus that forms a pattern with a desired line width on a substrate with a thin film,
A temperature measuring device for measuring the temperature of the substrate during pre-baking;
From the relationship between the substrate temperature at the time of pre-baking and the resist sensitivity obtained in advance, a resist sensitivity calculating means for calculating the resist sensitivity with respect to the measured temperature of the substrate,
A line width correction amount determining means for determining a line width correction amount after development or after etching with respect to the calculated resist sensitivity based on a relationship between the exposure amount with respect to the line width after development or after etching and the resist sensitivity obtained in advance. When,
Exposure amount correction means for correcting a set exposure amount of the exposure machine to obtain the desired line width according to the determined line width correction amount;
An exposure apparatus comprising: After pre-baking the thin film forming substrate coated with the resist, the pre-baked substrate is scanned and exposed with an exposure machine controlled on and off by image data, then developed, post-baked, and further etched, and the remaining portion In an exposure apparatus that forms a pattern with a desired line width on a substrate with a thin film,
A temperature measuring device for measuring the temperature of the substrate during post-baking;
A resist taper angle calculating means for calculating a resist taper angle with respect to the measured temperature of the substrate from a relationship between the substrate temperature and the resist taper angle during post-baking, which has been obtained in advance,
Line width correction amount determining means for determining a post-etching line width correction amount for the calculated resist taper angle based on the relationship between the resist taper angle and the resist line width with respect to the post-etching line width obtained in advance;
Exposure amount correction means for correcting a set exposure amount of the exposure machine to obtain the desired line width according to the determined line width correction amount;
An exposure apparatus comprising: In the exposure apparatus according to claim 4 or 5,
The exposure apparatus is configured to correct the set exposure amount of the exposure device based on the image data or the exposure amount of the exposure device.

Images