JP2004281791A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

An object of the present invention is to improve the uniformity of a remaining film in a half-exposed portion.
A processing chamber is where a substrate G is actually heated, and an upper plate 45 for heating a resist R from the front surface of the substrate G, a lower plate 46 for heating the resist R from the back surface of the substrate G, and a process. An exhaust port 47 for exhausting the gas in the chamber 42 is provided. The upper plate 45 is provided so as to be vertically movable in the processing chamber 42 by the upper air cylinder 51 constituting the upper drive mechanism 43. The lower plate 46 is placed on the floor 42 b of the processing chamber 42. The exhaust port 47 is connected to a pump 50 via a pipe 48. The heating temperature and heating time of the upper plate 45 and the lower plate 46 are controlled by a heating control unit 70. The control of the air pressure in the processing chamber 42 is performed by controlling the pump 50 by the air pressure control unit 73.
[Selection diagram] Fig. 4

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate processing method and a substrate processing apparatus for processing a glass substrate or a semiconductor substrate used for, for example, a liquid crystal display device.
[0002]
[Prior art]
In a manufacturing process of an LCD (Liquid Crystal Display), a photolithography technique similar to that used for manufacturing a semiconductor device is used to form an ITO (Indium Tin Oxide) thin film and an electrode pattern on a glass substrate for an LCD. Used. In the photolithography technique, a photoresist is applied to a glass substrate, which is exposed and further developed.
[0003]
There is a so-called half exposure as a method for the above exposure. In the case of normal exposure, a portion that is not exposed is covered with a mask and shielded from light. On the other hand, in the half exposure, a halftone mask or the like in which a difference in light transmittance is provided in one mask to be used is used. However, it is possible to intentionally form a part where the depth is shallow. As a result, there is a difference in the exposure depth between a portion not covered by the mask (portion completely exposed), a portion covered by halftone (shallow exposure portion) and a portion covered by the mask (portion not exposed). It is possible to form different resist film thicknesses with one mask. Therefore, in half exposure, the number of masks to be used can be reduced, and the processing time can be shortened by the mask replacement step (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-09-080740 (paragraphs [0002], [0003], etc.).
[0005]
[Problems to be solved by the invention]
Usually, a halftone mask is provided with a plurality of semi-light-shielding portions having the same shape and the same area, and it is desired that the half exposure depth and width are the same.
[0006]
However, when half-exposure is performed, the depth and width of the half-exposure differ depending on the portion to be irradiated with light, and the remaining resist film after development becomes non-uniform. That is, there is a problem that the aspect ratio and the pitch of the developed resist pattern become non-uniform. Actually, a variation of 10% or more with respect to a desired value is observed. For this reason, for example, the distance between a plurality of electrodes formed after the etching becomes non-uniform, and the switching time differs depending on the location, which causes color unevenness when an image is displayed by a liquid crystal, for example.
[0007]
In view of the above circumstances, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of improving the uniformity of a remaining film in a half-exposed portion.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a substrate processing method according to the present invention includes: (a) a step of applying a resist to a surface of a substrate; and (b) a step of applying the resist applied to the surface of the substrate to a surface side of the substrate. And (c) half-exposing the heated resist.
[0009]
With such a configuration, the resist can be dried from the back side of the substrate, and the surface of the resist can be hardened. The resist surface is baked to suppress evaporation of water due to heating from the back surface, and a certain amount of water remains in the resist. As a result, a flat layer having a small moisture content is formed on the back surface side of the resist, and a layer containing residual moisture is formed from the surface to the middle of the resist. Moisture is required for the resist to undergo an exposure reaction, and half exposure does not cause an exposure reaction in a region of the resist having a small amount of moisture, so that the flat layer on the back surface side of the resist is not exposed. By development, a flat layer in which this exposure reaction does not occur becomes a residual film. As described above, at a certain depth of the resist, the residual film after development can form a flat layer that is not affected by the exposure dose, and the dissolution characteristics of the resist in the depth direction can be controlled. Thereby, the uniformity of the remaining film in the half-exposed portion can be improved. Here, half-exposure means, for example, a halftone mask or the like having a difference in light transmittance, and a portion having a smaller exposure amount than in the case of normal exposure, that is, a depth of a resist to be exposed is partially reduced. An exposure method for intentionally forming a shallow portion (hereinafter the same).
[0010]
In the substrate processing method according to one embodiment of the present invention, the step (b) includes: (d) a step of heating at a first temperature from the front side of the substrate; and (e) a second step of heating the second side from the back side of the substrate. And heating at a temperature of
[0011]
With such a configuration, the first temperature and the second temperature can be set separately, so that even when the type of resist is different, heating can be performed independently at an optimum temperature in each step.
[0012]
In the substrate processing method according to an embodiment of the present invention, the step (d) includes a step of heating the substrate at a temperature of 70 ° C. to 200 ° C. from the front side.
[0013]
With such a configuration, by varying the first temperature from 70 ° C. to 200 ° C., heating can be performed at an optimal temperature according to the type of resist.
[0014]
In the substrate processing method according to one aspect of the present invention, the step (e) includes a step of heating at 90 ° C. to 150 ° C. from the back side of the substrate.
[0015]
With such a configuration, by varying the second temperature from 90 ° C. to 150 ° C., heating can be performed at an optimum temperature according to the type of resist.
[0016]
The substrate processing method according to one embodiment of the present invention further includes (f) adjusting at least the pressure applied to the resist during the step (b).
[0017]
With such a configuration, even when the type of the resist is different, it is possible to perform heating at an optimum pressure according to the type of the resist in each step.
[0018]
In the substrate processing method according to one aspect of the present invention, the step (f) includes a step of reducing at least the pressure applied to the resist in the course of the step (b) from normal pressure by 5 Pa to 100 Pa.
[0019]
With such a configuration, the pressure applied to the resist is variably reduced from normal pressure to 5 Pa to 100 Pa, so that even if the type of the resist is different, it is possible to heat the resist at an optimum pressure according to the type of the resist. it can.
[0020]
In the substrate processing method according to one embodiment of the present invention, the step (b) includes a step of adjusting a heating time for heating the resist to 60 seconds to 300 seconds.
[0021]
With such a configuration, by varying the heating time of the resist from 60 seconds to 300 seconds, even if the type of the resist is different, heating can be performed with an optimal heating time according to the type of the resist.
[0022]
A substrate processing apparatus according to the present invention is a substrate processing apparatus capable of transferring the substrate to and from an exposure apparatus that performs half-exposure of a resist applied on the substrate, wherein the resist is applied to the surface of the substrate. A coating unit for coating, a heating unit for heating the resist applied on the surface of the substrate from the front side and the back side of the substrate, and a substrate heated by the heating unit can be transferred to the exposure apparatus Interface unit.
[0023]
With such a configuration, the resist applied in the application section can be dried by heating from the back side of the substrate in the heating section, and the surface of the resist can be baked and hardened by heating from the front side of the substrate. . The resist surface is baked to suppress evaporation of water due to heating from the back surface, and a certain amount of water remains in the resist. As a result, a flat layer having a small moisture content is formed on the back surface side of the resist, and a layer containing residual moisture is formed from the surface to the middle of the resist. Moisture is required for the resist to undergo an exposure reaction, and half exposure does not cause an exposure reaction in a region of the resist having a small amount of moisture, so that the flat layer on the back surface side of the resist is not exposed. By development, a flat layer in which this exposure reaction does not occur becomes a residual film. In this manner, the heating unit can form a flat layer in which the residual film after development at a certain depth of the resist is not affected by the exposure dose, and as a result, the dissolution characteristics of the resist in the depth direction during development can be controlled. can do. Thereby, the uniformity of the remaining film in the half-exposed portion can be improved.
[0024]
The substrate processing apparatus according to an aspect of the present invention, the heating unit, the first resist is applied to the surface of the substrate, the first heating plate to heat at a first temperature from the surface side of the substrate, A second hot plate for heating the resist applied on the front surface of the substrate at a second temperature from the back surface side of the substrate.
[0025]
With this configuration, the temperature of the hot plate heated at the first temperature and the temperature of the hot plate heated at the second temperature can be set independently of each other. The hot plate can be heated at an optimum temperature according to the type of the resist.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0027]
(Coating and developing equipment)
FIG. 1 is a plan view showing an LCD substrate coating and developing apparatus to which the present invention is applied, FIG. 2 is a front view thereof, and FIG. 3 is a rear view thereof.
[0028]
The coating and developing apparatus 1 includes a cassette station 2 on which a cassette C accommodating a plurality of glass substrates G is mounted, and a plurality of processing units for performing a series of processing including resist coating and development on the substrate G. The processing unit 3 includes an interface unit 4 for transferring a substrate G between the exposure unit 32 and the cassette unit 2 and the interface unit 4 at both ends of the processing unit 3.
[0029]
The cassette station 2 includes a transport mechanism 10 for transporting an LCD substrate between the cassette C and the processing unit 3. Then, the cassette C is loaded and unloaded at the cassette station 2. The transport mechanism 10 includes a transport arm 11 that can move on a transport path 12 provided along the direction in which the cassettes are arranged. The transport arm 11 transports the substrate G between the cassette C and the processing unit 3. Done.
[0030]
The processing unit 3 includes an upstream part 3b in which processing units including a resist coating processing unit (CT) are arranged in parallel along the X direction and a downstream part in which processing units including a development processing unit (DEV) are arranged in parallel. 3c is provided.
[0031]
In the upstream portion 3b, an excimer UV processing unit (e-UV) 19 for removing organic substances on the substrate G from the cassette station 2 side and a cleaning process for the substrate G with a scrubbing brush are provided at the end of the cassette station 2 side. And a scrubber cleaning processing unit (SCR) for performing the following.
[0032]
Next to the scrubber cleaning processing unit (SCR), heat treatment system blocks 24 and 25 in which units for performing thermal processing on the glass substrate G are stacked in multiple stages are arranged. The vertical transfer unit 5 is disposed between the heat treatment system blocks 24 and 25, and the transfer arm 5a is movable in the Z direction and the horizontal direction, and is rotatable in the θ direction. The substrate G is transported by accessing each heat treatment system unit in the blocks 24 and 25. The vertical transport unit 7 has the same configuration as the vertical transport unit 5.
[0033]
As shown in FIG. 2, the heat treatment system block 24 includes a two-stage baking unit (BAKE) for performing a heat treatment before applying a resist to the substrate G, and an adhesion unit (AD) for performing a hydrophobic treatment with an HMDS gas. They are stacked in order from the bottom. On the other hand, in the heat treatment system block 25, a cooling unit (COL) for performing a cooling process on the substrate G is stacked in two stages, an adhesion unit (AD), and a transfer device 30 in this order from the bottom.
[0034]
A resist processing block 15 extends in the X direction adjacent to the heat treatment system block 25. The resist processing block 15 includes a resist coating processing unit (CT) for applying a resist to the substrate G, a reduced-pressure drying unit (VD) for drying the applied resist under reduced pressure, and a peripheral portion of the substrate G according to the present invention. And an edge remover (ER) for removing the resist. The resist processing block 15 is provided with a sub-arm (not shown) that moves from the resist coating processing unit (CT) to the edge remover (ER), and the substrate G is transported in the resist processing block 15 by the sub-arm. Has become.
[0035]
A heat treatment system block 26 having a multi-stage configuration is disposed adjacent to the resist processing block 15. In this heat treatment system block 26, a pre-baking unit (PREBAKE) for performing a heat treatment after applying a resist to the substrate G has three stages. They are stacked, and a transport device 40 is provided below them.
[0036]
In the downstream portion 3c, as shown in FIG. 3, a heat treatment system block 29 is provided at the end portion on the interface portion 4 side, which includes a cooling unit (COL), a heat treatment after exposure and before development. Are stacked in two stages from the bottom, in order from the bottom.
[0037]
A development processing unit (DEV) for performing the development processing is provided adjacent to the heat treatment system block 29 and extends in the X direction. Heat processing system blocks 28 and 27 are disposed adjacent to the development processing unit (DEV). Between the heat processing system blocks 28 and 27, the same structure as the vertical transport unit 5 is provided. And a vertical transport unit 6 accessible to each heat treatment system unit in 27. An i-line processing unit (i-UV) 33 is provided adjacent to the development processing unit (DEV).
[0038]
In the heat treatment system block 28, a cooling unit (COL) and a post-baking unit (POBAKE) for performing a heat treatment after development on the substrate G are stacked in two stages from the bottom. On the other hand, in the heat treatment system block 27, similarly, a cooling unit (COL) and a post-baking unit (POBAKE) are stacked in two stages from the bottom.
[0039]
The interface unit 4 is provided with a titler and a peripheral exposure unit (Titler / EE) 22 on the front side, an extension cooling unit (EXTCOL) 35 adjacent to the vertical transport unit 7, and a buffer cassette 34 on the back side. And a vertical transport unit 8 for transferring the substrate G between the titler / peripheral exposure unit (Titler / EE) 22, the extension cooling unit (EXTCOL) 35, and the exposure device 32 adjacent to the buffer cassette 34. Are located. The vertical transport unit 8 has the same configuration as the vertical transport unit 5.
[0040]
(Coating and developing process)
Processing steps of the coating and developing apparatus 1 configured as described above will be described. First, the substrate G in the cassette C is transported to the upstream section 3b in the processing section 3. In the upstream section 3b, surface modification and organic substance removal processing are performed in an excimer UV processing unit (e-UV) 19, and then, in a scrubber cleaning processing unit (SCR), cleaning processing is performed while the substrate G is transported substantially horizontally. A drying process is performed. Subsequently, the substrate G is taken out by the transfer arm 5a of the vertical transfer unit at the lowermost part of the heat treatment system block 24, heated by the baking unit (BAKE) of the heat treatment system block 24, and heated by the adhesion unit (AD). In order to enhance the adhesion between the glass substrate G and the resist film, a process of spraying the substrate G with HMDS gas is performed. Thereafter, a cooling process by the cooling unit (COL) of the heat treatment system block 25 is performed.
[0041]
Next, the substrate G is transferred from the transfer arm 5a to the transfer device 30, and the transfer device 30 transfers the substrate G to the resist coating unit (CT). After the resist is coated, the reduced-pressure drying unit ( VD), and a resist removal process at the periphery of the substrate is sequentially performed by an edge remover (ER).
[0042]
Next, the substrate G is transferred to the transfer device 40 and transferred to the transfer arm of the vertical transfer unit 7 by the transfer device 40. After the heat treatment is performed in the prebaking unit (PREBAKE) in the heat treatment system block 26, the cooling process is performed in the cooling unit (COL) in the heat treatment system block 29. Subsequently, the substrate G is cooled by an extension cooling unit (EXTCOL) 35 and is exposed by an exposure device.
[0043]
Next, the substrate G is transferred to the post-exposure baking unit (PEBAKE) of the heat treatment system block 29 via the transfer arms of the vertical transfer units 8 and 7, where the heat treatment is performed, and then the cooling unit (COL). The cooling process is performed. Then, the development processing, rinsing processing and drying processing are performed while the substrate G is transported substantially horizontally in the development processing unit (DEV) via the transport arm of the vertical transport unit 7.
[0044]
Next, the substrate G is transferred from the lowermost stage in the heat treatment system block 28 by the transfer arm 6a of the vertical transfer unit 6, and is subjected to heat treatment in the post baking unit (POBAKE) in the heat treatment system block 28 or 27, and the cooling unit A cooling process is performed at (COL). Then, the substrate G is delivered to the transport mechanism 10 and stored in the cassette C.
[0045]
(Heat treatment equipment)
Next, a prebaking unit provided in a heat treatment system block of the substrate processing apparatus according to the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of the prebaking unit, showing the internal structure.
[0046]
The pre-baking unit 38 for heating the resist R applied to the substrate G has a processing chamber 42 and an upper driving mechanism 43 therein. The processing chamber 42 is where the substrate G is actually heated. The upper plate 45 heats the resist R from the front side of the substrate G, the lower plate 46 heats the resist R from the back side of the substrate G, the processing chamber 42 It has an exhaust port 47 for exhausting gas inside.
[0047]
The upper plate 45 is provided so as to be vertically movable in the processing chamber 42 by the upper air cylinder 51 constituting the upper drive mechanism 43. The upper piston 52 of the upper air cylinder 51 is attached to the support member 54 through a through hole 42c formed in the ceiling 42a of the processing chamber 42. The vertical movement of the piston 52 allows the upper plate 45 to be moved up and down.
[0048]
The lower plate 46 is placed on the floor 42 b of the processing chamber 42. The lower plate 46 has a proximity pin 55 that forms a gap with the substrate G, and a through hole 56 that allows a support pin 57 that supports the substrate G to be mounted on the proximity 55 to pass therethrough. The support pin 57 can be moved up and down in the vertical direction by, for example, an air cylinder or a stepping motor (not shown).
[0049]
The upper plate 45 and the lower plate 46 are formed of, for example, metal such as aluminum, and internally provided with a heating mechanism such as a heating wire (not shown). Further, each of the plates 45 and 46 is provided with a heating control unit 70. The heating temperature and the heating time of the plates 45 and 46 are controlled by the heating control unit 70. The exhaust port 47 is connected to a pump 50 via a pipe 48. The pump 50 is provided with an air pressure control unit 73 for controlling the exhaust pressure during heating. The control of the air pressure in the processing chamber 42 is performed by controlling the pump 50 by the air pressure control unit 73.
[0050]
Next, a control system for controlling the heating temperature and heating time of each plate will be described with reference to FIG.
[0051]
As shown in FIG. 5A, the heating control unit 70 has a heating temperature control unit 71 and a heating time control unit 72. The heating temperature controller 71 is divided into an upper plate temperature controller 71a for controlling the temperature of the upper plate 45 and a lower plate temperature controller 71b for controlling the temperature of the lower plate 46, and the temperature of the upper plate 45 and the lower plate 46 is controlled. Are controlled independently. This makes it possible to heat at an optimum temperature according to the type of the resist. The upper plate temperature controller 71a and the lower plate temperature controller 71b are connected to, for example, heating wires of the plates 45 and 46, respectively, and control the magnitudes of currents flowing through the heating wires to control the respective plates 45 and 46. Control the temperature. The heating time control unit 72 for controlling the heating time of the upper plate 45 and the lower plate 46 is attached to a heating mechanism such as a heating wire of each of the plates 45 and 46. After a predetermined time, the heating time of the plates 45 and 46 is controlled, for example, by stopping the current flowing through the heating wire. As shown in FIG. 5B, the heating time control unit 72 has an upper plate time control unit 72a and a lower plate time control unit 72b, and controls the heating time of the plates 45 and 46 independently. You may do it. This makes it possible to heat at an optimum temperature according to the type of the resist.
[0052]
(Substrate processing step)
Next, a substrate processing step will be described.
[0053]
FIG. 6 is a flowchart showing the steps of the present invention. In the resist processing block 15, a resist R is applied to the surface of the substrate G by, for example, spin coating (Step 1). As the material of the resist R, for example, a novolak resin-based material is used.
[0054]
Next, in the pre-baking unit 38 of the heat treatment system block 26, the resist R is heated by the upper plate 45 and the lower plate 46 (Step 2). When carrying the substrate into the pre-baking unit 38, the upper plate may be moved up and down by the upper drive mechanism 43 as appropriate to facilitate carrying the substrate G. The substrate G is placed on the support pins 57, and is placed on the proximity pins 55 by the lower drive mechanism as shown in FIG. In this state, the resist R is heated by the upper plate 45 and the lower plate 46. In order to facilitate understanding of the drawing, the ratio of the thickness of the resist R to the thickness of the substrate is schematically shown in an enlarged manner. At the stage of starting the heating, the resist R contains a sufficient amount of moisture, and the resist R in such a state that the moisture is sufficiently contained is indicated by reference numeral 62. The heating may be performed by appropriately moving the upper plate 45 up and down by the upper drive mechanism 43.
[0055]
FIG. 8 shows the heating conditions in step 2 in a table. The upper column of the table shows the optimal control range of the heating controller 70 and the atmospheric pressure controller 73, and the lower column shows the optimal values when the novolak resin system in this embodiment is used as the resist material. Regarding the optimal control range, it is preferable that the upper plate 45 is heated at a temperature of 70 ° C. to 200 ° C. and the lower plate 46 is heated at a temperature of 90 ° C. to 150 ° C. This is because the optimum heating temperature differs depending on the type of the resist. For this reason, the upper plate temperature controller 71a and the lower plate temperature controller 71b of the heating temperature controller 71 are set in advance so that they can be controlled to temperatures within the above range. By setting the temperature range in this manner, heating can be performed at an optimum value according to the type of the resist.
[0056]
As for the heating time of the plate, it is preferable to set the heating time control unit 72 and control the heating time in the range of 60 seconds to 300 seconds depending on the type of the resist. Further, it is preferable that the exhaust pressure from the exhaust port 47 be controlled by setting the air pressure control unit 73 to reduce the pressure from normal pressure by 5 Pa to 100 Pa according to the type of the resist.
[0057]
In the novolak resin-based resist R of the present embodiment, the temperature of the upper plate 45 is 70 ° C. to 200 ° C., the temperature of the lower plate 46 is about 135 ° C., the heating time is about 180 seconds, and the exhaust pressure is reduced from normal pressure to 10 Pa to 50 Pa. The optimal value is the value obtained. Therefore, the heating temperature control unit 71, the heating time control unit 72, and the atmospheric pressure control unit 73 perform control so that heating is performed in this range.
[0058]
When the resist R is heated under these conditions, as shown in FIG. 7B, a hardened portion 63 in which the surface of the resist R is hardened is formed by heating by the upper plate 45. In addition, the moisture is evaporated by the heating by the lower plate 46, and the drying section 64 having relatively little moisture is formed. By forming the hardened portion 63, the moisture that evaporates due to heating from the lower plate 64 is suppressed, and the water-containing portion 62 having a relatively large amount of water remains between the hardened portion 63 and the drying portion 64.
[0059]
Next, in this state, heating of the resist R is completed, and exposure is performed (step 3). FIG. 9 shows this state.
[0060]
FIG. 9A shows a state in which exposure is performed on the exposure regions A, B, and C of the resist R. Hereinafter, in the present embodiment, when there is a difference in the amount of exposure light applied to the resist R between the exposure region B and the exposure region C, for example, it is assumed that the exposure amount is larger in the exposure region C than in the exposure region B. explain.
[0061]
Exposure is performed by the exposure device 32. The resist R is covered with a mask 65, and the resist R is irradiated with ultraviolet light from above the mask 65. In the exposure area A, normal exposure is performed. For this reason, a hole is formed in a portion of the mask 65 corresponding to the exposure region A, so that the irradiation light is completely transmitted. In the exposure areas B and C, half exposure is performed. For this reason, the halftone 65a is used in the portions corresponding to the exposure regions B and C, so that the irradiation light is substantially semi-transmitted.
[0062]
FIG. 9B shows a state in which the resist R is being exposed, and shows a state in which the exposure reaction in the region C has been performed up to the drying unit 64. In the region A, the exposure reaction is performed up to a point slightly advanced on the surface of the drying unit 64. In the region B, the exposure reaction is performed up to about half of the water-containing portion 62. Since the exposure reaction occurs in accordance with the magnitude of the exposure amount, there is a difference in the progress of the reaction in each region at the stage during the exposure.
[0063]
FIG. 9C shows a state where the resist R is further irradiated with ultraviolet rays (g-line and i-line) from this state, and the exposure is completed. In the region A, an exposure reaction occurs in all of the hardened portion 63, the moisture containing portion 62, and the dried portion 64 of the resist R. In the regions B and C, the intensity of the exposure light applied to the resist R is lower than that in the exposure region A. Although the exposure reaction occurs in the hardened portion 63 and the water containing portion 62, the exposure reaction occurs up to the drying portion 64. Absent. As compared with FIG. 9B, in the region C, the exposure reaction has not occurred from the point where it has reached the water-containing portion 63. As described above, in the regions B and C, the exposure depth of the resist R does not change even if the irradiation amount is different.
[0064]
Next, the resist R is developed (step 4). The situation at this time is shown in FIG. FIG. 10A shows how the developing solution is supplied to the exposed resist R. The development is performed by a developing unit processing unit (DEV) provided in the downstream part 3 of the coating and developing processing apparatus 1. The developer 67 discharged from the nozzle 66 is supplied to the surface of the resist R. As shown in FIG. 10B, the developer 67 dissolves a portion of the resist R where the exposure reaction has occurred. In this process, the resist R remains undissolved in the portion covered with the mask at the time of exposure, and the resist R in the region A is completely dissolved. In the regions B and C covered with the halftone 65a, only the dried portions 64 in which the exposure reaction has not occurred remain without being dissolved. According to the present embodiment, the thickness of the remaining film in the exposure regions B and C is the thickness of the drying portion 64, which is approximately 8000 °. In this manner, the remaining film can be made constant despite the different exposure amounts in the regions B and C.
[0065]
FIG. 11 to FIG. 13 show the results of an experiment performed on the present embodiment. Each graph is a graph showing the relationship between the exposure amount and the remaining resist film thickness, with the horizontal axis representing the exposure amount and the vertical axis representing the remaining resist film thickness. As the type of the resist, a novolak resin type was used as in the present embodiment.
[0066]
FIG. 11 shows the relationship between the exposure amount and the remaining resist film thickness when heating was performed by changing the temperature of the lower plate 46 to 135 ° C. and changing the temperature of the upper plate 45 to 70 ° C., 135 ° C., and 200 ° C., respectively. Is shown. In addition, the relationship when the upper plate 45 is not used at the time of heating is also shown.
[0067]
When the temperature of the upper plate 45 is set to 70 ° C., 135 ° C., and 200 ° C., the resist remaining film thickness shows a constant value of about 3000 ° when the exposure amount is in the range of 10 to 20 (mJ / cm ² ). It can be seen that the temperature of the upper plate 45 has little effect on the remaining film thickness of the resist. From these results, if the exposure amount of the half exposure is controlled so as to be in the range of 10 to 20 (mJ / cm ² ), preferably 15 to 20 (mJ / cm ² ), the resist remaining film can be formed even by the fluctuation of the exposure amount. The thickness can be made uniform.
[0068]
FIG. 12 shows that when the temperature of the lower plate 46 is set to 135 ° C., the temperature of the upper plate 46 is arbitrarily set in a range of 70 ° C. to 200 ° C., and heating is performed for 180 seconds, the exhaust pressure is set to 10 Pa, 50 Pa, and 100 Pa. And the relationship between the exposure amount and the remaining resist film thickness when changing.
[0069]
When the value of the exhaust pressure is 10 Pa, the remaining resist film thickness is 8000 °, which is almost constant, in the range of the exposure amount of 10 to 20 (mJ / cm ² ). When the exhaust pressure value is 50 Pa, the resist remaining film thickness slightly changes from 6000 to 7000 ° when the exposure amount is in the range of 10 to 20 (mJ / cm ² ). On the other hand, when the value of the exhaust pressure is 100 Pa, even if the exposure amount is in the range of 10 to 20 (mJ / cm ² ), the remaining resist film thickness decreases with the increase in the exposure amount, and changes largely to 1000 ° to 6000 °. . From this result, it is possible to make the residual resist film uniform in the range of the exposure amount of 10 to 20 (mJ / cm ² ) by controlling the exhaust amount at the time of heating to 10 to 50 Pa, preferably approximately 10 Pa. If the exhaust amount is set to the above value, an almost ideal remaining resist film thickness of about 8000 ° can be obtained.
[0070]
FIG. 13 shows the case where the lower plate 46 is heated to 115 ° C., the upper plate is not used, the temperature is set to 200 ° C. using the upper plate, and the temperature is set to 200 ° C. using the upper plate. C., and the value when the substrate is heated upside down (with the surface coated with the resist R facing the lower plate 46).
[0071]
In any case, the residual resist film thickness does not take a constant value, and the residual resist film thickness decreases with an increase in the exposure amount. However, for example, it is conceivable that the residual resist film thickness has a constant value by setting the exhaust pressure and the heating time to appropriate values.
[0072]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the uniformity of the remaining film in the half-exposed portion.
[Brief description of the drawings]
FIG. 1 is a plan view showing an overall configuration of a coating and developing apparatus according to an embodiment of the present invention.
FIG. 2 is a front view of the coating and developing apparatus shown in FIG.
FIG. 3 is a rear view of the coating and developing apparatus shown in FIG. 1;
FIG. 4 is a sectional view of a pre-baking unit.
FIG. 5 is a diagram illustrating a control system of a heat treatment.
FIG. 6 is a process chart showing a substrate processing method according to the present invention.
FIG. 7 is a diagram showing a state in which a resist is subjected to a heat treatment.
FIG. 8 is a diagram showing optimum conditions during heat treatment.
FIG. 9 is a diagram illustrating a change when a resist is irradiated with exposure light.
FIG. 10 is a diagram showing a state when a developing solution is supplied to a resist.
FIG. 11 is a graph showing a relationship between an exposure amount and a residual resist film thickness after development.
FIG. 12 is a graph showing a relationship between an exposure amount and a residual film thickness of a resist after development.
FIG. 13 is a graph showing a relationship between an exposure amount and a residual film thickness of a resist after development.
[Explanation of symbols]
G ... Substrate R ... Resist 1 ... Coating / developing apparatus 45 ... Upper plate 46 ... Lower plate 47 ... Exhaust port 62 ... Moisture containing part 63 ... Hardening part 64 ... Drying part 65a ... Half tone part 71a ... Upper plate temperature control part 71b: lower plate temperature controller 72: heating time controller 73: air pressure controller

Claims (9)

(A) applying a resist on the surface of the substrate;
(B) heating the resist applied to the surface of the substrate from the front side and the back side of the substrate;
(C) half-exposing the heated resist. The substrate processing method according to claim 1,
The step (b) comprises:
(D) heating at a first temperature from the front side of the substrate;
(E) heating at a second temperature from the back side of the substrate. 3. The substrate processing method according to claim 2, wherein
The step (d) includes:
A method of processing a substrate, comprising a step of heating at a temperature of 70 ° C. to 200 ° C. from the front side of the substrate. 3. The substrate processing method according to claim 2, wherein
The step (e) includes:
A method of processing a substrate, comprising a step of heating at 90 ° C. to 150 ° C. from the back side of the substrate. The substrate processing method according to claim 1,
(F) a method of processing a substrate, further comprising a step of adjusting at least the pressure applied to the resist during the step (b). The substrate processing method according to claim 5, wherein
The step (f) includes:
A substrate processing method comprising a step of reducing at least the pressure applied to the resist from normal pressure by 5 Pa to 100 Pa. The substrate processing method according to claim 1,
The step (b) comprises:
A method of processing a substrate, comprising: adjusting a heating time for heating the resist to 60 seconds to 300 seconds. A substrate processing apparatus capable of transferring the substrate between an exposure apparatus that performs half exposure of a resist applied on the substrate,
A coating unit for coating a resist on the surface of the substrate,
A heating unit that heats the resist applied to the surface of the substrate from the front side and the back side of the substrate,
A substrate processing apparatus, comprising: an interface unit that can transfer the substrate heated by the heating unit to the exposure apparatus. The substrate processing apparatus according to claim 8, wherein:
The heating unit is
A first hot plate that heats the resist applied to the surface of the substrate at a first temperature from the surface side of the substrate;
A second heating plate for heating the resist applied to the front surface of the substrate at a second temperature from the back surface side of the substrate.

Images