JPH113843A - Method for treating wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the line width uniformity of a pattern on a resist film formed on the surface of a wafer by supplying a developing solution to the resist film in a scanning state, by moving a developing solution supplying nozzle from the baking starting side to the ending side of a chip pattern along the wafer at the time of developing the resist film. SOLUTION: A developing solution is supplied to a resist film formed on the surface of a wafer W in a scanning state by discharging the developing solution from the slit-like discharge port 28 of a discharge nozzle 26, while the wafer W is held by a pin chuck and the nozzle 26 is moved in the direction (a). Since the development of the resist film is carried out in such a way that the development is started earlier in an area where a chip pattern is printed earlier and delayed in an area where the pattern is printed later, the variation of the time until the development is started after the chip pattern is printed on the whole surface of the substrate W becomes smaller, and no difference occurs in the time until the development is started after the chip pattern is printed between areas S and E. Therefore, the line width uniformity of the pattern on the resist film can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor wafer,
The present invention relates to a substrate processing method in which a substrate such as a glass substrate for a liquid crystal display (LCD), a glass substrate for a photomask, or a substrate for an optical disk is exposed to light and then developed, and in particular, a chip pattern is formed on a resist film formed on the surface of the substrate. The present invention relates to a substrate processing method for developing a resist film by supplying a developing solution to the surface of a stationary substrate which is held in a horizontal position and then baked after sequential printing.

In a semiconductor manufacturing process or an LCD manufacturing process, when a resist film formed on the surface of a substrate is exposed and then developed, conventionally, the substrate is held in a horizontal position and rotated around a vertical axis. By discharging the developing solution from the spray type discharging nozzle toward the center of the substrate, or by discharging the developing solution from the discharging nozzle while moving the discharging nozzle from the center of the substrate to the periphery, the developing solution is discharged over the entire surface of the substrate. Had to supply. Also, while slowly rotating the substrate around the vertical axis while holding the substrate in a horizontal position, the developer is slowly discharged from the discharge nozzle onto the substrate, thereby spreading the developer over the entire surface of the substrate. The substrate has been stationary or rotated at a low speed.

[0003] In recent years, there has been a demand for a technique for increasing the definition of a circuit pattern as semiconductor devices become more highly integrated. In order to meet this demand, a chemically amplified resist is used in a semiconductor device manufacturing process. That is being done. This chemically amplified resist is exposed to a desired pattern on a substrate to which the resist is applied, and the photoacid generator contained in the resist generates an acid, and then the substrate is heated to perform a catalytic action. Is activated to promote a crosslinking reaction (in the case of a negative type) or a decomposition reaction (in the case of a positive type) in an exposed portion of the resist. After the heat treatment, the substrate is cooled to reduce the reaction of the resist, and then the substrate is developed, so that the unreacted portion (in the case of a negative type) or the reactive portion (in the case of a positive type) of the resist is developed. , And a desired resist film is obtained.

FIG. 5 shows a schematic configuration example of an apparatus for processing a substrate using a chemically amplified resist. In this example,
The entire apparatus is composed of the substrate processing apparatus 1 and the exposure apparatus ST. In the substrate processing apparatus 1, a cassette (not shown) capable of storing a plurality of substrates is placed, and a substrate to be processed is taken out of the cassette one by one, carried out, and a substrate on which all the processing is completed. Indexer unit ID for receiving each sheet one by one and storing it again in a cassette, a transfer unit TR provided with a self-propelled substrate transfer robot (not shown) equipped with a substrate transfer arm, and predetermined processing for the substrate. , A substrate processing area 2 having a plurality of substrate processing units, each of which performs the following, and an interface unit IF for transferring a substrate to and from the exposure apparatus ST. In this example, the plurality of substrate processing units in the substrate processing area 2 include a coating processing unit S having a spin coater (not shown).
C, an adhesion part AH for heating the substrate in an atmosphere of HMDS (hexamethyldisilazane) in order to improve the adhesion between the surface of the substrate and the resist, and four heating units each having a hot plate (not shown). Processing unit HP
1, a heat treatment unit (hereinafter, referred to as a “bake unit”) PEB which is provided with HP2, HP3, HP4, a hot plate (not shown), and performs a heat treatment (post-exposure bake) on the substrate after the exposure treatment. Four cooling processing units CP1, CP2, CP with plates (not shown)
3, development processing units SD1 and SD2 each having a spin developer (not shown). The exposure apparatus ST has an exposure processing unit (not shown) including a stepper for exposing the substrate.

FIG. 6 shows an example of a substrate processing flow in the substrate processing apparatus 1 and the exposure apparatus ST shown in FIG.
The processing procedure of the substrate will be briefly described with reference to FIG. 6. First, the substrates before processing stored in the cassette are supplied to the transport unit TR one by one from the indexer unit ID.
The substrate transport robot includes an adhesion section AH, a cooling section CP1, a coating section SC, and a heating section HP1.
Alternatively, while sequentially moving to the HP2 and the cooling processing unit CP2, in each of the substrate processing units, the substrate that has been put in is taken out and the substrate to be processed is put in. Is performed. Thereby, a resist film is applied and formed on the surface of the substrate. Next, the substrate having the resist film formed on the surface is transferred from the transport unit TR to the interface unit IF, and is carried into the exposure apparatus ST through the interface unit IF. Then, the substrate is subjected to the exposure processing in the exposure processing section of the exposure apparatus ST, and the substrate on which the exposure processing has been completed is returned from the exposure apparatus ST to the interface section IF, and transferred to the transport unit TR through the interface section IF.

[0006] The substrate after the exposure processing returned to the transport unit TR is transported to the bake unit PEB by the substrate transport robot, and is heated by the bake unit PEB. This heat treatment promotes the chemical reaction in the exposed portion of the chemically amplified resist as described above. Then, the substrate is transferred from the baking unit PEB to the cooling unit CP3 by the substrate transfer robot, and the substrate is cooled in the cooling unit CP3. This cooling reduces the reaction in the exposed portion of the chemically amplified resist. Thereafter, the substrate transfer robot moves the cooling processing unit CP3 to the developing processing unit SD1,
While sequentially moving to SD2, the heat treatment section HP3 or HP4, and the cooling processing section CP4, in each of the substrate processing sections, the substrate that has entered earlier is taken out, and the substrate to be processed is put in, and the respective substrate processing is performed. A required process is performed on the substrate by the unit. Thus, a resist film having a desired pattern is formed on the surface of the substrate. The substrate on which the resist film having the desired pattern is formed is transferred from the transport unit TR to the indexer unit ID.
To the cassette on the indexer unit ID.

As described above, in the substrate processing using the chemically amplified resist, the time required for the heat treatment in the bake portion PEB after exposing the substrate by the exposure apparatus ST,
If the time until the cooling processing in the cooling processing unit CP3 and the time until the development processing in the developing processing units SD1 and SD2 vary between the substrates, the cross-linking reaction or the decomposition reaction progresses between the substrates. Variations will occur.
As a result, the line width of the pattern on the resist film formed on the surface of the substrate by the development process varies between the substrates. For this reason, the respective times from the exposure of the substrate to the heat treatment in the PEB, to the cooling treatment in the cooling treatment unit CP3, and to the development treatment in the development treatment units SD1 and SD2 are accurately determined between the substrates. The time management of the substrate processing and the substrate transfer is performed so as to match.

[0008]

However, looking at each of the substrates, when the chip patterns are sequentially printed on the entire surface of the resist film on the substrate surface by the stepper in the exposure apparatus ST, after each chip pattern is printed. Conventionally, no consideration has been given to variations in the time until the development processing in the development processing sections SD1 and SD2. For this reason, there is a problem that the line width of the pattern on the resist film formed on the surface of the substrate by the developing process varies between the chip pattern baking areas in one substrate. With the recent increase in the size of substrates, the time difference between the time when the first chip pattern is printed on one substrate and the time when the last chip pattern is printed tends to increase. In order to improve the line width uniformity of a pattern in the plane of one substrate, the time difference has become a factor that cannot be ignored.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and when a resist pattern is developed after a chip pattern is sequentially printed on a resist film formed on the surface of a substrate, the resist film is formed. To provide a substrate processing method capable of improving the line width uniformity of a pattern on a resist film formed on the surface of one substrate after a development process by reducing the influence of the baking order of the chip patterns. Aim.

[0010]

The invention according to claim 1 is
In a substrate processing method, a chip pattern is sequentially printed on a resist film formed on a surface of a substrate, and a developing solution is supplied from a developing solution supply nozzle to the resist film on the substrate surface to develop the resist film. When developing the resist film of the above, the developer supply nozzle is moved along the substrate from the baking start side of the chip pattern to the resist film on the substrate surface toward the baking end side, and the resist film on the substrate surface is It is characterized in that the developer is supplied in a scanning manner.

According to a second aspect of the present invention, in the substrate processing method of the first aspect, the resist film formed on the surface of the substrate is a chemically amplified resist film, and after the substrate is exposed, heat-treated and then developed. It is characterized by.

According to the substrate processing method of the first aspect of the present invention, during the development processing, the resist film formed on the substrate surface is moved from the side where the baking of the chip pattern is started to the side where the baking is completed. Since the developing solution is sequentially supplied so as to scan, development is started from an area where the chip pattern is baked first on the resist film in a plane of one substrate, and then developed to an area where the chip pattern is baked later. The start time is delayed. Therefore, the variation in the time from the baking of the chip pattern to the start of the developing process over the entire surface of one substrate is reduced, and the order of baking the chip pattern on the resist film causes the resist pattern to be formed on the surface of the substrate after the developing process. Is less affected by the line width uniformity of the pattern.

[0013] In the substrate processing method according to the second aspect of the present invention,
On the entire surface of the chemically amplified resist film formed on the surface of one substrate, the variation in the time from the baking of the chip pattern to the start of the development process through the heat treatment is reduced, and the progress of the crosslinking reaction or decomposition reaction proceeds. Variation in condition is suppressed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS.

First, FIG. 3 is a schematic diagram showing an example of the entire configuration of an apparatus used to carry out the substrate processing method according to the present invention. In this example, as in the apparatus shown in FIG. 5, the entire apparatus is composed of a substrate processing apparatus 10 and an exposure apparatus ST, and the substrate processing apparatus 10 also has an indexer unit I.
D, a transport unit TR, a substrate processing area 12, and an interface unit IF. Further, the substrate processing area 12 also has the same structure as the substrate processing apparatus 1 shown in FIG.
Coating processing part SC, adhesion part AH, four heating processing parts HP1 to HP4, baking part PEB, four cooling processing parts CP1 to CP4, and two development processing parts SD
1 and SD2. In the substrate processing area 12, an orientation flat alignment unit OF for aligning the orientation flat of the substrate in a predetermined direction is further disposed.

Next, referring to FIG. 1, the development processing sections SD1, SD1
An example of the configuration of the spin developer installed in No. 2 will be described. The spin developer develops the substrate,
Thereafter, it is a device that sequentially performs a rinsing process (cleaning process) and a spin dry process, and has a developing solution supply mechanism for supplying a developing solution to the surface of the substrate and a cleaning solution supply mechanism for supplying a cleaning solution to the surface of the substrate. However, in FIG. 1, the illustration of the cleaning liquid supply mechanism is omitted, and the description thereof is omitted in this specification.

The spin developer 14 is a spin chuck 1 for holding a substrate W having an exposed resist film, for example, a chemically amplified resist film on its surface, in a horizontal position.
6. A rotating shaft 18 vertically suspended at the center of the lower surface of the spin chuck 16 and rotatably supporting the spin chuck 16 around a vertical axis. The substrate W held by the spin chuck 16 by rotating the rotating shaft 18 A spin motor 20 for rotating the substrate W about a vertical axis, and a spin chuck 16 for collecting a cleaning solution or the like scattered from above the substrate W to the periphery.
A cup 22 is provided so as to surround the side and the lower side of the substrate W held in the box 22, and is supported so as to be able to move up and down (a support mechanism and an elevation drive mechanism are not shown). Further, the spin developer 14 includes a development supply mechanism 24 that supplies a developer to the surface of the substrate W.

The developer supply mechanism 24 includes the spin chuck 1
6 has a developing solution discharge nozzle 26 for discharging the developing solution to the surface of the substrate W held by 6. The discharge nozzle 26 is shown in FIG.
Has a rod shape extending in a direction perpendicular to the paper surface of
As shown in the plan view of FIG. 2, the lower end surface thereof has a slit shape longer than the diameter of the substrate W (FIG. 2 shows only the discharge nozzle 26 and the substrate W and omits other members). It has a discharge port 28. Then, the discharge nozzle 26
Is connected to the developing solution supply source, and discharges the developing solution sent from the developing solution supply source to the surface of the substrate W through the slit-like discharge port 28 at the lower end surface.

The developing solution supply mechanism 24 has a nozzle horizontal movement mechanism for reciprocating the discharge nozzle 26 along the substrate W in a horizontal direction orthogonal to the longitudinal direction.
The nozzle horizontal moving mechanism includes a driving motor 32 fixed to the lifting frame 30, a driving pulley 34 fixed to the rotating shaft of the driving motor 32, and a horizontal extending from the lifting frame 30 in a horizontal direction integrated with the lifting frame 30. A driven pulley 38 rotatably supported by a distal end portion of the frame 36;
8, the discharge belt 26 is connected to a part of the timing belt 40. When the drive motor 32 is driven to rotate forward and backward, the timing belt 40 rotates and the discharge nozzle 26 connected to the timing belt 40 reciprocates in the horizontal direction. Further, the developing solution supply mechanism 24 is provided with a nozzle raising / lowering drive unit 42 for reciprocating the discharge nozzle 26 and the nozzle horizontal moving mechanism in the vertical direction. 26 and the nozzle horizontal movement mechanism are retracted to the upper position.

When supplying the developing solution to the surface of the substrate W by the developing solution supply mechanism 24, the substrate W is kept stationary without driving the spin motor 20, and the cup 22 is lowered. Then, the discharge nozzle 26 is arranged near the substrate W as shown in FIGS. 1 and 2, and the discharge nozzle 26 is moved from that position to a position where the discharge nozzle 26 passes above the substrate W and deviates from above the substrate W by the nozzle horizontal movement mechanism. The developer sent from the developer supply source to the discharge nozzle 26 is discharged from the slit-like discharge port 28 of the discharge nozzle 26 while moving the developer 26 in the direction of the arrow a (see FIG. 2) perpendicular to the longitudinal direction. Thus, the developing solution is supplied to the surface of the substrate W in a scanning manner, and a film-like developing solution layer is formed (a liquid level) on the entire surface of the substrate W. When the developing solution layer is formed on the entire surface of the substrate W, the cup 22 is raised, the substrate W is kept still for a predetermined time, and the exposed resist film formed on the surface of the substrate W is developed. It is processed. And
After a lapse of a predetermined time after the developer layer is formed on the entire surface of the substrate W, the spin motor 20 is driven to rotate the substrate W around a vertical axis, a rinsing process is performed, and then a spin dry process is performed.

Next, FIG. 4 shows a substrate processing flow in the substrate processing apparatus 10 and the exposure apparatus ST shown in FIG. After the unprocessed substrates stored in the cassette are supplied one by one to the transport unit TR from the indexer unit ID, the substrates are heated by the bake unit PEB, and then the cooling unit C
The procedure up to the step of cooling the substrate at P3 is exactly the same as the processing flow of the substrate shown in FIG. In this processing flow, the substrate that has completed the cooling processing in the cooling processing unit CP3 is transferred from the cooling processing unit CP3 to the orientation flat alignment unit OF by the substrate transfer robot. Then, in the orientation flat alignment unit OF,
The substrate is rotated in a horizontal plane such that the orientation flat always faces a predetermined direction. The substrate with the orientation of the orientation flat adjusted to a predetermined direction is transported by the substrate transport robot from the orientation flat alignment unit OF to the development processing units SD1 and SD2, and the previously entered substrate is taken out at the development processing units SD1 and SD2. It is put in later and developed.

In the developing units SD1 and SD2, the developing solution is supplied to the entire surface of the substrate W by the developing solution supply mechanism 24 as described above, and the liquid is built up. Thus, the supply of the developing solution is performed in a time series in which the chip pattern is printed on the resist film on the surface of the substrate W. That is, since the orientation of the substrates fed into the development processing units SD1 and SD2 is adjusted by the orientation flat alignment unit OF such that the orientation of the orientation flats is always a predetermined direction, the substrates are held on the spin chuck 16 of the spin developer 14. The substrate W is
The orientation flat F always faces a predetermined direction. At this time, as shown in FIG. 2, in the exposure apparatus ST, an area S (on the opposite side of the orientation flat F) where the chip pattern has been printed on the substrate W planting resist film by the stepper is located at the movement start position of the developer discharge nozzle 26. The orientation of the substrate W is adjusted by the orientation flat aligning unit OF such that the area E (the orientation flat F side) which is closest to the position and where the chip pattern printing is completed is located farthest from the movement start position of the developer discharge nozzle 26. To keep. Two-dot chain line 4 in FIG.
4 shows the order of baking the chip pattern on the resist film on the surface of the substrate W.

As shown in FIG. 2, the substrate W is held stationary by the pin chuck 16, and the developing solution is discharged from the slit-shaped discharge port 28 of the discharge nozzle 26 while moving the discharge nozzle 26 in the direction of arrow a. When a developing solution is supplied to the resist film on the surface of the substrate W in a scanning manner, development is started from an area where the chip pattern is first printed on the resist film in the surface of one substrate W, and the chip pattern is printed later. The more the area becomes, the later the development starts. As a result, the variation in the time from the chip pattern baking to the start of the developing process on the entire surface of one substrate W is reduced, and the area between the area S and the area E from the chip pattern baking to the start of the developing process is reduced. The time difference is reduced. The substrate W thus developed is sequentially moved to the heat treatment unit HP3 or HP4 and the cooling unit CP4, and is transferred from the transport unit TR to the indexer unit I.
D and stored in the cassette on the indexer ID.

In the above-described embodiment, the orientation processing unit OF is provided in the substrate processing area 12 of the heat treatment apparatus 10.
And the orientation of the substrate carried out from the exposure apparatus ST is always fixed by adjusting the orientation of the substrate before entering the developing units SD1 and SD2 by the orientation flat alignment unit OF. Therefore, the substrate is transported directly from the cooling processing unit CP3 to the development processing units SD1 and SD2 without being provided with the orientation flat alignment unit OF, and is loaded into the development processing units SD1 and SD2 and the spin developer 14
The substrate W placed on the spin chuck 16 is constantly rotated around the vertical axis by a fixed angle, for example, 90 ° by driving the spin motor 20, and the substrate W is stopped in a state as shown in FIG. You may make it do. Further, the exposure apparatus S
Since it is known that the direction of baking of the chip pattern on the substrate carried out from T is always constant, the present invention can be applied to processing of a substrate without an orientation flat.

[0025]

According to the substrate processing method of the present invention, when the resist film is developed after the chip patterns are sequentially printed on the resist film formed on the surface of the substrate, the entire surface of one substrate is processed. Since the variation in the time from the baking of the chip pattern to the start of the development processing is reduced, the influence of the baking order of the chip pattern on the resist film is reduced, and the resist film formed on the surface of one substrate after the development processing is reduced. The line width uniformity of the pattern can be improved.

In the substrate processing method according to the second aspect of the present invention,
On the entire surface of the chemically amplified resist film formed on the surface of one substrate, the variation in the time from the baking of the chip pattern to the start of the development process through the heat treatment is reduced, and the progress of the crosslinking reaction or decomposition reaction proceeds. Since the occurrence of variation in the condition is suppressed, the line width uniformity of the pattern on the resist film formed on the surface of one substrate after the development processing can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration example of a spin developer installed in a development processing unit of a development processing apparatus used to carry out a substrate processing method according to the present invention.

FIG. 2 is a plan view showing only a developer discharge nozzle and a substrate of the spin developer shown in FIG. 1;

FIG. 3 is a schematic view showing an example of the entire configuration of an apparatus used to carry out the substrate processing method according to the present invention.

4 is a diagram showing a processing flow of a substrate in the substrate processing apparatus and the exposure apparatus shown in FIG.

FIG. 5 is a schematic diagram showing a configuration example of an apparatus for processing a substrate using a chemically amplified resist.

6 is a diagram showing a processing flow of the substrate in the substrate processing apparatus and the exposure apparatus shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Substrate processing apparatus ST Exposure apparatus 12 Substrate processing area SC Coating processing part SD1, SD2 Development processing part PEB Heat processing part (baking part) OF orientation flat alignment unit 14 Spin developer 16 Spin chuck 18 Rotation support shaft 20 Spin motor 22 Cup 24 Development Liquid supply mechanism 26 Developing solution discharging nozzle 28 Slit-shaped discharging opening of developing solution discharging nozzle 30 Elevating frame 32 Drive motor 34, 38 Pulley 36 Horizontal frame 40 Timing belt 42 Nozzle elevating driving unit 44 Chip pattern on resist film on substrate surface Line indicating the order of baking

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Imanishi 322 Hahazushi Furukawa-cho, Fushimi-ku, Kyoto-shi Dainichi Screen Manufacturing Co., Ltd. Dainichi Screen Manufacturing Co., Ltd. (72) Inside the Rakusai Office (72) Inventor Yoichi Nishimura Kyoto City 322 Hashinashi Furukawacho Dainichi Screen Manufacturing Co., Ltd.Rakusai Office

Claims (2)

[Claims] 1. A substrate processing method for developing a resist film by sequentially printing a chip pattern on a resist film formed on a surface of the substrate and then supplying a developing solution to the resist film on the substrate surface from a developing solution supply nozzle. In developing the resist film on the surface of the substrate, the developer supply nozzle is moved along the substrate from the start of baking of the chip pattern to the resist film on the substrate surface toward the end of baking, and And supplying a developing solution to the resist film in a scanning manner. 2. The substrate processing method according to claim 1, wherein the resist film formed on the substrate surface is a chemically amplified resist film, and after the substrate is exposed, heat-treated and then developed.