JP2003209036A - Resist coating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist coating device capable of controlling an amount of residual solvent, which causes the fluctuation of the width of a line. <P>SOLUTION: A resist coating unit (COT) is equipped with a spin chuck 71 rotating while retaining a wafer W, a cup 72 surrounding the spin chuck 71, and a resist liquid supply nozzle 73 supplying resist liquid to the wafer W. In the resist coating unit, a plurality of solvent gas supply nozzles 80 capable of supplying solvent gas toward different concentric circles on the surface of the wafer W, mixers 85 capable of adjusting the concentration of the solvent gas supplied by the solvent gas supply nozzles 80 and opening and closing valves V3, for example, capable of adjusting the amount of the solvent gas supplied from the solvent gas supply nozzles 80, are provided to control the vaporizing speed of residual solvent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist coating apparatus capable of controlling the quality of a resist film formed on the surface of a substrate to be processed such as a semiconductor wafer.

[0002]

2. Description of the Related Art Generally, in the process of manufacturing a semiconductor wafer, a resist pattern is formed on the surface of a semiconductor wafer, LCD substrate or the like (hereinafter referred to as wafer).
Photolithography technology is used. This photolithography technique involves a resist film forming step of supplying (discharging and coating) a resist solution on the surface of a wafer or the like, an exposure step of exposing a circuit pattern to the formed resist film, and a post-exposure step. Developing process of supplying (discharging, applying) a developing solution to the wafer or the like.

In order to improve the adhesion between the wafer and the resist film by evaporating the residual solvent in the resist film, which is carried out between the resist coating process and the exposure processing process, for example, between the above processing steps. Heat treatment {prebake (PAB)}, or to prevent fringes that occur between the exposure processing step and the development processing step, or a chemically amplified resist (CAR).
heat treatment for inducing an acid-catalyzed reaction in ist) (post-exposure bake (PEB)), a residual solvent (residual solvent) in the resist and a rinse liquid taken into the resist during development, which is performed after the development processing step. And various heat treatments such as a heat treatment (post-baking) for improving the penetration during wet etching.

In the photolithography process, as the circuit pattern and the line width (CD) are miniaturized, the in-wafer uniformity (CD uniformity) of the pattern line width is strictly required, and the pattern size is greatly affected. In addition to the developing process and the PEB process, which are said to give the above, it is required to improve the line width variation factor in the process before exposure.

Therefore, conventionally, the line width variation has been improved by improving the film thickness uniformity of the resist film formed on the wafer surface.

[0006]

However, in recent years,
Even if the film thickness of the resist film is uniform, for example, the amount distribution of the resist constituents such as the amount of solvent remaining in the resist film, the ratio distribution difference of the protective groups in the resist, the difference in the aggregation state of the polymer in the resist, etc. Line width changes due to differences in chemical and physical properties (hereinafter referred to as film quality) of the resist film. Line width fluctuation due to film quality change is confirmed, and it is very important to improve the uniformity of resist film quality. Has become.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resist coating apparatus capable of controlling the amount of residual solvent (the amount of residual solvent) that affects the uniformity of film quality.

[0008]

In order to achieve the above object, the first resist coating apparatus of the present invention comprises a holding means for holding and rotating a substrate to be processed, and a processing container surrounding the holding means. In a resist coating apparatus comprising a resist liquid supply means for supplying a resist liquid to the substrate to be processed, in a different concentric circle of the surface of the substrate to be processed,
A plurality of solvent gas supply means capable of supplying a solvent gas containing the solvent of the resist solution, a solvent concentration adjusting means capable of adjusting the solvent concentration of the solvent gas supplied by the solvent gas supply means, and the solvent gas supply means A supply amount adjusting means capable of adjusting the supply amount of the solvent gas to be supplied is provided (Claim 1). Here, the solvent gas means a solvent (solvent) of the resist liquid that is volatilized into an inert gas. In this case, it is preferable that the solvent gas supply means is provided in the processing container or a nozzle arm that can move back and forth in the processing container (claims 2 and 3).

Further, the second resist coating apparatus of the present invention comprises a holding means for holding and rotating the substrate to be processed, a processing container surrounding the holding means, and a resist for supplying a resist solution to the substrate to be processed. In a resist coating apparatus including a liquid supply means, a top plate having different thicknesses is provided on the lower surface side on different concentric circles above the holding means (claim 4).

Further, the third resist coating apparatus of the present invention is such that a holding means for holding and rotating the substrate to be processed, a processing container surrounding the holding means, and a resist for supplying a resist solution to the substrate to be processed. In a resist coating apparatus provided with a liquid supply means, a top plate having different aperture ratios on different concentric circles is provided above the holding means (claim 5). In this case, it is preferable that the top plate has different thicknesses on the lower surface side on different concentric circles (claim 6).

In the second and third resist coating apparatuses according to the present invention, it is preferable to provide a ceiling plate elevating means capable of relatively elevating the holding means and the ceiling plate (claim 7). Further, it is preferable to provide a top plate temperature adjusting means capable of adjusting the temperature of the top plate on different concentric circles (claim 8).

Further, a fourth resist coating apparatus of the present invention is a resist means for holding and rotating a substrate to be processed, a processing container surrounding the holding means, and a resist for supplying a resist solution to the substrate to be processed. In a resist coating apparatus including a liquid supply means, a plurality of gap forming means for forming a constant gap on the substrate to be processed and the plurality of gap forming means are respectively arranged horizontally in the radial direction on the substrate to be processed. It is characterized in that movable position adjusting means and space adjusting means capable of adjusting the size of the gap formed by the plurality of gap forming means are provided (claim 9). In this case, it is preferable to provide a gap temperature adjusting means capable of adjusting the temperature of the gap forming means (claim 10).

The fifth resist coating apparatus of the present invention is a resist for supplying a resist solution to the substrate to be processed, a holding means for holding and rotating the substrate to be processed, a processing container surrounding the holding means. In a resist coating apparatus including a liquid supply unit, an air cleaning unit that is divided into a plurality of regions and can supply clean air toward the surface of the substrate to be processed, and a temperature of the air supplied by the air cleaning unit. , A plurality of air temperature adjusting means adjustable for each region, a plurality of temperature detecting means capable of detecting the temperature in the vicinity of the surface on different concentric circles of the substrate to be processed, the detection signal detected by the temperature detecting means And control means for controlling the air temperature adjusting means on the basis of information stored in advance (claim 11). In this case, it is preferable to provide an elevating / lowering means for the air cleaning means capable of relatively elevating / lowering the holding means and the air cleaning means (claim 12).

According to the present invention, the rate of volatilization of the residual solvent (residual solvent) on the substrate to be processed can be controlled, so that the amount of residual solvent on the surface of the substrate to be processed can be made uniform.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic plan view of one embodiment of a resist solution coating / developing system, FIG. 2 is a front view of FIG. 1, and FIG.
FIG. 3 is a rear view of FIG.

In the above processing system, a plurality of semiconductor wafers W (hereinafter referred to as wafers W) as substrates to be processed are transferred into or out of the system from the outside in units of a plurality of wafer cassettes, for example, 25 wafers, or transferred to the wafer cassette 1. On the other hand, a cassette station 10 (conveying section) for carrying out and carrying in the wafer W, and various single-wafer processing units for performing a predetermined process on the wafer W one by one in a coating / developing process are set at predetermined positions. A processing station 20 including a plurality of processing apparatuses of the present invention, and an exposure apparatus 40 (EXP) provided adjacent to the processing station 20.
A main part is constituted by an interface part 30 for transferring the wafer W between the and.

In the cassette station 10, as shown in FIG. 1, a plurality of wafer cassettes 1, for example, up to four wafer cassettes 1 are provided at the positions of the protrusions 3 on the cassette mounting table 2, with their respective wafer entrances and exits facing the processing station 20 side. Wafer transfer which is placed in a row along the horizontal X direction and is movable in the wafer arrangement direction (Z direction) of the wafers W accommodated in the cassette arrangement direction (X direction) and in the wafer cassette 1 along the vertical direction. The tweezers 4 are configured to be selectively transported to each wafer cassette 1. Further, the wafer transfer tweezers 4 are configured to be rotatable in the horizontal θ direction, and the third set G on the side of the processing station 20 described later.
Alignment unit (A
LIM) and extension unit (EXT) can also be transported.

As shown in FIG. 1, the processing station 20 is provided with a vertical transfer type main wafer transfer mechanism 21 at the center thereof, and a chamber 22 for accommodating the main wafer transfer mechanism 21.
All the processing units are arranged in a multi-stage around one set or a plurality of sets. In this example, 5 sets G1, G
2, G3, G4 and G5 are arranged in multiple stages, the first and second sets G1 and G2 of the multistage units are arranged in parallel on the front side of the system (front side in FIG. 1), and the third set of G3 multistage units are The multistage unit of the fourth group G4 is arranged adjacent to the cassette station 10, the multistage unit of the fourth group G4 is arranged adjacent to the interface portion 30, and the multistage unit of the fifth group G5 is arranged on the back side.

In this case, as shown in FIG. 2, the first set G
In the first example, the wafer W is placed on the spin chuck 71 (holding means) (see FIG. 4) in the cup 23 (processing container) to perform a predetermined process, for example, on the surface of the wafer W. A resist coating unit (COT) {resist coating device} for supplying a resist solution to form a resist film and a developing unit (DEV) for supplying a developing solution to the surface of the wafer W to perform a developing process are vertically arranged in two stages. Are overlaid on. Similarly, in the second group G2, two spinner type processing units, for example, a resist coating unit (COT) and a developing unit (DEV) are stacked in two stages in order from the bottom in the vertical direction. In this way, the resist coating unit (C
The reason for disposing the OT) on the lower side is that draining of the resist solution is troublesome both mechanically and in terms of maintenance. However, if necessary, a resist coating unit (CO
It is also possible to arrange T) in the upper stage.

As shown in FIG. 3, in the third group G3, an oven type processing unit for mounting the wafer W on the wafer mounting table 24 and performing a predetermined process, for example, a cooling unit (COL) for cooling the wafer W. , An adhesion unit (AD) for hydrophobicizing the wafer W, an alignment unit (ALIM) for aligning the wafer W, and an extension unit (EX for loading / unloading the wafer W).
T), four hot plate units (HP) for baking the wafer W are sequentially stacked from the bottom in the vertical direction in eight stages, for example. Similarly, the fourth set G4 is also an oven type processing unit such as a cooling unit (COL), an extension cooling unit (EXTCOL), an extension unit (EXT), a cooling unit (COL), and two chilling hot plate units having a quenching function. (CHP) and two hot plate units (HP) are stacked, for example, in eight stages from the bottom in the vertical direction.

As described above, the cooling unit (COL) having a low processing temperature and the extension cooling unit (EXTCOL) are arranged in the lower stage, and the hot plate unit (HP), the chilling hot plate unit (CHP) and the add unit having a high processing temperature are arranged. By arranging the fusion unit (AD) in the upper stage, it is possible to reduce thermal mutual interference between the units. Of course, it is also possible to make a random multi-stage arrangement.

As shown in FIG. 1, in the processing station 20, the third and fourth groups G3 and G4 adjacent to the multistage unit (spinner type processing unit) of the first and second groups G1 and G2 are arranged. Ducts 65 and 66 are vertically provided in the side wall of the multi-stage unit (oven type processing unit). These ducts 6
Downflow clean air or specially temperature-controlled air is made to flow through the valves 5, 66. With this duct structure, the heat generated in the oven type processing units of the third and fourth groups G3 and G4 is blocked and does not reach the spinner type processing units of the first and second groups G1 and G2. ing.

Further, in this processing system, the multistage unit of the fifth group G5 can be arranged on the back side of the main wafer transfer mechanism 21 as shown by the dotted line in FIG.
The multi-stage unit of the fifth group G5 can move laterally along the guide rail 67 as viewed from the main wafer transfer mechanism 21. Therefore, even when the multistage unit of the fifth group G5 is provided, the space is secured by sliding the unit, so that the main wafer transfer mechanism 21
The maintenance work can be easily performed from behind.

The interface section 30 has the same dimensions as the processing station 20 in the depth direction,
It is made small in the width direction. A portable pickup cassette 31 and a stationary buffer cassette 32 are arranged in two stages on the front surface of the interface portion 30, a peripheral exposure device 33 is arranged on the rear surface, and a wafer is formed in the central portion. A transfer arm 34 is provided.

The wafer transfer arm 34 is configured to move in the X and Z directions and transfer it to both the cassettes 31, 32 and the peripheral exposure device 33. Further, the wafer transfer arm 34 is configured to be rotatable in the θ direction, and the extension unit (EXT) belonging to the multistage unit of the fourth group G4 on the processing station 20 side and the adjacent exposure apparatus 4 are included.
The wafer transfer table (not shown) on the 0 (EXP) side can also be carried.

The processing system configured as described above is
Although it is installed in the clean room 50, the cleanliness of each part is enhanced by the efficient vertical laminar flow system in the system.

Next, the operation of the above processing system will be described. First, in the cassette station 10, the wafer transfer tweezers 4 access the cassette 1 containing the unprocessed wafer W on the cassette mounting table 2,
One wafer W is taken out from the cassette 1. When the wafer W is taken out of the cassette 1, the wafer transfer tweezers 4 is arranged in the alignment unit (A) arranged in the multistage unit of the third set G3 on the processing station 20 side.
The wafer W is placed on the wafer mounting table 24 in the unit (ALIM). The wafer W undergoes orientation flat alignment and centering on the wafer mounting table 24. Then, the main wafer transfer mechanism 21 accesses the alignment unit (ALIM) from the opposite side and receives the wafer W from the wafer mounting table 24.

In the processing station 20, the main wafer transfer mechanism 21 first carries the wafer W into the adhesion unit (AD) belonging to the multistage unit of the third group G3. The wafer W is subjected to a hydrophobizing process in this adhesion unit (AD). When the hydrophobic treatment is completed, the main wafer transfer mechanism 21 carries the wafer W out of the adhesion unit (AD), and then the third group G3 or the fourth group G3.
It is carried into the cooling unit (COL) belonging to the multi-stage unit of the group G4. This cooling unit (CO
In L), the wafer W is cooled to a set temperature before the resist coating process, for example, 23 ° C. When the cooling process is completed, the main wafer transfer mechanism 21 carries the wafer W out of the cooling unit (COL), and then the resist coating unit (C) belonging to the multi-stage unit of the first group G1 or the second group G2.
OT). This resist coating unit (CO
In T), the wafer W is coated with a resist having a uniform film thickness on the wafer surface by a spin coating method.

When the resist coating process is completed, the main wafer transfer mechanism 21 transfers the wafer W to the resist coating unit (C
OT), then the hot plate unit (H
P). The wafer W is mounted on the mounting table in the hot plate unit (HP) and kept at a predetermined temperature, for example, 10
Prebaking is performed at 0 ° C. for a predetermined time. by this,
The residual solvent (solvent) can be removed by evaporation from the coating film on the wafer W. When the pre-baking is completed, the main wafer transfer mechanism 21 transfers the wafer W to the hot plate unit (H
P), and then an extension cooling unit (EXTC) belonging to the multi-stage unit of the fourth group G4.
Transport to OL). In this unit (COL), the wafer W is cooled to a temperature suitable for the next step, that is, the peripheral exposure processing in the peripheral exposure apparatus 33, for example, 24 ° C. After this cooling, the main wafer transfer mechanism 21 transfers the wafer W to the extension unit (EXT) immediately above, and the wafer W is placed on a mounting table (not shown) in this unit (EXT).
To place. This extension unit (EXT)
When the wafer W is placed on the table, the wafer transfer arm 34 of the interface unit 30 is accessed from the opposite side to receive the wafer W. Then, the wafer transfer arm 34 carries the wafer W into the peripheral exposure apparatus 33 in the interface section 30. Here, the wafer W is exposed to the edge portion. It is also possible to provide a film thickness measuring device in the peripheral exposure device 33, measure the film thickness of the wafer W regularly, and inspect the film thickness uniformity or the film quality uniformity.

When the peripheral exposure is completed, the wafer transfer arm 34 carries the wafer W out of the peripheral exposure apparatus 33 and transfers it to a wafer receiving table (not shown) on the adjacent exposure apparatus 40 (EXP) side. In this case, the wafer W is exposed to the exposure device 4
It may be temporarily stored in the buffer cassette 32 before being transferred to 0 (EXP).

When the wafer W is returned to the wafer receiving table on the side of the exposure apparatus 40 (EXP) after the exposure of the entire surface by the exposure apparatus 40 (EXP), the wafer transfer arm 34 of the interface unit 30 is moved to the wafer receiving table. To receive the wafer W, carry the received wafer W into the extension unit (EXT) belonging to the multistage unit of the fourth group G4 on the processing station 20 side, and place it on the wafer receiving table. Also in this case, the wafer W may be temporarily stored in the buffer cassette 32 in the interface unit 30 before being transferred to the processing station 20 side.

Wafer W placed on the wafer receiving table
Is transferred to the chilling hot plate unit (CHP) by the main wafer transfer mechanism 21 to prevent the generation of fringes, or is chemically amplified resist (CAR).
A post-exposure bake (PEB) treatment is carried out to induce the acid-catalyzed reaction in.

After that, the wafer W is transferred to the developing unit (DE) belonging to the multistage unit of the first group G1 or the second group G2.
V). In this developing unit (DEV), the wafer W is placed on a spin chuck, and the developing solution is evenly applied to the resist on the surface of the wafer W by, for example, a spray method. When the development is completed, the rinse liquid is applied to the surface of the wafer W and the developer is washed off.

When the developing process is completed, the main wafer transfer mechanism 21 carries the wafer W out of the developing unit (DEV) and then the hot plate unit belonging to the multistage unit of the third group G3 or the fourth group G4. Carry in to (HP).
In this unit (HP), the wafer W is post-baked at 100 ° C. for a predetermined time. As a result, the resist swollen by development is cured and chemical resistance is improved.

After the post bake is completed, the main wafer transfer mechanism 21 transfers the wafer W to the hot plate unit (H
P) and then to any cooling unit (COL). Here, after the wafer W has returned to room temperature, the main wafer transfer mechanism 21 then transfers the wafer W to the extension unit (EXT) belonging to the third set G3. When the wafer W is mounted on the mounting table (not shown) of the extension unit (EXT), the wafer transfer tweezers 4 on the cassette station 10 side is accessed from the opposite side to receive the wafer W. And
The wafer transfer tweezers 4 inserts the received wafer W into a predetermined wafer accommodation groove of the cassette 1 for accommodating the processed wafer on the cassette mounting table, and the processing is completed.

Next, the structure of the resist coating unit (COT) {resist coating device} in the present invention will be described.

The resist coating unit (COT) is shown in FIG.
As shown in FIG. 2, for example, a spin chuck 71 (holding means) that spins and holds the wafer W, a cup 72 (processing container) that surrounds the outer side and the lower side of the spin chuck 71, and has an upper opening, and a spin chuck. The resist liquid supply nozzle 73 (resist liquid supply means) is movable mainly to a position above 71 and is capable of supplying (discharging and coating) the resist liquid to the wafer W.

The spin chuck 71 is formed of, for example, a heat-resistant synthetic resin material made of polyether ether ketone (PEEK), and a mounting portion 71a capable of holding the lower surface of the wafer W by vacuum suction and the mounting portion 71a. It is composed of a rotation shaft 71b which projects to the center of the lower surface of the mounting portion 71a and is connected to a rotation driving means such as a motor M. In this case, the motor M is
For example, it is formed of a servo motor, and the number of rotations is controlled based on a preprogrammed signal. Further, the rotation shaft 71b is configured to move in the vertical direction by driving an elevating cylinder (not shown) or the like so that the wafer W can be delivered to and received from the main wafer transfer mechanism 21.

The cup 72 is formed of, for example, a stainless steel member and has a tapered surface 72b whose upper portion of the side wall 72a is reduced in diameter toward the upper side.

The resist solution supply nozzle 73 is connected to a resist solution supply source 76 for storing the resist solution via a resist solution supply conduit 74. Further, the resist solution supply pipeline 74 is provided with an opening / closing valve V1, a pumping means such as a pump 75 for pumping the resist solution, and a supply amount of the resist solution supplied to the surface of the wafer W in order from the resist solution supply source 76 side. Adjustable resist solution supply amount adjusting means, for example, the mass flow controller C1 and the resist solution remaining in the supply section 73a of the resist solution supply nozzle 73 when the resist solution supply nozzle 73 stops the supply of the resist solution. A processing liquid suction means for suppressing liquid dripping from the port 73b, for example, a suck back valve SV is provided.

Further, the resist solution supply nozzle 73 is integrally formed with a solvent supply nozzle 77 capable of supplying a solvent for the resist solution at an adjacent position. This solvent supply nozzle 77
Is connected to a solvent tank 79 via a solvent supply pipe line 78, and controls the pressurization of nitrogen gas or the like supplied into the solvent tank 79 to remove the solvent in the solvent tank 79 from the solvent supply nozzle 77. It can be supplied to the surface of the wafer W. Further, the solvent supply conduit 78 is provided with a mass flow controller C2 capable of adjusting the amount of solvent supplied, and an opening / closing valve V2.
Is provided.

Next, the operation mode of the resist coating unit (COT) configured as described above will be described below.

When the wafer W is loaded by the main wafer transfer mechanism 21, the spin chuck 71 is lifted to the outside of the cup 72 by the lifting cylinder and holds the wafer W by vacuum suction.

Next, when the spin chuck 71 descends to a predetermined position in the cup 72, the wafer W on the spin chuck is
Is rotated at a speed lower than the steady rotation during processing by the motor drive, for example, 200 to 800 rpm, and the solvent is supplied from the solvent supply nozzle 77 onto the surface of the wafer W for a predetermined time, for example, 20 rpm.
It is supplied (dropped, applied) for 2 seconds. The solvent may be supplied while the wafer W is stationary without being rotated, and then the wafer W may be rotated.

After supplying the solvent in this manner, the supply of the solvent is stopped while the rotation speed of the spin chuck 71 is maintained at the low rotation speed. At this time, the solvent is diffused and applied to the entire surface of the wafer W.

Next, the spin chuck 71 is rotated at a high speed, for example, 1000 rpm, and at the same time, the resist liquid is supplied from the resist liquid supply nozzle 73 moved above the central portion of the wafer W for 8 seconds, for example, 8 cc (dripping, coating). And a resist film is formed.

Thereafter, in order to accelerate the drying of the resist film spread on the surface of the wafer W, the wafer W is rotated at a predetermined number of rotations for a certain time (hereinafter referred to as drying rotation), and then the rotation is stopped to apply the resist. The process ends. When the resist coating process is completed, the spin chuck 71 is lifted and the wafer W is transferred to the main wafer transfer mechanism 21 and transferred to the next step.

The resist coating apparatus of the present invention will be described below with reference to FIGS.

First Embodiment In the first embodiment of the present invention, in the resist coating unit (COT) configured as described above, the solvent gas is supplied (discharged and sprayed) onto different concentric circles on the surface of the wafer W. ) A plurality of possible solvent gas supply nozzles 80 (solvent gas supply means), a mixer 85 (solvent concentration adjustment means) capable of adjusting the solvent concentration of the solvent gas supplied by the solvent gas supply nozzle 80, and a solvent gas supply nozzle For example, a mass flow controller C3 capable of adjusting the supply amount of the solvent gas supplied by 80
(Supply amount adjusting means).

In this case, a plurality of solvent gas supply nozzles 80 are provided on the tapered surface 72b in the cup 72, for example, as shown in FIG. In addition, each solvent gas supply nozzle 8
0 is provided by adjusting the angle so that the solvent gas can be supplied toward different concentric circles on the surface of the wafer W.

As shown in FIG. 5, the mixer 85 is connected to the solvent supply source 83 via the opening / closing valve V3 and to the inert gas supply source 84 via the opening / closing valve V4. Heater with temperature control function (not shown)
The solvent is volatilized into an inert gas in a stable manner to generate a solvent gas. In addition, the mixer 85 is provided with, for example, a vaporization concentration control valve (not shown) capable of adjusting the concentration of the solvent contained in the solvent gas. The concentration of the contained solvent can be adjusted to a predetermined concentration that controls the volatilization of the residual solvent (remaining solvent) of the wafer W described later.

Further, the solvent gas supply nozzle 80 and the mixer 8
As shown in FIG. 5, 5 is connected by a solvent gas supply pipeline 82, and the solvent gas supply pipeline 82 can measure the flow rate (supply amount) of the solvent gas in order from the mixer 85 side. In addition, a mass flow controller C3 capable of adjusting the supply amount (flow rate) of the solvent gas and a pressure regulator 86 such as a regulator capable of adjusting the pressure of the solvent gas are provided.

The on-off valves V3, V4, the mixer 85, the pressure regulator 86, and the mass flow controller C3 are electrically connected to the control means, for example, the CPU 100, and have a predetermined residual solvent amount of the wafer W. Accordingly, the concentration of the solvent contained in the solvent gas, the pressure of the solvent gas, the flow rate (supply amount) of the solvent gas, and the like can be controlled.

By configuring the resist coating unit (COT) in this way, for example, when the volatilization rate of the residual solvent (residual solvent) in the central portion of the wafer W is smaller than the volatilization rate of the residual solvent in the peripheral portion. Supplies (sprays) a solvent gas with a low solvent concentration to the center to promote volatilization of residual solvent and supplies a solvent gas with a high solvent concentration to the periphery (spray).
By controlling the volatilization of the residual solvent, it is possible to control the volatilization rate of the residual solvent on the substrate to be volatilized during the drying rotation, so that the residual solvent amount on the surface of the substrate to be treated can be made uniform. You can That is, the film quality uniformity can be improved.

As shown in FIGS. 6 (a) and 6 (b),
The volatilization rate of the residual solvent in the resist film of the wafer W is not constant during the drying rotation, and becomes smaller with time, that is, as the residual solvent decreases.

On the other hand, as a result of earnest studies by the present inventors,
When the residual solvent amount after the drying rotation is uniform in the plane of the wafer W, the volatilization rate during the drying rotation in the plane, particularly the volatilization rate in the initial stage of the drying rotation, is set to a constant rate (ideally below. It was found that the film quality becomes more uniform when the evaporation rate is set).

Therefore, by controlling the concentration and supply amount of the solvent gas supplied by the solvent gas supply nozzle 80 during the drying rotation of the wafer W by the CPU 100, the uniformity of the film quality can be further improved.

For example, as shown in FIGS. 6A and 6B, when the volatilization rate is lower than the ideal volatilization rate (dashed line), the solvent gas supply nozzle 80 supplies the solvent to the surface of the wafer W. The solvent concentration of the gas is adjusted to 0% by the mixer 85, that is, only the inert gas, and
As indicated by the broken line in (d), the supply amount of the inert gas may be adjusted by the mass flow controller C3, and the volatilization rate may be increased so as to approach the ideal volatilization rate.

As shown in FIG. 6B, when the volatilization rate is higher than the ideal volatilization rate, the solvent concentration of the solvent gas supplied from the solvent gas supply nozzle 80 to the surface of the wafer W is set to the mixer 85. 6 and at the same time, as shown by the solid line in FIG. 6D, the supply amount of the solvent gas may be adjusted by the mass flow controller C3 to reduce the volatilization rate so as to approach the ideal volatilization rate.

With this structure, the volatilization rate in the initial stage of the drying rotation can be adjusted to the ideal volatilization rate, so that the film quality uniformity can be further improved.

In the above description, the case where the solvent gas supply nozzle 80 is provided on the tapered surface 72b in the cup 72 has been described, but the position at which the solvent gas supply nozzle 80 is provided is not limited to this, and the solvent gas supply nozzle 80 is moved forward and backward in and out of the cup 72. A plurality of movable nozzle arms 88 may be provided (see FIG. 7).

In this case, the nozzle arm 88 is connected to the cup 7
A moving means (not shown) composed of, for example, a motor and a ball screw mechanism capable of moving horizontally on the cup 2, and the cup 72
It may be configured with an elevating means (not shown) such as an air cylinder that can be moved up and down.

If the solvent gas supply nozzle 80 is provided with an angle adjusting means capable of adjusting the angle, the type of wafer W (shape, size, etc.) or the type of resist solution, or the wafer W being dried and rotated. Depending on the amount of the residual solvent, the angle of the solvent gas supply nozzle 80 can be changed for processing.

Next, regarding the resist film forming method when the solvent gas supply nozzle 80 is provided on the nozzle arm 88,
This will be described with reference to FIG.

First, when the wafer W is loaded into the cup 72, the nozzle arm 88 is temporarily kept outside the cup 72 to raise the spin chuck 71 in order to avoid interference with the main wafer transfer mechanism 21. Then, the wafer W is received from the main wafer transfer mechanism 21. The spin chuck 71 is
After sucking and holding the received wafer W, it descends into the cup 72 (FIG. 7A).

Next, the resist solution supply nozzle 73 is moved above the wafer W to supply the resist solution to the surface of the wafer W, and the spin chuck 71 is rotated to form a resist film {FIG. 7 (b). )}.

When the resist film is formed, the resist liquid supply nozzle 73 is moved from above the wafer W to a standby position (not shown), and the spin chuck 71 starts drying rotation. When the drying rotation is started, the nozzle arm 88 is moved above the wafer W {FIG. 7C}.

During the drying rotation, each solvent gas supply nozzle 80
Controls (controls) the volatilization rate of the residual solvent on the wafer W by supplying (discharging and spraying) solvent gases having different solvent concentrations toward different concentric circles on the surface of the wafer W based on a control signal from the CPU 100. 7 (d)}.

When the drying process is completed, the nozzle arm 88
Is withdrawn from the cup 72 {FIG. 7 (e)}, and the back surface of the edge portion of the wafer W is rinsed.

Thereafter, the spin chuck 71 is lifted, the wafer W is carried out of the resist coating unit (COT) by the main wafer transfer mechanism 21, and the resist coating process is completed.

Second Embodiment The second embodiment of the present invention is a resist coating unit (C
In OT), a top plate 90 having different bottom surface thicknesses on different concentric circles is provided above the spin chuck 71 to control the volatilization rate of the residual solvent.

For example, when the evaporation rate of the residual solvent at the peripheral portion of the wafer W during the drying rotation is higher than the evaporation rate of the residual solvent at the central portion, the wafer W is held by the spin chuck 71 as shown in FIG. On the wafer W, a top plate 90 having substantially the same shape as the wafer W having a tapered concave portion that widens toward the lower surface may be provided close to above the wafer W.

When the top plate 90 is constructed in this way, the space above the peripheral edge of the wafer W becomes narrower, so that the volatilized solvent is less likely to diffuse, the solvent concentration in the processing atmosphere increases, and the solvent volatilization rate is suppressed. To be done. On the other hand, since the space on the wafer W is large in the central portion of the wafer W, the volatilized solvent is easily diffused and the solvent concentration in the processing atmosphere does not become so high, so that the volatilization rate of the residual solvent is not suppressed. Therefore,
The amount of residual solvent on the surface of the wafer W can be made uniform by adjusting the volatilization rates of the central portion and the peripheral portion of the wafer W.

The top plate 90 may be detachably provided on a top plate transfer arm that can move back and forth in and out of the cup 72, or a lid body can be provided on the cup 72 and can be detached on the lower surface of the lid body. May be provided.

In this case, the top plate 90 is the solvent gas supply nozzle 8 held by the nozzle arm 88 of the first embodiment.
As in the case of 0, the wafer W is moved above the wafer W in the cup 72 during the drying rotation after the resist application, and after the drying rotation for a predetermined time, the wafer W is evacuated to the outside of the cup 72.

Further, the top plate 90 is not limited to the one formed in a tapered concave shape whose cross section widens toward the lower surface, and for example, the top plate 91 {where the lower surface side has a stepwise cross section and the central portion is formed thinnest. 9 (a)} is also possible. Further, when the evaporation rate of the residual solvent in the central portion of the wafer W during the drying rotation is higher than the evaporation rate of the residual solvent in the peripheral portion, the top plate formed into a tapered convex shape whose cross section is reduced in diameter toward the lower surface side. 92 (FIG. 9 (b)), or a top plate 93 {FIG. 9 (c)} whose lower surface side has a stepwise cross-section and whose center portion is thickest. Further, it is of course possible to adopt other various shapes, for example, the shape of the top plate 94 shown in FIG. 9D, depending on the amount of residual solvent or the evaporation rate of the resist film.

Further, the top plate 90 is provided with a top plate elevating means so that the top plate 90 can be moved up and down, and the top plate 9 is rotated during the drying rotation.
If the distance between 0 and the wafer W is adjusted, the volatilization rate can be controlled more reliably.

If the top plate 90 is provided with a top plate temperature adjusting means such as a heater so that the temperature on different concentric circles of the top plate can be adjusted, the center portion and the peripheral portion of the wafer W can be more surely removed. The volatilization rate can be controlled.

Third Embodiment The third embodiment of the present invention is a resist coating unit (C
In OT), a top plate 95 having different aperture ratios on different concentric circles is provided above the spin chuck 71 to control the volatilization rate of the residual solvent.

For example, when the evaporation rate of the residual solvent in the central portion of the wafer W during the drying rotation is lower than the evaporation rate of the residual solvent in the peripheral portion, as shown in FIG. High, for example, the aperture ratio is 10-40%
A porous material 95a, 95b having a certain degree is used, and a metal 9 such as aluminum or stainless steel having an opening ratio of 0% is used in the peripheral portion.
The top plate 95 using 5c may be provided on the wafer W held by the spin chuck 71.

By constructing the top plate 95 in this manner, the porous materials 95a, 95 are provided above the central portion of the wafer W.
Since the opening ratio of b is high, the volatilized solvent is
a and 95b can be transmitted and diffused,
Above the peripheral portion, the vaporized solvent is blocked by the metal 95c, so that the concentration of the solvent in the processing atmosphere becomes high. Therefore, the amount of residual solvent on the surface of the wafer W can be made uniform by adjusting the volatilization rate at the central portion and the peripheral portion of the wafer W.

In the above description, the case where the top plate 95 is made of a porous material and a metal has been described. However, the top plate 95 is not limited to this, and a metal top plate 95 such as aluminum or stainless steel may be used. It is also possible to provide a plurality of vent holes through which solvent vapor (solvent vapor) can pass and to use the vent holes having different numbers and sizes on different concentric circles.

Further, the aperture ratio of the top plate 95 can be freely changed according to the volatilization rate of the residual solvent. For example, the volatilization rate of the residual solvent in the central portion of the wafer W during the drying rotation is different from that in the peripheral portion. If the rate of volatilization of residual solvent is greater than,
It is also possible to form the aperture ratio of the central portion smaller than the aperture ratio of the peripheral portion.

Further, if the shape of the top plate 95 is formed so as to have different thicknesses on the lower surface side on different concentric circles, as in the second embodiment, the size of the space above the wafer W is changed so that it remains. The effect that the evaporation rate of the solvent can be controlled can be obtained {see FIG. 10 (b)}. Further, similarly to the second embodiment, it is of course possible to provide the top plate 95 with a top plate elevating means and a top temperature adjusting means.

Fourth Embodiment The fourth embodiment of the present invention is a resist coating unit (C
In OT), a plurality of blocks 110 (gap forming means) that form a certain gap on the wafer W, and a block 11
0 is a block arm 111 (position adjusting means) that can be horizontally moved in the radial direction on the wafer W, and a block elevating means 112 (spacing adjusting means) that can adjust the size of the gap formed by the block 110. And
This is the case where the volatilization rate of the residual solvent is controlled.

As shown in FIGS. 11 and 12, the block 110 has, for example, a cylindrical shape whose lower surface is parallel to the surface of the wafer W, and maintains a constant gap with the wafer W during the drying rotation so that the residual solvent remains. Volatilization can be suppressed.
The block 110 is formed of a material such as aluminum or stainless steel.

As shown in FIG. 11, four block elevating means 112 are provided at equal intervals, for example, at positions that do not interfere with each other when the wafer W is held by the spin chuck 71.
For example, the block 110 can be moved up and down by driving an elevating means (not shown) composed of a motor and a ball screw mechanism, and the distance between the lower surface of the block 110 and the surface of the wafer W can be adjusted. It is configured.

As shown in FIG. 11, the block arm 111 has one end capable of holding the block 110 and the other end connected to the upper part of the block elevating means 112, and a rotating means such as a motor (not shown). The block arm 111 is formed so as to be horizontally movable in the radial direction of the wafer W by driving (1). Also, the block arm 11
1 is formed to have a length such that the block 110 can pass over the center of rotation of the spin chuck during rotation.

Next, a processing method using the resist coating unit (COT) having the above structure will be described.

First, before the resist solution supply nozzle 73 starts the supply of the resist solution, as shown in FIG. 12A, the block 110 is about 30 mm from the surface of the wafer W at the standby position on the outer periphery of the wafer W. Waiting in the upper position.

Next, when the resist solution supply nozzle 73 starts supplying the resist solution, the block arm 111
As shown in FIG. 12B, the block 110 is rotated by a predetermined angle by driving the rotating means, and moves the block 110 to a predetermined position above the wafer W.

When the block 110 moves to a predetermined position,
As shown in FIG. 12C, the block elevating / lowering means 112 descends the block 110 to provide a predetermined distance between the lower surface of the block 110 and the front surface of the wafer W, for example, 0.3 to 3 m.
Adjust so as to form a gap of m.

When the predetermined time has elapsed, block 110
Is moved to the next position by the block arm 111, and the size of the gap is adjusted by driving the block elevating means 112.

In this way, after the plurality of blocks 110 have been moved to various positions during the resist solution coating process or the drying rotation, they are finally returned to the standby position and the resist coating process is completed.

With this configuration, the position and size of the gap formed on the surface of the wafer W during the drying rotation can be changed to control the volatilization rate of the residual solvent, so that the residual solvent on the surface of the wafer W can be controlled. The amount can be uniform.

In the block 110, for example, 15 to 3
If the temperature control water conduit that can flow water whose temperature is adjusted to 0 ° C. is provided in a spiral shape, the temperature of the block 110 can be adjusted, and the volatilization of the residual solvent can be controlled more reliably. it can.

In the above description, the block 110 has a cylindrical shape, but the block 1
The shape of 10 is not limited to this, and it is also possible to form, for example, a quadrangular prism or a hemisphere as long as a certain gap is formed on the wafer W.

Fifth Embodiment A fifth embodiment of the present invention is a resist coating unit (C
OT), the air cleaning means 120 is divided into a plurality of regions and is capable of supplying clean air toward the surface of the wafer W.
And a plurality of temperature controllers (air temperature adjusting means) capable of adjusting the temperature of the air supplied by the air cleaning means 120 for each region.
And a plurality of thermocouples 122 (temperature detecting means) capable of detecting the temperature near the surface on different concentric circles of the wafer W, and a CPU 100 (control which controls the temperature controller based on the detection signal detected by the thermocouple 122. Means) is provided to control the volatilization rate of the residual solvent.

As shown in FIG. 13, the air cleaning means 120 has a plurality of areas on different concentric circles, for example, three areas 1.
It is divided into 20a, 120b, and 120c, and is formed so that clean air can be supplied to the surface of the wafer W by, for example, a ULPA filter that can remove particles and the like.

Further, as shown in FIG. 13, the areas 120a, 120b, 120c of the air cleaning means 120 are connected to the air supply source 126 via the air supply pipelines 124a, 124b, 124c, respectively. Air supply means 125a, 125b, 125c such as fans and pumps
By this, a predetermined amount of air can be supplied to each region 120a, 120b, 120c.

Further, the air supply pipelines 124a, 124b,
124c is provided with temperature controllers 121a, 121b, 121c between the regions 120a, 120b, 120c and the air supply means 125a, 125b, 125c, respectively, and based on a control signal from the CPU 100 described later, The temperature of the air is adjustable.

As shown in FIG. 13, a plurality of thermocouples 122, for example, three thermocouples 122 are provided on a thermocouple transfer arm 123 extending in the radial direction of the wafer W held by the spin chuck 71, on different concentric circles of the wafer W. The temperature is formed near the surface, for example, at a height position of about 2 to 3 mm from the surface of the wafer W so that it can be detected.

The thermocouple 122 is the CPU 1 described later.
00 is electrically connected to the CPU to detect the detected temperature.
It is formed so that it can be transmitted to 100.

Further, the thermocouple transfer arm 123 is provided by penetrating the cup 72, and is configured to be horizontally movable in the radial direction above the wafer W by a driving means composed of, for example, a motor and a ball screw mechanism. Has been done.

By constructing the thermocouple transfer arm 123 in this manner, when the wafer W is loaded and unloaded, the structure shown in FIG.
As shown in FIG. 4A, the wafer W and the thermocouple transfer arm 1
23, for example, the thermocouple transfer arm 12
Wafer W whose tip is held by the spin chuck 71
14B, the tip of the thermocouple transfer arm 123 is positioned at the center of the wafer W held by the spin chuck 71 during the resist coating process, as shown in FIG. 14B. It can be moved horizontally to the upper position.

The CPU 100, based on the detection signal detected by the thermocouple 122 and the previously stored correlation information between the solvent volatilization rate and the temperature, controls the temperature controllers 121a, 121b, 1b.
21c is formed to be controllable.

With the above structure, the volatilization rate can be controlled on different concentric circles on the surface of the wafer W, depending on the temperature of the air supplied by the regions 120a, 120b, 120c of the air cleaning means 120. A resist film having a uniform film quality can be formed.

If the air cleaning means 120 is provided with an air cleaning means elevating means composed of, for example, a motor and a ball screw mechanism so that the air cleaning means 120 can be moved up and down during the resist coating process, the operation is more reliable. The evaporation rate can be controlled by adjusting the temperature of the surface of the wafer W.

In the above embodiments, the case where the substrate to be processed is a semiconductor wafer has been described, but it goes without saying that the present invention can be applied to an LCD substrate, a reticle substrate for a photomask, etc. other than the wafer.

[0111]

As described above, according to the present invention, the rate of volatilization of the residual solvent (residual solvent) on the substrate to be processed can be controlled, so that the amount of residual solvent on the surface of the substrate to be processed can be made uniform. Can be Therefore, the pattern line width can be made uniform.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an example of a resist solution coating / developing system according to the present invention.

FIG. 2 is a schematic front view of the resist solution coating / developing system.

FIG. 3 is a schematic rear view of the resist solution coating / developing system.

FIG. 4 is a schematic configuration diagram showing a main part of the resist coating apparatus of the present invention.

FIG. 5 is a schematic configuration diagram showing a resist coating apparatus according to the first embodiment of the present invention.

FIG. 6 is a graph illustrating a processing method using the resist coating apparatus according to the first embodiment of the present invention.

FIG. 7 is a schematic explanatory diagram illustrating an operating mode of the nozzle arm according to the present invention.

FIG. 8 is a schematic configuration diagram showing a resist coating apparatus according to a second embodiment of the present invention.

FIG. 9 is a sectional view showing the shape of a top plate in the second embodiment of the present invention.

FIG. 10 is a schematic configuration diagram showing a resist coating apparatus according to a third embodiment of the present invention.

FIG. 11 is a schematic configuration diagram showing a resist coating apparatus of a fourth embodiment of the present invention.

FIG. 12 is a schematic configuration diagram illustrating a processing method using the resist coating apparatus according to the fourth embodiment of the present invention.

FIG. 13 is a schematic configuration diagram showing a resist coating apparatus of a fifth embodiment of the present invention.

FIG. 14 is a schematic configuration diagram showing an operation mode of a thermocouple transfer arm according to the fifth embodiment of the present invention.

[Explanation of reference numerals] W semiconductor wafer (substrate to be processed) V3 open / close valve (supply amount adjusting means) 71 spin chuck (holding means) 72 cup (processing container) 73 resist solution supply nozzle (resist solution supply means) 80 solvent gas supply Nozzle (solvent gas supply means) 85 Mixer (solvent concentration adjusting means) 88 Nozzle arms 90, 91, 92, 93, 94 Top plate 95 Top plate 100 CPU (control means) 110 Block (gap forming means) 111 Block arm (Position adjusting means) 112 Block elevating means (spacing adjusting means) 120 Air cleaning means 120a, 120b, 120c Regions 121a, 121b, 121c Temperature controller (air temperature adjusting means) 122 Thermocouple (temperature detecting means)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H025 AB16 EA05                 4F042 AA02 AA07 AB00 BA18 BA19                       CB08 CB19 CB26 EB06 EB09                       EB13 EB18 EB24 EB25 EB30                 5F046 JA09 JA16 JA21 JA24

Claims (12)

[Claims] 1. A resist coating apparatus comprising: a holding unit that holds and rotates a substrate to be processed; a processing container that surrounds the holding unit; and a resist solution supply unit that supplies a resist solution to the substrate to be processed. , A plurality of solvent gas supply means capable of supplying a solvent gas containing a solvent of the resist solution toward different concentric circles on the surface of the substrate to be processed, and adjusting the solvent concentration of the solvent gas supplied by the solvent gas supply means A resist coating apparatus comprising: a possible solvent concentration adjusting means; and a supply amount adjusting means capable of adjusting a supply amount of the solvent gas supplied by the solvent gas supplying means. 2. The resist coating apparatus according to claim 1, wherein the solvent gas supply means is provided in a processing container. 3. The resist coating apparatus according to claim 1, wherein the solvent gas supply means is provided in a nozzle arm that can move back and forth in a processing container. 4. A resist coating apparatus comprising: a holding unit that holds and rotates a substrate to be processed; a processing container that surrounds the holding unit; and a resist liquid supply unit that supplies a resist liquid to the substrate to be processed. A resist coating apparatus, characterized in that a top plate having a different thickness is provided on the lower surface side on different concentric circles above the holding means. 5. A resist coating apparatus comprising: a holding unit that holds and rotates a substrate to be processed; a processing container that surrounds the holding unit; and a resist liquid supply unit that supplies a resist liquid to the substrate to be processed. A resist coating apparatus, characterized in that a top plate having different aperture ratios on different concentric circles is provided above the holding means. 6. The resist coating apparatus according to claim 5, wherein the top plate is formed on different concentric circles with different thicknesses on the lower surface side. 7. The resist coating apparatus according to claim 4, further comprising a ceiling plate elevating means capable of relatively elevating the holding means and the ceiling plate. apparatus. 8. The resist coating apparatus according to claim 4, further comprising a top plate temperature adjusting means capable of adjusting the temperature of the top plate on different concentric circles. . 9. A resist coating apparatus comprising: a holding means for holding and rotating a substrate to be processed; a processing container surrounding the holding means; and a resist solution supply means for supplying a resist solution to the substrate to be processed. A plurality of gap forming means for forming a constant gap on the substrate to be processed, position adjusting means capable of horizontally moving the plurality of gap forming means in the radial direction on the substrate to be processed, respectively. A resist coating apparatus comprising: a gap adjusting unit capable of adjusting the size of the gap formed by the gap forming unit. 10. The resist coating apparatus according to claim 9, further comprising a gap temperature adjusting unit capable of adjusting the temperature of the gap forming unit. 11. A resist coating apparatus comprising: a holding unit that holds and rotates a substrate to be processed; a processing container that surrounds the holding unit; and a resist solution supply unit that supplies a resist solution to the substrate to be processed. , An air cleaning unit that is divided into a plurality of regions and that can supply clean air toward the surface of the substrate to be processed, and a plurality of air units that can adjust the temperature of the air supplied by the air cleaning unit for each region. Based on the temperature adjusting means, a plurality of temperature detecting means capable of detecting the temperature in the vicinity of the surface on different concentric circles of the substrate to be processed, the detection signal detected by the temperature detecting means, and the information stored in advance, And a control unit for controlling the air temperature adjusting unit. 12. The resist coating apparatus according to claim 11, further comprising an air cleaning means elevating means capable of relatively elevating the holding means and the air cleaning means.