JP2007081177A - Development processing method and development processor of substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a development processing method of a substrate, with which resist pattern collapse due to thinning of a pattern size and a problem by water repellence of resist, which occurs in relation to technical progress for thinning the pattern size, can be solved and device structure and control are prevented from becoming complicated. <P>SOLUTION: Before developer is discharged onto an exposed resist film formed on a surface of the substrate W from a developer discharge nozzle 28, and the resist film is developed; solution comprising surfactant is discharged onto the resist film from a liquid discharge nozzle 30 as pre-wetting liquid, and a pre-wetting processing is performed. Same solution comprising surfactant is discharged onto the resist film from the liquid discharge nozzle 30 as rinse liquid after a development processing and a rinse processing is performed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a substrate for developing a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, etc., by supplying a developer to an exposed photoresist film formed on the surface of the substrate. The present invention relates to a development processing method and a development processing apparatus.

  In recent years, in a semiconductor device manufacturing process, high integration has been promoted by miniaturization of pattern dimensions. As the pattern dimensions become finer, the aspect ratio of the resist pattern becomes higher. As a result, there arises a problem that the resist pattern falls down in the development process. As a means for solving this problem, conventionally, in a rinsing process performed after the development process, water is discharged onto the substrate to wash away developer and resist elution components, and then a low surface tension liquid (for example, propyl alcohol and water). In which the water on the substrate is replaced with a low surface tension solution, and then the substrate is dried (see, for example, Patent Document 1).

  On the other hand, as a typical means for reducing the processing size of a resist pattern in the exposure / development process, resolution is improved by shortening the wavelength of light from an exposure light source. That is, from the near-ultraviolet ray (wavelength: 400 nm to 300 nm) conventionally used to the use of KrF excimer laser (wavelength: 248 nm), from the KrF excimer laser to use of ArF excimer laser (wavelength: 193 nm), and further to ArF excimer. Technological progress has been made such as the use of radiation with shorter wavelengths such as far ultraviolet rays, X-rays, and electron beams from lasers, and various lithography processes using these exposure light sources have been proposed and put into practical use.

  By the way, the resist corresponding to the shortening of the wavelength of light for exposure has extremely high water repellency. For this reason, in the development processing after exposure, for example, when the developer is deposited on the resist film by the slit scan method, it is difficult to form a liquid film having a uniform thickness as desired. ) Will consume a large amount of developer. Further, when the water repellency of the resist is further increased, it becomes difficult to form the developer film itself.

As a method for solving such a problem, a process called pre-wet is performed in which the surface state of the resist film is changed to hydrophilic before the developer is deposited. By this treatment, the wettability of the resist film surface to the developer is improved, a developer film having a uniform thickness is formed on the resist film on the substrate surface, and the consumption of the developer can be reduced. Conventionally, pure water has been used for this pre-wet treatment, but in recent years, for example, tetramethylammonium hydroxide (TMAH), isopropyl alcohol (IPA), There has been proposed a method for improving the wettability of the resist film surface with respect to a developing solution by performing a hydrophilic treatment on the resist film surface using a hydrophilizing agent such as diethylethanolamine (see, for example, Patent Document 2). ).
JP-A-7-106226 (page 3, FIG. 1) JP-A-9-106081 (page 2-3, FIG. 1 and FIG. 2)

  As described above, for the problem of resist pattern collapse caused by the miniaturization of pattern dimensions, and the problem that it becomes difficult to form a developer film in connection with the technological progress for miniaturization of pattern dimensions. Conventionally, suitable rinse solutions and pre-wet solutions have been proposed for each. For this reason, in the development processing apparatus, it is necessary to separately provide a rinse liquid discharge system and a pre-wet liquid discharge system, and a waste liquid separation and recovery system is also required. As described above, in order to solve the two problems that become apparent due to the miniaturization of the pattern dimensions, there is a problem that the configuration of the development processing apparatus and the control of the apparatus become complicated.

  The present invention has been made in view of the circumstances as described above, and is a resist that occurs in connection with the problem of resist pattern collapse that occurs with the miniaturization of pattern dimensions and the technological progress for miniaturization of pattern dimensions. It is possible to solve both of the problems caused by water repellency, and to provide a development processing method for a substrate that does not complicate apparatus configuration and control, and a substrate that can suitably implement the method An object of the present invention is to provide a development processing apparatus.

  The invention according to claim 1 includes a step of pre-wetting the resist film by discharging a pre-wet liquid onto the exposed resist film formed on the surface of the substrate, and a developer onto the pre-wet treated resist film. In the substrate development processing method, the method includes a step of developing the resist film by discharging and a step of discharging the rinse liquid onto the developed resist film and rinsing the resist film. The same solution containing a surfactant is used as the wet solution.

  According to a second aspect of the present invention, there is provided a substrate holding means for holding the substrate in a horizontal posture, and a developer discharge for discharging the developer onto the resist film after exposure formed on the surface of the substrate held by the substrate holding means. A nozzle, a developer supply means for supplying the developer to the developer discharge nozzle, a rinse liquid discharge nozzle for discharging a rinse liquid onto the resist film after the development process formed on the substrate surface, and the rinse liquid discharge nozzle In the development processing apparatus for a substrate having a rinse liquid supply means for supplying a rinse liquid, the rinse liquid supply means supplies a solution containing a surfactant as a rinse liquid to the rinse liquid discharge nozzle, and the rinse liquid The discharge nozzle is commonly used for pre-wetting the resist film by discharging a pre-wet liquid onto the resist film before development processing formed on the substrate surface.

According to the development processing method of the first aspect of the invention, since the same solution is used as the rinse liquid and the pre-wet liquid, one discharge is performed to discharge the rinse liquid and the pre-wet liquid onto the resist film on the substrate surface, respectively. It is only necessary to provide a system, and it is not necessary to separate and collect the waste liquid. In addition, selection of the optimum concentration of the rinse liquid and the pre-wet liquid may be performed only for the rinse liquid, for example, and the man-hour for setting the condition is reduced. Then, when the solution containing the surfactant is used as the rinsing liquid, when the substrate is dried after the rinsing process, the rinsing liquid is scattered and evaporated from the resist film and removed. The surface tension of the rinsing liquid, which is a force causing the resist pattern collapse phenomenon, is smaller than that of pure water. In this way, the force that causes the resist pattern collapse phenomenon is reduced, so that the resist pattern can be prevented from collapsing. Even if the water repellency of the resist film is high, the surface of the resist film is made hydrophilic by supplying a solution containing a surfactant as a pre-wet liquid before supplying the developer onto the resist film. As a result, the wettability of the resist film surface to the developer is improved. For this reason, when the developer is supplied onto the resist film after the pre-wet treatment, a developer film having a uniform thickness can be formed on the resist film on the substrate surface, and the consumption of the developer is reduced. be able to.
Therefore, according to the development processing method of the first aspect of the present invention, the resist water repellency generated in connection with the problem of resist pattern collapse accompanying the miniaturization of pattern dimensions and the technical progress for miniaturization of pattern dimensions. Both of the above problems can be solved, and the apparatus configuration and control can be simplified.

  When the development processing apparatus of the invention according to claim 2 is used, the development processing method of the invention of claim 1 can be suitably implemented, and the above-described effects can be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best embodiment of the present invention will be described with reference to the drawings.
1 to 3 show an example of a configuration of a development processing apparatus used for carrying out a substrate development processing method according to the present invention, and FIG. 1 is a plan view showing a schematic configuration of the development processing apparatus. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

  This development processing apparatus includes a spin chuck 10 that holds the substrate W in a horizontal position at the center of the apparatus where the development processing of the substrate W is performed, and a rotary support shaft 12 that is vertically supported with the spin chuck 10 fixed to the upper end. In addition, a rotary motor 14 that rotates the spin chuck 10 and the rotary support shaft 12 around a vertical axis is provided. A circular inner cup 16 is disposed around the spin chuck 10 so as to surround the substrate W on the spin chuck 10, and the inner cup 16 is supported by a support mechanism (not shown) so as to be reciprocally movable in the vertical direction. ing. A rectangular outer cup 18 is disposed around the inner cup 16.

  Standby pots 20 and 20 are disposed on the left and right sides of the outer cup 18, respectively. A guide rail 22 is disposed on one side of the outer cup 18 and the standby pot 20 in parallel with the connecting direction of the outer cup 18 and the standby pot 20. An arm drive unit 24 is slidably engaged with the guide rail 22, and a nozzle arm 26 is held by the arm drive unit 24. A developer discharge nozzle 28 is suspended from the nozzle arm 26 in a horizontal posture. Although the detailed illustration of the developer discharge nozzle 28 is omitted, the developer discharge nozzle 28 has a slit-like discharge port extending in the longitudinal direction on the lower end surface. A developer supply pipe (not shown) connected to the developer supply source in a flow path is connected to the developer discharge nozzle 28 in communication. The developer discharge nozzle 28 is disposed in a direction orthogonal to the guide rail 22. Then, the arm driving unit 24 linearly reciprocates the nozzle arm 26 along the guide rail 22 in the horizontal direction, scans the developer discharge nozzle 28 in the direction indicated by the arrow A, and returns to the opposite direction. It has a configuration that can.

  Further, in the vicinity of the rear side of the outer cup 18, a liquid discharge nozzle 30 that discharges liquid from the discharge port at the tip onto the substrate W is disposed. The liquid discharge nozzle 30 is connected to a liquid supply source through a liquid supply pipe (not shown). The liquid discharge nozzle 30 is held by the nozzle holding portion 32 so as to be rotatable in a horizontal plane in the direction indicated by the arrow B, and the standby position and the discharge port at the tip shown in FIG. It is configured to reciprocate between the discharge position. A solution containing a surfactant is supplied to the liquid discharge nozzle 30, and the solution containing the surfactant is discharged from the tip discharge port of the liquid discharge nozzle 30 onto the center of the substrate W. The type of the surfactant is not particularly limited. A general anionic surfactant or cationic surfactant may be used, and an aqueous solution having a predetermined concentration is prepared by dissolving the surfactant in pure water. And stored in a liquid supply source. The solution containing this surfactant is commonly used as a rinse liquid and a pre-wet liquid.

  Next, an example of processing operation by the development processing apparatus having the above-described configuration will be described.

  When the substrate W having the exposed resist film formed on the surface is carried into the apparatus and the substrate W is held by the spin chuck 10, the liquid discharge nozzle 30 rotates to discharge the tip of the liquid discharge nozzle 30. The outlet moves to a position directly above the center of the substrate W, and a predetermined amount of a solution containing a surfactant (pre-wet liquid) is dropped and supplied to the center of the substrate W from the tip discharge port of the liquid discharge nozzle 30. The surfactant solution supplied onto the substrate W spreads over the entire surface of the substrate W and covers the entire surface of the resist film on the substrate W. At this time, the substrate W may be rotated at a low speed. When the discharge of the surfactant solution is finished, the liquid discharge nozzle 30 is rotated back to the original position shown in FIG. After a predetermined time has elapsed since the surfactant solution was discharged, the substrate W is rotated, and excess surfactant solution is scattered from the substrate W by centrifugal force to be removed. At this time, the inner cup 16 is raised. In this way, the pre-wetting process of the resist film is performed.

  Subsequently, while the developer is being discharged from the slit-like discharge port of the developer discharge nozzle 28, the arm driver 24 scans the developer discharge nozzle 28 in the direction indicated by the arrow A. As a result, the developer is supplied onto the substrate W and accumulated. When the developer discharge nozzle 28 moves to the position of the standby pot 20 on the right side, the discharge of the developer is stopped, and the arm drive unit 24 moves the developer discharge nozzle 28 in the direction opposite to the direction indicated by the arrow A, thereby developing. The liquid discharge nozzle 28 is returned to the position of the original left standby pot 20. Then, the resist film on the surface of the substrate W is developed by keeping the substrate W stationary until a predetermined time elapses after the liquid is deposited on the substrate W.

  When a predetermined time elapses after the liquid is deposited on the substrate W, the liquid discharge nozzle 30 is rotated again, the tip discharge port of the liquid discharge nozzle 30 is moved to a position directly above the center of the substrate W, and the liquid discharge nozzle 30 A solution (rinse liquid) containing a surfactant is supplied to the central portion of the substrate W from the tip discharge port. Thereby, the development reaction of the resist film on the surface of the substrate W is stopped. When the discharge of the surfactant solution is completed, the liquid discharge nozzle 30 is rotated back to the original position shown in FIG. Then, after discharging the surfactant solution, the substrate W is rotated, the surfactant solution is scattered and removed from the substrate W by centrifugal force, and the substrate W is dried. At this time, the inner cup 16 is raised. When the drying process of the substrate W is completed, the substrate W is removed from the spin chuck 10 and carried out of the apparatus.

  Next, FIGS. 4 and 5 show another configuration example of the development processing apparatus used for carrying out the substrate development processing method according to the present invention, and FIG. 4 shows a schematic configuration of the development processing apparatus. It is a top view and FIG. 5 is the schematic longitudinal cross-sectional view.

  The development processing apparatus includes a spin chuck 34 that holds the substrate W in a horizontal position at the center of the apparatus where the development processing of the substrate W is performed, and a rotation support shaft 36 that is vertically supported with the spin chuck 34 fixed to the upper end. A rotation shaft is connected to the rotation support shaft 36, and a rotation motor 38 that rotates the spin chuck 34 and the rotation support shaft 36 about the vertical axis is disposed. A circular cup 40 is disposed around the spin chuck 34 so as to surround the substrate W on the spin chuck 34, and the cup 40 is supported by a support mechanism (not shown) so as to reciprocate in the vertical direction. .

  In the vicinity of the front side of the cup 40, a developer discharge nozzle 42 for discharging the developer onto the substrate W from the discharge port at the tip is disposed. The developer discharge nozzle 42 is connected to a developer supply source through a developer supply pipe (not shown). The developer discharge nozzle 42 is held by the nozzle holding portion 44 so as to be rotatable in a horizontal plane in the direction indicated by the arrow C, and the standby position and the discharge port at the front end shown in FIG. It is the structure which reciprocates between the discharge positions arrange | positioned in this.

  Further, in the vicinity of the side of the cup 40, a liquid discharge nozzle 46 that discharges liquid onto the substrate W from the discharge port at the tip is disposed. The liquid discharge nozzle 46 is connected to a liquid supply source through a liquid supply pipe (not shown). The liquid discharge nozzle 46 is held by the liquid discharge nozzle 46 so as to be rotatable in a horizontal plane in the direction indicated by the arrow D, and the standby position and the discharge port at the front end shown in FIG. It is configured to reciprocate between the discharge position. A solution containing a surfactant is supplied to the liquid discharge nozzle 46, and a solution containing a surfactant adjusted to a predetermined concentration is discharged from the tip discharge port of the liquid discharge nozzle 46 onto the center of the substrate W. It is like that. The solution containing this surfactant is commonly used as a rinse liquid and a pre-wet liquid.

  A drainage pipe 50 is connected to the bottom of the cup 40, and the drainage pipe 50 is connected to the inflow side connection port of the flow path switching valve 52. Although the details of the internal structure of the flow path switching valve 52 are not shown, the inflow side connection port is configured to selectively communicate with the two outflow side connection ports by switching the internal flow path. The developer recovery pipe 54 is connected to one outflow side connection port, and the rinse liquid / prewet liquid recovery pipe 56 is connected to the other outflow side connection port. With such a configuration, the developer and the rinse liquid / pre-wet liquid can be collected separately.

  Next, an example of processing operation by the development processing apparatus shown in FIGS. 4 and 5 will be described.

  When the substrate W having the exposed resist film formed on the surface thereof is carried into the development processing apparatus and the substrate W is held by the spin chuck 34, the liquid discharge nozzle 46 is rotated to rotate the liquid discharge nozzle 46. The tip discharge port is moved to a position directly above the center of the substrate W, and a solution containing a surfactant (pre-wet liquid) is supplied from the tip discharge port of the liquid discharge nozzle 46 to the center of the substrate W. The surfactant solution supplied onto the substrate W spreads over the entire surface of the substrate W and covers the entire surface of the resist film. At this time, the substrate W may be rotated at a low speed. After a predetermined time has elapsed since the surfactant solution was discharged, the substrate W is rotated, and the surfactant solution is scattered and removed from the substrate W by centrifugal force. At this time, the cup 40 is raised. In this way, the pre-wetting process of the resist film is performed. When the discharge of the surfactant solution is finished, the liquid discharge nozzle 46 is rotated back to the original position shown in FIG.

  Subsequently, the developer discharge nozzle 42 is rotated to move the tip discharge port of the developer discharge nozzle 42 to a position directly above the center of the substrate W. Then, a predetermined amount of the developer is dropped and supplied from the tip discharge port of the developer discharge nozzle 42 to the center of the substrate W while rotating the substrate W at a low speed. The developer supplied onto the substrate W spreads over the entire surface of the substrate W and is applied onto the resist film so as to cover the entire surface of the resist film. When the application of the developer is finished, the developer discharge nozzle 42 is rotated back to the original position shown in FIG.

  When a predetermined time elapses after the developer is applied onto the substrate W, the liquid discharge nozzle 46 is rotated again to move the tip discharge port of the liquid discharge nozzle 46 to a position directly above the center of the substrate W, thereby discharging the liquid. A solution (rinse solution) containing a surfactant is supplied from the tip discharge port of the nozzle 46 to the center of the substrate W. Thereby, the development reaction of the resist film on the surface of the substrate W is stopped. When the discharge of the surfactant solution is completed, the liquid discharge nozzle 46 is rotated back to the original position shown in FIG. Then, after discharging the surfactant solution, the substrate W is rotated, the surfactant solution is scattered and removed from the substrate W by centrifugal force, and the substrate W is dried. At this time, the inner cup 16 is raised. When the drying process of the substrate W is completed, the substrate W is removed from the spin chuck 10 and carried out of the apparatus.

  In the development processing method according to the present invention, as described above, by using a solution containing a surfactant as a rinsing liquid, when the substrate is dried after the rinsing process, the resist pattern collapses during the drying process. The surface tension of the rinsing liquid, which is the force to cause, is smaller than that of pure water. For this reason, the collapse of the resist pattern is prevented. Even if the water repellency of the resist film is high, a solution containing a surfactant as a prewetting liquid is supplied onto the resist film, so that the resist film surface is hydrophilized and the resist film surface is wetted with the developer. Improves. For this reason, when the developer is supplied onto the resist film after the pre-wet treatment, a developer film having a uniform thickness can be formed on the resist film on the substrate surface, and the consumption of the developer is also reduced. It will be. Since the same solution containing a surfactant is used as the rinse liquid and the pre-wet liquid, only one liquid discharge nozzle 30, 46 is used to discharge the rinse liquid and the pre-wet liquid onto the resist film on the substrate surface, respectively. Will be installed. Further, it is not necessary to separate and collect the waste liquids of the rinse liquid and the pre-wet liquid. Furthermore, since the optimum concentration of the rinsing liquid and the pre-wet liquid need only be selected for the rinsing liquid, for example, it is possible to reduce the man-hour for setting the conditions.

  In the above-described embodiment, a slit scan method in which the developer discharge nozzle 28 is scanned while discharging the developer from the slit-like discharge port of the developer discharge nozzle 28, and the developer is deposited on the resist film on the substrate surface. The developing method has been described in which the developing solution is supplied from the developing solution discharge nozzle 42 (straight nozzle) to the center of the surface of the substrate and the substrate is rotated to spread the developing solution over the entire surface of the substrate. However, the developing method is particularly limited. In addition, the present invention can be widely applied to a developing system in which a developer is ejected from a spray nozzle onto a resist film on a substrate surface while rotating the substrate. Further, the discharge form of the solution containing the surfactant (rinse liquid and pre-wet liquid) is not particularly limited.

1 is a schematic plan view showing an example of the configuration of a development processing apparatus used for carrying out a substrate development processing method according to the present invention. FIG. 2 is a cross-sectional view taken along arrow II-II in FIG. 1. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1. It is a schematic plan view which shows another structural example of the development processing apparatus used in order to implement the development processing method of the board | substrate concerning this invention. FIG. 5 is a schematic longitudinal sectional view of the development processing apparatus shown in FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 34 Spin chuck 12, 36 Rotation spindle 14, 38 Rotation motor 16 Inner cup 18 Outer cup 20 Standby pot 22 Guide rail 24 Arm drive part 26 Nozzle arm 28, 42 Developer discharge nozzle 44 Nozzle holding of developer discharge nozzle Portions 30 and 46 Liquid discharge nozzles 32 and 48 Nozzle holding portions of the liquid discharge nozzles 40 Cup 50 Drainage pipe 52 Flow path switching valve 54 Developer recovery pipe 56 Rinse / prewet liquid recovery pipe W Substrate

Claims (2)

A step of pre-wetting the resist film by discharging a pre-wet liquid onto the exposed resist film formed on the surface of the substrate;
A step of developing the resist film by discharging a developer onto the pre-wet processed resist film;
A step of rinsing the resist film by discharging a rinsing liquid onto the developed resist film;
In a method for developing a substrate including
A developing method for a substrate, wherein the same solution containing a surfactant is used as the rinse liquid and the pre-wet liquid. Substrate holding means for holding the substrate in a horizontal position;
A developer discharge nozzle for discharging the developer onto the resist film after exposure formed on the surface of the substrate held by the substrate holding means;
Developer supply means for supplying the developer to the developer discharge nozzle;
A rinsing liquid discharge nozzle for discharging a rinsing liquid onto the resist film after development processing formed on the substrate surface;
Rinsing liquid supply means for supplying a rinsing liquid to the rinsing liquid discharge nozzle;
In a substrate development processing apparatus comprising:
The rinse liquid supply means supplies a solution containing a surfactant as a rinse liquid to the rinse liquid discharge nozzle,
The rinsing liquid discharge nozzle is commonly used to pre-wet the resist film by discharging a pre-wet liquid onto the resist film before the development process formed on the substrate surface. .

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