JP2007201048A - Semiconductor substrate processing apparatus, and manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor substrate processing apparatus capable of suppressing in-plane variation in terms of processing amount. <P>SOLUTION: The semiconductor substrate processing apparatus comprises a stage 10 which holds a semiconductor substrate 1; a rotating shaft 12 which is attached to the lower surface of the stage 10 for rotating the stage 10, with the fitting position variable; and a chemical supplying means 16 which supplies chemical on the semiconductor substrate 1 held by the stage 10. In the semiconductor substrate processing apparatus, the chemical is stirred by rotating the semiconductor substrate while it is treated with the chemical. Although the stirring amount of the chemical positioned at rotational center is small when compared to other region, the fitting position of the rotating shaft 12 to the stage 10 can be changed in the semiconductor substrate processing apparatus. By changing rotational center while the chemical is stirred, in-plane variation can be suppressed in the process amount of the chemical. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor substrate processing apparatus for processing a semiconductor substrate using a chemical solution and a method for manufacturing the semiconductor device. In particular, the present invention relates to a semiconductor substrate processing apparatus and a method for manufacturing a semiconductor device that can suppress in-plane variation in processing amount.

  FIG. 6 is a side view for explaining the configuration of a conventional semiconductor substrate processing apparatus. This semiconductor substrate processing apparatus is an apparatus for developing a photoresist film (not shown) formed on the silicon wafer 101. The silicon wafer 101 is held on the stage 110. A developer is discharged from the discharge nozzle 116 onto the silicon wafer 101. The developer discharged from the discharge nozzle 116 is held on the silicon wafer 101 by the surface tension of the developer to form the paddle 102.

A rotating shaft 112 is attached to the center of the lower surface of the stage 110. Power from the motor 114 is transmitted to the rotating shaft 112. Thereby, the stage 110 and the silicon wafer 101 rotate around the rotation axis 112. As the silicon wafer 101 rotates, a centrifugal force acts on the developer forming the paddle 102, and the developer is stirred. For this reason, in-plane variation in the development amount of the photoresist film is suppressed.
Japanese Patent Laid-Open No. 11-54427 (FIG. 1)

  In the prior art described above, the developer forming the paddle is agitated by centrifugal force. On the other hand, centrifugal force does not act on the developer located at the center of rotation. For this reason, the amount of agitation of the developer located at the center of rotation is small, and the amount of development of the photoresist film located at the center of rotation is small compared to other portions.

  The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to manufacture a semiconductor substrate processing apparatus and a semiconductor device capable of suppressing in-plane variations in the amount of treatment with a chemical compared to the conventional case. It is to provide a method.

In order to solve the above problems, a semiconductor substrate processing apparatus according to the present invention includes a stage for holding a semiconductor substrate,
A rotating shaft attached to the lower surface of the stage for rotating the stage and having a variable mounting position;
And a chemical supply means for supplying the chemical onto the semiconductor substrate held on the stage.

  According to this semiconductor substrate processing apparatus, the chemical solution is agitated by rotating the semiconductor substrate when the semiconductor substrate is being processed with the chemical solution. Although the amount of stirring of the chemical solution located at the center of rotation is small compared to other regions, in this semiconductor substrate processing apparatus, the mounting position of the rotating shaft with respect to the stage can be changed. Therefore, by changing the rotation center during the process of stirring the chemical solution, it is possible to suppress the occurrence of in-plane variation in the treatment amount of the chemical solution.

  You may further comprise the stage lifting means which lifts the said stage with respect to the said rotating shaft, and the rotating shaft moving means which moves the said rotating shaft to a horizontal direction. In this case, while the stage lifting means lifts the stage, the rotating shaft moving means moves the rotating shaft, thereby changing the mounting position of the rotating shaft with respect to the stage.

  The chemical solution is, for example, a photoresist film developer or a photoresist solution.

The method for manufacturing a semiconductor device according to the present invention includes a step of holding a semiconductor substrate on a stage having a rotating shaft attached to the lower surface,
Supplying a chemical onto the semiconductor substrate;
Rotating the stage and the semiconductor substrate by rotating the rotating shaft;
Changing the mounting position of the rotating shaft with respect to the stage;
A step of rotating the stage and the semiconductor substrate again by rotating the rotating shaft again.

  The step of changing the mounting position of the rotating shaft may include a step of lifting the stage with respect to the rotating shaft, a step of moving the rotating shaft in a lateral direction, and a step of lowering the stage.

Another method of manufacturing a semiconductor device according to the present invention includes a step of forming a photoresist film on a semiconductor substrate,
Exposing the photoresist film;
Developing the photoresist film;
Implanting impurities into the semiconductor substrate using the developed photoresist film as a mask;
Comprising
The step of developing the photoresist film includes:
Holding the semiconductor substrate coated with the photoresist film on a stage having a rotating shaft attached to the lower surface;
Supplying a developer onto the semiconductor substrate;
Stirring the developer on the semiconductor substrate by rotating the stage and the semiconductor substrate by rotating the rotating shaft;
Changing the mounting position of the rotating shaft with respect to the stage;
A step of stirring the developer on the semiconductor substrate by rotating the rotating shaft again to rotate the stage and the semiconductor substrate again.

  According to this method for manufacturing a semiconductor device, in-plane variation in the development amount is suppressed in the step of developing the photoresist film. Therefore, even when the photoresist film is thick (for example, 0.5 μm or more), the dimensional accuracy of the opening formed in the photoresist film is increased, and the region of the semiconductor substrate where the impurity is implanted is increased. Dimensional accuracy increases.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a side view for explaining the configuration of the semiconductor substrate processing apparatus according to the first embodiment of the present invention. This semiconductor substrate processing apparatus is an apparatus for developing a photoresist film (not shown) formed on the silicon wafer 1. The silicon wafer 1 is held on a disk-shaped stage 10. A developer is discharged from the discharge nozzle 16 onto the surface of the silicon wafer 1. The developer discharged from the discharge nozzle 16 is held on the silicon wafer 1 by the surface tension of the developer to form a paddle 20.

  A rotating shaft 12 is attached to the lower surface of the stage 10. The rotating shaft 12 is fitted in a groove 10 a provided on the lower surface of the stage 10. Power from the motor 22 is transmitted to the rotary shaft 12. Thereby, the stage 10 and the silicon wafer 1 rotate around the rotation axis 12. As the silicon wafer 1 rotates, a centrifugal force acts on the developer forming the paddle 20, and the developer is stirred. For this reason, in-plane variation in the development amount of the photoresist film is suppressed.

  Further, the mounting position of the rotary shaft 12 with respect to the lower surface of the stage 10 is variable. Specifically, the rotating shaft 12 can be attached to the center of the stage 10 and a place slightly away from the center of the stage 10 (for example, a place about 10% to 50% away from the radius).

  Further, the semiconductor substrate processing apparatus is provided with a plurality of (for example, four) lift pins 14 for lifting the stage 10 and a moving mechanism 24 for moving the rotating shaft 12 in the lateral direction. The moving mechanism 24 is a combination of a motor (not shown) serving as a power source and a power transmission mechanism such as a rack or gear.

  FIG. 1B is a side view for explaining a method of changing the mounting position of the rotating shaft 12 with respect to the stage 10. When changing the mounting position of the rotary shaft 12 with respect to the stage 10, the lift pin 14 moves upward and pushes up the edge of the lower surface of the stage 10 upward. Thereby, the stage 10 is lifted upward with respect to the rotating shaft 12. In this state, the moving mechanism 24 moves the rotating shaft 12 in the lateral direction. Thereafter, the lift pin 14 moves downward, and the rotating shaft 12 is fitted into the groove 10 a of the stage 10.

  FIG. 2A is a plan view showing the lower surface of the stage 10, and FIG. 2B is a top view of the rotating shaft 12. The groove 10 a provided on the lower surface of the stage 10 has a substantially rectangular planar shape and passes through the center of the stage 10. The length of the short side of the groove 10 a is substantially equal to the diameter of the rotating shaft 12. In each of the two long sides of the groove 10a, a recess 10b is provided at each of both ends and the center of the long side.

  At the upper end of the rotating shaft 12, two convex portions 12a that fit into the concave portion 10b are provided. The two convex portions 12a are provided at positions facing each other across the center of the rotating shaft 12, and have a shape that fits into the concave portion 10b of the groove 10a. The lift pin 14 and the moving mechanism 24 shown in FIG. 1 change the position of the rotary shaft 12 with respect to the stage 10 by changing the concave portion 10b into which the two convex portions 12a are fitted.

  FIG. 3 is a flowchart for explaining a method of developing the photoresist film formed on the silicon wafer 1 using the semiconductor substrate processing apparatus shown in FIG. 4A is a diagram showing the state of the paddle 20 in S4 of FIG. 3, and FIG. 4B is a diagram showing the state of the paddle 20 in S8 of FIG.

  First, the rotating shaft 12 is attached to the center of the lower surface of the stage 10. Next, the silicon wafer 1 coated with the photoresist film is held on the stage 10. The film thickness of the photoresist film is 0.5 μm or more. At this time, the silicon wafer 1 and the stage 10 are concentric. Next, the developer is discharged from the discharge nozzle 16 onto the silicon wafer 1. Thereby, the paddle 20 is formed on the surface of the silicon wafer 1 (S2).

  Next, the motor 22 is operated to rotate the stage 10 and the silicon wafer 1. At this time, the developer forming the paddle 20 is prevented from jumping out of the silicon wafer 1 by centrifugal force. As a result, the developer forming the paddle 20 is stirred (S4). As shown in FIG. 4A, in this state, since the rotation center is the center of the silicon wafer 1, the developer located on the center of the silicon wafer 1 has a small amount of stirring.

  Next, the motor 22 is stopped, and the stage 10 and the silicon wafer 1 are stopped. Next, using the lift pins 14 and the moving mechanism 24, the attachment position of the rotary shaft 12 with respect to the stage 10 is moved from the center of the stage 10 to another place (S6).

  Next, the motor 22 is operated again, and the stage 10 and the silicon wafer 1 are rotated. At this time, the developer forming the paddle 20 is prevented from jumping out of the silicon wafer 1 by centrifugal force. As a result, the developer forming the paddle 20 is stirred (S8).

  As shown in FIG. 4B, in the process of S8, since the rotation center has moved to a place other than the center of the silicon wafer 1, even in the part where the stirring amount of the developer was small in the process of S4, S6 In this process, the mixture is sufficiently stirred. For this reason, variation in the development amount of the photoresist film is suppressed over the entire surface of the silicon wafer 1.

  Thereafter, the rotational speed is increased, and the developer forming the paddle 20 is removed from the surface of the silicon wafer 1 by centrifugal force (S10). In addition, before performing the process of S10, you may repeat the process shown to S6 and S8 several times.

  As mentioned above, according to the 1st Embodiment of this invention, the rotating shaft 12 attached to the lower surface of the stage 10 can be attached to several places. Therefore, the developer can be sufficiently stirred over the entire paddle 20 by moving the rotary shaft 12 while the developer for forming the paddle 20 is being stirred. For this reason, variation in the development amount of the photoresist film is suppressed over the entire surface of the silicon wafer 1.

  Next, a second embodiment will be described. In the second embodiment, the semiconductor processing apparatus shown in FIG. 1 is used as an apparatus for forming a photoresist film on a silicon wafer 1. In this case, a photoresist solution is discharged from the discharge nozzle 16.

  When a photoresist film is formed using this semiconductor processing apparatus, a plurality of processes for rotating the stage 10 and the silicon wafer 1 after discharging the photoresist solution onto the silicon wafer 1 while changing the position of the rotary shaft 12 are performed. Do it once. Thereby, the in-plane variation in the film thickness of the photoresist film is suppressed.

  FIG. 5 is a cross-sectional view for explaining the method for manufacturing a semiconductor device according to the third embodiment of the present invention. The present embodiment is a method of forming and developing a photoresist film using the semiconductor substrate processing apparatus shown in the first and second embodiments, and manufacturing a semiconductor device using the photoresist film.

  First, as shown in FIG. 5A, a photoresist film 50 is formed on the silicon wafer 1, and the photoresist film 50 is exposed and developed. As a result, an opening 50 a is formed in the photoresist film 50. The thickness of the photoresist film 50 is 0.5 μm or more. The process for forming the photoresist film 50 is performed using the semiconductor substrate processing apparatus shown in the second embodiment, and the process for developing the photoresist film 50 is performed in the semiconductor substrate shown in the first embodiment. This is done using a processing device. For this reason, the in-plane variation in the film thickness of the photoresist film 50 is suppressed, and the in-plane variation in the development amount of the photoresist film 50 is suppressed. Therefore, even if the photoresist film 50 is thick, the dimensional accuracy of the opening 50a is increased.

  Next, N-type impurity ions are implanted into the silicon wafer 1 using the photoresist film 50 as a mask. Thereby, an N-type well 1a is formed in the silicon wafer 1 located in the opening 50a. Since the dimensional accuracy of the opening 50a is high, the dimensional accuracy of the N-type well 1a is also high.

  Thereafter, as shown in FIG. 5B, the photoresist film 50 is removed. Next, a photoresist film 51 is formed on the silicon wafer 1, and the photoresist film 51 is exposed and developed. As a result, an opening 51 a located on a part of the N-type well 1 a is formed in the photoresist film 51. The process for forming the photoresist film 51 is performed using the semiconductor substrate processing apparatus shown in the second embodiment, and the process for developing the photoresist film 51 is performed in the semiconductor substrate shown in the first embodiment. This is done using a processing device. For this reason, the in-plane variation in the film thickness of the photoresist film 51 is suppressed, and the in-plane variation in the development amount of the photoresist film 51 is suppressed. Therefore, even if the photoresist film 51 is thick, the dimensional accuracy of the opening 51a is increased.

  Next, P-type impurity ions are implanted into the silicon wafer 1 using the photoresist film 51 as a mask. At this time, the concentration of the P-type impurity is set to be higher than the N-type impurity concentration of the N-type well 1a. As a result, a P-type well 1b located in the N-type well 1a is formed in the silicon wafer 1 located in the opening 51a. Since the dimensional accuracy of the opening 51a is high, the dimensional accuracy of the P-type well 1b is also high. 5A and 5B, the implantation energy of P-type impurity ions and N-type impurity ions is adjusted so that the P-type well 1b is shallower than the N-type well 1a.

  Thereafter, as shown in FIG. 5C, the photoresist film 51 is removed. Next, the element isolation film 2 is formed, and the region where the N-type well 1a is formed and the region where the P-type well 1b is formed are separated from each other. The element isolation film 2 is formed by, for example, a LOCOS oxidation method, but may be embedded in the silicon wafer 1 by a trench isolation method.

  Next, the silicon wafer 1 is thermally oxidized. As a result, the gate oxide film 3a is formed on the silicon wafer 1 on which the N-type well 1a is formed, and the gate oxide film 3b is formed on the silicon wafer 1 on which the P-type well 1b is formed. Next, a polysilicon film is formed on the entire surface including the gate oxide films 3a and 3b. Next, a resist pattern (not shown) is formed on the polysilicon film, and the polysilicon film is selectively etched using this resist pattern as a mask. Thereby, the gate electrode 4a located on the gate oxide film 3a and the gate electrode 4b located on the gate oxide film 3b are formed. Thereafter, the resist pattern is removed.

  Next, a photoresist film (not shown) is applied on the entire surface including the region where the N-type well 1a is formed and the region where the P-type well 1b is formed, and this photoresist film is exposed and developed. As a result, an opening located on the region where the N-type well 1a is formed is formed in the photoresist film. Next, P-type impurities are implanted into the silicon wafer 1 using the photoresist film, the element isolation film 2, and the gate electrode 4a as a mask. Thereby, a low concentration impurity region 6a of a P-type transistor is formed in the N-type well 1a. Thereafter, the photoresist film is removed.

  Next, a photoresist film (not shown) is applied again on the entire surface including the region where the N-type well 1a is formed and the region where the P-type well 1b is formed, and this photoresist film is exposed and developed. To do. As a result, an opening located on the region where the P-type well 1b is formed is formed in the photoresist film. Next, N-type impurities are implanted into the silicon wafer 1 using the photoresist film, the element isolation film 2, and the gate electrode 4b as a mask. As a result, a low-concentration impurity region 6b of an N-type transistor is formed in the P-type well 1b. Thereafter, the photoresist film is removed.

  Next, a silicon oxide film is formed on the entire surface including the gate electrodes 4a and 4b by the CVD method, and this silicon oxide film is etched back. Thereby, side walls 5a and 5b are formed on the side walls of the gate electrodes 4a and 4b.

  Next, a photoresist film (not shown) is applied on the entire surface including the region where the N-type well 1a is formed and the region where the P-type well 1b is formed, and this photoresist film is exposed and developed. As a result, an opening located on the region where the N-type well 1a is formed is formed in the photoresist film. Next, P-type impurities are implanted into the silicon wafer 1 using the photoresist film, the element isolation film 2, the gate electrode 4a, and the sidewall 5a as a mask. As a result, impurity regions 7a serving as the source and drain of the P-type transistor are formed in the N-type well 1a. Thereafter, the photoresist film is removed.

Next, a photoresist film (not shown) is applied again on the entire surface including the region where the N-type well 1a is formed and the region where the P-type well 1b is formed, and this photoresist film is exposed and developed. To do. As a result, an opening located on the region where the P-type well 1b is formed is formed in the photoresist film. Next, N-type impurities are implanted into the silicon wafer 1 using the photoresist film, the element isolation film 2, the gate electrode 4b, and the sidewalls 5b as masks. As a result, impurity regions 7b serving as the source and drain of the N-type transistor are formed in the P-type well 1b. Thereafter, the photoresist film is removed.
In this way, a P-type transistor and an N-type transistor are formed.

  As described above, according to the third embodiment of the present invention, the photoresist films 50 and 51 for forming the N-type well 1a and the P-type well 1b are formed using the apparatus described in the second embodiment. Development is performed using the apparatus described in the first embodiment. Accordingly, the dimensional accuracy of the openings 50a and 51a formed in the photoresist films 50 and 51 is increased, and the dimensional accuracy of the N-type well 1a and the P-type well 1b is increased.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the third embodiment, each of the P-type transistor and the N-type transistor may be another type of transistor. In the first embodiment, the chemical solution discharged from the discharge nozzle 16 may be a chemical solution (for example, an etching solution) other than the developer and the photoresist solution.

(A) is a side view for demonstrating the structure of the semiconductor substrate processing apparatus which concerns on the 1st Embodiment of this invention, (B) is for demonstrating the method to change the attachment position of the rotating shaft 12 with respect to the stage 10. FIG. Side view. FIG. 4A is a plan view showing a lower surface of the stage 10, and FIG. 4B is a top view of the rotating shaft 12. The flowchart explaining the method to develop a photoresist film. (A) is a figure which shows the state of the paddle 20 in S4 of FIG. 3, (B) is a figure which shows the state of the paddle 20 in S8 of FIG. Sectional drawing for demonstrating the manufacturing method of the semiconductor device which concerns on the 3rd Embodiment of this invention. The side view for demonstrating the structure of the conventional semiconductor substrate processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Silicon wafer, 1a ... N type well, 1b ... P type well, 2 ... Element isolation film, 3a, 3b ... Gate oxide film, 4a, 4b ... Gate electrode, 5a, 5b ... Side wall, 6a, 6b ... low concentration impurity region, 7a, 7b ... impurity region, 10, 110 ... stage, 10a ... groove, 10b ... concave portion, 12, 112 ... rotating shaft, 12a ... convex portion, 14 ... lift pin, 16, 116 ... discharge nozzle, 20, 102 ... Paddle (developer), 22, 114 ... Motor, 24 ... Moving mechanism, 50, 51 ... Photoresist film, 50a, 50b ... Opening

Claims (8)

A stage for holding a semiconductor substrate;
A rotating shaft attached to the lower surface of the stage for rotating the stage and having a variable mounting position;
A chemical supply means for supplying a chemical onto the semiconductor substrate held on the stage;
A semiconductor substrate processing apparatus comprising: Stage lifting means for lifting the stage relative to the rotation axis;
A rotating shaft moving means for moving the rotating shaft in a lateral direction;
The semiconductor substrate processing apparatus according to claim 1, further comprising:   The semiconductor substrate processing apparatus according to claim 1, wherein the chemical solution is a developer for a photoresist film.   The semiconductor substrate processing apparatus according to claim 1, wherein the chemical solution is a photoresist solution. Holding the semiconductor substrate on a stage having a rotating shaft attached to the lower surface;
Supplying a chemical onto the semiconductor substrate;
Rotating the stage and the semiconductor substrate by rotating the rotating shaft;
Changing the mounting position of the rotating shaft with respect to the stage;
Rotating the stage and the semiconductor substrate again by rotating the rotating shaft again;
A method for manufacturing a semiconductor device comprising: The step of changing the mounting position of the rotating shaft includes:
Lifting the stage relative to the rotational axis;
Moving the rotating shaft in a lateral direction;
Lowering the stage;
A method for manufacturing a semiconductor device according to claim 5. Forming a photoresist film on a semiconductor substrate;
Exposing the photoresist film;
Developing the photoresist film;
Implanting impurities into the semiconductor substrate using the developed photoresist film as a mask;
Comprising
The step of developing the photoresist film includes:
Holding the semiconductor substrate coated with the photoresist film on a stage having a rotating shaft attached to the lower surface;
Supplying a developer onto the semiconductor substrate;
Stirring the developer on the semiconductor substrate by rotating the stage and the semiconductor substrate by rotating the rotating shaft;
Changing the mounting position of the rotating shaft with respect to the stage;
A step of stirring the developer on the semiconductor substrate by rotating the rotating shaft again to rotate the stage and the semiconductor substrate again;
A method for manufacturing a semiconductor device comprising: The method of manufacturing a semiconductor device according to claim 7, wherein a thickness of the photoresist film is 0.5 μm or more.

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