JP2005243813A - Method and device for substrate processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing method and a substrate processing device capable of processing not only the front surface of a substrate but also the end surface and the rear surface of the substrate. <P>SOLUTION: A spin chuck 1 comprises a spin shaft 11 extending substantially vertically, a thin-dish-shaped spin base 12 provided at the upper end of the spin shaft 11, and a plurality of support members 13 arranged in this thin-dish-shaped spin base 12 for supporting a wafer W cooperatively. An unwanted resist formed on the upper surface and end surface of the wafer W is separated with an SPM to be supplied from an SPM nozzle 2 to the upper surface of the wafer W. Further, when the SPM is supplied to the upper surface of the wafer W, the SPM flowing downstream from the upper surface of the wafer W is stored in the thin-dish-shaped spin base 12, and the unwanted resist formed on the lower surface of the wafer W is separated with the stored SPM. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for processing a substrate. Substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal display devices, glass substrates for plasma displays, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, and the like. .

  In the manufacturing process of a semiconductor device or a liquid crystal display device, for example, a process (resist stripping process) is performed to remove an unnecessary resist from the surface of a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display panel. As a method of resist stripping, a batch method for processing a plurality of substrates at once has been the mainstream, but recently, with the increase in size of the substrate to be processed, the resist stripping is performed on the surface of the substrate. A single-wafer method that supplies a liquid and processes substrates one by one has been attracting attention.

A conventional apparatus for performing a single-wafer type resist stripping process is a spin chuck that rotates while holding a substrate substantially horizontally, and a resist stripping solution for supplying a resist stripping solution to the surface (upper surface) of the substrate held by the spin chuck. And a nozzle. While the substrate is rotated by the spin chuck, the resist stripping solution is supplied to the entire surface of the substrate by supplying the resist stripping solution from the nozzle to the surface of the rotating substrate, and the resist stripping process is performed on the surface of the substrate. Is achieved (for example, see Patent Document 1).
JP-A 61-1229829

  The resist on the surface of the substrate is formed by rotating the substrate around a vertical axis passing through its center in a substantially horizontal posture and supplying a resist solution to the surface of the rotating substrate. A part of the resist solution supplied to the front surface of the substrate travels along the end surface of the substrate to the back surface (lower surface), and flows down from the peripheral portion of the back surface (a region having a very small width along the peripheral surface). Therefore, the resist is formed not only on the front surface of the substrate but also on the peripheral edge portions of the end surface and the back surface of the substrate. In addition, a fine resist may be formed due to adhesion of a mist of a resist solution in the central portion (region inside the peripheral portion) of the back surface of the substrate.

The resist formed on the end surface and the back surface of the substrate becomes particles and may cause a problem of substrate contamination.
Accordingly, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can perform processing not only on the surface of a substrate but also on the end surface and the back surface of the substrate.

  According to the first aspect of the present invention for achieving the above object, there is provided a substrate support step (S1) in which the substrate (W) to be processed is supported by the substrate support means (13) in a substantially horizontal posture with its surface facing upward. ), A processing liquid supply step (S3) for supplying a processing liquid to the surface of the substrate supported by the substrate support means, and a processing liquid storage dish (12) for the processing liquid flowing down from the substrate during the processing liquid supply step And a processing liquid storage step (S3, S4) for storing the processing liquid in the processing liquid storage dish at a height higher than the height contacting the back surface of the substrate. is there.

The surface of the substrate refers to a device formation surface of the substrate. Further, the back surface of the substrate refers to a non-device forming surface of the substrate.
In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to the first aspect of the present invention, in the processing liquid supply step, the processing liquid supplied to the surface of the substrate flows on the surface of the substrate and flows down from the peripheral edge of the surface of the substrate along the end surface. As a result, the surface of the substrate and the end surface can be processed with the processing liquid. Further, in the processing liquid storage step, the processing liquid flowing down from the substrate is stored in the processing liquid storage dish, and the stored processing liquid contacts at least the back surface of the substrate, so that the processing liquid is applied to the back surface of the substrate. Can be processed.

2. The substrate according to claim 1, further comprising a substrate rotating step of rotating the substrate supported by the substrate supporting means around a rotation axis intersecting the surface of the substrate. It is a processing method.
According to the second aspect of the present invention, for example, the substrate rotation process is performed in parallel with the process liquid supply process, so that the centrifugal force is applied to the process liquid supplied to the upper surface of the substrate so that the upper surface of the substrate A good flow of processing liquid can be formed. In addition, by performing the substrate rotation step in parallel with the processing liquid storage step, it is possible to replace the reacted processing liquid that has contributed to the processing and the unreacted processing liquid that has not contributed to the processing on the back surface of the substrate. And better processing of the backside of the substrate can be achieved.

According to a third aspect of the present invention, the processing liquid may be a resist stripping liquid for stripping a resist formed on a substrate to be processed. In this case, unnecessary resist can be satisfactorily peeled from the front surface, back surface, and end surface of the substrate.
According to a fourth aspect of the present invention, the processing liquid storage step stores the processing liquid in the processing liquid storage dish until the liquid level reaches the upper edge of the end surface of the substrate supported by the substrate support means. The substrate processing method according to claim 1, wherein the substrate processing method is provided.

According to the invention described in claim 4, since the processing liquid is stored up to a height where the liquid surface reaches the upper edge of the end surface of the substrate, the processing liquid is processed not only on the back surface of the substrate but also on the end surface of the substrate. Can do.
According to the fifth aspect of the present invention, there is provided a substrate support means (13) for supporting the substrate (W) in a substantially horizontal posture with the surface thereof facing upward, and a treatment liquid on the surface of the substrate supported by the substrate support means. Receiving the processing liquid flowing from the substrate supported by the substrate support means and the processing liquid supply means (2), and storing the processing liquid at a height above which the processing liquid contacts the back surface of the substrate The substrate processing apparatus includes a processing liquid storage dish (12).

In the substrate processing apparatus having such a configuration, the invention of claim 1 can be implemented, and the effects described in relation to claim 1 can be achieved.
The invention according to claim 6 further includes substrate rotating means (14) for rotating the substrate supported by the substrate supporting means around a rotation axis intersecting the surface of the substrate. It is a substrate processing apparatus of description.

In the substrate processing apparatus having such a configuration, the invention of claim 2 can be implemented, and the effects described in relation to claim 2 can be achieved.
According to a seventh aspect of the present invention, the processing liquid storage dish rises from a bottom surface portion (121) facing the back surface of the substrate supported by the substrate support means at a predetermined interval, and a peripheral edge of the bottom surface portion. The upper end edge has a side surface portion (122) formed at a height located above the surface of the substrate supported by the substrate support means. The substrate processing apparatus according to claim 1.

  In the substrate processing apparatus having such a configuration, the invention of claim 4 can be implemented, and the effects described in relation to claim 4 can be achieved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing the configuration of a substrate processing apparatus according to an embodiment of the present invention. This substrate processing apparatus supplies a resist stripping solution to the surface of a silicon semiconductor wafer W (hereinafter simply referred to as “wafer W”), which is an example of a substrate, and strips unnecessary resist formed on the wafer W. The wafer W is held almost horizontally with its surface (device forming surface) facing upward and around the vertical axis passing through the substantially center of the held wafer W. A rotating spin chuck 1 and an SPM nozzle for supplying SPM (sulfuric acid / hydrogen peroxide mixture) as a resist stripping solution to the upper surface (surface) of the wafer W held by the spin chuck 1 2 and a DIW nozzle 3 for supplying DIW (deionized pure water) to the upper surface of the wafer W held by the spin chuck 1.

For example, the spin chuck 1 is provided with a spin shaft 11 extending substantially vertically, a thin plate-like spin base 12 serving as a processing liquid storage dish provided at the upper end of the spin shaft 11, and the thin plate-like spin base 12. And a plurality of support members 13 as substrate support means for supporting the wafer W in cooperation.
The thin dish-shaped spin base 12 has a disk-shaped bottom surface portion 121 coupled to the upper end of the spin shaft 11 and a side surface portion 122 that rises upward from the periphery of the bottom surface portion 121. The bottom surface portion 121 is provided so that the central axis of the spin axis 11 passes through the center thereof in a state substantially along the horizontal plane. Further, the side surface portion 122 is formed such that when the wafer W is supported by the plurality of support members 13, the upper edge thereof is positioned slightly above the upper surface of the wafer W.

  The plurality of support members 13 are arranged on the upper surface of the bottom surface portion 121 of the thin plate-like spin base 12, and the wafer W is held in a thin plate shape by sandwiching the end surface of the wafer W at a plurality of different positions. Above the bottom surface portion 121 of the spin base 12, it can be supported in a state (substantially horizontal posture) facing the bottom surface portion 121 substantially parallel to the bottom surface 121 at a position spaced apart from the upper surface of the bottom surface portion 121. Further, the plurality of support members 13 are arranged on a circumference centered on the central axis of the bottom surface portion 121 (the central axis of the spin shaft 11), and when the wafer W is supported by the plurality of support members 13. In addition, the center of the wafer W is located on the central axis of the bottom surface portion 121.

  The spin shaft 11 is coupled to a rotation drive mechanism 14 as a substrate rotation means including a drive source such as a motor. By inputting a rotational force to the spin shaft 11 from the rotational drive mechanism 14, the spin shaft 11 can be rotated about its central axis. Therefore, when the wafer W is supported by the plurality of support members 13, a rotational force is input from the rotation drive mechanism 14 to the spin shaft 11, so that the wafer W is moved to the center of the spin shaft 11 together with the thin plate-like spin base 12. Can be rotated around the axis.

  The spin shaft 11 is a hollow shaft, and a DIW supply pipe 15 is inserted through the spin shaft 11. The DIW supply pipe 15 is supplied with DIW from a DIW supply source (not shown) via a DIW valve 16. The upper end (tip) of the DIW supply pipe 15 forms a discharge port in the vicinity of the upper surface of the bottom surface portion 121 of the thin plate-like spin base 12, and the DIW flowing through the DIW supply pipe 15 supports a plurality of supports from the discharge port. The ink is discharged toward the center of the lower surface of the wafer W supported by the member 13.

  The SPM nozzle 2 is attached to the tip of an arm 21 extending substantially horizontally above the spin chuck 1 with the discharge port facing downward. The arm 21 is supported by a support shaft 22 extending substantially vertically on the side of the spin chuck 1. The support shaft 22 is coupled to an elevating mechanism 23 including a cylinder or the like, and the elevating mechanism 23 can elevate the support shaft 22 in the vertical direction. As a result, the arm 21 can be moved up and down as the support shaft 22 moves up and down, and the position of the SPM nozzle 2 with the arm 21 retracted above the spin chuck 1 and the wafer W held on the spin chuck 1. It can be raised and lowered to a position where the discharge port is close to the upper surface of the plate.

  An SPM supply path 41 is connected to the SPM nozzle 2. The SPM supply path 41 is supplied with the sulfuric acid supplied from the sulfuric acid supply path 42 and the hydrogen peroxide solution supplied from the hydrogen peroxide solution supply path 43 through a mixing valve 44. A sulfuric acid valve 45 for switching supply / stop of sulfuric acid to the mixing valve 44 is interposed in the middle of the sulfuric acid supply path 42. On the other hand, a hydrogen peroxide water valve 46 for switching supply / stop of the hydrogen peroxide water to the mixing valve 44 is interposed in the middle of the hydrogen peroxide water supply path 43.

  In the middle of the SPM supply path 41, a circulation pipe 47 with stirring fins for stirring sulfuric acid and hydrogen peroxide solution supplied from the mixing valve 44 to the SPM supply path 41 is interposed. The stirring fin-equipped flow pipe 47 includes a plurality of stirring fins, each of which is formed of a rectangular plate having a twist of about 180 degrees around the liquid flow direction in the pipe member, around the central axis of the pipe along the liquid flow direction. The rotation angles of the two are alternately arranged by 90 degrees. For example, the trade name “MX Series: Inline Mixer” manufactured by Noritake Company Limited Advance Electric Industries, Ltd. can be used.

In the flow pipe 47 with stirring fins, the mixed solution of sulfuric acid and hydrogen peroxide solution is sufficiently stirred, so that a chemical reaction between sulfuric acid and hydrogen peroxide solution (H ₂ SO ₄ + H ₂ O ₂ → H ₂ SO _5). + H ₂ O) occurs, and SPM containing H ₂ SO ₅ having strong oxidizing power is generated. At that time, heat is generated due to a chemical reaction (reaction heat), and due to this heat generation, the liquid temperature of the SPM is sufficiently higher than the temperature at which the resist formed on the surface of the wafer W can be satisfactorily peeled (for example, 120 To 130 ° C.).

The high-temperature SPM generated by the stirring fin-equipped flow pipe 47 in this way is supplied to the SPM nozzle 2 through the SPM supply path 41, and the wafer W held on the spin chuck 1 from the discharge port of the SPM nozzle 2. Discharged toward the center of the upper surface.
The DIW nozzle 3 is provided above the spin chuck 1 with the discharge port facing downward. The DIW nozzle 3 is supplied with DIW from a DIW supply source (not shown) via a DIW valve 31. DIW supplied to the DIW nozzle 3 is discharged from the discharge port of the DIW nozzle 3 toward the center of the upper surface of the wafer W held by the spin chuck 1.

The resist stripping apparatus further includes a control unit 5 having a configuration including a microcomputer. The controller 5 controls the operations of the rotation drive mechanism 14 and the lifting mechanism 23. Further, the control unit 5 controls the opening and closing of the DIW valves 16 and 31, the sulfuric acid valve 45 and the hydrogen peroxide solution valve 46.
FIG. 2 is a flowchart for explaining a process (resist stripping process) in the resist stripping apparatus.

The wafer W to be processed is carried in by a transfer robot (not shown), transferred from the transfer robot to the spin chuck 1, and held on the spin chuck 1 with the device forming surface facing upward. (Supported by a plurality of support members 13) (step S1). At this time, the SPM nozzle 2 is retracted above the spin chuck 1.
When the wafer W is held on the spin chuck 1, first, the wafer W is rotated at a predetermined low rotation speed (for example, 30 rpm). Further, the SPM nozzle 2 is lowered and the SPM nozzle 2 is brought close to the upper surface of the wafer W (step S2).

  Next, the sulfuric acid valve 45 and the hydrogen peroxide water valve 46 are opened, and SPM is discharged from the SPM nozzle 2 toward the center of the upper surface of the rotating wafer W (step S3). Since the SPM nozzle 2 is brought close to the upper surface of the wafer W, it is possible to prevent the high-temperature SPM discharged from the SPM nozzle 2 from being cooled before reaching the upper surface of the wafer W. SPM can be supplied. Further, it is possible to prevent the SPM from splashing around the upper surface of the wafer W and being scattered around.

  The high-temperature SPM supplied to the upper surface of the wafer W receives a weak centrifugal force due to the rotation of the wafer W and flows from the supply position (the center of the upper surface) toward the peripheral edge of the upper surface of the wafer W. A liquid film of SPM having a flow from the center toward the periphery is formed. As a result, the high-temperature SPM uniformly spreads over the entire upper surface of the wafer W, and unnecessary resist formed on the upper surface of the wafer W is peeled off. Further, the SPM that forms a liquid film on the upper surface of the wafer W overflows from the peripheral edge of the upper surface of the wafer W and flows down along the end surface of the wafer W by supplying a new SPM. As a result, the resist formed on the end face of the wafer W is peeled off.

  SPM discharge from the SPM nozzle 2 is continued for a predetermined time (for example, 30 seconds). During this time, the SPM flowing down from the wafer W is received and stored in the thin dish-shaped spin base 12. At the time when the SPM discharge is stopped, the height at which the SPM that has flowed down from the upper surface of the wafer W contacts at least the lower surface of the wafer W (the back surface that is a non-device forming surface) in the thin plate-like spin base 12. It will be in the state accumulated above.

  When the SPM discharge is stopped, the SPM flow from the peripheral edge of the upper surface of the wafer W almost disappears, and a substantially stationary SPM liquid film is formed on the upper surface of the wafer W. The state where the stationary SPM liquid film is formed (paddle state) is maintained until a predetermined paddle time (for example, 30 seconds) elapses after the SPM discharge is stopped (step S4). In the meantime, the resist remaining on the upper surface of the wafer W is peeled off cleanly. Further, since the SPM stored in the thin plate-like spin base 12 is always in contact with the lower surface of the wafer W, the resist formed on the lower surface of the wafer W is peeled off.

  Even while the paddle state is maintained, the wafer W continues to be rotated at the low rotation speed continuously from before the SPM discharge is stopped. Thereby, on the lower surface of the wafer W, the reacted SPM that has contributed to resist stripping can be replaced with the unreacted SPM that has not contributed to resist stripping, and unnecessary resist formed on the lower surface of the wafer W can be removed. It can peel well.

  When the paddle time has elapsed, after the SPM nozzle 2 is raised (step S5), the rotation speed of the wafer W by the spin chuck 1 is increased to a predetermined rinse rotation speed (for example, 500 rpm). Thereafter, the DIW valves 31 and 16 are opened, and DIW is supplied from the DIW nozzle 3 and the DIW supply pipe 15 to the center of the upper surface and the center of the lower surface of the wafer W, respectively (step S6). The DIW supplied to the center of the upper surface and the lower surface of the wafer W is guided from the supply position to the outer side in the rotational radius direction of the wafer W by the centrifugal force received as the wafer W rotates. Further, a part of DIW supplied to the upper surface of the wafer W flows down along the end surface of the wafer W. Thereby, the SPM adhering to the upper surface, the lower surface and the end surface of the wafer W can be washed away cleanly (DIW rinse).

  When the DIW is supplied for a predetermined rinsing time (for example, 30 seconds), the rotation speed of the wafer W is increased to a predetermined high rotation speed (for example, 3000 rpm), and the DIW adhering to the wafer W is shaken off. A spin dry process for drying is performed (step S7). This spin dry process is performed over a predetermined spin dry time (for example, 30 seconds). After the spin dry process, the rotational speed of the wafer W is reduced, and when the wafer W is stationary, the processed wafer W is unloaded from the spin chuck 1 by a transfer robot (not shown).

  As described above, according to this embodiment, unnecessary resist formed on the upper surface and the end surface of the wafer W can be peeled off satisfactorily by the SPM supplied to the upper surface of the wafer W. Further, when the SPM is supplied to the upper surface of the wafer W, the SPM flowing down from the upper surface of the wafer W is stored in the thin plate-like spin base 12, and the stored SPM comes into contact with the lower surface of the wafer W, thereby The unnecessary resist formed on the lower surface of W can be peeled off satisfactorily.

Furthermore, if the SPM in the thin plate-like spin base 12 is stored up to a height at which the liquid level reaches the upper end of the end surface of the wafer W, while the paddle state is maintained, not only the lower surface of the wafer W, The end surface of the wafer W can also be processed by SPM, and the possibility that the resist remains on the end surface of the wafer W can be further eliminated.
The description of one embodiment of the present invention is as described above, but the present invention can be implemented in other forms. For example, while the paddle state is maintained, the wafer W may be rotated at a rotation speed lower than the low rotation speed, or the rotation of the wafer W may be stopped.

In the above-described embodiment, SPM, which is a mixed solution of sulfuric acid and hydrogen peroxide solution, is used as the resist stripping solution. However, a mixed solution of sulfuric acid and ozone water may be used as the resist stripping solution.
Furthermore, the wafer W is taken up as an example of a substrate to be processed. However, the present invention is not limited to the wafer W, but a glass substrate for a liquid crystal display device, a glass substrate for a plasma display panel, a glass substrate for a photomask, and a magnetic / optical disk substrate. Other types of substrates may be targeted for processing.

  In addition, various design changes can be made within the scope of matters described in the claims.

1 is a diagram schematically showing a configuration of a substrate processing apparatus according to an embodiment of the present invention. It is a flowchart for demonstrating the process in the resist peeling apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spin chuck 2 SPM nozzle 12 Thin plate-shaped spin base 13 Support member 14 Rotation drive mechanism 121 Bottom face part 122 Side face part W Silicon semiconductor wafer

Claims (7)

A substrate support step of supporting the substrate to be processed by the substrate support means in a substantially horizontal posture with the surface facing upward;
A treatment liquid supply step of supplying a treatment liquid to the surface of the substrate supported by the substrate support means;
A processing liquid storage step for receiving the processing liquid flowing down from the substrate during the processing liquid supply step by the processing liquid storage dish and storing the processing liquid in the processing liquid storage dish at a height higher than the height in contact with the back surface of the substrate. And a substrate processing method.   2. The substrate processing method according to claim 1, further comprising a substrate rotating step of rotating the substrate supported by the substrate supporting means around a rotation axis intersecting the surface of the substrate.   The substrate processing method according to claim 1, wherein the processing liquid is a resist stripping liquid for stripping a resist formed on a substrate to be processed.   The processing liquid storage step is a step of storing the processing liquid in the processing liquid storage dish until the liquid level reaches the upper end of the end surface of the substrate supported by the substrate support means. 4. The substrate processing method according to any one of 1 to 3. Substrate support means for supporting the substrate in a substantially horizontal posture with the surface facing upward;
Treatment liquid supply means for supplying a treatment liquid to the surface of the substrate supported by the substrate support means;
Receiving a processing liquid flowing down from the substrate supported by the substrate support means, and storing a processing liquid on a back surface of the substrate at a height higher than a level at which the processing liquid contacts the processing liquid storage dish. Substrate processing apparatus.   6. The substrate processing apparatus according to claim 5, further comprising substrate rotating means for rotating the substrate supported by the substrate supporting means about a rotation axis intersecting the surface of the substrate. The processing liquid storage dish rises from a bottom surface portion opposed to the back surface of the substrate supported by the substrate support means at a predetermined interval, and a peripheral edge of the bottom surface portion, and an upper end edge of the treatment liquid storage dish serves as the substrate support means. The substrate processing apparatus according to claim 5, further comprising a side surface portion formed at a height above the surface of the supported substrate.

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