JP2007234814A - Substrate processing apparatus, and charge eliminating method of processing liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing apparatus and a charge eliminating method of a processing liquid which can achieve charge elimination of the processing liquid without causing a problem of contamination of the processing liquid due to metal. <P>SOLUTION: The apparatus is provided with a processing chamber 1 for executing processing using the processing liquid for a wafer W, and a processing liquid cabinet 2 for supplying the processing liquid to the processing chamber 1. The processing liquid cabinet 2 is provided with a supply piping 10 for supplying the processing liquid reserved in a processing liquid tank 9 to the processing chamber 1. A heater 12 is provided to intervene in the middle of the supply piping 10. The heater 12 is provided with a quartz tube 15 formed using a quartz and capable of circulating the processing liquid, and the quartz tube 15 is grounded via a grounding wire 17. With this configuration, when the processing liquid flowing through the supply piping 10 contacts the quartz tube 15, charges on the processing liquid can be eliminated via the quartz tube 15 and the grounding wire 17. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a plasma display, a glass substrate for FED (Field Emission Display), an optical disk substrate, a magnetic disk substrate, a magneto-optical disk substrate, a photomask substrate, etc. The present invention relates to a substrate processing apparatus for processing various substrates typified by (1) and a method for neutralizing a processing liquid in the substrate processing apparatus.

In the manufacturing process of a semiconductor device or a liquid crystal display device, a treatment liquid is supplied to the surface of a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display panel, and the surface of the substrate is washed with the treatment liquid.
For example, an apparatus for carrying out a single wafer cleaning process that processes substrates one by one holds the substrate substantially horizontally with a plurality of chuck pins in a processing chamber partitioned by a partition wall. A spin chuck to be rotated and a nozzle for supplying a processing liquid to the surface of the substrate rotated by the spin chuck are provided. At the time of processing, the processing liquid is supplied from the nozzle near the rotation center of the surface of the substrate while the substrate is rotated by the spin chuck. The processing liquid supplied on the surface of the substrate receives centrifugal force due to the rotation of the substrate and flows on the surface of the substrate toward the periphery. As a result, the processing liquid spreads over the entire surface of the substrate, and a cleaning process with the processing liquid is achieved on the surface of the substrate.

A processing liquid cabinet for supplying a processing liquid to the nozzle is provided adjacent to the processing chamber. The processing liquid cabinet is provided with a processing liquid tank and the like, and the processing liquid stored in the processing liquid tank is supplied to the nozzle through a supply pipe. Further, when it is necessary to adjust the temperature of the processing liquid, a heater for heating the processing liquid is interposed in the middle of the supply pipe, and downstream of the heater in the flow direction of the processing liquid, A return pipe for returning the processing liquid to the processing liquid tank is branched and connected. And while supply of the processing liquid with respect to a nozzle is stopped, the processing liquid sent out from a processing liquid tank is returned to a processing liquid tank via return piping. As a result, the processing liquid circulates through the processing liquid tank, the supply pipe, and the return pipe, and the processing liquid stored in the processing liquid tank is maintained at a constant temperature.
JP 2006-24793 A

  In such an apparatus, since a chemical solution such as hydrochloric acid is often used as a processing solution, a resin material having excellent chemical resistance is generally used as a material for the processing solution tank, supply piping, and return piping. . However, if they are formed of a resin material, the treatment liquid is charged by friction with the resin material during circulation of the treatment liquid. When the charged processing liquid is supplied to the substrate, a discharge from the processing liquid to the substrate occurs, and this discharge may destroy a device formed on the substrate. Further, if the charge amount of the processing liquid exceeds the limit amount, discharge to the temperature measuring sensor or the like disposed in the processing liquid tank may occur, and the temperature measuring sensor or the like may be destroyed.

  In order to avoid these problems, for example, a conductive member such as amorphous carbon or metal is provided at a position where it can come into contact with the processing liquid, and this conductive member is grounded to achieve neutralization of the processing liquid. It is possible. However, in this method, a new problem of processing solution contamination (metal contamination) due to the elution of components of the conductive member such as amorphous carbon and metal into the processing solution occurs.

  Accordingly, an object of the present invention is to provide a substrate processing apparatus and a processing liquid neutralizing method capable of achieving neutralization of the processing liquid without causing a problem of metal contamination of the processing liquid.

  The invention according to claim 1 for achieving the above object includes a processing section (1) for performing processing with a processing liquid on a substrate, a storage tank (9) for storing the processing liquid, A pipe (10) for supplying a processing liquid from the storage tank to the processing unit, and at least a part (15; 21) of the storage tank or the pipe is formed of quartz and grounded. A substrate processing apparatus.

In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to this configuration, at least a part of the storage tank or the pipe is formed using quartz, and the quartz part formed of the quartz is grounded. Therefore, when the treatment liquid comes into contact with the quartz part, the treatment is performed. Liquid neutralization can be achieved. Quartz has insulating properties, and the mechanism of charge removal due to contact between the quartz part and the treatment liquid is not always clear, but when the charged treatment liquid comes into contact with the quartz part, induction charging occurs in the quartz part. As a result, the charge of the quartz part is released, and as a result, it is considered that neutralization of the treatment liquid is achieved. Further, since quartz is not a metal material, even if quartz is used for a storage tank or a part of piping, there is no possibility of causing metal contamination of the processing liquid. Therefore, it is possible to achieve neutralization of the processing liquid without causing the problem of metal contamination of the processing liquid. As a result, device destruction, sensor destruction, and the like can be prevented, and good substrate processing can be achieved with a processing solution that does not cause metal contamination and charging.

  Further, the invention described in claim 2 is a processing unit (1) for performing processing with a processing liquid on a substrate (W), a storage tank (9) for storing the processing liquid, and the storage tank. And a pipe (10) for supplying a processing liquid to the processing section from the substrate processing apparatus, wherein the storage tank or the pipe is a quartz portion formed using quartz ( 15; 21), wherein the quartz part is grounded, the treatment liquid is brought into contact with the quartz part, and the treatment liquid supplied to the treatment part is discharged. This is a static elimination method.

  According to this method, an effect similar to the effect described in relation to claim 1 can be achieved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view schematically showing the configuration of a substrate processing apparatus according to an embodiment of the present invention.
This substrate processing apparatus is a single-wafer type apparatus that processes semiconductor wafers (hereinafter simply referred to as “wafers”) W, which is an example of a substrate, one by one. And a processing liquid cabinet 2 for supplying the processing liquid to the processing chamber 1 separately from the processing chamber 1.

The processing chamber 1 is partitioned by a partition wall, and a spin chuck 3 for rotating the wafer W while holding the wafer W substantially horizontally, and a surface (upper surface) of the wafer W held by the spin chuck 3. A nozzle 4 for supplying the processing liquid and a cup 5 for receiving the processing liquid flowing down or splashing from the wafer W are provided.
The spin chuck 3 can hold the wafer W in a substantially horizontal posture, for example, by holding the wafer W with a plurality of holding members 6, and further rotates around a substantially vertical axis in that state. The held wafer W can be rotated while maintaining a substantially horizontal posture.

The spin chuck 3 is not limited to such a configuration. For example, the lower surface of the wafer W is vacuum-sucked to hold the wafer W in a substantially horizontal posture, and in that state, a substantially vertical axis. A vacuum chucking type (vacuum chuck) that can rotate the held wafer W by rotating around may be employed.
The nozzle 4 is attached to the tip of an arm 7 provided above the spin chuck 3. The arm 7 is supported by a support shaft 8 extending substantially vertically on the side of the cup 5, and extends substantially horizontally from the upper end portion of the support shaft 8. The support shaft 8 is provided so as to be rotatable about its central axis, and by rotating the support shaft 8, the arm 7 is swung in a horizontal plane, and the nozzle 4 is held by the spin chuck 3. It can arrange | position to the waiting position set outside the cup 5, or the outer side of the cup 5.

The nozzle 4 is not limited to having such a scan nozzle configuration, and a fixed nozzle that is fixedly disposed in the processing chamber 1 may be employed.
During the processing of the wafer W, the processing liquid is supplied from the nozzle 4 to the surface of the rotating wafer W while the wafer W is rotated by the spin chuck 3. The processing liquid supplied to the surface of the wafer W receives centrifugal force due to the rotation of the wafer W and flows from the supply position toward the periphery of the wafer W. In parallel with this, the arm 7 is swung within a predetermined angle range, and the supply position of the processing liquid from the nozzle 4 is scanned (moved) on the surface of the wafer W. As a result, the processing liquid is evenly distributed over the entire surface of the wafer W, and the processing using the processing liquid on the surface of the wafer W is achieved.

  If the process for the wafer W is a process using a processing solution, for example, a chemical solution such as hydrochloric acid or pure water is supplied to the surface of the wafer W, and unnecessary substances such as particles and various metal impurities are supplied from the surface of the wafer W. It may be a cleaning process that removes. When a chemical solution is used, it is preferable to perform a rinsing process in which pure water is supplied to the surface of the wafer W and the chemical solution is washed from the surface of the wafer W after the treatment with the chemical solution. Alternatively, an oxidation treatment may be performed in which an oxidation treatment liquid is supplied to the surface of the wafer W to form an oxide film on the surface of the wafer W. Alternatively, a resist stripping process is performed in which a resist stripping solution such as SPM (sulfuric acid / hydrogen peroxide mixture) is supplied to the surface of the wafer W to remove unnecessary resist films from the surface of the wafer W. Alternatively, it may be a polymer removal process in which a polymer removing solution is supplied to the surface of the wafer W to remove the polymer (resist residue) on the surface of the wafer W.

  The processing liquid cabinet 2 is provided with a processing liquid tank 9 for storing the processing liquid and a supply pipe 10 for supplying the processing liquid stored in the processing liquid tank 9 to the nozzle 4. The treatment liquid tank 9 is formed of a resin material having chemical resistance. Further, the supply pipe 10 is mainly formed of a resin material having chemical resistance, but a part thereof is formed of quartz as will be described later.

  One end of the supply pipe 10 is disposed in the processing liquid stored in the processing liquid tank 9, extends from the processing liquid cabinet 2 to the processing chamber 1, and the other end is connected to the nozzle 4. In the middle of the supply pipe 10, a pump 11 for pumping out the processing liquid stored in the processing liquid tank 9 in order from the processing liquid tank 9 side, and a process that flows through the supply pipe 10 by the action of the pump 11. A heater 12 for adjusting the temperature of the liquid, a filter 18 for removing foreign substances contained in the processing liquid, and a valve 13 for opening and closing the supply pipe 10 are provided. A return pipe 14 is branched and connected to the supply pipe 10 between the filter 18 and the valve 13. A valve 19 is interposed in the return pipe 14. The tip of the return pipe 14 is connected to the processing liquid tank 9.

  During the operation of the apparatus, the pump 11 and the heater 12 are always driven, and when processing the wafer W, the valve 19 is closed and the valve 13 is opened. 4 is supplied. On the other hand, when the processing of the wafer W is not performed (when the processing liquid is not supplied to the surface of the wafer W), the valve 19 is opened and the valve 13 is closed, so that the processing liquid flowing through the supply pipe 10 is discharged. It returns to the processing liquid tank 9 through the return pipe 14. Thus, when the wafer W is not processed, the processing liquid is circulated through the circulation path including the processing liquid tank 9, the supply pipe 10 and the return pipe 14. By circulating the processing liquid in this way, the temperature of the processing liquid can be adjusted to a constant temperature, and the processing liquid whose temperature has been adjusted can be stored in the processing liquid tank 9. When the valve 19 is closed and the valve 13 is opened, the processing liquid whose temperature is adjusted to the constant temperature can be supplied to the nozzle 4 promptly.

  As shown in FIG. 3, the heater 12 includes a quartz tube 15 made of quartz and a heating lamp 16. The quartz tube 15 constitutes a part of the supply pipe 10, and the processing liquid sent from the processing liquid tank 9 side can be circulated to the valve 13 side by driving the pump 11. More specifically, the quartz tube 15 is a cylindrical hollow container having a U-shaped cross section, and includes an outer tube 15a and an inner tube 15b having different diameters. And between the outer tube 15a and the inner tube 15b, the flow path SP which can distribute | circulate a process liquid is formed. A heating lamp 16 is fitted in the inner tube 15b. A fluid inlet pipe 15c and a fluid outlet pipe 15d are formed between the outer pipe 15a and the inner pipe 15b on the opposite side of the top wall of the outer pipe 15a. Then, the pump 11 is driven to circulate the processing liquid from the fluid inlet pipe 15 c of the quartz tube 15 to the flow path SP, and the heating lamp 16 is turned on to add the processing liquid flowing through the quartz tube 15. Can be warmed.

The quartz tube 15 is grounded via a ground wire 17. As a result, when the processing liquid flowing through the supply pipe 10 comes into contact with the quartz tube 15, the charge on the processing liquid can be removed via the quartz tube 15 and the ground wire 17.
For example, a processing liquid (for example, SPM) is put in a beaker made of quartz, and a charged fluororesin member is brought close to the beaker to charge the processing liquid to −5 kV, and then a ground wire is connected to the beaker and grounded. When the experiment was conducted, the treatment liquid was gradually neutralized, and the voltage of the treatment liquid dropped to 0 V when about 10 seconds had elapsed. From this experimental result, when the charged processing solution comes into contact with the quartz tube 15, induction charging occurs in the quartz tube 15, and the charge in the quartz tube 15 is released through the ground wire 17, resulting in the processing solution. It is thought that the static elimination of this is achieved.

  Since quartz is not a metal material, even if a part of the supply pipe 10 is composed of the quartz pipe 15 (even if the quartz pipe 15 is interposed in the supply pipe 10), there is a possibility of causing metal contamination of the processing liquid. Absent. Therefore, in this substrate processing apparatus, neutralization of the processing liquid can be achieved without causing the problem of metal contamination of the processing liquid. As a result, device breakdown or sensor breakdown due to discharge of the processing liquid can be prevented, and processing liquid free from metal contamination and charging can be supplied to the wafer W. Processing can be achieved.

FIG. 2 is a cross-sectional view schematically showing the configuration of a substrate processing apparatus according to another embodiment of the present invention. In FIG. 2, parts corresponding to the parts shown in FIG. 1 are denoted by the same reference numerals as those parts. Further, in the following, detailed description of each part given the same reference numeral is omitted.
In the substrate processing apparatus shown in FIG. 2, a part 21 of the processing liquid tank 9 is formed using quartz, and the remaining part is formed using a resin material having chemical resistance. A portion (quartz portion) 21 formed of quartz is disposed so as to be exposed on the inner surface of the processing liquid tank 9 and is in contact with the processing liquid stored in the processing liquid tank 9. The quartz portion 21 is grounded via a ground wire 22.

When the processing liquid stored in the processing liquid tank 9 comes into contact with the quartz portion 21, the charge on the processing liquid can be removed via the quartz portion 21 and the ground wire 22. Therefore, the same effect as the substrate processing apparatus shown in FIG. 1 can be achieved.
As mentioned above, although embodiment of this invention was described, this invention can also be implemented with another form. For example, in the substrate processing apparatus shown in FIG. 1, the heater formed using quartz is grounded. However, a part of the supply pipe 10 may be formed of quartz and grounded. Further, in the substrate processing apparatus shown in FIG. 1, a part of the supply pipe 10 is formed using quartz, and in the substrate processing apparatus shown in FIG. 2, a part of the processing liquid tank 9 is formed using quartz. However, the entire processing liquid tank 9 and / or the supply pipe 10 may be formed of quartz.

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

1 is a cross-sectional view schematically showing a configuration of a substrate processing apparatus according to an embodiment of the present invention. It is sectional drawing which shows schematically the structure of the substrate processing apparatus which concerns on other embodiment of this invention. It is sectional drawing which shows the structure of a heater illustratively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing chamber 9 Processing liquid tank 10 Supply piping 15 Quartz tube 17 Ground wire 21 Quartz part 22 Ground wire W Wafer

Claims (2)

A processing unit for performing processing with a processing liquid on the substrate;
A storage tank for storing the processing liquid;
A pipe for supplying a processing liquid from the storage tank to the processing unit,
At least a part of the storage tank or the pipe is formed using quartz and is grounded. In a substrate processing apparatus comprising: a processing unit for processing a substrate with a processing liquid; a storage tank for storing the processing liquid; and a pipe for supplying the processing liquid from the storage tank to the processing unit. A method for neutralizing a processing solution,
The storage tank or the pipe has a quartz portion formed using quartz,
A neutralizing method for a processing liquid, wherein the quartz part is grounded, a processing liquid is brought into contact with the quartz part, and the processing liquid supplied to the processing unit is neutralized.

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