JP2009267005A - Substrate cleaning method, substrate cleaning apparatus and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a substrate cleaning method capable of reducing a sticking possibility of particles to a substrate as compared with a conventional one and capable of purely cleaning the substrate; a substrate cleaning apparatus; and a substrate processing apparatus. <P>SOLUTION: The substrate cleaning apparatus 1 includes a substrate support mechanism 2 supporting a periphery portion of a semiconductor wafer W. An injection mechanism 4 provided at a front surface side of the semiconductor wafer W injects at an ordinary temperature and in a normal pressure gaseous cleaning body, for example, at least part of carbon oxide from an injection nozzle 3 to the front surface of the semiconductor wafer W as solid or liquid particulates. A heating mechanism 6 for a back surface side of the semiconductor wafer W supplies a heated gas from a gas nozzle 5 to the backside of the semiconductor wafer W and locally heats a site corresponding to an injection position of the injection nozzle 3. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a substrate cleaning method, a substrate cleaning apparatus, and a substrate processing apparatus for cleaning a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal device.

  Substrate cleaning methods for cleaning substrates such as semiconductor wafers and glass substrates for liquid crystal devices are roughly classified into wet cleaning using a liquid cleaning agent at room temperature and normal pressure, and dry cleaning without using such a cleaning agent. is there. Dry cleaning includes removing air particles attached to the substrate with air pressure, applying ultrasonic waves to such air, and blowing carbon dioxide solid particles (dry ice) (carbon dioxide blast cleaning). It has been known.

In the dry cleaning described above, a technique is known in which carbon dioxide and the like blown onto the substrate and particles peeled off from the substrate are sucked and collected (see, for example, Patent Document 1). In addition, a technique is known in which the entire substrate is heated to promote evaporation of carbon dioxide solid particles (dry ice) (see, for example, Patent Document 2).
JP 2004-165229 A JP 7-8928 A

  As described above, conventionally, a cleaning method for performing dry cleaning of a substrate by spraying carbon dioxide solid particles (dry ice) or the like on the substrate has been used. In addition, a technique for collecting particles peeled from a substrate by sucking from the periphery of the substrate during dry cleaning of the substrate is also known. However, even if suction is performed in this way, it is difficult to completely prevent reattachment of particles peeled from the substrate, and there is a possibility that particles contained in the gas to be sprayed adhere to the substrate. Furthermore, there has been a need to develop a substrate cleaning method and the like that can reduce the possibility of particles adhering to the substrate and cleanly clean the substrate.

  The present invention has been made in response to such a conventional situation, and can reduce the possibility of adhesion of particles to the substrate as compared with the conventional case, and can clean the substrate cleanly and the substrate. An object is to provide a cleaning apparatus and a substrate processing apparatus.

  The substrate cleaning method according to claim 1, wherein at least a part of a gas cleaning body at normal temperature and pressure is sprayed as a solid or liquid fine particle from a spray nozzle onto a surface to be cleaned of the substrate, and the spray is performed from the back side of the substrate. A site corresponding to the spray position of the nozzle is locally heated.

  A substrate cleaning method according to claim 2 is the substrate cleaning method according to claim 1, wherein the substrate is scanned by relatively moving the injection nozzle and the substrate with respect to the injection position from the injection nozzle. The heating position from the back side is scanned.

  A substrate cleaning method according to claim 3 is the substrate cleaning method according to claim 1 or 2, wherein the cleaning body is carbon dioxide.

  The substrate cleaning method according to claim 4 is the substrate cleaning method according to any one of claims 1 to 3, wherein heated gas is supplied from a back surface side of the substrate to a portion corresponding to an injection position of the injection nozzle. And the said site | part is heated locally.

  A substrate cleaning method according to a fifth aspect is the substrate cleaning method according to the fourth aspect, wherein the gas is air or nitrogen gas.

  The substrate cleaning apparatus according to claim 6 includes: an injection mechanism that injects at least a part of a gas cleaning body at normal temperature and pressure as solid or liquid fine particles from an injection nozzle onto a surface to be cleaned; and a back surface side of the substrate. And a heating mechanism for locally heating a portion corresponding to the spray position of the spray nozzle.

  A substrate cleaning apparatus according to a seventh aspect is the substrate cleaning apparatus according to the sixth aspect, wherein the injection position from the injection nozzle is scanned by relatively moving the injection nozzle and the substrate, and the substrate A scanning mechanism for scanning the heating position from the back side of the substrate is provided.

  A substrate cleaning apparatus according to an eighth aspect is the substrate cleaning apparatus according to the sixth or seventh aspect, wherein the injection mechanism injects carbon dioxide as the cleaning body.

  The substrate cleaning apparatus according to claim 9 is the substrate cleaning apparatus according to any one of claims 6 to 8, wherein the heating mechanism is disposed at a portion corresponding to an injection position of the injection nozzle from the back surface side of the substrate. A heated gas is supplied to locally heat the part.

  A substrate cleaning apparatus according to a tenth aspect is the substrate cleaning apparatus according to the ninth aspect, wherein the gas is air or nitrogen gas.

  The substrate processing apparatus according to claim 11 is a mounting unit for mounting a substrate storage container capable of storing a plurality of substrates, a processing unit for performing a predetermined process on the substrate, and a normal temperature and a normal pressure. An injection mechanism that injects at least a part of the gas cleaning body into solid or liquid fine particles from the injection nozzle onto the surface to be cleaned of the substrate, and a region corresponding to the injection position of the injection nozzle from the back side of the substrate. A substrate cleaning unit having a heating mechanism for automatically heating, a transport mechanism for transporting the substrate between the substrate container placed on the mounting unit, the processing unit, and the upper part of the substrate line It was characterized by comprising.

  A substrate processing apparatus according to a twelfth aspect is the substrate processing apparatus according to the eleventh aspect, in which the substrate cleaning unit relatively moves the spray nozzle and the substrate at a spray position from the spray nozzle. A scanning mechanism for scanning and scanning the heating position from the back side of the substrate is provided.

  A substrate processing apparatus according to a thirteenth aspect is the substrate cleaning apparatus according to the eleventh or twelfth aspect, wherein the injection mechanism of the substrate cleaning unit injects carbon dioxide as the cleaning body.

  The substrate processing apparatus of Claim 14 is a substrate processing apparatus of any one of Claims 11-13, Comprising: The said heating mechanism of the said board | substrate washing | cleaning part is in the injection position of the said injection nozzle from the back surface side of the said board | substrate. A heated gas is supplied to a corresponding part to locally heat the part.

  A substrate processing apparatus according to a fifteenth aspect is the substrate processing apparatus according to the fourteenth aspect, wherein the gas is air or nitrogen gas.

  According to the present invention, it is possible to provide a substrate cleaning method, a substrate cleaning apparatus, and a substrate processing apparatus that can reduce the possibility of adhesion of particles to the substrate as compared with the conventional case and can clean the substrate cleanly. it can.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a schematic configuration of a substrate cleaning method and a substrate cleaning apparatus according to an embodiment of the present invention, and FIG. 2 schematically shows a schematic configuration of a substrate processing apparatus according to an embodiment of the present invention. Show.

  As shown in FIG. 1, the substrate cleaning apparatus 1 includes a substrate support mechanism 2 that supports a peripheral portion of a semiconductor wafer W as a substrate to be cleaned. In FIG. 1, the upper side is the surface (surface to be cleaned) of the semiconductor wafer W, and the lower side is the back surface of the semiconductor wafer W.

An injection mechanism 4 having an injection nozzle 3 is provided on the surface side of the semiconductor wafer W. This injection mechanism 4 is a solid or liquid (solid in this embodiment) at least part of a gaseous cleaning body (for example, carbon dioxide, argon, nitrogen, etc. (carbon dioxide in the present embodiment)) at normal temperature and pressure. The fine particles are jetted from the jet nozzle 3 onto the surface (surface to be cleaned) of the semiconductor wafer W. That is, in the present embodiment, the injection mechanism 4 is constituted by a so-called CO ₂ blast cleaning mechanism. In addition, in this embodiment, although it has the structure which pumps said microparticles | fine-particles with other gas, such as air, it does not necessarily need to be the structure pumped with other gas, such as air.

  On the other hand, on the back side of the semiconductor wafer W, a heating mechanism 6 including a gas nozzle 5 provided at a position corresponding to the above-described injection nozzle 3 is provided. The heating mechanism 6 supplies heated gas (for example, air or nitrogen (air in this embodiment)) from the gas nozzle 5 toward the back surface of the semiconductor wafer W, and corresponds to the injection position of the injection nozzle 3. Is configured to be heated locally. The heating mechanism 6 can supply air having a temperature of, for example, about 100 ° C. at a flow rate of, for example, several tens to several hundreds of liters per minute.

Further, the substrate support mechanism 2 described above includes a drive mechanism 7, and the semiconductor wafer W is moved two-dimensionally in the xy direction, whereby the injection position from the injection nozzle 3 and the heating by the gas nozzle 5 are performed. The position (cleaning position) is scanned within the surface of the semiconductor wafer W.
Such scanning of the cleaning position may be performed by moving the injection nozzle 3 and the gas nozzle 5 while the semiconductor wafer W is fixed. The semiconductor wafer W, the injection nozzle 3 and the gas nozzle may be scanned. You may carry out by moving both.

  FIG. 3 shows an example of scanning of the cleaning position in the surface of the semiconductor wafer W described above. In this example, the surface of the semiconductor wafer W is scanned in a zigzag manner as indicated by a curve S shown in FIG. Such scanning of the cleaning position is performed in a straight line as shown by a straight line S shown in FIG. 4 when using the injection nozzle 3 and the gas nozzle 5 for injecting in a line as shown in FIG. That's fine. As shown in FIG. 5, when the substrate support mechanism 2 a that supports the center of the back surface of the semiconductor wafer W and can rotate the semiconductor wafer W is used, the straight line shown in FIG. The injection nozzle 3 and the gas nozzle 5 may be scanned linearly in the radial direction of the semiconductor wafer W as in S.

  In this way, in the substrate cleaning apparatus 1 of the present embodiment, the solid fine particles of carbon dioxide, that is, the dry fine particles of dry ice are pumped by air from the spray nozzle 3 and sprayed onto the surface of the semiconductor wafer W. The back surface side of the semiconductor wafer W corresponding to the above is cleaned by locally heating by supplying heated air from the gas nozzle 5. Then, the entire surface of the semiconductor wafer W is cleaned by performing such cleaning by scanning. As a result, the possibility of adhesion of particles to the semiconductor wafer W can be reduced as compared with the conventional case, and the semiconductor wafer W can be cleaned cleanly.

  Next, in this embodiment, the reason why the back surface side corresponding to the spray position of the spray nozzle 3 of the semiconductor wafer W is locally heated as described above will be described.

  The inventor has conventionally studied a particle adhesion preventing technique for preventing particles from adhering to a substrate by using thermophoresis by heating the substrate. In this technique, the entire substrate is heated to a temperature higher than the atmospheric temperature, thereby generating a temperature gradient in the atmosphere near the surface of the substrate. Due to this temperature gradient, the closer the floating particles are to the surface of the substrate, the greater the force acting in the direction away from the substrate, so that the particles can be prevented from adhering to the substrate surface.

  Therefore, an experiment was attempted to prevent the adhesion of particles in blast cleaning by using the particle adhesion prevention technology using thermophoresis for blast cleaning. In this experiment, a semiconductor wafer was mounted on a mounting table equipped with a resistance heater, and solid ice fine particles were pumped from the spray nozzle by air and sprayed while heating the entire semiconductor wafer.

  As a result of the above experiment, when the semiconductor wafer W is heated with the set heating temperature of the mounting table being 24 ° C. when the room temperature is 18 ° C., particles adhering to the semiconductor wafer W are compared with the case where the semiconductor wafer W is not heated. It was confirmed that there was an effect of reducing the number to about 70%. However, this result was much lower than the particle adhesion prevention effect using thermophoresis in the normal case. As a result of this experiment, low temperature dry ice or the like is sprayed onto the surface of the semiconductor wafer W by blast cleaning, so that the temperature of the surface of the semiconductor wafer W does not rise to a temperature at which the effect of preventing particle adhesion by thermophoresis is sufficiently exerted. It was thought because.

  Then, when the same experiment was conducted by raising the set heating temperature of the mounting table to 28 ° C., 43 ° C., and 68 ° C., the 28 ° C. was substantially the same as the case of 24 ° C., and 43 ° C. and 68 ° C. Then, it was found that the number of particles adhering to the semiconductor wafer W was larger than that at 24 ° C. Note that the effect of preventing particle adhesion using thermophoresis when the temperature is raised excessively is thought to be due to the occurrence of thermal convection on the substrate.

  Therefore, in the present embodiment, only the part corresponding to the injection position by the injection mechanism 4 in which the temperature of the semiconductor wafer W is likely to decrease due to blast cleaning is locally heated by the heating mechanism 6, so that this part of the semiconductor wafer W is heated. The temperature can be maintained at a temperature at which the effect of preventing particle adhesion by thermophoresis is exhibited. Accordingly, reattachment of particles once separated from the surface of the semiconductor wafer W by cleaning can be suppressed, and particles contained in the injection product by the injection mechanism 4 can be suppressed from attaching to the semiconductor wafer W.

  Next, the configuration of the substrate processing apparatus 100 according to the present embodiment will be described with reference to FIG. The substrate processing apparatus 100 includes one or two or more vacuum processing units 110 that perform various processes such as a film forming process and an etching process on a semiconductor wafer W as a substrate to be processed, and the vacuum processing unit 110. And a transfer unit 120 for loading and unloading the semiconductor wafer W. Further, the transfer unit 120 has a transfer chamber 200 that is shared when transferring the semiconductor wafer W.

  FIG. 2 shows an example in which two vacuum processing units 110 </ b> A and 110 </ b> B are arranged on the side surface of the transport unit 120. Each of the vacuum processing units 110A and 110B has processing chambers 140A and 140B, and load lock chambers 150A and 150B that are connected to the respective processing chambers and configured to be evacuated. The vacuum processing units 110A and 110B perform, for example, the same type of processing or different types of processing on the semiconductor wafer W in the processing chambers 140A and 140B. In the processing chambers 140A and 140B, mounting tables 142A and 142B for mounting the semiconductor wafer W are provided, respectively. The number of vacuum processing units 110 is not limited to two, and may be additionally provided.

  The transfer chamber 200 of the transfer unit 120 is configured by, for example, a box having a substantially rectangular cross section to which nitrogen gas, clean air, or the like is supplied. A plurality of mounting tables 132A to 132F on which one side of the transfer chamber 200 is configured to have a long side having a substantially rectangular cross-section is mounted with front opening unified pods (or cassettes) 400A to 400C as substrate storage containers. 132C is arranged in parallel. The number of mounting tables 132A to 132C is not limited to three and may be any number.

  Each of the FOUPs 400A to 400C has a sealed structure that can accommodate, for example, a maximum of 25 semiconductor wafers W placed in multiple stages at an equal pitch, and the inside is filled with, for example, a nitrogen gas atmosphere. Then, by opening the opening / closing doors 220 </ b> A to 220 </ b> C, the semiconductor wafer W can be carried in and out between the respective FOUPs 400 </ b> A to 400 </ b> C and the transfer chamber 200.

  In the transfer chamber 200, a transfer mechanism 160 for transferring the semiconductor wafer W along the longitudinal direction (the arrow direction shown in FIG. 2) is provided. The transport mechanism 160 is fixed on a base 162, and the base 162 can be slid on a guide rail 168 provided along the longitudinal direction at the center in the transport chamber 200 by, for example, a linear motor drive mechanism. It is configured. The transport mechanism 160 may be a double arm mechanism having two articulated arms 164A and 164B and two picks 166A and 166B as two substrate holding portions as shown in FIG. 2, or a single arm having one pick. It may be a mechanism.

  On the other side of the long side having a substantially rectangular cross section in the transfer chamber 200, the base ends of the two load lock chambers 150A and 150B are configured to be openable and closable gate valves (atmosphere side gate valves) 152A and 152B. Are connected to each other. The distal ends of the load lock chambers 150A and 150B are connected to the processing chambers 140A and 140B via gate valves (vacuum side gate valves) 144A and 144B configured to be openable and closable, respectively.

  In each of the load lock chambers 150A and 150B, a pair of buffer mounting tables 154A, 156A and 154B, 156B for temporarily placing the semiconductor wafer W on standby are provided. Here, the buffer mounting tables 154A and 154B on the transfer chamber 200 side are the first buffer mounting tables, and the buffer mounting tables 156A and 156B on the opposite side are the second buffer mounting tables. Between the buffer mounting tables 154A and 156A and between 154B and 156B, there are provided individual transfer mechanisms (vacuum-side transfer mechanisms) 170A and 170B composed of articulated arms configured to be able to bend, extend, turn and lift. Yes.

  Picks 172A and 172B are provided at the tips of the individual transfer mechanisms 170A and 170B, and the semiconductor wafer W is interposed between the first and second buffer mounting tables 154A and 156A and 154B and 156B using the picks 172A and 172B. Can be transferred. The loading / unloading of the semiconductor wafer W from the load lock chambers 150A and 150B into the processing chambers 140A and 140B is performed using the individual transfer mechanisms 170A and 170B, respectively.

  An endor (pre-alignment) as a positioning device for the semiconductor wafer W via a gate valve 228 is provided at one end of the transfer chamber 200, that is, one side surface (the left side surface in FIG. 2) constituting a short side having a substantially rectangular cross section. Stage) 180 is connected. The orienter 180 includes, for example, a rotary mounting table 182 and an optical sensor 184 that optically detects the peripheral portion of the semiconductor wafer W, and performs alignment by detecting an orientation flat, a notch, or the like of the semiconductor wafer W. The above-described substrate cleaning apparatus 1 is disposed on the opposite side surface (right side surface in FIG. 2) of the transfer chamber 200 via the gate valve 10.

  The substrate processing apparatus 100 is provided with a control unit 300 that controls the operation of the entire apparatus. This control unit 300 controls each unit by executing a predetermined program based on predetermined setting information. Thus, for example, process processing in the processing chambers 140A and 140B, transfer processing in the transfer chamber 200 and load lock chambers 150A and 150B, alignment processing in the orienter 180, and cleaning processing in the substrate cleaning apparatus 1 are performed.

  In the above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment and the like, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof.

The figure which shows typically the schematic structure of the substrate cleaning method and substrate cleaning apparatus which concern on one Embodiment of this invention. The figure which shows typically schematic structure of the substrate processing apparatus which concerns on one Embodiment of this invention. The figure which shows an example of the scanning of the washing | cleaning position in the board | substrate cleaning method of FIG. The figure which shows the example of the scanning of another washing position. The figure which shows the example of the scanning of another washing position.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Substrate cleaning apparatus, 2 ... Substrate support mechanism, 3 ... Injection nozzle, 4 ... Injection mechanism, 5 ... Gas nozzle, 6 ... Heating mechanism, W ... Semiconductor wafer.

Claims (15)

  At least a part of the gaseous cleaning body at room temperature and normal pressure is injected as a solid or liquid fine particle from the injection nozzle onto the surface to be cleaned of the substrate, and a portion corresponding to the injection position of the injection nozzle from the back side of the substrate A substrate cleaning method comprising heating locally. The substrate cleaning method according to claim 1,
A substrate cleaning method, wherein the spray position from the spray nozzle is scanned by relatively moving the spray nozzle and the substrate, and the heating position from the back side of the substrate is scanned. A substrate cleaning method according to claim 1 or 2,
The substrate cleaning method, wherein the cleaning body is carbon dioxide. The substrate cleaning method according to any one of claims 1 to 3,
A substrate cleaning method, wherein heated gas is supplied from a rear surface side of the substrate to a portion corresponding to an injection position of the injection nozzle to locally heat the portion. The substrate cleaning method according to claim 4,
The substrate cleaning method, wherein the gas is air or nitrogen gas. An injection mechanism for injecting at least a part of a gas cleaning body at normal temperature and pressure as solid or liquid fine particles from an injection nozzle onto a surface to be cleaned;
A substrate cleaning apparatus, comprising: a heating mechanism that locally heats a portion corresponding to the spray position of the spray nozzle from the back side of the substrate. The substrate cleaning apparatus according to claim 6,
A substrate comprising a scanning mechanism that scans a spray position from the spray nozzle by relatively moving the spray nozzle and the substrate, and scans a heating position from the back side of the substrate. Cleaning device. The substrate cleaning apparatus according to claim 6 or 7,
The substrate cleaning apparatus, wherein the spray mechanism sprays carbon dioxide as the cleaning body. A substrate cleaning apparatus according to any one of claims 6 to 8,
The substrate cleaning apparatus, wherein the heating mechanism supplies heated gas to a portion corresponding to an injection position of the injection nozzle from the back side of the substrate to locally heat the portion. The substrate cleaning apparatus according to claim 9, wherein
The substrate cleaning apparatus, wherein the gas is air or nitrogen gas. A placement section for placing a substrate container that can accommodate a plurality of substrates;
A processing unit for performing predetermined processing on the substrate;
Corresponds to the injection mechanism that injects at least part of the gas cleaning body at normal temperature and pressure as solid or liquid fine particles from the injection nozzle onto the surface to be cleaned of the substrate, and the injection position of the injection nozzle from the back side of the substrate A substrate cleaning section having a heating mechanism for locally heating the part to be performed;
A substrate processing apparatus comprising: the substrate container placed on the placement unit; the transport unit configured to transport the substrate between the processing unit and the upper part of the substrate line. The substrate processing apparatus according to claim 11, comprising:
The substrate cleaning unit includes a scanning mechanism that scans the spray position from the spray nozzle by relatively moving the spray nozzle and the substrate, and scans the heating position from the back side of the substrate. A substrate processing apparatus. The substrate cleaning apparatus according to claim 11 or 12,
The substrate processing apparatus, wherein the spray mechanism of the substrate cleaning section sprays carbon dioxide as the cleaning body. The substrate processing apparatus according to claim 11, wherein:
The substrate processing characterized in that the heating mechanism of the substrate cleaning unit supplies heated gas to a portion corresponding to the spray position of the spray nozzle from the back side of the substrate to locally heat the portion. apparatus. The substrate processing apparatus according to claim 14, comprising:
The substrate processing apparatus, wherein the gas is air or nitrogen gas.

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