JP2010177267A - Conveyance tray, and vacuum treatment apparatus using the conveyance tray - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveyance tray used for a vacuum treatment apparatus such as an etching apparatus and a sputtering apparatus, the conveyance tray being easy to be assembled while having substantially the same high sealing property even during processing. <P>SOLUTION: The conveyance tray 1 capable of conveying a substrate S to be treated under a vacuum, in a holding state, to the vacuum treatment apparatus which performs predetermined processing on the substrate S has at least one recessed portion 11, conforming with the external shape of the substrate, on its substrate mounting surface, and also includes an annular seal means 2 disposed on a bottom surface of the recessed portion and a pressing means 3 of pressing an outer peripheral edge of the substrate installed by being dropped in the recessed portion against the seal means. At lest one pass passage is opened which communicates with the recessed portion, and a cooling gas can be supplied, through the gas passage, to a space defined on the back side of the substrate being supported by the seal means. The seal means is an O ring, which is installed in an annular groove formed in the bottom surface of the recessed portion and having a width larger than the wirer diameter of the O ring. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transport tray that can be transported to a vacuum processing apparatus capable of performing predetermined processing such as CVD, sputtering, and etching, and a vacuum processing apparatus that uses the transport tray.

  In a vacuum processing apparatus such as a CVD apparatus, a sputtering apparatus, or an etching apparatus, the temperature of the substrate to be processed has a large influence on the processing speed, so it is necessary to control the substrate to a substantially uniform temperature over the entire surface. become. For example, a holder (holding base) capable of mounting a substrate is provided in the processing chamber of the vacuum processing apparatus, and a predetermined space is provided between the substrate mounting surface, which is the upper surface of the holder to which the heating unit is assembled, and the back surface of the substrate. Japanese Patent Application Laid-Open No. H10-228473 discloses a method of forming a recess in which a substrate can be placed and circulating an inert gas such as Ar gas in this space to realize temperature control of the substrate by heating and cooling the substrate. .

  On the other hand, in the above vacuum processing apparatus, a plurality of substrates are simultaneously transferred to the processing chamber for processing, or the same processing is performed on substrates having different external dimensions without changing the apparatus configuration. Therefore, it is generally known to use a transport tray that can hold a plurality of substrates.

  In such a case, the temperature control of the substrate is performed via the transport tray. However, when the transport tray is used, the contact of the transport tray with the holder and the contact of the substrate with the transport tray are likely to be insufficient. There is a possibility that a minute gap is generated between them. Here, since the amount of heat transfer in vacuum through the gap is smaller than in the atmosphere, the heat transfer rate between the holder and the transfer tray or between the transfer tray and the substrate is poor, and as a result, the accuracy of substrate temperature control and Efficiency is likely to deteriorate.

  Therefore, the present applicant has proposed the following transport tray. That is, at least one recess corresponding to the outer shape of the substrate is formed on the substrate mounting surface of the transport tray, and the substrate is installed by dropping into the recess along the peripheral edge of the bottom surface of the recess. And pressing means for pressing the outer peripheral surface of the sealing member against the sealing means, and at least one gas passage leading to the recess is opened, and is supported by the sealing means through the gas passage so that it is supported on the back side of the substrate. A cooling gas can be supplied to the defined space (see Japanese Patent Application No. 2007-3402).

  In the above, it is exemplified that a ring-shaped flat plate made of heat-resistant resin or metal is used as the sealing means. However, the substrate is placed over the entire circumference of the sealing means so that no gap is generated. In order to ensure contact, it is practical to form an annular groove on the bottom surface of the recess, and fix the O-ring by fitting an O-ring made of Fluoroplus or Viton having a wire diameter larger than the groove width. It was.

  However, when the above-described configuration is adopted, there is a problem in that when the O-ring is fitted, the O-ring is twisted or the contact surface of the O-ring with the substrate is easily undulated, and the sealing performance cannot be made substantially constant. is there. In addition, the O-ring itself is also heated or cooled along with the heating and cooling of the substrate, and thermal deformation, thermosetting, and the like locally occur in the portions exposed from the grooves. At this time, a part of the O-ring is fixed and the degree of freedom of deformation is limited, so that the sealability between the substrate and the substrate is locally degraded (changed) during processing without being able to follow thermal deformation. However, there is a problem that the amount of gas leaking from the gap becomes large. For example, in a known etching apparatus, when plasma etching is performed by applying high frequency power while cooling the substrate, it is confirmed that the amount of gas leaking from the gap increases dramatically as the power increases. It was confirmed that the substrate was insufficiently cooled.

JP-A-5-13350

  SUMMARY OF THE INVENTION In view of the above, the present invention provides a transport tray that is easy to assemble and that can provide substantially the same high sealing performance even during processing, and a vacuum processing apparatus using the transport tray. It is what.

  In order to solve the above problems, the invention according to claim 1 is a transport tray that can be transported in a state where the substrate is held in a vacuum processing apparatus that performs a predetermined process on the substrate to be processed in a vacuum, At least one concave portion corresponding to the outer shape of the substrate is formed on the substrate mounting surface of the transport tray, and an annular sealing means disposed on the bottom surface of the concave portion and the outer peripheral edge of the substrate installed by dropping into the concave portion A pressing means for pressing the portion against the sealing means, and at least one gas passage leading to the recess is opened, and the gas is defined on the back side of the substrate by being supported by the sealing means through the gas passage. In this embodiment, the cooling means is an O-ring, and the O-ring is formed on the bottom surface of the recess, and is installed in an annular groove having a width larger than the wire diameter of the O-ring. Tena I am characterized in.

  According to the present invention, since the O-ring is installed in an annular groove having a width larger than the wire diameter of the O-ring, there is no need to fit the O-ring into the groove as described above, and the O-ring is twisted. There will be no malfunctions that occur or wave. In addition, a troublesome operation such as fitting the O-ring into the groove is not required, that is, assembly is easy. Even if the O-ring is heated or cooled during processing, the degree of freedom of deformation is not limited because of the structure in which the O-ring is not fixed to the groove. (That is, the amount of inert gas leaking from between the substrate and the O-ring does not greatly increase).

  As described above, according to the present invention, a sufficient sealing property with the substrate can be ensured during processing. Therefore, an inert gas atmosphere is formed on the back surface of the substrate to assist heat transfer from the holder on which the transport tray is installed. Thus, the local heating or cooling efficiency can be prevented from being lowered, the substrate can be efficiently heated or cooled, and the temperature of the substrate can be accurately and substantially uniformly controlled over the entire surface.

  In this case, it is preferable to provide another gas passage that allows the cooling gas supplied through the gas passage to be discharged from the space so that the cooling gas can be circulated.

  Furthermore, in order to solve the above-described problem, a vacuum processing apparatus according to claim 3 is a vacuum processing apparatus in which the transfer tray according to claim 1 or 2 is used, and a processing chamber capable of being maintained at a predetermined pressure, A holder for holding the transport tray in the processing chamber, and when the transport tray is held by the holder, a gas supply path that communicates with a gas passage formed in the transport tray, and a heating means that enables heating of the transport tray; Is provided.

The top view explaining the conveyance tray of the embodiment of the present invention. Sectional drawing along the II-II line of FIG. The figure explaining the discharge separation type dry etching apparatus using the conveyance tray of this invention. The top view explaining the structure of the conveyance tray mounting surface of a holder. Sectional drawing explaining holding | maintenance of the conveyance tray with a holder.

  Hereinafter, a transport tray 1 according to an embodiment of the present invention will be described with reference to the drawings. The transport tray 1 is used in a vacuum processing apparatus such as a CVD apparatus, a sputtering apparatus, or an etching apparatus. For example, the transport tray 1 is provided in a processing chamber of the vacuum processing apparatus, and a holder (not shown) on which the transport tray 1 is placed. ) And a disc having a predetermined thickness. The transport tray 1 is appropriately selected from materials that have good thermal conductivity and do not affect the processing according to the processing performed in the processing chamber of the vacuum processing apparatus. For example, the transport tray 1 can be selected from materials such as silicon oxide, stainless steel, and aluminum. It is formed. In the present embodiment, a description will be given assuming that one surface on which the substrate S to be processed is placed with its processing surface open is the top surface.

  On the substrate mounting surface, which is the upper surface of the transfer tray 1, six concave portions 11 that are circular and have the same diameter in a plan view so that a plurality of substrates S can be simultaneously transferred into the processing chamber and processed in order to increase productivity. Are formed on the same circumference. The shape of the opening surface of the recess 11 substantially matches the outline of the substrate S, and the substrate S is placed on the transport tray 1 by dropping the substrate S into the recess 11 with the processing surface side of the substrate S facing up. The Note that the number of concave portions and the arrangement position are not limited thereto.

  An annular groove 12 is formed on the bottom surface 11 a of each recess 11 so as to correspond to the outer peripheral edge of the back surface of the substrate S, and the O-ring 2 is installed in the annular groove 12. Here, the annular groove 12 is formed such that its groove width is larger than the wire diameter R of the O-ring 2 and its groove depth is lower than the height of the O-ring (same as the wire diameter), and its bottom surface is It is processed to a predetermined surface roughness and flatness so as to improve the adhesion to the O-ring. And when the below-mentioned pressing means 3 is mounted, the O-ring 2 is compressed and deformed, and the outer peripheral edge of the substrate S contacts over the entire circumference. At this time, the O-ring 2 is preferably a side wall of the annular groove. It is comprised so that it may not touch. As the O-ring, an off-the-shelf product made of Fluoroplus or Viton is used, and can be appropriately selected according to the processing performed in the processing chamber and the substrate size.

  A pressing means 3 that presses the outer peripheral edge of the upper surface of the substrate S against the O-ring 2 can be detachably mounted on the transport tray 1. The pressing means 3 is a disc having a predetermined thickness in which a central opening 31 facing the substrate S is formed, and the material (for example, quartz) is made according to the processing to be performed in the processing chamber, like the transport tray 1. It is selected appropriately. The pressing means 3 is formed with a plurality of through holes (not shown), and the bolt B is screwed into the screw holes formed on the outer periphery of the recess 11 of the transport tray 1 through the through holes. 3 is attached.

  When the substrate S is dropped into the recess 11, the substrate S is supported by its outer peripheral edge by the O-ring 2, and a space 11 b is defined between the back surface of the substrate S and the bottom surface of the recess 11. When the O-ring 2 is attached, the O-ring 2 is compressed and deformed to come into contact with the outer peripheral edge of the substrate S over the entire circumference thereof, and the bottom surface of the recess 11 is also brought into contact with the entire circumference of the substrate 11 to substantially seal the space 11b ( (See FIG. 5).

  The transport tray 1 is provided with two gas passages 13a and 13b communicating with the space 11b from the back side. Then, when an inert gas such as helium or argon is introduced through the gas passages 13a and 13b, an inert gas atmosphere is formed in the space 11b, and assists heat transfer from the holder as will be described later to efficiently perform the substrate. The substrate can be heated and cooled, and the temperature of the substrate can be accurately and substantially uniformly controlled over the entire surface. When the substrate is cooled, the inert gas can be circulated by supplying the cooling gas to one gas passage 13a and exhausting the cooling gas from the other gas passage 13b.

  As described above, in the present embodiment, it is not necessary to fit the O-ring 2 into the annular groove, and there is no problem that the O-ring 2 is twisted or wavy. Moreover, troublesome work such as fitting the O-ring 2 into the annular groove 12 is not required. Even if the O-ring 2 is heated or cooled during the process, the O-ring 2 is not fixed to the annular groove 12, so that the degree of freedom of deformation is not limited, and the pressing force from the pressing means 3 is reduced. Accordingly, a certain sealing property with the substrate S can be maintained. Even if plasma etching is performed by applying a high frequency power with a known etching apparatus, the amount of gas leaking from the gap does not increase so much even if the power is increased, and the substrate is not cooled during etching. It was confirmed that it was possible to avoid becoming sufficient. As a result, by forming an inert gas atmosphere on the back surface of the substrate S, local heating or cooling efficiency is not lowered when the substrate temperature is controlled by assisting heat transfer from or to the holder. The substrate S can be efficiently heated or cooled, and the temperature of the substrate S can be accurately and substantially uniformly controlled over the entire surface.

  Next, with reference to FIG. 3 thru | or FIG. 5, the vacuum processing apparatus 10 in which the conveyance tray 1 of this invention is used is demonstrated. The vacuum processing apparatus 10 is, for example, a discharge separation type dry etching apparatus having a known structure, and the dry etching apparatus 10 includes a vacuum chamber 100 provided with a vacuum exhaust means 101 such as a turbo molecular pump or a rotary pump. Then, the processing chamber 100a that can be maintained at a predetermined vacuum pressure is formed. A plasma processing apparatus 4 is also connected to the processing chamber 100a.

  The plasma processing apparatus 4 has a known structure, a cylindrical discharge tube 41 made of a dielectric, a discharge tube 41, and a microwave waveguide 42 connected in a direction perpendicular to the discharge tube 41. A microwave having a predetermined frequency can be introduced through a microwave power source 42 a connected to one end of the microwave waveguide 42.

Then, a process gas such as CF ₄ , NF ₃ , Ar, O ₂ or the like appropriately selected according to the dry etching process is supplied from the gas source 43 to the discharge tube 41 in a selectively or mixed state. When the microwave power source 42a is operated to irradiate the discharge tube 41 with a microwave having a predetermined frequency to the process gas flowing at a constant flow rate from the upstream side to the downstream side, the discharge tube 41, the microwave waveguide 42, The process gas is excited to become plasma in the intersecting region, and is guided to the processing chamber 100a by the gas introduction pipe 44 made of a conductor, and the substrate S on the transfer tray 1 placed on the holder described later is etched.

  The holder 110 provided in the processing chamber 100 a has a substantially cylindrical shape, and is installed on the floor surface of the processing chamber 100 a via an insulator 111. The upper surface 110a of the holder 110 is formed so as to substantially match the outer shape of the transport tray 1, and forms a transport tray mounting surface. In this case, for example, a plurality of pins projecting upward from the transport tray mounting surface 110a are provided, and a hole for engaging the pins is provided on the back surface of the transport tray 1, and transported by a known multi-indirect robot. When the tray 1 is transported to the processing chamber 100a and placed on the holder 110, it is preferable that the transport tray 1 can be positioned and placed.

  An electrode 112 for an electrostatic chuck having a known structure that attracts the transport tray 1 by static electricity is provided on the mounting surface 110a of the transport tray. In addition, the holder 110 includes, for example, a resistance heating type heater (not shown) so that the substrate S placed on the transport tray 1 can be heated by heating the transport tray 1 during the etching process. It has become. In this case, since the transport tray 1 is attracted to the transport tray mounting surface 110 a by the electrostatic chuck with a uniform force over the entire surface, the heat transfer coefficient is locally increased between the holder 110 and the transport tray 1. It can be prevented from becoming worse.

  In addition, when the transport tray 1 is positioned and placed on the transport tray mounting surface 110a, two transport tray mounting surfaces 110a are aligned with the lower ends of the gas passages of the transport tray 1 in the vertical direction. Annular grooves 113a, 113b are formed, and each of the annular grooves 113a, 113b communicates with two through holes 114a, 114b extending from the lower surface to the upper surface of the holder 110, and each of the annular grooves 113a, 113b and the through holes 114a, 114b forms a gas supply path. Sealing means 115 such as an O-ring or an annular metal seal is provided so as to surround each of the annular grooves 113a and 113b. When the transport tray 1 is adsorbed by static electricity by the seal means 115, the annular grooves 112 are surrounded by the surroundings. Cooling gas does not leak out.

  A mass flow controller (not shown) interposed in the gas pipe 116a is connected to the lower end of each through hole 114a, 114b by connecting a gas pipe 116a having one end connected to a gas source 116 of a cooling gas such as helium gas. The cooling gas is supplied to the space 11b formed by installing the substrate S through the gas passages 13a and 13b through the through holes 114a and 114b and the annular grooves 113a and 113b. Can supply. In this case, as shown in FIG. 3, the cooling gas is supplied to one through hole 113a, the other gas passage 113b is connected to another vacuum exhaust means 117 such as a rotary pump, and the cooling gas is supplied by the vacuum exhaust means 117. The cooling gas may be circulated in the space 11b. Thus, the temperature of the substrate S can be controlled with high accuracy by controlling the operation of the heating means and the circulation of the cooling gas while measuring the temperature with a thermocouple (not shown) in contact with the holder 110.

  Although the discharge separation type dry etching apparatus 10 has been described as an example in the present embodiment, the vacuum processing apparatus is not limited to this, and may be a vacuum treatment apparatus that requires temperature control of the substrate S. The present invention can be applied. In addition, the transport tray 1 has been described as being capable of transporting a plurality of substrates to the processing chamber and simultaneously processing them, but is not limited to this, and for substrates having different external dimensions without changing the apparatus configuration The present invention can also be applied to a transport tray configured to perform the same processing.

DESCRIPTION OF SYMBOLS 1 Conveyance tray 11 Recessed part 11b Space 12 Annular groove 13a, 13b Gas passage 2 O-ring 3 Pressing means

Claims (3)

A transport tray that is transportable in a state where the substrate is held in a vacuum processing apparatus that performs a predetermined process on a substrate to be processed in a vacuum,
At least one concave portion corresponding to the outer shape of the substrate is formed on the substrate mounting surface of the transport tray, and an annular sealing means disposed on the bottom surface of the concave portion and the outer peripheral edge of the substrate installed by dropping into the concave portion A pressing means for pressing the portion against the sealing means, and at least one gas passage leading to the recess is opened, and the gas is defined on the back side of the substrate by being supported by the sealing means through the gas passage. In which the cooling gas can be supplied to the space
The transport tray according to claim 1, wherein the sealing means is an O-ring, and the O-ring is formed on the bottom surface of the recess and is installed in an annular groove having a width larger than the wire diameter of the O-ring.   The transport tray according to claim 1, further comprising another gas passage that allows the cooling gas supplied through the gas passage to be discharged from the space, thereby enabling the circulation of the cooling gas. 3. A vacuum processing apparatus in which the transport tray according to claim 1 or 2 is used, comprising: a processing chamber that can be maintained at a predetermined pressure; and a holder that holds the transport tray in the processing chamber, and the transport tray is held by the holder. A vacuum processing apparatus comprising: a gas supply path that communicates with a gas passage formed in the transfer tray; and a heating unit that enables heating of the transfer tray.

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