JP2011119418A - Method of conveying subject to be processed in semiconductor manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing apparatus that reduces the number of foreign particles adhering to the subject to be processed during, before and after the conveying of the subject to be processed. <P>SOLUTION: A method of conveying the subject 207 to be processed in the semiconductor manufacturing apparatus 100 having a vacuum conveyance chamber 110, a plurality of interconnected process chambers, a process chamber evacuation unit, a first gate valve 214, a second gate valve 215, and a vertical drive mechanism 209 of a sample stand 208 disposed inside the process chamber is disclosed. During the opening and closing movements of the first and second gate valves 214, 215 upon the conveying of the subject 207 to be processed between the vacuum conveyance chamber 110 and the process chamber, and during fluctuations of pressure in the conveyance chamber and the process chamber, the height of the sample stand 208 is such that the position of the upper surface of the sample stand is at a position higher than the upper surface of the second gate valve 215 to convey the subject to be processed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for transferring an object to be processed in a semiconductor processing apparatus, and more particularly, to a method for transferring between a vacuum transfer chamber and a processing chamber.

  With the progress of miniaturization and multilayering of semiconductor devices, high-precision processing is required, and it is necessary to minimize the factors that hinder the uniformity of process processing. One of the problems is to reduce the number of foreign substances adhering to a target object such as a wafer. For example, if foreign particles fall on the fine pattern of the object to be processed during or before the etching process, the etching is locally inhibited at that part. As a result, a defect such as disconnection occurs in the fine pattern of the object to be processed, resulting in a decrease in yield. Therefore, many methods have been devised to control the transport of foreign particles using gas viscous force, thermophoretic force, Coulomb force, etc., and reduce the number of foreign matters adhering to the object to be processed.

  For example, in Patent Document 1, a first gate valve that can completely block the passage of gas between a transfer chamber and a processing chamber, and a second gate valve disposed closer to the processing chamber than the gate valve, It has been described that the number of foreign matters adhered during conveyance of the object to be processed can be reduced by adjusting the gas flow by optimally adjusting the gas flow rate and pressure in the processing chamber.

JP 2009-64873 A

  In the conventional semiconductor processing apparatus, the number of foreign particles adhering to the object to be processed is reduced during the transfer of the object to be processed between the vacuum transfer chamber and the process chamber, or before and after the transfer, and the inner cover of the process chamber is formed. There was not enough consideration for contamination and foreign matter caused by circulated plasma and reaction products to the transport port.

  In order to solve the above problems, the present invention employs the following means. A vacuum transfer chamber in which the object to be processed is transferred, a plurality of connected processing chambers for processing the object to be processed transferred by a vacuum robot disposed inside the vacuum transfer chamber, and the pressure in the process chamber is reduced. Provided on the processing chamber side with respect to the processing chamber exhaust means, a first gate valve for communicating and closing the transfer path of the object to be processed that connects the vacuum transfer chamber and the processing chamber, and the first gate valve A sample stage arranged inside the processing chamber is provided with a vertical drive mechanism, and the vacuum transfer chamber is in a positive pressure with respect to the processing chamber, The first gate valve is opened, and then the second gate valve is opened to transfer the object to be processed while the vacuum transfer chamber and the processing chamber are in communication with each other, and a sample table disposed inside the processing chamber Carrying a target object on which the target object is placed In the method, during the first and second gate valve opening and closing operations when the object to be processed is transferred between the vacuum transfer chamber and the processing chamber, and during pressure fluctuations in the transfer chamber and the processing chamber, The height of the stage is such that the position of the upper surface of the sample stage is higher than the upper surface of the second gate valve, and the object to be processed is transported.

  According to the present invention, the means can suppress the pressure fluctuation on the object to be processed in the processing chamber, and as a result, can suppress the foreign substance diffusion and the foreign substance falling on the object to be processed due to the pressure fluctuation. By disposing the upper surface at a position higher than the upper surface of the second gate valve, the number of foreign particles adhering to the object to be processed can be minimized during the transfer of the object to be processed or before and after the transfer. Yield can be improved.

FIG. 1 is a diagram illustrating a main part of a processing chamber according to the first embodiment. FIG. 2 is a schematic view of the entire semiconductor processing apparatus according to the first embodiment as viewed from above. FIG. 3 is a diagram in which the sample stage is arranged in a temperature-controlled region at the top of the processing chamber. FIG. 4 is a diagram for explaining the outline of the transfer sequence of the sample stage and the gate valve when the wafer is replaced. FIG. 5 is an enlarged view of a gate valve (process valve) valve body according to an embodiment of the present invention. FIG. 6 is a view for explaining a method of exhausting gas flowing from the vacuum transfer chamber according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a main part of a processing chamber of a plasma processing apparatus which is an embodiment of the present invention. The plasma processing chamber 200 has a double structure of a vacuum chamber 201 that is an outer container and an inner container, and an inner case 202 that constitutes an upper side wall of the processing chamber as an inner container and has a temperature control function; An inner cover 203 and a hiki cover 204 are provided that constitute the lower side wall and the like of the processing chamber.

  Furthermore, the antenna 205 for supplying high-frequency power for generating plasma, the shower plate 206 having a dispersion plate for distributing and supplying the processing gas to the plasma processing chamber 200, and the plasma processing chamber 200. A sample stage 208 for processing an object to be processed (wafer) 207 placed on a placement surface disposed therein, and a vertical drive mechanism 209 are provided on the sample stage 208. The inner case 202 is a replacement part for efficiently replacing the inside of the vacuum chamber 201, which is a container outside the processing chamber, so as to efficiently perform periodic disassembly and cleaning of the apparatus.

  Further, a turbo molecular pump 210 is attached to the plasma processing chamber 200 as exhaust means for reducing the pressure in the processing chamber. Further, a butterfly valve 211 is attached to the upper part of the turbo molecular pump 210 in order to control the pressure in the processing chamber. Furthermore, a coil 212 and a yoke 213 for forming a magnetic field are attached to the plasma processing chamber 200.

  A first gate valve 214 is connected between the vacuum chamber 201 and the vacuum transfer chamber 110 to communicate and close the transfer path of the workpiece 207. Further, a second gate valve (process valve) 215 is installed on the processing chamber side with respect to the first gate valve 214.

  The first gate valve 214 has a function of completely closing the vacuum, and by closing the first gate valve, the gas can be completely blocked between the transfer chamber and the processing chamber. On the other hand, the second gate valve 215 is provided so that the side wall can be seen as an axial object with respect to electromagnetic waves so that the plasma is not decentered, and when the first gate valve is opened, the transfer chamber and the processing chamber are opened. The purpose is to suppress the diffusion of foreign matter due to the rapid flow of gas caused by the differential pressure.

  Therefore, when the object to be processed 207 is carried into the processing chamber, the first gate valve 214 is opened first, and then the second gate valve 215 is opened. By opening the first gate valve 214, the transfer chamber and the processing chamber are in communication with each other through the gap around the second gate valve 215, and the pressure difference between both chambers gradually decreases. The effect of suppressing the diffusion of foreign matter can be obtained.

  FIG. 2 shows an outline of the entire semiconductor processing apparatus 100 according to the embodiment of the present invention as viewed from above. The semiconductor processing apparatus 100 includes a plurality of (four) processing chambers 101, 102, 103, 104 and a plurality (three) of cassette mounting tables 105, such as wafers by an atmospheric transfer robot 108 and a vacuum transfer robot 111. The object to be processed can be transferred.

  These processing chambers 101, 102, 103, and 104 are constituted by a vacuum processing container having a sample stage on which an object to be processed is placed in an internal space that can be depressurized to a predetermined pressure (vacuum pressure). A processing vessel for processing the surface of a sample by supplying a processing gas to the space and applying an electric field or a magnetic field from an electric field or magnetic field supply means (not shown) to form plasma in the space above the object to be processed in the processing chamber. It has become.

  The vacuum transfer chamber 110 of the semiconductor processing apparatus 100, which is a vacuum processing apparatus, is composed of a vacuum container whose inside can be adjusted to the same pressure as the inside of the processing chamber 101 or the like, and for introducing the object to be processed to the vacuum side. A plurality of mounted load lock chambers 106 and 107 are connected. Note that the processing chambers 101, 102, 103, and 104, the vacuum transfer chamber 110, and the lock chambers 106 and 107 constitute a vacuum block that transfers and processes the sample under reduced pressure conditions.

  The plurality of lock chambers 106 and 107 are connected to an atmospheric transfer chamber 109 in which an atmospheric transfer robot 108 is disposed in an internal space. The atmospheric transfer chamber 109 has a cassette on which an object to be processed is placed on the upper surface. A cassette mounting table 105 is provided on the front side.

  The lock chambers 106 and 107 are opening / closing mechanisms for taking out and delivering the object to be processed between the atmospheric transfer chamber 109 to which the cassette is connected and the vacuum side block, and also function as a variable pressure interface.

  When loading / unloading the workpiece 207 between the vacuum transfer chamber 110 and the processing chamber, due to the pressure difference between the vacuum transfer chamber 110 and the processing chamber, the processing chamber is caused by pressure fluctuations generated immediately after the first gate valve 214 is opened. In order to minimize the rise of foreign matter and the separation of foreign matter from the side wall, the upper surface position (wafer placement surface) of the sample stage 208 is arranged at a position higher than the upper surface of the second gate valve 215, and the gate By opening and closing the valve, it is effective to suppress the number of foreign particles adhering to the object to be processed.

  FIG. 3 is a view in which the upper surface position of the sample stage 208 is arranged at a position higher than the upper surface of the second gate valve 215. The rising position of the sample stage 208 is arranged in the region of the inner wall of the temperature-controlled inner case 202 at the upper part of the processing chamber, so that the side wall of the inner case 202 has less deposits due to the temperature-controlled wall environment. Foreign matter peeling is also reduced.

  In the present invention, the height position of the sample stage is operated in conjunction with the opening / closing operation of the first gate valve 214 and the second gate valve (process valve) 215.

  The outline of the transfer sequence of the sample stage 208 and the first and second gate valves 214 and 215 when replacing the object to be processed (wafer) will be described below using FIG. 4 as an example. 4A shows the sample stage position, FIG. 4B shows the first gate valve open / closed state, and FIG. 4C shows the second gate valve open / closed state.

  Timing A1 is a state in which the height of the sample stage is arranged at a position where the upper surface position of the sample stage is higher than the upper surface of the second gate valve 215 (hereinafter referred to as a standby position) before carrying out the wafer. The details of the timing A1 are a state in which the sample stage 208 is raised to the standby position, the first gate valve is opened, and then the second gate valve is opened, and then the sample stage 208 is lowered to the transport surface. .

  Timing B1 is a state in which wafers are replaced. Both the first and second gate valves 214 and 215 at the timing B1 are kept open. Timing A2 is immediately after the replacement of the wafer, and the sample stage 208 is in the standby position. The details of the timing A2 are a state in which the sample stage 208 is kept in the standby position after the sample gate 208 is in the standby position, the second gate valve is closed, and then the first gate valve is closed.

  Timing C1 is a state in which the next wafer after the replacement is processed. For details of the timing C1, the sample stage 208 is moved to the processing surface, and the first and second gate valves 214 and 215 are both kept closed. If the second gate valve 215 is closed when the first gate valve 214 is opened, the sample stage 208 is further moved to the standby position without being directly affected by the pressure fluctuation due to the differential pressure into the processing chamber. By arranging, the number of foreign particles adhering to the wafer can be further reduced.

  FIG. 5 shows an enlarged view of the second gate valve (process valve) valve body 215. The valve body has a valve body shape that can be arranged flush with the inner wall of the inner cover 203, and includes an O-ring 216 for sealing the gas flow against the gas flow, as shown in FIG. The purpose is to suppress the plasma from flowing into the gap between the cover 203 and the valve body 215 and the deposition of reaction products.

  FIG. 6 is a schematic view showing a method of exhausting gas flowing from the vacuum transfer chamber. When the first gate valve 214 on the vacuum transfer chamber side is opened and the second gate valve 215 provided on the process chamber side is closed, the gas flowing from the vacuum transfer chamber passes through the process chamber. Instead, the gas is exhausted by the turbo molecular pump 210 via the exhaust pipe 217 and the filter 218 provided between the inner cover 203 which is a container inside the processing chamber and the first gate valve 214. Therefore, generation of a rapid gas flow in the processing chamber can be suppressed.

100 Semiconductor processing apparatus 101 Processing chamber 1
102 Processing chamber 2
103 Processing chamber 3
104 Processing chamber 4
105 Cassette stand 106 Lock room 1
107 Lock room 2
108 atmospheric transfer robot 109 atmospheric transfer chamber 110 vacuum transfer chamber 111 vacuum transfer robot 200 plasma processing chamber 201 vacuum chamber 202 inner case 203 inner cover 204 hiki cover 205 antenna 206 shower plate 207 target object (wafer)
208 Sample stage 209 Vertical drive mechanism 210 Turbo molecular pump 211 Butterfly valve 212 Coil 213 Yoke 214 First gate valve 215 Second gate valve (process valve)
216 Valve body O-ring 217 Exhaust piping 218 Filter

Claims (4)

In a semiconductor manufacturing apparatus, a vacuum transfer chamber in which a target object is transferred, a plurality of connected processing chambers for processing a target object transferred by a vacuum robot disposed inside the vacuum transfer chamber, and the processing A processing chamber exhaust means for depressurizing the chamber, a first gate valve for communicating and closing a transfer path of the workpiece to be connected between the vacuum transfer chamber and the processing chamber, and the processing with respect to the first gate valve. A sample stage provided with a vertical drive mechanism, and the vacuum transfer chamber is set to a positive pressure with respect to the processing chamber. In this state, the first gate valve is opened, and then the second gate valve is opened, and the object to be processed is transported with the vacuum transport chamber and the processing chamber in communication with each other, and is disposed inside the processing chamber. The object to be processed is placed on the sample stage A transfer method of the object to be placed,
During the opening and closing operation of the first and second gate valves when the object to be processed is transferred between the vacuum transfer chamber and the processing chamber, and during pressure fluctuations in the transfer chamber and the processing chamber, the height of the sample stage is A method for transporting an object to be processed in a semiconductor manufacturing apparatus, wherein the upper surface of the sample stage is positioned higher than the upper surface of the second gate valve and the object to be processed is transported. A method for transporting an object to be processed in the semiconductor manufacturing apparatus according to claim 1,
During the opening and closing operation of the first and second gate valves when transferring the object to be processed between the vacuum transfer chamber and the processing chamber, and during pressure fluctuations in the transfer chamber and the processing chamber, the height of the sample stage is An object to be processed in a semiconductor manufacturing apparatus, wherein the upper surface of the sample stage is positioned higher than the upper surface of the second gate valve, and the object to be processed is transported by being disposed in a temperature-controlled inner wall region. Transport method. A method for transporting an object to be processed in the semiconductor manufacturing apparatus according to claim 1,
A cylindrical inner cover is provided as an inner container of the processing chamber, and a workpiece inlet of the inner cover is opened and closed by a valve body of the second gate valve, and the second gate valve An object to be processed in a semiconductor manufacturing apparatus having a valve body shape that is flush with the inner wall of the cover, and has a structure that suppresses plasma from flowing into a gap between the inner cover and the valve body and deposition of reaction products. Transport method. A method for transporting an object to be processed in the semiconductor manufacturing apparatus according to claim 1,
The processing chamber includes an outer container and an inner container that is exchangeable inside thereof, and is provided between the inner container and the first gate valve on the vacuum transfer chamber side, A pipe and a filter for exhausting gas without passing through the processing chamber are provided, the first gate valve on the vacuum transfer chamber side is opened, and the second gate valve provided on the processing chamber side is closed. In the semiconductor manufacturing apparatus, the gas flowing from the vacuum transfer chamber is exhausted through the pipe and the filter.

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