JP2006013215A - Substrate processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing device capable of suppressing chemical reaction of a by-product produced in substrate processing as it comes into contact with water remaining in a load lock chamber. <P>SOLUTION: The substrate processing device is equipped with: a processing chamber 201; the load lock chamber 102 having an opening 161 and an opening (wafer conveyance opening) 125, and communicating with the processing chamber 201 through the opening 161 to communicate with an atmospheric space through the wafer conveyance opening 125; a sensor 301 which measures the water density in the load lock chamber; a seal cap 219 airtightly closing the opening 161 and a load lock door 123 which airtightly closes a gate valve 244 and the wafer conveyance opening 125; and a control unit 162 which controls the seal cap 219 or gate valve 244 when a measurement result of the sensor 301 decreases below a predetermined prescribed value to make the processing chamber 201 and load lock chamber communicate with each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substrate processing apparatus, and more particularly, to a substrate processing apparatus including a Rhodock chamber as an airtight chamber connected to a substrate processing chamber, and using a corrosive gas such as dichlorosilane or hydrogen chloride as a source gas. The present invention relates to a processing apparatus.

In the process of manufacturing a semiconductor device such as an IC or LSI, a thin film is formed on a semiconductor silicon substrate (wafer) by a low pressure CVD method (low pressure chemical vapor deposition method). In recent years, a load lock chamber as an airtight chamber has been installed immediately before the processing chamber in order to solve problems such as an increase in natural oxide film when introducing wafers into the substrate processing chamber and adhesion of impurities. The pressure is reduced to sufficiently remove oxygen, moisture, organic substances, etc. in the load lock chamber, and after the nitrogen in the load lock chamber is replaced with nitrogen, the wafer is introduced into the processing chamber. In the processing chamber, thin films are formed on wafers using various chemical reactions, and corrosive properties such as dichlorosilane (SiH ₂ Cl ₂ ) and hydrogen chloride (HCl) are used as source gases. Gas may be used.

  In the substrate processing apparatus having such a load lock chamber, the wafer is transferred from the wafer transfer space in the atmospheric atmosphere to the load lock chamber, and then transferred into the processing chamber, where film formation is performed in the processing chamber. After the film forming process is performed in the processing chamber, the process is performed in reverse order, from the processing chamber to the wafer transfer space in the atmospheric atmosphere via the load lock chamber, and then carried out of the substrate processing apparatus.

  As described above, the load lock chamber communicates with the wafer transfer space in the atmosphere when the wafer is loaded into the load lock chamber or when the wafer is unloaded from the load lock chamber. Place in the atmosphere. At this time, moisture in the atmospheric atmosphere adheres to the inner wall surface of the load lock chamber and remains.

  On the other hand, when a corrosive gas such as dichlorosilane or hydrogen chloride is used as a source gas, or a film is formed on a wafer continuously using such a corrosive gas as a part of a reaction gas, By-products gradually accumulate in the processing chamber.

  In such a state, when the wafer is brought into or out of the load lock chamber and the process chamber communicates with the low lock chamber, this by-product will cause residual moisture in the load lock chamber. HCl gas is released by reacting with the gas, causing rust on the parts of the gate valve provided between the processing chamber and the low lock chamber, and in the vicinity of the substrate processing equipment, the release of HCl gas is dangerous to the human body. There is also a risk of becoming.

  Accordingly, a main object of the present invention is to provide a substrate processing apparatus capable of suppressing a by-product generated during substrate processing from contacting and chemically reacting with moisture remaining in a load lock chamber.

According to the present invention,
A processing chamber for supplying a desired processing gas therein and performing a desired processing on the substrate;
An airtight chamber having first and second openings, wherein the airtight chamber communicates with the processing chamber via the first opening, and communicates with an atmospheric atmosphere space via the second opening;
A sensor for measuring the moisture concentration in the hermetic chamber;
First and second closing means for hermetically closing the first opening and the second opening, respectively,
By-products are generated in the processing chamber by the processing of the substrate, and the by-products react with moisture to generate harmful or corrosive gas,
A substrate processing apparatus comprising control means for controlling the first closing means and communicating the processing chamber and the hermetic chamber when a measurement result of the sensor becomes a predetermined value or less. Is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the substrate processing apparatus which can suppress that the by-product produced | generated at the time of a board | substrate process contacts the water | moisture content which remains in a load-lock chamber, and chemically reacts is provided.

  Next, a preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic longitudinal sectional view for explaining a hot wall type vertical reduced pressure CVD apparatus in this embodiment, and FIG. 2 is a view for explaining a processing furnace of the hot wall type vertical reduced pressure CVD apparatus in this embodiment. FIG. 3 is a schematic perspective view for explaining a low pressure CVD apparatus in the present embodiment.

  As shown in FIG. 3, a cassette stage 105 is provided on the front side inside the housing 101 as a holder transfer member that transfers a cassette 100 as a substrate storage container to and from an external transfer device (not shown). A cassette elevator 115 as an elevating means is provided on the rear side of the cassette stage 105, and a cassette transfer machine 114 as a conveying means is attached to the cassette elevator 115. On the rear side of the cassette elevator 115, a cassette shelf 109 as a means for placing the cassette 100 is provided, and the cassette shelf 109 is provided on the slide stage 122 so as to be able to traverse. Further, a buffer cassette shelf 110 as a means for placing the cassette 100 is provided above the cassette shelf. Further, a clean unit 118 is provided on the rear side of the buffer cassette shelf 110 so as to distribute clean air through the inside of the housing 101.

  A processing furnace 202 is provided above the rear portion of the housing 101. In the processing furnace 202, a processing chamber 201 for performing predetermined processing on the wafer 200 is formed. A load lock chamber 102 as an airtight chamber is connected to a lower side of the processing furnace 202 by a gate valve 244 as a gate valve, and a load as partition means is provided at a position facing the cassette shelf 109 on the front surface of the load lock chamber 102. A lock door 123 is provided. Inside the load lock chamber 102, a boat elevator as a lifting means for lifting and lowering a boat 217 as a substrate holding means for holding wafers 200 as substrates in a multi-stage in a horizontal posture between the processing chamber 201 and the load lock chamber 102. 121 is installed, and a seal cap 219 as a lid is attached to the boat elevator 121 to support the boat 217 vertically. Between the load lock chamber 102 and the cassette shelf 109, a transfer elevator (not shown) as an elevating means is provided, and a wafer transfer machine 112 as a transfer means is attached to the transfer elevator.

  The transport operation of the cassette transfer machine 114 and the like is controlled by the transport control means 124.

  As shown in FIGS. 1 and 2, the processing furnace 202 includes a manifold 209 provided on the ceiling plate 106 of the load lock chamber, an outer tube 205, an inner tube 204 provided therein, and an outer tube 205. A heater 207 provided outside and a heat insulating material 208 provided so as to cover the heater 207 and the outer tube 205 are provided. The entire inside of the outer tube 205 is heated by the heater 207 and the heat insulating material 208. The outer tube 205 is provided on the upper flange 211 of the manifold 209, and the inner tube 204 is provided on a flange 212 protruding inward in the middle of the manifold 209.

  A boat 217 is mounted on the seal cap 219. When the seal cap 219 on which the boat 217 is mounted is inserted from the opening 161 of the ceiling plate 106 of the load lock chamber 102 and the seal cap 219 is lifted and the opening 161 is closed by the seal cap 219, the boat 217 is positioned in the inner tube 204. To do. The seal cap 219 serves as a closing unit that hermetically closes the opening 161 of the ceiling plate 106 of the load lock chamber 102. The boat 217 is rotated by the rotation mechanism 156. A plurality of wafers 200 are stacked and mounted on the boat 217 in the vertical direction. The inside of the inner tube 204 is a processing chamber 201 for processing the wafer 200. A heat insulating plate 210 is mounted on a portion corresponding to the height of the manifold 209 at the bottom of the boat.

An exhaust pipe 231 is attached to the side wall of the manifold 209. An exhaust valve 175 is provided in the middle of the exhaust pipe 231, and the exhaust pipe 231 is connected to a vacuum exhaust device (not shown). . A gas supply pipe 232 is provided on the side wall of the manifold 209. The gas supply pipe 232 is connected to the gas supply device 220. Dichlorosilane (SiH ₂ Cl ₂ ), hydrogen chloride (HCl), or the like as a source gas is introduced from the lower portion of the inner tube 204 through the supply pipe 232 from the gas supply device 220. After that, the inside of the inner tube 204 is raised, and then exhausted by a vacuum exhaust device (not shown) connected to the gas exhaust pipe 231 through a gap between the outer tube 205 and the inner tube 204.

  A wafer transfer port 125 is opened in the front side wall 103 of the load lock chamber 102 as an airtight chamber, and a load lock door 123 as a closing means is provided so as to airtightly close the wafer transfer port 125. In addition, a moisture concentration measurement sensor 301 is provided in communication with the load lock chamber 102 at the upper portion of the front side wall 103 of the load lock chamber 102.

  A purge nozzle 234 is provided in communication with the load lock chamber 102 at the upper portion of the side wall 104 on the rear surface of the load lock chamber 102, and an exhaust pipe 236 is provided in communication with the load lock chamber 102 at the lower portion of the side wall 104. The purge nozzle 234 is provided with a valve 177, and the exhaust pipe 236 is provided with a valve 237. The exhaust pipe 236 is connected to a vacuum exhaust device (not shown). From the purge nozzle 234, nitrogen gas as an inert gas is supplied into the load lock chamber 102.

  The load lock chamber 102 is provided with a boat elevator 121 (see FIG. 3), and the seal cap 219 on which the boat 217 is mounted is lifted so that the seal cap 219 closes the opening 161 to enable wafer processing. . When the processing of the wafer is completed, the seal cap 219 and the boat 217 are lowered into the load lock chamber 102 by the boat elevator 121 (see FIG. 3). After the seal cap 219 is lowered and the boat 217 is unloaded from the inner tube 204, the opening 161 is closed by the gate valve 117 (see FIG. 1). The gate valve 117 serves as a closing unit that hermetically closes the opening 161 of the ceiling plate 106 of the load lock chamber 102. Referring to FIG. 1, the wafers 200 are transferred by the transfer device 112 between the boat 217 and the wafer cassette 100 that have been transferred into the load lock chamber 102 in this manner.

  Heater 207, rotation mechanism 156, gas supply device 220, vacuum exhaust device (not shown), valves 175, 234, 237, load lock door 123, gate valve 244, transfer machine 112, boat elevator 121 (see FIG. 3) .), The moisture concentration measurement sensor 301 and the like are controlled by the control unit 162, and are moved up and down between the processing chamber 201 of the boat 217 on which the wafer 200 is mounted and the row lock chamber 102, and the gate valve 244 and the load lock door 123 are opened and closed. Temperature control in the processing furnace 202, supply of processing gas into the processing chamber 201 and exhaust of the processing chamber 201, supply of nitrogen gas as an inert gas to the load lock chamber 102, exhaust of the load lock chamber 102, load lock Measurement of the moisture concentration in the chamber 102 is controlled by the controller 162.

Next, as an example of the processing of the semiconductor wafer 200 in the hot wall type vertical reduced pressure CVD apparatus which is the substrate processing apparatus of this embodiment, dichlorosilane (SiH ₂ Cl ₂ ) and hydrogen chloride (HCl) are applied to the semiconductor silicon wafer. A case where an epitaxial Si film is formed using the above will be described.

  A cassette 100 transported from an external transport device (not shown) is placed on a cassette stage 105, the orientation of the cassette 100 is converted by 90 ° on the cassette stage 105, and the cassette elevator 115 is moved up and down, traversed and moved. The cassette 114 is transported to the cassette shelf 109 or the buffer cassette shelf 110 in cooperation with the advance / retreat operation of the loading machine 114.

  Wafers 200 are transferred from the cassette shelf 109 to the boat 217 by the wafer transfer device 112. In preparation for transferring the wafer 200 to the boat 217, the boat 217 is lowered by the boat elevator 121, the processing chamber 201 is closed by the gate valve 244, and a purge gas of nitrogen gas is introduced from the purge nozzle 234 into the load lock chamber 102. Is done. After the load lock chamber 102 is restored to atmospheric pressure, the load lock door 123 is opened.

  The horizontal slide mechanism 122 moves the cassette shelf 109 horizontally and positions the cassette 100 to be transferred so as to face the wafer transfer device 112. The wafer transfer device 112 transfers the wafers 200 from the cassette 100 to the boat 217 by cooperation of the raising / lowering operation and the rotating operation. The wafer 200 is transferred to several cassettes 100, and after the transfer of a predetermined number of wafers to the boat 217 is completed, the load lock door 123 is closed and the load lock chamber 102 is connected via the exhaust pipe 236. It is evacuated.

  After completion of evacuation, nitrogen gas, which is an inert gas having a higher purity than the gas purge nozzle 234, is introduced into the load lock chamber 102 through a filter or the like, and the inside of the load lock chamber 102 is restored to atmospheric pressure with nitrogen gas. At this time, the moisture concentration in the load lock chamber 102 is measured by the moisture concentration measurement sensor 301, and the gate valve 244 can be opened only when the moisture concentration in the load lock chamber 102 becomes a specified value or less (preferably 100 ppm or less). Thus, control is performed by the control device 162. By controlling in this way, it is possible to perform safe wafer 200 processing without the by-product in the processing chamber 201 coming into contact with the residual moisture in the load lock chamber 102. Note that the moisture concentration in the load lock chamber 102 can be lowered by supplying an inert gas having high purity to the load lock chamber through a filter or the like.

  After the gate valve 244 is thus opened, the boat 217 is inserted into the processing chamber 201 by the boat elevator 121, and the furnace port 161, which is the opening of the processing furnace 202, is closed by the seal cap 219. 201 is closed. The load lock chamber 102 is maintained at substantially atmospheric pressure with nitrogen gas until the processing of the wafers 200 is completed and the boat 217 descends again to the load lock chamber 102.

  Next, the exhaust valve 175 is opened, the atmosphere in the processing chamber 201 is exhausted, and the processing chamber 201 is decompressed. Then, the control device 162 controls the heater 207 to maintain the temperature in the processing chamber 201 at a predetermined temperature. Thereafter, the rotation mechanism 156 is driven to rotate the boat 217 at a predetermined rotation speed.

Dichlorosilane (SiH ₂ Cl ₂ ), hydrogen chloride (HCl), and hydrogen as a carrier gas are supplied from the gas supply device 220 to the processing chamber 201 through the gas supply pipe 232, while exhausted through the gas exhaust pipe 231. Thus, an epitaxial Si film is formed on the wafer 200 by the low pressure CVD method while keeping the pressure in the processing chamber 201 at a predetermined pressure.

After a predetermined film forming process is performed on the wafer 200 in the processing chamber 201, the inside of the processing chamber 201 is replaced with nitrogen gas as a purge gas. That is, after film formation, (1) the inside of the processing chamber 201 is depressurized via the gas exhaust pipe 231, and then the inside of the processing chamber 201 is purged by flowing nitrogen gas (N ₂ ) through the gas supply pipe 232 into the processing chamber 201. Then, (2) the nitrogen gas is stopped and the inside of the processing chamber 201 is again depressurized through the gas exhaust pipe 231, and then the nitrogen gas is caused to flow into the processing chamber 201 through the gas supply pipe 232 to flow inside the processing chamber 201. Purge. The operations (1) and (2) are repeated a predetermined number of times. Thereafter, nitrogen gas is introduced into the processing chamber 201 from the gas supply pipe 232, and the inside of the processing chamber 201 is returned to almost atmospheric pressure with nitrogen gas. Note that the load lock chamber 102 is maintained at substantially atmospheric pressure by nitrogen gas as described above.

  In this state, the water concentration in the load lock chamber 102 is measured by the water concentration measurement sensor 301, and only when the water concentration in the load lock chamber 102 is not more than a specified value (preferably 100 ppm or less), the boat elevator 121 The control device 162 controls so that the lowering of the seal cap 219 and the boat 217 is started, the seal cap 219 is opened, and the boat 217 loaded with the wafer 200 is lowered from the processing chamber 201 into the load lock chamber 102. ing. By controlling in this way, it is possible to perform safe wafer 200 processing without the by-product in the processing chamber 201 coming into contact with the residual moisture in the load lock chamber 102.

  Thereafter, the inside of the load lock chamber 102 is evacuated to 10 Torr or less through the exhaust pipe 236, and then nitrogen gas is introduced into the processing chamber 201 from the purge nozzle 234, and the inside of the load lock chamber 102 is returned to atmospheric pressure with nitrogen gas. .

  Thereafter, the load lock door 123 is opened, and the processed wafer 200 is transferred from the boat 217 through the cassette shelf 109 to the cassette stage 105 by the reverse procedure of the above-described operation, and is carried out by an external transfer device (not shown).

  Next, the horizontal slide mechanism 122 horizontally moves the cassette shelf 109 and positions the cassette 100 to be transferred next so as to face the wafer transfer device 112. The wafer transfer device 112 transfers the wafer 200 to be processed next from the cassette 100 to the boat 217 by cooperation of the raising / lowering operation and the rotating operation. The wafer 200 is transferred to several cassettes 100, and after the transfer of a predetermined number of wafers to the boat 217 is completed, the load lock door 123 is closed and the load lock chamber 102 is connected via the exhaust pipe 236. It is evacuated.

  After completion of evacuation, nitrogen gas, which is an inert gas having a higher purity than the gas purge nozzle 234, is introduced into the load lock chamber 102 through a filter or the like, and the inside of the load lock chamber 102 is restored to atmospheric pressure with nitrogen gas. At this time, the moisture concentration in the load lock chamber 102 is measured by the moisture concentration measurement sensor 301, and the gate valve 244 can be opened only when the moisture concentration in the load lock chamber 102 becomes a specified value or less (preferably 100 ppm or less). Thus, control is performed by the control device 162.

  After the gate valve 244 is thus opened, the boat 217 is inserted into the processing chamber 201 by the boat elevator 121, and the wafer 200 is processed in the same manner as described above.

  As described above, in the present embodiment, when the moisture concentration measurement sensor 301 for measuring the moisture concentration is attached to the load lock chamber 102, and the moisture concentration in the load lock chamber 102 falls below a specified value (preferably 100 ppm or less). Only the seal cap 219 and the gate valve 244 are controlled by the control device 162 so that they can be opened. As a result, even in the case of the present embodiment using corrosive gas of dichlorosilane and hydrogen chloride as the raw material gas, the by-product in the processing chamber 201 touches the residual moisture in the load lock chamber 102, and HCl It is possible to release gas, cause rust to occur in parts of the gate valve 244 provided between the processing chamber 201 and the low lock 1102 chamber, and further suppress the release of HCl gas in the vicinity of the substrate processing apparatus. As a result, wafers can be processed safely.

  In the present embodiment, there are a seal cap 219 and a gate valve 244 as closing means for closing the opening 161 of the load lock chamber 102, and the moisture concentration in the load lock chamber 102 is determined to Control is performed by the control device 162 so that the seal cap 219 or the gate valve 244 can be opened only when the concentration measurement sensor 301 measures and the moisture concentration in the load lock chamber 102 becomes a specified value or less. When one of the seal cap 219 and the gate valve 244 is opened, when it is clear that the moisture concentration in the load lock chamber 102 is equal to or less than a specified value, the load lock chamber 102 is opened only when the other is opened. The seal cap 219 or the gate bar only when the water concentration in the inside is below the specified value. As Bed 244 can be opened, it may be controlled by the control unit 162.

1 is a schematic longitudinal sectional view for explaining a hot wall type vertical reduced pressure CVD apparatus in a preferred embodiment of the present invention. 1 is a schematic structural longitudinal sectional view for explaining a processing furnace of a hot wall type vertical reduced pressure CVD apparatus in a preferred embodiment of the present invention. It is a schematic perspective view for demonstrating the low pressure CVD apparatus in the preferable Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Cassette 101 ... Case 102 ... Load lock chamber 103, 104 ... Side wall 106 ... Ceiling board 109 ... Cassette shelf 112 ... Wafer transfer device 118 ... Clean unit 121 ... Boat elevator 123 ... Load lock door 124 ... Conveyance control means 125 ... wafer transfer port 156 ... rotation mechanism 161 ... opening 162 ... control device 175 ... exhaust valve 177 ... valve 180 ... gas supply device 200 ... wafer 201 ... processing chamber 202 ... processing furnace 204 ... inner tube 205 ... outer tube 207 ... heater 208 Insulating material 209 ... Manifold 210 ... Insulating plate 211, 212 ... Flange 217 ... Boat 219 ... Seal cap 220 ... Gas supply device 231 ... Exhaust pipe 232 ... Gas supply pipe 234 ... Purge nozzle 236 ... Exhaust pipe 237 ... Exhaust bar Breakfast 244 ... gate valve 301 ... moisture concentration measurement sensor

Claims (1)

A processing chamber for supplying a desired processing gas therein and performing a desired processing on the substrate;
An airtight chamber having first and second openings, wherein the airtight chamber communicates with the processing chamber via the first opening, and communicates with an atmospheric atmosphere space via the second opening;
A sensor for measuring the moisture concentration in the hermetic chamber;
First and second closing means for airtightly closing the first opening and the second opening, respectively,
By-products are generated in the processing chamber by the processing of the substrate, and the by-products react with moisture to generate harmful or corrosive gas,
A substrate processing apparatus comprising control means for controlling the first closing means and communicating the processing chamber and the hermetic chamber when a measurement result of the sensor becomes a predetermined value or less. .

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