JP2003229373A - Substrate treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of a clogging phenomenon of an evacuation pipe due to sucking in clean air from a gap to a second evacuation pipe by an evacuation force acting in the gap when evacuating a treatment chamber by the evacuation pipe, to dilute evacuation gas which flows downward from a first evacuation pipe, so that the strictness of maintenance of a diffusing device is relaxed to raise throughput. <P>SOLUTION: The evacuation pipe 40 has one end connected to a treatment chamber 14 of an inner tube 12 of a diffusion device and the other end connected to an evacuation device, and comprises a first evacuation pipe 41 and a second evacuation pipe 42. A male tapered part 44 of the first evacuation pipe 41 interconnected with the internal space of a manifold 20 faces a widen-out female tapered part 45 of a second evacuation pipe 42 inserted into a hollow chamber 5 of a scanvenger 4 via a gap 43. The dimension of the gap 43 can be freely adjusted by the radial position of a bracket 47 and a change in the height of a hoisting tool 50. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus, and more particularly, to a technology for exhausting a processing gas, and more particularly to an apparatus effectively used for a diffusion apparatus. 2. Description of the Related Art Generally, a semiconductor integrated circuit device (hereinafter referred to as I
Called C. In the manufacturing method of (1), a batch-type vertical hot wall type diffusion device is used in a diffusion step of diffusing antimony (Sb) into a semiconductor wafer (hereinafter, referred to as a wafer). [0003] A batch type vertical hot wall type diffusion device (hereinafter, referred to as a diffusion device) forms a processing chamber into which a wafer is loaded and is provided with a vertical process tube and a gas inlet for introducing a raw material gas into the processing chamber. An opening, an exhaust pipe system for exhausting the processing chamber, and a heater laid outside the process tube to heat the processing chamber, and the processing is performed in a state where a plurality of wafers are long aligned and held by the boat. The apparatus is configured such that antimony and the like are diffused into the wafer by being carried into the chamber from the furnace port at the lower end, the source gas being introduced into the processing chamber from the gas inlet, and the processing chamber being heated by the heater. . In general, when antimony is diffused into a wafer using a diffusion device, reaction products of antimony accumulate in easily adhering places such as a joint portion of an exhaust pipe system to block the exhaust pipe system. Therefore, by introducing a large amount of a diluent gas such as nitrogen gas into the processing chamber, the exhaust gas containing antimony is sufficiently diluted and allowed to flow through the exhaust pipe system, so that the reaction product of antimony flows into the exhaust pipe system. Prevention of deposition has been implemented. [0005] However, in a diffusion apparatus in which a large amount of diluent gas prevents clogging of an exhaust pipe system by reaction products of antimony, it is necessary to introduce a large amount of diluent gas into a processing chamber. There is a problem that there is. An object of the present invention is to provide a substrate processing apparatus capable of preventing clogging of an exhaust pipe system without introducing a large amount of dilution gas into a processing chamber. [0007] A substrate processing apparatus according to the present invention includes a processing chamber for accommodating and processing a substrate, and an exhaust having one end connected to the processing chamber and the other end connected to an exhaust device. And a dilution port for introducing an atmosphere outside the exhaust pipe into the exhaust pipe and diluting an atmosphere flowing down the exhaust pipe is provided in the middle of the exhaust pipe. I do. According to the above-described means, when the exhaust gas is exhausted, the atmosphere outside the exhaust pipe is taken in from the dilution port, so that the exhaust gas flowing down the exhaust pipe is diluted by the taken-in atmosphere outside the exhaust pipe. Become. as a result,
It is possible to prevent clogging of the exhaust pipe system due to reaction products such as antimony contained in the exhaust gas flowing down the exhaust pipe and easily accumulating on the exhaust pipe system. An embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, a substrate processing apparatus according to the present invention is configured as shown in FIGS. 1 to 5 as a diffusion apparatus for diffusing antimony into a wafer. As shown in FIG. 1, the diffusion apparatus includes a casing 1 forming an airtight chamber, a process tube installation chamber 2 is set on the upper part of the casing 1, and a boat is located on the lower part. A standby chamber 3 is provided to wait for loading and unloading to the processing chamber. The process tube 11 is vertically arranged in the process tube installation chamber 2 such that the center line is vertical. The process tube 11 includes an inner tube 12 and an outer tube 13. The inner tube 12 is made of quartz glass and is formed in a cylindrical shape with upper and lower ends open. The hollow portion of the inner tube 12 is a process in which a plurality of wafers held long by a boat are loaded. A chamber 14 is formed.
The lower end opening of the inner tube 12 constitutes a furnace port 15 for taking in and out a wafer as a processing object, and the upper end opening of the inner tube 12 has a deformation preventing cap 16.
Is inserted. The outer tube 13 is made of silicon carbide (SiC), has an inner diameter larger than the outer diameter of the inner tube 12, is formed in a cylindrical shape having an upper end closed and a lower end opened, and the outer tube 13 is surrounded by the inner tube 12. Concentric circles. As shown in FIG. 1 to FIG.
A scavenger 4 forming a disk-shaped hollow chamber 5 is installed on the ceiling wall of the standby chamber 3. The hollow chamber 5 and the standby chamber 3 communicate with the scavenger 4 as shown in FIG. A communication hole 6 is provided. As shown in FIGS. 4A and 5, a circular ring-shaped support plate 17 is concentrically fixed to the hollow chamber 5 of the scavenger 4 on the ceiling wall of the standby chamber 3. The flange at the lower end of the outer tube 13 is supported from below. An inner tube 12 is erected on the bottom wall of the hollow chamber 5 of the scavenger 4, and the inner tube 12 is held by a holding member 18 at a lower flange portion. A spacer 19 and a manifold 20 are stacked on the retainer 18, and a partition 21 protruding in a radially outward circular ring shape on the outer periphery of the lower end of the inner tube 12 is provided on the manifold 20. Touched. A plurality of communication holes 22 penetrating in the vertical direction are formed in the partition wall portion 21 in a ring shape, and the communication holes 22 are provided with an exhaust passage 23 formed between the inner tube 12 and the outer tube 13. The inside space of the manifold 20 is communicated. As shown in FIG. 1, the furnace port 15 of the inner tube 12 is opened and closed by a shutter 7 driven by a rotary actuator (not shown) so as to come into contact with the lower end surface of the scavenger 4. . As shown in FIGS. 1 and 5, a heater unit 24 for heating the inside of the process tube 11 is installed concentrically outside the outer tube 13 so as to surround the outer tube 13. The heater unit 24 is configured to uniformly heat the entire inside of the process tube 11. The heater unit 24 is formed by spirally laying a resistance heater 25 on the inner periphery of a heat insulating tank 26 formed in a cylindrical shape. The support unit 27 is provided on the bottom wall of the process tube installation chamber 2 of the housing 1. It is installed through. A boat elevator in which only the arm 29 is shown in FIG. 1 is installed in the waiting room 3. The boat elevator supports the seal cap 30 by the arm 29 and moves up and down vertically with respect to the waiting room 3. Is configured. The seal cap 30 is formed in a disk shape having an outer diameter larger than the furnace port 15 of the inner tube 12, and opens and closes the furnace port 15 by contacting the lower surface of the scavenger 4 from below in the vertical direction. I have. On the center line of the seal cap 30, a boat 31 for holding the wafer 10 as an object to be processed is vertically supported via a heat insulating cap section 36. The boat 31 has a pair of upper and lower end plates 32, 33, and both end plates 32, 3
A plurality of vertically arranged holding members 3 erected between the three
The wafer 10 is inserted between a plurality of holding grooves 35 which are arranged at equal intervals in the longitudinal direction of each holding member 34 and are formed so as to open in the same plane with each other. The plurality of wafers 10 are arranged and held horizontally and in a state where their centers are aligned with each other. Further, a thermocouple 37 is vertically inserted into and supported by the seal cap 30. As shown in FIGS. 2 and 3, a gas introduction pipe 38 is provided at the lower end of the side wall of the inner tube 12 on the back side of the standby chamber 3.
The gas inlet tube 38 is connected to a processing gas supply source and an inert gas supply source (both not shown) to be described later. . The gas introduced into the furnace port 15 by the gas introduction pipe 38 flows through the processing chamber 14 of the inner tube 12, passes through the exhaust path 23, and is exhausted by the exhaust pipe 40. As shown in detail in FIG. 4, in this embodiment, an exhaust pipe 40 for exhausting the processing chamber 14 includes a first exhaust pipe 41 and a second exhaust pipe 42. The first exhaust pipe 41 and the second exhaust pipe 42 are connected via a gap 43 as a dilution port for introducing an atmosphere outside the exhaust pipe 40 into the exhaust pipe 40 and diluting exhaust gas flowing down the exhaust pipe 40. ing. That is, as shown in FIGS. 1 to 4, one end of the first exhaust pipe 41 is connected to communicate with the inside space of the manifold 20 at a position on the side wall of the manifold 20 on the rear side of the standby chamber 3. The middle portion is bent in a substantially S-shape, and the hollow chamber 5 of the scavenger 4 is appropriately piped. A male tapered portion 4 is provided at the end of the first exhaust pipe 41 opposite to the end connected to the manifold 20.
4 is tapered. On the other hand, the second exhaust pipe 42 is connected to the standby chamber 3 of the housing 1.
Are inserted into the hollow chamber 5 of the scavenger 4 through the rear wall of the scavenger 4 and the divergent female taper 45 formed at the insertion end thereof. 44, with a gap 43 therebetween. An angle-shaped bracket 47 is screwed to the ceiling wall of the hollow chamber 5 of the scavenger 4 with a bolt 46, and the bracket 47 is a long hole 48 that is provided in the angled horizontal piece and is elongated in the radial direction of the scavenger 4. The position in the radial direction is adjusted by inserting the bolt 46 into the hole. At the lower end of the vertical piece of the bracket 47, a suspending device 50 fixed near the female tapered portion 45 of the second exhaust pipe 42 is suspended by bolts 51. The height position in the vertical direction can be adjusted by inserting a bolt 51 into a pair of long holes 49, 49 formed at the lower end of the piece. That is, the male tapered portion 44 of the first exhaust pipe 41
The size (cross-sectional area) of the gap 43 formed between the taper portion 45 of the second exhaust pipe 42 and the female exhaust portion 42 is appropriately changed by changing the radial position of the bracket 47 and the height position of the suspending device 50. Thus, the concentric circles are adjusted to a predetermined value. The outer end of the second exhaust pipe 42 is connected to an exhaust device constituted by a vacuum pump (blower), a flow control valve, a flow meter, and the like. The exhaust device has an exhaust pressure of atmospheric pressure (about 1013 hPa). ) And 90 Pa or more can be created. As shown in FIGS. 1 and 2, a clean air inlet 52 is formed in an upper portion of a rear wall of the standby chamber 3 of the housing 1, and a butterfly valve is provided in the clean air inlet 52. A normally-closed clean air intake valve 53 constituted by the above is installed. Clean air intake valve 5
The opening and closing of 3 is automatically controlled by the controller of the diffusion device. Next, a description will be given of a diffusion step in which antimony is diffused into a wafer by using the diffusion device having the above structure. The boat 21 in which the plurality of wafers 10 are aligned and held in the standby chamber 3 is placed on the seal cap 30 with the direction in which the wafers 10 are lined up vertically, and is raised by the arm 29 of the boat elevator. 5 is carried into the processing chamber 14 from the furnace port 15 of the inner tube 12 (boat loading), and is left in the processing chamber 14 while being supported by the seal cap 30 as shown in FIG. In this state, the seal cap 30
Becomes a state in which the processing chamber 14 is airtightly closed. With the processing chamber 14 airtightly closed by the seal cap 30, the exhaust pipe 40 is set to a predetermined pressure (90 Pa or less as a differential pressure from the atmospheric pressure).
The inside of the process tube 11 is heated to a predetermined temperature (800 to 1200) by the heater unit 24.
(° C.). Next, the processing gas is supplied to the processing chamber 14 at a predetermined flow rate by the gas introduction pipe 38. When antimony is diffused into the wafer, antimony gas is used as a source gas, and is introduced into the processing chamber 14 using argon gas as a carrier gas. The introduced processing gas is supplied to the inner tube 12.
And flows out of the communication hole formed in the deformation prevention cap 16 into the exhaust path 23 formed by the gap between the inner tube 12 and the outer tube 13. The processing gas flowing out to the exhaust passage 23 flows down the exhaust passage 23, passes through the communication hole 22 of the partition 21, and passes through the manifold 20.
And is exhausted by the exhaust pipe 40. When passing through the processing chamber 14, antimony in the processing gas contacts the surface of the wafer 10 and thermally diffuses. When a predetermined processing time has elapsed, the processing chamber 14 is opened by lowering the seal cap 30 by the arm 29 of the boat elevator, and the boat 31 holding the group of processed wafers 10 is placed in the furnace. It is carried out of the processing chamber 14 through the port 15 (boat unloading). Subsequently, the shutter 7 is brought into contact with the lower end surface of the scavenger 4 in a sealed state, and the processing chamber 14 is closed.
The atmosphere in the processing chamber 14 is exhausted by the exhaust pipe 40.
While the processing chamber 14 is being evacuated, in the standby chamber 3, the work of replacing the processed wafer 10 with the wafer 10 to be processed is progressing. When the replacement operation is completed, the boat 31 is carried into the processing chamber 14 again. Thereafter, the above-described operation is repeated. By the way, when the atmosphere in the processing chamber is exhausted by the exhaust pipe, the remaining of the processing gas, reaction products (metal components and chlorine components), and all substances such as dust are removed while flowing through the exhaust pipe. Since it comes into contact with the very fine uneven surface of the inner wall surface or the joint of the joint portion, a phenomenon that it adheres to or adheres to these surfaces or gaps and accumulates as foreign matter occurs. In particular, when a sublimable substance such as antimony is used as a raw material gas, it is known that the generation thereof becomes remarkable. Therefore, in the present embodiment, when the processing chamber 14 is exhausted by the exhaust pipe 40, the clean air intake valve 53 is opened, so that the clean air outside the casing 1 is supplied into the exhaust pipe 40. By taking in and diluting the exhaust gas exhausted from the exhaust pipe 40 by the clean air, the clogging phenomenon of the exhaust pipe system is prevented. That is, the exhaust pipe 40 according to the present embodiment
When the processing chamber 14 is evacuated, the exhaust force of the exhaust device connected to the second exhaust pipe 42 acts on the gap 43 formed between the first exhaust pipe 41 and the second exhaust pipe 42. When the clean air intake valve 53 is opened, the clean air in the clean room in which the diffusion device is installed is taken into the standby room 3 from the clean air intake 52,
The communication hole 6 flows into the hollow chamber 5 of the scavenger 4 and is taken in. As shown in FIG. 4B, the clean air 61 introduced into the hollow chamber 5 of the scavenger 4 is sucked into the second exhaust pipe 42 from the gap 43 and exhausted from the first exhaust pipe 41. The exhaust gas 62 is diluted by merging with the gas 62. Incidentally, the exhaust gas 62 diluted by the clean air 61 is discharged into the atmosphere after harmful components are eliminated by an abatement apparatus (not shown) connected to the exhaust pipe 40. Here, the first exhaust pipe 41 and the second exhaust pipe 42
If the size of the gap 43 formed between them is too small, the flow rate of the clean air 61 introduced into the exhaust pipe 40 is insufficient, so that the exhaust gas 62 flowing through the exhaust pipe 40 is not sufficiently diluted by the clean air 61. Things happen. Conversely, if the size of the gap 43 is too large, the exhaust power of the exhaust pipe 40 is relatively reduced, so that an adverse effect such as the exhaust gas 62 remaining in the processing chamber 14 occurs. Therefore, by adjusting the radial position of the bracket 47 that suspends the second exhaust pipe 42, the dimension of the gap 43 formed between the first exhaust pipe 41 and the second exhaust pipe 42 is appropriately adjusted in advance. It needs to be adjusted. It is desirable that the optimum value of the gap 43 be set by an empirical method based on experiments, simulation experiments using a computer, past data, and the like. For example, in the case of diluting exhaust gas containing antimony, when the pressure in the processing chamber 14 is about 50 Pa and the pressure in the processing chamber 14 is about 50 Pa under the condition that the clean air intake valve 53 is fully open, When the size of the gap 43 was adjusted so that the pressure difference between the pressure in the hollow chamber 5 and the atmospheric pressure was about 90 Pa, the clogging phenomenon of the exhaust pipe system could be effectively prevented. According to the above embodiment, the following effects can be obtained. 1) By forming a gap for taking clean air in the middle of the exhaust pipe, the exhaust gas flowing down the exhaust pipe can be diluted by the clean air, thereby preventing the occurrence of a clogging phenomenon in the exhaust pipe system. be able to. 2) By preventing the exhaust pipe system from being clogged, the strictness of maintenance of the entire diffusion device can be reduced, so that the downtime of the entire diffusion device can be reduced, and the throughput can be reduced. Can be improved. 3) By diluting the exhaust gas with the clean air introduced into the exhaust pipe, it is not necessary to introduce a large amount of the diluent gas into the processing chamber. Running cost can be greatly reduced. 4) By forming a gap in the middle of the exhaust pipe, clean air as a diluent gas can be taken in. Therefore, compared with a case where a flow control valve is provided in the middle of the exhaust pipe, the initial setting of the diffusion device is performed. An increase in cost can be suppressed. It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention. For example, the exhaust pipe is not limited to the configuration in which the clean air of the clean room, which is the atmosphere outside the exhaust pipe, is introduced, but may be the configuration in which nitrogen gas or the like supplied to the standby chamber is introduced. . Therefore, the intake valve may be omitted or may be installed in a scavenger. The gap formed between the first exhaust pipe and the second exhaust pipe is not limited to the male tapered part and the female tapered part, but may be a labyrinth structure or the like. The dilution port opened in the middle of the exhaust pipe to take in the atmosphere outside the exhaust pipe is not limited to the gap formed between the first exhaust pipe and the second exhaust pipe.
It may be constituted by a valve opening of a flow control valve installed in the middle of the exhaust pipe. In the above embodiment, the case where antimony is diffused into the wafer has been described. However, the diffusion device is not limited to this and can be used when other impurities are diffused into the wafer. However, it can be used not only for thermal diffusion but also for reflow for activation of carriers after ion implantation and flattening. The diffusion device is not limited to the batch type vertical hot wall type diffusion device, but may be another type of diffusion device such as a horizontal hot wall type diffusion device, a single wafer type diffusion device and the like. Further, the present invention is not limited to the diffusion apparatus, but can be applied to all substrate processing apparatuses such as an oxide film forming apparatus and a CVD apparatus. In the above-described embodiment, the case where the processing is performed on the wafer has been described. As described above, according to the present invention,
The clogging of the exhaust pipe system can be prevented without introducing a large amount of dilution gas into the processing chamber.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially omitted side sectional view showing a diffusion device according to an embodiment of the present invention. FIG. 2 is a plan cross-sectional view passing through an exhaust pipe. FIG. 3 is a rear sectional view of a main part. 4A is a rear cross-sectional view showing a connection part of an exhaust pipe, and FIG. 4B is an enlarged cross-sectional view of a part b of FIG. FIG. 5 is a partially omitted side sectional view showing a state during processing. [Description of Signs] 1 ... Case, 2 ... Process tube installation room, 3 ... Standby room,
4 Scavenger, 5 Hollow chamber, 6 Communication hole, 7 Shutter, 10 Wafer (substrate), 11 Process tube, 12 Inner tube, 13 Outer tube, 1
4 processing chamber, 15 furnace port, 16 deformation prevention cap, 1
7 ... Support plate, 18 ... Holder, 19 ... Spacer, 20 ...
Manifold, 21: partition, 22: communication hole, 23: exhaust path, 24: heater unit, 25: resistance heater, 26
... heat insulation tank, 27 ... support base, 29 ... boat elevator arm, 30 ... seal cap, 31 ... boat, 32, 3
DESCRIPTION OF SYMBOLS 3 ... End plate, 34 ... Holding member, 35 ... Holding groove, 36 ... Heat insulation cap part, 37 ... Thermocouple, 38 ... Gas introduction pipe, 40 ...
Exhaust pipe, 41 ... First exhaust pipe, 42 ... Second exhaust pipe, 43 ...
Gap (dilution port), 44: male taper, 45: female taper, 46: bolt, 47: bracket, 48, 49: long hole, 50: hanging tool, 51: bolt, 52: clean air intake, 53: Clean air intake valve, 61: Clean air (atmosphere outside the exhaust pipe), 62: Exhaust gas.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Shinya Morita             3-14-20 Higashinakano, Nakano-ku, Tokyo Stock             Hitachi Kokusai Electric Inc. (72) Inventor Hidenari Yoshida             3-14-20 Higashinakano, Nakano-ku, Tokyo Stock             Hitachi Kokusai Electric Inc. F term (reference) 4K030 CA04 CA12 EA12

Claims (1)

Claims: 1. A processing chamber for accommodating and processing a substrate, and an exhaust pipe having one end connected to the processing chamber and the other end connected to an exhaust device, wherein the exhaust pipe is provided. A dilution port for introducing an atmosphere outside the exhaust pipe into the exhaust pipe and diluting an atmosphere flowing down the exhaust pipe is provided in the middle of the exhaust pipe.