JP2010153480A - Process of fabricating semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise a cooling rate while minimizing an increase in initial cost or running cost. <P>SOLUTION: In a heat treatment apparatus 10 including a processing chamber 25 which processes a wafer 1 while holding the wafer 1 by means of a boat 21, a standby chamber 12 where the boat 21 stays before being carried into the processing chamber 25, a boat elevator 19 which elevates/lowers the boat 21 between the standby chamber 12 and the processing chamber 25, and a clean unit 41 which supplies clean air 40 to the standby chamber 12, a maximum volume of air flow is supplied for cooling when a boat 21 holding a processed wafer 1 is in the standby chamber 12. When the wafer 1 is not in the standby chamber 12, supply of air flow is stopped. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method for manufacturing a semiconductor device.
For example, in a method for manufacturing a semiconductor integrated circuit device (hereinafter referred to as an IC), the semiconductor integrated circuit device (hereinafter referred to as an IC) is used in a heat treatment process in which a semiconductor wafer (hereinafter referred to as a wafer) on which a semiconductor integrated circuit including a semiconductor element is fabricated is subjected to a thermal treatment. It relates to what is valid.

In an IC manufacturing method, a heat treatment apparatus (furnace) is widely used in a heat treatment step of forming a CVD film such as an insulating film, a metal film, or a semiconductor film on a wafer or diffusing impurities.
A conventional heat treatment apparatus of this type includes a processing chamber for batch processing while holding a plurality of wafers in a boat, a standby chamber in which the boat waits before and after loading into and out of the processing chamber, and a filter that supplies a clean atmosphere to the standby chamber And a clean unit including a blower, and a boat elevator provided in the standby chamber so as to face the filter and moving the boat up and down between the standby chamber and the processing chamber. For example, see Patent Document 1.
In this type of conventional heat treatment apparatus, the air volume of the clean unit is generally controlled to be constant.
JP 2007-95879 A

In the heat treatment apparatus that controls the air volume of the clean unit to be constant, it takes a long time to cool the boat and wafer group after heat treatment by the clean unit.
Therefore, it is conceivable to install a nitrogen gas cooling pipe in the standby chamber and increase the cooling rate of the boat and the wafer group by the nitrogen gas blown out from the nitrogen gas cooling pipe.
However, in the heat treatment apparatus in which the nitrogen gas cooling pipe is laid in the waiting room, it is necessary to lay the nitrogen gas cooling pipe and supply nitrogen gas, which increases the initial cost and running cost. There was a point.

  An object of the present invention is to provide a method of manufacturing a semiconductor device capable of increasing a cooling rate while suppressing an increase in initial cost and running cost.

Means for solving the above-described problems are as follows.
(1) carrying the substrate from the transfer chamber into the processing chamber;
Processing the substrate in the processing chamber;
Unloading the substrate from the processing chamber to the transfer chamber;
Supplying a maximum airflow during operation to the substrate in the transfer chamber;
A method for manufacturing a semiconductor device comprising:
(2) The method for manufacturing a semiconductor device according to (1), wherein the supply of the airflow is stopped in the step in which the substrate does not exist in the transfer chamber.
(3) The method for manufacturing a semiconductor device according to (1), wherein the supply of the airflow is started a predetermined time ago.
(4) a processing chamber for processing the substrate;
A transfer chamber adjacent to the processing chamber;
An airflow supply system for supplying airflow into the transfer chamber;
When the substrate does not exist in the transfer chamber, the supply of the airflow is stopped, and when the substrate exists in the transfer chamber, the flow rate of the airflow so as to supply the maximum airflow during operation. An air flow control unit for controlling
A substrate processing apparatus.

  According to the semiconductor device manufacturing method described above, the cooling rate can be increased while suppressing an increase in initial cost and running cost. Furthermore, it is possible to contribute to power saving and energy saving due to cost reduction, and at the same time, the wafer cooling time can be shortened, so that the processing time can be shortened as a whole.

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

In the present embodiment, the method for manufacturing a semiconductor device according to the present invention is performed by a heat treatment apparatus which is an example of the substrate processing apparatus shown in FIGS.
By the way, there are an open cassette and a FOUP (front opening unified pod, hereinafter referred to as a pod) as a carrier (conveying jig) for accommodating and transporting a wafer. The open cassette is formed in a substantially cubic box shape in which a pair of surfaces facing each other are opened. The pod is formed in a substantially cubic box shape with one surface opened, and a cap is detachably attached to the opening surface.
When a pod is used as a wafer carrier, the wafer is transported in a sealed state. Therefore, even if particles are present in the surrounding atmosphere, the cleanness of the wafer (cleanness) is Can be maintained.
Therefore, in this embodiment, the pod 2 is used as the carrier for the wafer 1.

The heat treatment apparatus 10 according to the present embodiment includes a housing 11 constructed in an airtight structure having an airtight performance of about atmospheric pressure, and the housing 11 constitutes a standby chamber 12 as a transfer chamber.
A mounting plate 13 is in contact with and fastened to the front wall of the housing 11. A pair of ports (hereinafter referred to as wafer loading ports) 14 for loading and unloading (loading and unloading) the wafer 1 are provided on the mounting plate 13 in the vertical direction. A pod opener 15 that opens and closes the pod 2 by attaching and detaching the cap 3 (see FIG. 1) of the pod 2 is installed at a position corresponding to the wafer loading ports 14 and 14.

  A maintenance port 16 is formed in the rear wall of the housing 11, and a maintenance door 17 is attached to the maintenance port 16 so as to be opened and closed.

An elevator 18 that raises and lowers a wafer transfer equipment 18 </ b> A is installed in a space in front of the waiting room 12.
The wafer transfer device elevator 18 is screwed into a feed screw shaft 18a that is vertically supported and rotatably supported, a motor 18b as a drive device that rotates the feed screw shaft 18a forward and backward, and a feed screw shaft 18a. The elevator 18c moves up and down with forward / reverse rotation, and the arm 18d on which the wafer transfer device 18A is installed in a cantilevered manner.
The wafer transfer device 18 </ b> A is moved up and down by the wafer transfer device elevator 18 to convey the wafer 1 between the wafer loading port 14 and the boat 21 and deliver it to the pod 2 and the boat 21.

A boat elevator 19 is vertically installed in the rear space of the waiting room 12.
The boat elevator 19 includes a feed screw shaft 19a that is vertically supported and rotatably supported, a motor 19b that rotates the feed screw shaft 19a in forward and reverse directions, and a screw screw that engages with the feed screw shaft 19a to perform forward and reverse rotation. An elevator 19c that moves up and down, and an arm 19d that is cantilevered by the elevator 19c and on which the boat 21 is installed via a seal cap 20 are provided. The boat elevator 19 raises and lowers the seal cap 20 that supports the boat 21 in the vertical direction.
The seal cap 20 is formed in a disk shape, and a boat 21 is vertically erected on the center line of the seal cap 20.
The boat 21 holds a large number of wafers 1 serving as substrates in a state where they are arranged horizontally with their centers aligned.

A heater unit 22 is concentrically arranged at the upper part of the rear end of the housing 11, and the heater unit 22 is supported by the housing 11.
An outer tube 23 and an inner tube 24 are concentrically installed in the heater unit 22. The outer tube 23 is made of a heat-resistant material such as quartz or silicon carbide, and has an inner diameter larger than the outer diameter of the inner tube 24 and has a cylindrical shape with the upper end closed and the lower end opened. The inner tube 24 is made of a heat-resistant material such as quartz or silicon carbide, and is formed in a cylindrical shape with an upper end and a lower end opened.
The hollow cylindrical portion of the inner tube 24 constitutes a processing chamber 25 that can accommodate the boat 21.

A manifold 26 is disposed below the outer tube 23 so as to be concentric with the outer tube 23. The manifold 26 is made of stainless steel or the like, and is formed in a cylindrical shape with upper and lower ends opened. The manifold 26 is engaged with and supports the outer tube 23 and the inner tube 24.
The lower end opening (furnace port) of the manifold 26 is opened and closed by a shutter 27.

An exhaust pipe 28 for exhausting the processing chamber 25 is connected to a side wall portion of the manifold 26 so as to communicate with a space between the outer tube 23 and the inner tube 24.
A gas supply pipe 29 as a gas introduction part is connected to the seal cap 20 so as to communicate with the inside of the processing chamber 25.

  A suction side duct portion 34 is laid on one side surface (hereinafter referred to as a right side surface) in the standby chamber 12. The suction-side duct portion 34 isolates the wafer transfer device elevator 18 and the boat elevator 19 from the standby chamber 12 (however, the portions where both arms are movable communicate with each other), and is substantially perpendicular to the entire surface. It is laid to extend. A suction port 33 is formed in the suction side duct portion 34 in a range in which the arm 19 d of the boat elevator 19 and the arm of the wafer transfer device elevator 18 move up and down.

On the left side surface in the standby chamber 12, the blowout side duct portion 39 is laid vertically. A large number of air outlets 38 are formed in the outlet side duct portion 39 over substantially the entire surface.
A clean unit 41 for supplying clean air 40 is built in the air outlet 38 of the air outlet side duct portion 39.
The clean unit 41 includes a filter 42 that collects particles and a plurality of blowers 43 that blow the cleaned clean air 40. The filter 42 is exposed to the standby chamber 12 and is disposed downstream of the blower 43 group. It is comprised so that it may become.

  As shown in FIG. 2, a fresh air supply pipe 44 that supplies fresh air is connected to the upstream side of the clean unit 41 of the blowout side duct portion 39, and the fresh air supply pipe 44 includes A damper 45 as an on-off valve is interposed.

As shown in FIGS. 3 and 4, a discharge passage 49 for exhausting the standby chamber 12 is formed at the rear end of the suction side duct portion 34.
A plurality of discharge ports 58 are provided in the vertical direction between the suction side duct portion 34 and the discharge path 49 and between the standby chamber 12 and the discharge path 49. The plurality of discharge ports 58 discharge the clean air 40 to the discharge path 49 from the suction side duct portion 34 and the standby chamber 12 via the discharge port 58.
As shown in FIG. 4, a discharge duct 50 is connected to the upper end of the discharge path 49, and a main discharge path 51 is formed at the downstream end of the discharge duct 50. A damper 52 as an on-off valve is interposed in the main discharge path 51.
A bypass path 53 that bypasses the damper 52 is connected to the main discharge path 51, and the flow rate of the bypass path 53 is set to be smaller than the flow rate of the main discharge path 51.

As shown in FIG. 4, a motor installation chamber 54 is set right above the suction side duct portion 34, and the motor installation chamber 54 has a motor 19 b of the boat elevator 19 and a wafer transfer device elevator 18. A motor 18b is installed. The motor installation chamber 54 is formed in a rectangular parallelepiped box shape having a sufficiently larger volume than the motor 19b and the motor 18b.
A communication port 56 is formed in the partition wall 55 that separates the motor installation chamber 54 and the standby chamber 12 so as to communicate the inside of the motor installation chamber 54 and the inside of the suction side duct portion 34.

  The heat treatment apparatus 10 includes an air flow control unit 60 (see FIG. 2) that controls the flow rate of the clean air 40. The air flow control unit 60 controls the flow of the clean air 40 when the wafer 1 is not present in the standby chamber 12 which is a transfer chamber by controlling the air volume of the blower 43 and the opening degree of the damper 45 or the damper 52, for example. When the wafer 1 is stopped and the wafer 1 exists in the standby chamber 12, a clean air flow having a maximum flow rate during operation can be supplied.

  Next, an IC manufacturing method according to an embodiment of the present invention using the heat treatment apparatus having the above-described configuration will be described.

The pod 2 transferred to the mounting table of the pod opener 15 is opened by removing the cap 3 (see FIG. 1) by the pod opener 15.
When the pod 2 is opened by the pod opener 15, the plurality of wafers 1 stored in the pod 2 are transferred to the boat 21 and loaded (wafer charging) by the wafer transfer device 18A.
When a predetermined number of wafers 1 are loaded, the boat 21 is lifted by the boat elevator 19 and loaded into the processing chamber 25 (boat loading).
The above is the carry-in step.

Prior to this carry-in step, the damper 45 of the fresh air supply pipe 44 is opened, the blower 43 is operated with a predetermined air volume, and the damper 52 of the main discharge path 51 is closed.
The clean air 40 is blown out from the clean unit 41 built in the discharge side duct portion 39 to the standby chamber 12, flows through the standby chamber 12, and is sucked into the suction side duct portion 34 from the suction port 33. The clean air 40 sucked into the suction side duct portion 34 flows through the bypass passage 53 via the discharge passage 49 and the discharge duct 50 and is discharged (see FIGS. 2, 3 and 4).

When the boat 21 reaches the upper limit, the peripheral portion of the upper surface of the seal cap 20 that holds the boat 21 comes into contact with the lower surface of the manifold 26 in a sealed state, so that the processing chamber 25 is airtightly closed.
The processing chamber 25 is hermetically closed and is evacuated to a predetermined degree of vacuum by the exhaust pipe 28 and heated to a predetermined temperature by the heater unit 22.
Next, a predetermined processing gas is supplied from the gas supply pipe 29 to the processing chamber 25.
Thereby, a desired heat treatment is performed on the wafer 1.
The above is the processing step.

When the boat 21 reaches the upper limit and the seal cap 20 closes the processing chamber 25 in an airtight state, the wafer 1 group does not exist in the standby chamber 12, and therefore the air flow control unit 60 uses the fresh air supply pipe 44. The damper 45 is closed, the operation of the blower 43 is stopped, and the damper 52 of the main discharge path 51 is closed (air flow stop step).
Since the air flow stopping step can reduce power consumption, the running cost of the heat treatment apparatus 10 can be reduced.

When a preset processing time elapses, the boat 21 is lowered by the boat elevator 19 so that the boat 21 holding the processed wafers 1 is carried out to the original standby position in the standby chamber 12 (boat unloading). .
When the boat 21 is unloaded from the processing chamber 25, the processing chamber 25 is closed by the shutter 27. The above is the carry-out step.

Prior to the carry-out step, the damper 45 of the fresh air supply pipe 44 is fully opened in advance, the blower 43 is operated with the maximum air volume, and the damper 52 of the main discharge path 51 is fully opened.
The clean air 40 is blown out with a maximum air volume from the clean unit 41 built in the discharge side duct portion 39 to the standby chamber 12, flows through the standby chamber 12, and is sucked into the suction side duct portion 34 from the suction port 33. The clean air 40 sucked into the suction side duct portion 34 is discharged with a maximum air volume by the main discharge path 51 and the bypass path 53 via the discharge path 49 and the discharge duct 50 (see FIGS. 2 to 4).

While circulating through the standby chamber 12, the clean air 40 cools the wafer 1 by contacting the group of wafers heated to a high temperature and the boat 21 holding the wafer 1 for heat exchange.
At this time, since the clean air 40 having the maximum air volume blows against the wafer group 1 and the boat 21, the wafer group 1 and the boat 21 can be cooled with high heat exchange efficiency.
In addition, since the clean air 40 is the clean air 40 that has been cooled and is clean immediately after being supplied by the fresh air supply pipe 44, the wafer group 1 and the boat 21 can be cooled with higher heat exchange efficiency.
Further, the clean air 40 whose temperature has risen by cooling the wafer group 1 and the boat 21 flows to the discharge path 49 via the discharge port 58, and then passes through the discharge duct 50 to the main discharge path 51 and the bypass path. By being immediately evacuated by 53, the temperature does not rise in the clean unit 41 because it does not pass through the standby chamber 12 and the clean unit 41. As a result, it is possible to prevent organic pollutants from being generated from the clean unit 41.

The processed wafer 1 of the boat 21 carried out to the standby chamber 12 is picked up from the boat 21 by the wafer transfer device 18A, transferred to the wafer loading port 14 in advance, removed from the cap 3, and opened. 2 is stored.
When the pod 2 is filled with the processed wafer 1, the pod 2 is closed with the cap 3 attached by the pod opener 15. The pod 2 is transferred from the wafer loading port 14 to another location.
Thereafter, the next empty pod 2 is transferred to the wafer loading port 14.
These operations are repeated until all processed wafers 1 are transferred from the boat 21 to the pod 2.
When all the processed wafers 1 are transferred from the boat 21 to the pod 2 (wafer discharging), the wafer 1 group does not exist in the standby chamber 12, so that the airflow control unit 60 has a fresh air supply pipe. 44, the damper 45 is closed, the operation of the blower 43 is stopped, and the damper 52 of the main discharge path 51 is closed (air flow stop step).
Since the air flow stopping step can reduce power consumption, the running cost of the heat treatment apparatus 10 can be reduced.

  Subsequently, the wafer 1 is batch processed by the heat treatment apparatus 10 by repeating the above-described operation.

  According to the embodiment, the following effects can be obtained.

(1) When the processed wafer group and the boat are being unloaded into the standby chamber, the processed wafer group and the boat can be cooled with high heat exchange efficiency by supplying the maximum airflow during operation. Therefore, TAT (Turn Around Time), that is, the time required to complete the IC can be shortened.

(2) According to the above (1), the processed wafer group and the boat can be cooled with high heat exchange efficiency without laying a nitrogen gas cooling pipe in the standby chamber and without using nitrogen gas. Therefore, the initial cost of the heat treatment apparatus and the running cost of the heat treatment process can be reduced.

(3) Since the power consumption can be reduced by stopping the supply of airflow when the wafer is not present in the standby chamber, the running cost of the heat treatment process can be reduced.

(4) Since the supply of airflow is started a predetermined time before the stagnation in the waiting room can be eliminated, the waiting room can be cleaned in advance.
As described above, the point of the present invention is to supply the optimum amount of the cooling air flow at the optimum timing.

  Needless to say, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, the airflow may be intermittently supplied as in the present invention, or the airflow stop step may be omitted. That is, the air flow may always be supplied.

  Although the case of the batch type vertical heat treatment apparatus has been described in the above embodiment, the present invention is not limited to this, and can be applied to all substrate processing apparatuses such as a batch type vertical diffusion apparatus.

  Although the case of the IC manufacturing method has been described in the above embodiment, the present invention is not limited to this, and can be applied to all semiconductor device manufacturing methods such as liquid crystal panels, solar cells, magnetic disks, and optical disks.

It is side surface sectional drawing which shows the heat processing apparatus which is one embodiment of this invention. It is a partially cut front view. It is a plane sectional view showing a waiting room. It is side surface sectional drawing which follows the IV-IV line of FIG.

Explanation of symbols

1 ... wafer (substrate), 2 ... pod (wafer carrier), 3 ... cap,
DESCRIPTION OF SYMBOLS 10 ... Heat processing apparatus (substrate processing apparatus), 11 ... Housing | casing, 12 ... Standby room (transfer chamber),
13 ... Mounting plate, 14 ... Wafer loading port, 15 ... Pod opener, 16 ... Maintenance port, 17 ... Maintenance door,
18 ... Wafer transfer device elevator, 18a ... Feed screw shaft, 18b ... Motor, 18c ... Elevator, 18d ... Arm, 18A ... Wafer transfer device,
DESCRIPTION OF SYMBOLS 19 ... Boat elevator, 19a ... Feed screw shaft, 19b ... Motor, 19c ... Lifting platform, 19d ... Arm,
20 ... seal cap, 21 ... boat,
22 ... Heater unit, 23 ... Outer tube, 24 ... Inner tube, 25 ... Processing chamber, 26 ... Manifold, 27 ... Shutter, 28 ... Exhaust pipe, 29 ... Gas supply pipe,
33 ... Suction port, 34 ... Suction side duct part,
38 ... Air outlet, 39 ... Air outlet side duct part,
40 ... Clean air, 41 ... Clean unit, 42 ... Filter, 43 ... Blower, 44 ... Fresh air supply pipe, 45 ... Damper,
DESCRIPTION OF SYMBOLS 49 ... Discharge path, 50 ... Discharge duct, 51 ... Main discharge path, 52 ... Damper, 53 ... Bypass path, 54 ... Motor installation room, 55 ... Bulkhead, 56 ... Communication port, 58 ... Discharge port, 60 ... Air flow control part .

Claims (2)

Carrying the substrate from the transfer chamber into the processing chamber;
Processing the substrate in the processing chamber;
Unloading the substrate from the processing chamber to the transfer chamber;
Supplying a maximum airflow during operation to the substrate in the transfer chamber;
A method for manufacturing a semiconductor device comprising:   The method for manufacturing a semiconductor device according to claim 1, wherein the supply of the airflow is stopped in the step in which the substrate does not exist in the transfer chamber.

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