JP2002198411A - Pressure control method, transfer device and cluster tool - Google Patents

Abstract

(57) [Problem] To efficiently control the pressure in a transfer chamber. SOLUTION: The dry pump DP1 is shared between the cassette chambers CC1 and CC2 and the transfer chamber TC, and the exhaust in the transfer chamber TC is stopped when the wafer W is transferred, and the gate valves PG1 and PG2 are stopped.
Is opened, the N ₂ purge in the transfer chamber TC is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control method, a transfer apparatus, and a cluster tool, and more particularly, to a method suitably applied to a manufacturing process of a semiconductor device, a liquid crystal display device and the like.

[0002]

2. Description of the Related Art In a process of manufacturing a semiconductor or the like, a cluster tool in which a plurality of process chambers are connected to perform a plurality of processes without exposing a wafer to the air has become widespread. In such a cluster tool, a transfer chamber for transferring a wafer into and out of a plurality of process chambers is provided. Then, by controlling the pressure in the transfer chamber and transferring the wafer, the wafer is protected from contamination by the atmosphere, particles, and the like. Here, in the conventional pressure control method in the transfer chamber, the N ₂ purge is performed while constantly evacuating the inside of the transfer chamber in order to keep the pressure in the transfer chamber constant.

FIG. 5 is a sectional view showing a schematic configuration of a cluster tool to which a conventional pressure control method is applied. In FIG. 5, cassette chambers CC1 and CC2 are connected to transfer chamber TC via gate valves CG1 and CG2, and process chambers PC1 and P2 are connected to transfer chamber TC.
C2 is connected via gate valves PG1, PG2.

Here, the cassette chambers CC1, CC2
Is provided with a dry pump DP2 for evacuating the cassette chambers CC1 and CC2, and the transfer chamber TC is provided with a transfer chamber TC.
A dry pump DP3 for exhausting the inside is provided. Further, dry pumps DP4 and DP5 and a turbo pump TP1 for exhausting the inside of the process chambers PC1 and PC2 are provided in the process chambers PC1 and PC2.
TP2 is provided.

The cassette chambers CC1 and CC2 and the transfer chamber TC are provided with N ₂ discharge units 1 to 3 for purging N ₂ , and the transfer chamber TC is provided with a pressure in the transfer chamber TC. A capacitance manometer 4 and a convexron (Pirani gauge) 5 for detection are provided, and a pressure control valve PCV for controlling the pressure in the transfer chamber TC is provided.

Here, the process chambers PC1, PC2
When loading the wafer W into the cassette, the cassettes C1 and C2 accommodating the wafer W are set in the cassette chambers CC1 and CC2. Then, with the gate valves CG1 and CG2 closed, the inside of the cassette chambers CC1 and CC2 is evacuated by the dry pump DP2 to reduce the pressure in the cassette chambers CC1 and CC2 to about 170 mTorr. finish.

[0007] Further, in the transfer chamber TC,
While performing N ₂ purge, exhaust is performed by the dry pump DP3, and the pressure is maintained at about 100 or 200 mTorr.

Further, process chambers PC1, PC2
In the inside, exhaust is performed by dry pumps DP4 and DP5 and turbo pumps TP1 and TP2, and
The pressure is maintained at about orr.

When the pressure in each chamber reaches a predetermined value, the gate valves CG1 and CG2 are opened, and the transfer arm AR is used to transfer the wafers W stored in the cassettes C1 and C2 into the transfer chamber TC. Then, the gate valves PG1 and PG2 are opened, and the wafer W transferred into the transfer chamber TC is transferred into the process chambers PC1 and PC2.

Here, the gate valves CG1, CG2, P
When G1 and PG2 are opened, the transfer chamber TC
The pressure in the transfer chamber TC is constantly maintained (about 100 or 200 mTorr). Thus, the pressure difference between the respective chambers is kept within a predetermined range to prevent the particles from being wound up and to prevent the processing gases G1, G2 remaining in the process chambers PC1, PC2 from flowing out.

[0011]

However, according to the conventional pressure control method, the dry pumps DP2 and DP are provided in the cassette chambers CC1 and CC2 and the transfer chamber TC in order to constantly exhaust the inside of the transfer chamber TC.
3 had to be provided independently. In order to control the pressure in the transfer chamber TC, the capacitance manometer 4 and the pressure control valve PCV
It was necessary to use pressure control components such as For this reason,
There was a problem that the cost and power consumption for these maintenances were large. Furthermore, since the N ₂ purge is always performed during the exhaust in the transfer chamber TC, there is a problem that the consumption of N ₂ is large.

An object of the present invention is to provide a pressure control method, a transfer device, and a cluster tool that can efficiently control the pressure in a transfer chamber.

[0013]

According to the first aspect of the present invention, there is provided a transfer chamber for transferring a processing object from a cassette chamber to a process chamber via a transfer chamber. It is characterized in that the exhaust in the interior is stopped.

Thus, the object to be processed can be transported from the cassette chamber to the process chamber while maintaining the pressure in the transfer chamber at a substantially constant level. Exhaust equipment can be centralized.

According to a second aspect of the present invention, the method further comprises the step of purging the transfer chamber based on the open / close state of a gate valve of the process chamber.

[0016] This makes it possible to generate an airflow from the transfer chamber to the process chamber only when the gate valve of the process chamber is opened.
Even when the exhaust in the transfer chamber is stopped, it is possible to exhaust particles and contaminants in the transfer chamber through the process chamber while suppressing the consumption of the purge gas.

According to the third aspect of the present invention, the step of exhausting the transfer chamber during idling and the step of stopping the exhaust of the transfer chamber and exhausting the cassette chamber in which the object to be processed is mounted And stopping the exhaust in the cassette chamber when transferring the processing target from the cassette chamber to the transfer chamber.

This makes it possible to alternately evacuate the cassette chamber and the transfer chamber. Therefore, even when the cassette chamber and the transfer chamber share a dry pump, the intrusion of air between these chambers can be achieved. Can be prevented, and the cost of equipment can be reduced.

According to the fourth aspect of the present invention, the transfer means for transferring the processing object from the cassette chamber to the process chamber via the transfer chamber, and the transfer means for transferring the processing object to the process chamber. Pressure control means for stopping the exhaust in the chamber.

This makes it possible to evacuate the cassette chamber while the evacuation of the transfer chamber is stopped. Therefore, the dry pump is shared between the transfer chamber and the cassette chamber, and the supply and exhaust equipment is centralized. can do.

According to the fifth aspect of the present invention, a cassette chamber for mounting an object to be processed, a process chamber for processing the object to be processed, and the cassette chamber and the process chamber are connected to each other via a gate valve. A transfer chamber for transferring the processing target from the cassette chamber to the process chamber; a dry pump provided commonly to the cassette chamber and the transfer chamber; and a transfer pump for transferring the processing target to the process chamber. And pressure control means for stopping the exhaust in the transfer chamber.

As a result, the dry pump can be shared between the transfer chamber and the cassette chamber, and the cost of equipment can be suppressed while suppressing wafer contamination.

According to a sixth aspect of the present invention, the pressure control means exhausts the interior of the cassette chamber using the dry pump while the exhaust of the transfer chamber is stopped. I do.

Thus, even when a dry pump is shared between the cassette chamber and the transfer chamber, the pressure in the cassette chamber and the pressure in the transfer chamber can be controlled separately while preventing intrusion into the atmosphere. Becomes

According to a seventh aspect of the present invention, the power supply of the dry pump is turned off when the evacuation of the transfer chamber and the cassette chamber is stopped.

As a result, the power consumption of the dry pump can be significantly reduced.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pressure control method according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a schematic configuration of a cluster tool to which a pressure control method according to an embodiment of the present invention is applied. In FIG. 1, the transfer chamber T
Cassette chambers CC1 and CC2 are connected to C via gate valves CG1 and CG2, and process chambers PC1 and PC2 are connected to gate valves PG1 and PG.
2 are connected.

Here, the cassette chambers CC1, CC2
And in the transfer chamber TC, the dry pump D
P1 is shared, and the cassette pumps CC1, CC2 and the transfer chamber TC are separately evacuated by the dry pump DP1. The process chambers PC1 and PC2 are provided in the process chambers PC1 and PC2.
Dry pumps DP4, DP5 and turbo pumps TP1, TP2 for exhausting the inside are provided, respectively.

The cassette chambers CC1 and CC2 and the transfer chamber TC are provided with N ₂ discharge units 1 to 3 for purging N ₂ , and the transfer chamber TC is provided with a pressure in the transfer chamber TC. A convexron 5 for detection is provided.

The operation of the cluster tool shown in FIG. 1 will be described below.

FIG. 2 is a flowchart showing a pressure control method according to one embodiment of the present invention. In FIG.
During idling, the valve V6 is opened and exhaust is performed by the dry pump DP1 in order to prevent contamination by the atmosphere in the transfer chamber TC (step S1).

Next, when loading the wafer W into the process chambers PC1 and PC2, the cassettes C1 and C2 accommodating the wafer W are set in the cassette chambers CC1 and CC2. Then, by closing the valve V6 with the gate valves CG1 and CG2 closed, the exhaust in the transfer chamber TC is stopped (step S2), and the valves V1 to V4 are opened to open the cassette chamber C.
The exhaust in C1 and CC2 is performed by the dry pump DP1 (step S3).

Also, in the process chambers PC1 and PC2, the valves V7 to V12 are opened and closed, and the dry pumps DP4 and DP5 and the turbo pumps TP1 and TP are opened.
2 is evacuated.

Then, the cassette chambers CC1, CC2
When the evacuation of the inside is completed, the exhaust in the cassette chambers CC1 and CC2 is stopped by closing the valves V1 to V4 (step S4). Then, the gate valves CG1 and CG2 are opened (step S5), and the transfer arm A
By using R, the wafers W stored in the cassettes C1 and C2 are transferred into the transfer chamber TC, and the gate valves PG1 and PG2 are opened (Step S).
6) The wafer W transferred into the transfer chamber TC is transferred into the process chambers PC1 and PC2. Then, the wafer W is inserted into the process chambers PC1 and PC2.
Is completed, the gate valves PG1 and PG2 are closed (step S7).

Here, the valve V16 is opened and closed according to the opening and closing of the gate valves PG1 and PG2, and the gate valve P
Only when G1 and PG2 are opened, transfer chamber T
Performing _{N 2} purge in C (step S21, S22).
Thus, the transfer chamber TC becomes possible to generate an air flow toward the process chamber PC1, PC2 from while suppressing the consumption of N _2, the process chamber PC1 contaminants in the transfer chamber TC,
It becomes possible to discharge via PC2.

When the wafer W is loaded into the process chambers PC1, PC2, the valves V17, V1
8, the process chambers PC1, PC2
The processing gases G1 and G2 are introduced into the chamber, and the processing of the wafer W is performed (step S8). The process chamber PC1,
The processing performed by the PC 2 includes, for example, CVD, annealing,
Examples include etching, vapor deposition, sputtering, and ion implantation.

When the processing of the wafer W is completed, the gate valves PG1 and PG2 are opened (step S9), and the wafer W transferred into the transfer chamber TC is unloaded into the process chambers PC1 and PC2. When the unloading of the wafer W into the process chambers PC1 and PC2 is completed, the gate valves PG1 and PG2 are closed (Step S).
10). In this case, also in this case, the gate valves PG1, PG
The valve V16 is opened and closed in accordance with the opening and closing of the valve _{2 and} the N2 purge in the transfer chamber TC is performed only when the gate valves PG1 and PG2 are opened (steps S23 and S2).
4).

The above processing is repeated for all the cassette chambers CC1 and CC2 in which the wafers W to be processed are installed. When the processing for all the wafers W is completed, the gate valves CG1 and CG2 are closed (step S).
11) The transfer chamber TC is evacuated by opening the valve V6 (step S12).

As described above, the cassette chambers CC1, C
When the wafer W is transferred between C2 and the process chambers PC1 and PC2, the exhaust in the transfer chamber TC is stopped, and the cassette chambers CC1 and CC2 are evacuated using the dry pump DP1 for exhausting the transfer chamber TC. It is possible to exhaust the inside,
Cassette chambers CC1, CC2 and process chamber P
The dry pump DP1 can be shared by C1 and PC2.

Further, since the evacuation of the transfer chamber TC during the transfer of the wafer W is stopped, the pressure control in the transfer chamber TC during the transfer of the wafer W becomes unnecessary, and the capacitance manometer 4 and the pressure control valve shown in FIG. PCV can be removed.

FIG. 3 is a timing chart showing a pressure control method according to one embodiment of the present invention. In this embodiment, after the wafer W is first transferred from the cassette chamber CC1 to the process chamber PC1, the wafer W is transferred from the cassette chamber CC2 to the process chamber PC2.
Will be described.

In FIG. 3, during idling, the valve V6
Is opened, and exhaust is performed by the dry pump DP1. In addition,
At this time, the pressure in the transfer chamber TC is 1 mT
orr is maintained.

Next, the cassette C1 in which the wafer W is stored
Is set in the cassette chamber CC1. By closing the valve V6 with the gate valve CG1 closed, the exhaust in the transfer chamber TC is stopped (T1), the valve V1 is opened (T1), and the exhaust in the cassette chamber CC1 is performed gently. After that, the valve V1 is closed and the valve V2 is opened to quickly exhaust the cassette chamber CC1. At this time, the pressure in the cassette chamber CC1 is maintained at about 170 mTorr, and the evacuation of the transfer chamber TC is stopped.
The pressure in C gradually increases.

Further, in the process chamber PC1, exhaust is performed by the dry pump DP4 and the turbo pump TP1, and the pressure is maintained at about 0.1 mTorr.

When the evacuation of the cassette chamber CC1 is completed, the valve V2 is closed to stop the exhaust of the cassette chamber CC1, and the gate valve CG1 is opened (T2). At this time, the cassette chamber C
Although an airflow is generated due to a pressure difference between C1 and the transfer chamber TC, the cassette chamber CC1 and the transfer chamber TC are airtight, and the cassette chamber C
Since the pressure difference between C1 and the transfer chamber TC is small, the generation of the air current hardly causes the particles to be wound up.

When the gate valve CG1 is opened, the transfer arm AR is used to transfer the wafer W stored in the cassette C1 into the transfer chamber TC. Then, while opening the gate valve PG1, the valve V16
Is opened (T3), and the wafer W is transferred into the process chamber PC1 while ejecting the N ₂ gas from the N ₂ discharge unit 3.

Here, by opening the valve V16 when the gate valve PG1 is opened, it is possible to generate an airflow from the transfer chamber TC to the process chamber PC1, and the exhaust in the transfer chamber TC is stopped. Also, the particles in the transfer chamber TC are transferred to the process chamber PC.
1 can be discharged.

When the transfer of the wafer W into the process chamber PC1 is completed, the gate valve PG1 is closed, the valve V16 is closed (T4), and the introduction of the N ₂ gas into the transfer chamber TC is stopped.

Here, by closing the valve V16 when the gate valve PG1 is closed, the gate valve PG1 is closed.
Only when is opened, the N ₂ purge in the transfer chamber TC can be performed, and the particles in the transfer chamber TC can be discharged via the process chamber PC1 while suppressing the consumption of N _2. .

When the wafer W is loaded into the process chamber PC1, the processing gas G1 is introduced into the process chamber PC1 by opening the valve V17 as necessary, and the wafer W is processed. At this time, the pressure in the process chamber PC1 differs depending on the processing performed in the process chamber PC1. Also, the transfer chamber T
Since the exhaust in C is stopped, the pressure in the transfer chamber TC gradually increases.

When the processing of the wafer W is completed, the gate valve PG1 is opened and the valve V16 is opened (T
5) The wafer W is carried out of the process chamber PC1 while ejecting the N ₂ gas from the N ₂ discharge unit 3. And
When the transfer of the wafer W from the process chamber PC1 is completed, the gate valve PG1 is closed and the valve V is closed.
16 is closed (T6), and the introduction of N ₂ gas into the transfer chamber TC is stopped.

Next, the cassette C2 in which the wafer W is stored
Is set in the cassette chamber CC2. Then, the valve V3 is opened (T7), and the gas in the cassette chamber CC2 is gently exhausted. Thereafter, the valve V3 is closed and the valve V4 is opened, and the gas in the cassette chamber CC2 is rapidly exhausted. Here, in the process chamber PC2, exhaust is performed by the dry pump DP5 and the turbo pump TP2, and the pressure is maintained at about 0.1 mTorr.

When the evacuation of the cassette chamber CC2 is completed, the exhaust of the cassette chamber CC2 is stopped by closing the valve V4, and the gate valve CG2 is opened (T8).

When the gate valve CG2 is opened, the transfer arm AR is used to transfer the wafer W stored in the cassette C2 into the transfer chamber TC. Then, while opening the gate valve PG2, the valve V16
Is opened (T9), and the wafer W is transferred into the process chamber PC2 while ejecting the N ₂ gas from the N ₂ discharge unit 3.

When the transfer of the wafer W into the process chamber PC2 is completed, the gate valve PG2 is closed, the valve V16 is closed (T10), and the introduction of the N ₂ gas into the transfer chamber TC is stopped.

When the wafer W is loaded into the process chamber PC1, the processing gas G2 is introduced into the process chamber PC2 by opening the valve V18 if necessary, and the wafer W is processed. At this time, the pressure in the process chamber PC2 differs depending on the processing performed in the process chamber PC2. Also, the transfer chamber T
Since the exhaust in C is stopped, the pressure in the transfer chamber TC gradually increases.

When the processing of the wafer W is completed, the gate valve PG2 is opened and the valve V16 is opened (T1
1) The wafer W is unloaded from the process chamber PC2 while the N ₂ gas is ejected from the N ₂ discharge unit 3. When the transfer of the wafer W from the process chamber PC2 is completed, the gate valve PG2 is closed, the valve V16 is closed (T12), and the introduction of the N ₂ gas into the transfer chamber TC is stopped.

FIG. 4 is a diagram showing the number of generated particles by the transport method according to one embodiment of the present invention. In FIG. 4, when the wafer W is placed in the cassette chambers CC1 and CC2 (standby), the cassette chambers CC1 and CC2
When the wafer W is transferred between the chamber C2 and the process chambers PC1 and PC2 (vacuum transfer) and when the wafer W is etched for 30 seconds (RF transfer 30 seconds), the initial state, the running for 10 hours, The number of particles (size 0.2 μm or more) after running for 30 hours and running for 50 hours was examined. In this case, the number of particles hardly changed even if the evacuation of the transfer chamber TC was stopped during the transfer of the wafer W and the N ₂ purge was performed in the transfer chamber TC only when the gate valves PG1 and PG2 were opened. .

Therefore, according to the above-described embodiment, the dry pump DP1 can be shared between the cassette chambers CC1 and CC2 and the transfer chamber TC without causing contamination of the wafer W by particles. consumption of N ₂ can be reduced.

In the above-described embodiment, the case where the cassette chambers CC1 and CC2 are directly connected to the transfer chamber TC has been described. However, the cassette chambers CC1 and CC2 may be load lock chambers.

In the above-described embodiment, the case has been described in which the exhaust in the transfer chamber TC is constantly stopped during the transfer of the wafer W. However, the pressure in the transfer chamber TC exceeds the predetermined value during the transfer of the wafer W. In this case, the inside of the transfer chamber TC may be temporarily exhausted.

Further, with the stop of the exhaust of the transfer chamber TC and the cassette chambers CC1 and CC2, the power of these dry pumps DP1 may be turned off, thereby greatly reducing the power consumption of the dry pump DP1. Reduction is possible.

[0064]

As described above, according to the present invention,
By stopping the evacuation of the transfer chamber when transferring the processing target from the cassette chamber to the process chamber, the dry pump can be shared between the cassette chamber and the transfer chamber, and the transfer of the processing target can be performed. , Pressure control in the transfer chamber can be made unnecessary, and supply and exhaust equipment can be centralized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a cluster tool to which a pressure control method according to an embodiment of the present invention is applied.

FIG. 2 is a flowchart illustrating a pressure control method according to an embodiment of the present invention.

FIG. 3 is a timing chart showing a pressure control method according to an embodiment of the present invention.

FIG. 4 is a diagram showing the number of generated particles by a transport method according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a schematic configuration of a cluster tool to which a conventional pressure control method is applied.

[Explanation of symbols]

 CC1, CC2 Cassette chamber TC transfer chamber PC1, PC2 Process chamber DP1 to DP5 Dry pump CG1, CG2, PG1, PG2 Gate valve TP1, TP2 Turbo pump V1 to V19 Valve OF Orifice

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshimitsu Aoki 5-3-6 Akasaka, Minato-ku, Tokyo TBS Release Center Tokyo Electron Limited F-term (reference) 5F031 CA02 CA05 FA01 FA02 FA11 FA12 JA47 NA05 NA15 NA20

Claims (7)

[Claims] 1. A pressure control method comprising: stopping the exhaust in the transfer chamber when transferring a processing target from a cassette chamber to a process chamber via the transfer chamber. 2. The pressure control method according to claim 1, further comprising a step of purging the transfer chamber based on an open / closed state of a gate valve of the process chamber. 3. A step of evacuating the transfer chamber during idling, a step of stopping the evacuation of the transfer chamber, and an step of evacuating a cassette chamber on which the object to be processed is mounted, and from the cassette chamber to the transfer chamber. 3. The pressure control method according to claim 1, further comprising a step of stopping the exhaust in the cassette chamber when the processing target is transported. 4. A transfer means for transferring a processing target from a cassette chamber to a process chamber via a transfer chamber, and when transferring the processing target to the process chamber,
And a pressure control means for stopping the exhaust in the transfer chamber. 5. A cassette chamber for mounting an object to be processed, a process chamber for processing the object to be processed, the cassette chamber and the process chamber being connected via a gate valve, from the cassette chamber to the process chamber. A transfer chamber for transferring the processing target, a dry pump provided commonly to the cassette chamber and the transfer chamber, and a transfer processing unit for transferring the processing target to the process chamber.
And a pressure control means for stopping the exhaust in the transfer chamber. 6. The cluster tool according to claim 5, wherein said pressure control means performs exhaust in said cassette chamber using said dry pump while exhaust in said transfer chamber is stopped. 7. The dry pump according to claim 5, wherein the power supply of the dry pump is turned off when the exhaust of the transfer chamber and the cassette chamber is stopped.
The described cluster tool.