WO2005001925A1

WO2005001925A1 - Vacuum processing device operating method

Info

Publication number: WO2005001925A1
Application number: PCT/JP2004/009011
Authority: WO
Inventors: Masamichi Hara
Original assignee: Tokyo Electron Limited
Priority date: 2003-06-26
Filing date: 2004-06-25
Publication date: 2005-01-06
Also published as: JP2005019739A; JP4517595B2

Abstract

A vacuum processing device operating method for performing a high purification degree of processing for which contamination of atmosphere should be avoided and for performing a medium purification degree of processing for which contamination of atmosphere should be avoided in a less degree than for the high purification degree of processing. The processing device comprises processing chambers (4A, 4B) for performing a high purification degree of processing, processing chambers (4C, 4D) for performing a medium purification degree of processing, and a common transfer chamber (6) provided with a transfer mechanism for transferring a processing subject object. Each chamber (4A-4D, 6) is arranged so that it can be evacuated. Gate valves (G) are installed to allow the common transfer chamber (6) to communicate with or to be shut off from each processing chamber (4A-4D). In this operating method, it is arranged that when communication is to be established between the common transfer chamber (6) and the processing chambers (4A, 4B) for a high degree of purification, just before communication the pressures in the processing chambers (4A, 4B) become slightly higher than the pressure in the common transfer chamber and when communication is to be established between the common transfer chamber (6) and the processing chambers (4C, 4D) for a medium degree of purification, just before communication the pressures in the processing chambers (4C, 4D) become slightly lower than the pressure in the common transfer chamber.

Description

Specification

Operation method of vacuum processing equipment

Technical field

[0001] The present invention provides a vacuum processing apparatus for continuously performing a process such as PVD or CVD on a semiconductor wafer or the like using a vacuum processing apparatus having a plurality of processing chambers connected to a common transfer chamber. Related to the operation method.

^ Scenic technology

In general, in a semiconductor device manufacturing process, various processes such as dry etching, sputtering, and chemical vapor deposition (CVD) are repeatedly performed on a semiconductor wafer a plurality of times. Recently, in order to improve the efficiency of processing, a so-called cluster tool type vacuum processing system, which combines multiple processing chambers for performing these processing so that semiconductor wafers can be processed continuously without exposing them to the atmosphere. The device is receiving attention.

[0003] An apparatus of this type is disclosed, for example, in Japanese Patent Application Laid-Open No. 3-19252. The apparatus includes a pre / post-processing chamber, a common transfer chamber connected to the pre / post-processing chamber and having a transfer robot therein, and a plurality of processing chambers connected to the common transfer chamber. The wafer to be processed is transferred to the first processing chamber by the transfer robot in the common transfer chamber after preprocessing such as preheating in the pre-Z post-processing chamber. In addition, the wafer is transferred to each processing room by the transfer robot, and the processing is performed in each processing room.

[0004] In this type of apparatus, when a wafer is moved between processing chambers, the wafer is transferred between the common transfer chamber and each processing chamber. In that case, various gases and particles slightly remaining in each chamber may move between the processing chamber communicated for wafer transfer and the common transfer chamber. For this reason, contamination such as cross contamination may occur on the wafer. Therefore, a technique for preventing the occurrence of such contamination is disclosed in JP-A-4-100222 and JP-A-7-211761. The technology is to adjust the pressure between the chambers in advance, so that when the chambers communicate with each other, the atmosphere always flows in one direction only, so that the gas or particles that are the source of contamination can be directed in the intended direction. On the other hand, it does not flow in the opposite direction. [0005] Recently, high cleanliness processing of wafers that highly dislikes the contamination of the atmosphere in the processing chamber and medium cleanliness processing that dislikes the contamination of the atmosphere in the processing chamber to a moderate degree that is lower than that of the high cleanliness processing. And a cluster tool type vacuum processing apparatus for continuously performing the above processes have also been proposed. For example, high cleanliness processing is physical vapor deposition (PVD) and medium cleanliness processing is CVD. In this case, the common transfer room is connected to a PVD processing room as a high cleanliness processing room and a CVD processing room as a medium cleanliness processing room. PVD processing chambers must achieve a significantly lower pressure (base pressure) than CVD processing chambers, and must highly avoid contamination of the atmosphere inside the processing chamber. However, in the operation method as described above, the residual gas and particles in the CVD processing chamber, the gas (including outgas) and the contamination source generated from the wafer in a high temperature state after the CVD processing, etc. Etc. may enter through the common transfer chamber.

Disclosure of the invention

[0006] The present invention has been devised in view of the above problems and effectively solving them. That is, an object of the present invention is to provide a method of operating a vacuum processing apparatus capable of reliably preventing contamination in a high-cleanliness processing chamber connected to a medium-cleanliness processing chamber via a common transfer chamber. It is in.

[0007] Therefore, according to the present invention, a high-cleanliness processing chamber that is capable of being evacuated to perform a high-purity processing that highly dislikes atmospheric contamination is performed on an object to be processed. And a medium-cleanliness processing chamber capable of being evacuated for performing medium-cleanliness processing on the object, which dislikes contamination of the atmosphere to a level lower than the high-cleanliness processing. A medium transfer chamber having a medium cleanliness processing container and a transfer mechanism for transferring the object is defined, and the common transfer chamber communicates with the high cleanliness processing chamber and the medium cleanliness processing chamber, respectively. And a common transport container connected to the high-cleanliness processing container and the medium-cleanliness processing container via a gate vanoleb, respectively, so as to be able to shut off. Transfer room When communicating with the high-cleanliness processing chamber, immediately before the communication, the pressure in the high-cleanliness processing chamber is slightly higher than the pressure in the common transfer chamber, and the common transfer is performed. When communicating between the chamber and the medium cleanliness processing chamber, immediately before the communication, the medium cleanliness A method for operating a vacuum processing apparatus is provided, wherein the pressure in the processing chamber is slightly lower than the pressure in the common transfer chamber.

[0008] According to this operation method, when communicating the common transfer chamber and the high-cleanliness processing chamber, the pressure in the high-cleanliness processing chamber is slightly higher than the pressure in the common transfer chamber immediately before the communication. As a result, the atmosphere in the high-purity processing chamber flows toward the common transfer chamber during communication. Also, when communicating the common transfer chamber and the medium-cleanliness processing chamber, the pressure in the medium-cleanliness processing chamber was slightly lower than the pressure in the common transfer chamber immediately before the communication. At the time of communication, the atmosphere in the common transfer chamber flows toward the medium-cleanliness processing chamber. Therefore, it is possible to prevent gas and particles, which are a source of contamination in the medium-cleanliness processing chamber and the common transfer chamber, from entering the high-cleanliness processing chamber.

[0009] In this case, when the common transfer chamber and the high-cleanliness processing chamber are in communication with each other, the common transfer chamber and the middle-cleanliness processing chamber are shut off, and the common transfer chamber and the high-cleanliness processing chamber are disconnected. When the medium cleanliness processing chamber is in communication, it is preferable that the common transfer chamber and the high cleanliness processing chamber be shut off.

Typically, the high cleanliness process is physical vapor deposition and the medium cleanliness process is chemical vapor deposition.

Brief Description of Drawings

FIG. 1 is a schematic plan view showing an example of a vacuum processing apparatus to which the operation method of the present invention is applied.

FIG. 2 is a timing chart showing a pressure change by the operation method of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a method for operating a vacuum processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a vacuum processing apparatus to which the operation method of the present invention is applied. The processing apparatus 2 shown in FIG. 1 includes four processing chambers 4A, 4B, 4C, and 4D, one common transfer chamber 6, and two load lock chambers 8A and 8B. Each chamber is defined by a processing container 4A, 4B, 4C, 4D, a common transfer container 6, and a load lock container 8A, 8B. The common transfer container 6 has a substantially hexagonal prism shape, and the processing containers 4 are joined to four sides thereof, and the load lock containers 8A and 8B are joined to the other two sides. [0012] The common transfer chamber 6 and each of the processing chambers 4A-4D, and the common transfer chamber 6 and each of the load lock chambers 8A and 8B are connected via a gate vanoleb G that can be opened and closed in an airtight manner. ing . By opening and closing each gate valve G as needed, between the common transfer chamber 6 and each of the chambers 4A-4D, and between the common transfer chamber 6 and each of the load lock chambers 8A and 8B. Can be connected / disconnected, respectively. Further, a gate valve G which can be opened and closed in an airtight manner is provided on the opposite side of the common transfer chamber 6 of each of the load lock chambers 8A and 8B. By opening these gate vanolebs G, the semiconductor wafer W as an object to be processed can be carried in and out between the transfer chamber or cassette chamber (not shown) and the load lock chambers 8A and 8B. .

In each of the processing chambers 4A and 4D, susceptors 12A, 12B, 12

C and 12D are provided. In the common transfer chamber 6, a transfer mechanism 14 composed of an articulated arm that can be bent, extended, raised and lowered, and pivoted is provided at a position where the load lock chambers 8A and 8B and the processing chambers 4A to 4D can be accessed. . The transfer mechanism 14 has two picks Bl and B2 that can bend and stretch independently in the opposite directions, and can handle two wafers at a time. Note that the transport mechanism 14 may be one having only one pick.

[0014] Each of the processing chambers 4A to 4D has a predetermined processing containing an inert gas (Ar gas, N gas, or the like) therein.

2

Gas supply systems 16A, 16B, 16C and 16D for supplying the processing gas are connected respectively. In addition, vacuum evacuation systems 18A, 18B, 18C, and 18D for evacuating the internal atmosphere are connected to the processing chambers 4A to 4D, respectively. The common transfer chamber 6 and each of the load lock chambers 8A, 8B also have a gas supply system 22A, 24A, 26A for supplying inert gas, and a vacuum exhaust system 22B, 24B, 26B for evacuating the internal atmosphere, respectively. It is connected. Each processing room 4A 4

D, a pressure gauge P for detecting the internal pressure is provided in each of the common transfer chamber 6 and each of the load lock chambers 8A and 8B.

[0015] Of the four processing chambers 4A-4D, the two processing chambers 4A and 4B are high-cleanliness processing chambers for performing high-cleanliness processing that highly dislikes atmospheric contamination of the wafer W. . The other two processing chambers 4C and 4D are medium-cleanliness processing chambers for performing medium-cleanliness processing on wafers W, which dislikes atmospheric contamination to a lower degree than high-cleanliness processing. Here, "high cleanliness" "Medium cleanliness" does not indicate absolute cleanliness but merely indicates the relative degree of cleanliness between the two. The high cleanliness processing, for example, ^{1 X 10- 7 Torr (l.} 33 X 10- 5 Pa) less ultimate pressure there is a PVD processing required. Further, as the medium cleanliness processing, there is a CVD processing which requires an ultimate pressure of, for example, about 1 × 10 ⁻³ Torr (1.33 × 10 − ^ a).

In the present embodiment, PVD processing for forming a sputter film of Ti, Cu, or the like is performed in the high cleanliness processing chambers 4A and 4B, and TaN, WN, W, TiN, and the like are performed in the medium cleanliness processing chambers 4C and 4D. A case where a CVD process for forming a film is performed will be described. Each of the vacuum exhaust systems 18A and 18B of the high cleanliness processing chambers 4A and 4B has a cryopump in addition to a dry pump and a turbo molecular pump (not shown) in order to achieve the high vacuum described above. 30 are attached. Further, control of gas supply / exhaust and pressure of each chamber is performed by a controller (not shown) which controls the overall operation of the processing apparatus 2.

Next, a method of the present invention performed based on the processing apparatus 2 configured as described above will be described. Here, in order to facilitate understanding of the present invention, a Ti film is formed by PVD processing in both the high cleanliness processing chambers 4A and 4B, and a TiN film is formed by CVD processing in both the medium cleanliness processing chambers 4C and 4D. The case where a barrier film is formed on the wafer W by film formation will be described as an example.

In general, in the PVD process, an inert gas such as Ar gas necessary for forming a plasma is used as a process gas, and there is almost no risk of expanding contamination. On the other hand, in the CVD process, various source gases are used as a processing gas which is a source of expanding pollution. An important point of the present invention is that the atmosphere in the high-cleanliness processing chambers 4A and 4B is common in order to prevent cross contamination in the high-cleanliness processing chambers 4A and 4B when transferring the wafer W. This is to flow to the transfer chamber 6 side, and the atmosphere in the common transfer chamber 6 is to flow to the medium cleanliness processing chambers 4C and 4D.

First, the semiconductor wafer W to be processed is taken into the common transfer chamber 6 by the transfer mechanism 14 from the outside (atmosphere side) via one of the load lock chambers 8A and 8B. The wafer W is first introduced into one of the high-cleanliness processing chambers 4A and 4B for forming a Ti film by PVD processing, for example, into the processing chamber 4A, and the PVD processing has already been completed.ゥ C Replaced with W. The PVD-processed wafer W taken out of the processing chamber 4A is introduced into one of the medium-cleanliness processing chambers 4C and 4D, for example, the processing chamber 4C, to form a TiN film by C VD processing. Replaced with wafer W for which CVD processing has been completed.

[0020] In this manner, the wafer W that has been subjected to the continuous processing of the PVD processing (Ti film formation) and the CVD processing (TiN film formation) is unloaded to the outside via one of the load lock chambers 8A and 8B. Is performed. A series of operations as described above are sequentially and repeatedly performed. Note that two or more of the six gate valves G provided around the common transfer chamber 6 are not opened at the same time, and that when one gate valve G is opened, The five gate vanolebs G are always closed.

Next, with reference to FIG. 2, an example of pressure changes in the high cleanliness processing chamber 4A and the medium cleanliness processing chamber 4C according to the operation method of the present invention will be described. FIG. 2A shows a pressure change in the high-cleanliness processing chamber 4A, and FIG. 2B shows a pressure change in the medium-cleanliness processing chamber 4C. The interior of the common transfer chamber 6 is constantly evacuated, and a constant pressure of, for example, about 200 mTorr (27 Pa) is maintained. It is assumed that the process times of the PVD process and the CVD process are substantially the same for convenience of explanation.

First, as shown in FIG. 2 (A), if a Ti film is formed by PVD processing under a predetermined process pressure (for example, lOmTorr (lPa)) in the high cleanliness processing chamber 4A, Purging and exhausting the atmosphere in chamber 4A with inert gas. After that, inert gas such as Ar gas or N gas

2

Is introduced into the processing chamber 4A to adjust the pressure. Thus, in the period tl, the pressure in the processing chamber 4A is slightly higher than the pressure in the common transfer chamber 6, for example, 250 mTorr (33 Pa), which is higher by about 50 mTorr (7 Pa).

In parallel with this, as shown in FIG. 2 (B), a TiN film was formed by CVD under a predetermined process pressure (for example, 100 mTorr (13 Pa)) in the medium cleanliness processing chamber 4C. Then, the atmosphere in the processing chamber 4C is purged with an inert gas and exhausted. After that, Ar gas or N gas

2 Introduce inert gas into processing chamber 4C to adjust pressure. As a result, in the period t2, the pressure in the processing chamber 4C is slightly lower than the pressure in the common transfer chamber 6, for example, 150 mTorr (20 Pa), which is lower by about 50 mTorr (7 Pa). Next, as shown in FIG. 2A, the gate valve G of the processing chamber 4A is opened, and the wafer W on which the Ti film has been formed is taken out into the common transfer chamber 6 using the transfer mechanism 14. At the same time, the unprocessed wafer is carried into the processing chamber 4A. At this time, the pressure in the high-cleanliness processing chamber 4A is maintained slightly higher than the pressure in the common transfer chamber 6, so that the atmosphere in the processing chamber 4A flows into the common transfer chamber 6 side. . For this reason, it is possible to prevent the generation of cross contamination or the like that prevents gas as a source of particulate II contamination from entering the high-cleanliness processing chamber 4A. When the replacement of the wafer in the high-cleanliness processing chamber 4A is completed, the gate valve G of the processing chamber 4A is closed.

Next, as shown in FIG. 2 (B), the gate vanoleb G of the medium cleanliness processing chamber 4C is opened, and the wafer W on which the Ti film is formed is loaded into the processing chamber 4C using the transfer mechanism 14. . At the same time, the wafer W on which the TiN film has been formed in the processing chamber 4C is taken out into the common transfer chamber 6. At this time, since the pressure in the medium-cleanliness processing chamber 4C is maintained slightly lower than the pressure in the common transfer chamber 6, the atmosphere in the common transfer chamber 6 flows into the processing chamber 4C. For this reason, particles and gas that is a source of contamination do not enter the common transfer chamber 6. In the medium-cleanliness processing chamber 4C, the introduction of the inert gas and the exhaust of the internal atmosphere are continued, so that the particles and gases in the processing chamber 4C are exhausted more efficiently. When the replacement of the wafer in the medium-cleanliness processing room 4C is completed, the gate valve G of the processing room 4C is closed. As described above, the wafer W on which the Ti film and the TiN film are continuously formed is carried out to the atmosphere through one of the load lock chambers 8A and 8B.

[0026] The above-described series of operations are also performed in the other high-cleanliness processing chamber 4B and the other medium-cleanliness processing chamber 4D.

Therefore, when loading / unloading (swapping) the wafer W to / from the high-cleanliness processing chambers 4A and 4B, the atmosphere in the processing chambers 4A and 4B may always flow to the common transfer chamber 6 side. it can. Further, when loading / unloading (swapping) the wafer W to / from the medium-cleanliness processing chambers 4C and 4D, the atmosphere in the common transfer chamber 6 can always flow toward the processing chambers 4C and 4D. For this reason, it is possible to reliably prevent gas or particles serving as a contamination source from entering the high cleanliness processing chambers 4A and 4B. In particular, by performing PVD processing that does not use raw material gas as high-cleanliness processing, the atmosphere in the common transfer chamber 6 becomes medium-cleanliness processing chambers 4C and 4 Even if it flows into D, these processing chambers 4C and 4D are not contaminated.

[0028] In addition, while maintaining the internal pressure in the common transfer chamber 6 substantially constant, the pressure in each of the processing chambers 4A-4D having a smaller volume than the common transfer chamber 6 is changed, so that the pressure can be quickly adjusted. The ability to do S. Therefore, the throughput of the continuous processing is not reduced.

[0029] Each pressure value in the above-described embodiment is merely an example, and is not limited to the numerical values shown. For example, the pressure difference between the processing chambers 4A, 4B and 4C and 4D with respect to the common transfer chamber 6 may be about + 10- + 200 mTorr and about -10 ^ 200 mTorr, respectively. Further, as for the medium cleanliness processing chambers 4C and 4D, it is sufficient that the pressure is simply lower than that of the common transfer chamber 6, so that the pressure adjustment during the period t2 and the inert gas such as Ar gas and N gas are performed.

2

May be omitted.

[0030] In the high-cleanliness processing chambers 4A and 4B, since extremely low ultimate pressure is required, the cryopump 30 is used instead of this. A turbo molecular pump may be used. In this case, the temperature of the cryopanel is set at about 100-110 ° K. In this way, of the gas molecules exhausted from the processing chambers 4A and 4B, only water vapor is trapped in the cryopanel, and Ar gas, N gas, etc. are trapped.

2

Exhausted by the pump. This makes it possible to reduce the number of times of regeneration (raising the temperature of the trapped gas and exhausting it) as compared with a plug-in pump such as a cryopump for trapping all the gas. Operation efficiency can be improved. In particular, when an inert gas is continuously supplied so as to maintain the pressure in the high-cleanliness processing chambers 4A and 4B at 250 mTorr, it is preferable to use a cryopanel.

Next, a vacuum processing apparatus provided with two high-cleanliness processing chambers and two medium-cleanliness processing chambers was used. It can be any number greater than one. The number of each processing chamber should be set so as to obtain the optimum throughput in consideration of the processing time in each processing chamber.

[0032] The type of film to be formed is not limited to the combination of the Ti film and the TiN film. As described above, a Cu film formed by PVD processing, a TaN film formed by CVD processing, a WN film or a W film, or the like is used. The present invention can be applied to a case where a barrier film is formed by a combination of the above. In addition to the high cleanliness processing, in addition to PVD processing, etching processing is performed using only Ar gas plasma. The so-called soft etching process (PCEM: pre-clean etching module) can be used. Examples of the medium cleanliness processing include ALD (Atomic Layer Deposition) processing, RTP (Rapid Thermal Processing), and the like, in addition to CVD processing. The object to be processed is not limited to a semiconductor wafer, and the present invention can be applied to a case where an LCD substrate, a glass substrate, or the like is to be processed.

Claims

The scope of the claims

[1] A high-cleanliness processing container defining a vacuum-cleanable high-cleanliness processing chamber for performing high-cleanliness processing on objects to be processed, which highly dislikes atmospheric contamination,

Medium cleanliness processing that defines a vacuum-evacuable medium cleanliness processing chamber for performing medium cleanliness processing on the object, which dislikes contamination of the atmosphere to a lower degree than the high cleanliness processing. A container,

A common transfer chamber provided with a transfer mechanism for transferring the object is defined, and the common transfer chamber can communicate with and shut off the high-cleanliness processing chamber and the medium-cleanliness processing chamber, respectively. A common transport container connected to the high-cleanliness processing container and the medium-cleanliness processing container via a gate valve, respectively;

The operation method of the vacuum processing apparatus equipped with

When communicating the common transfer chamber and the high-cleanliness processing chamber, immediately before the communication, the pressure in the high-cleanliness processing chamber is slightly higher than the pressure in the common transfer chamber. West,

When communicating the common transfer chamber and the medium cleanliness processing chamber, immediately before the communication, the pressure in the medium cleanliness processing chamber is slightly lower than the pressure in the common transfer chamber. A method of operating a vacuum processing apparatus.

[2] The high cleanliness processing is physical vapor deposition, and the medium cleanliness processing is chemical vapor deposition.

2. The method for operating a vacuum processing apparatus according to claim 1, wherein:

[3] When the common transfer chamber and the high cleanliness processing chamber are in communication, the communication between the common transfer chamber and the medium cleanliness processing chamber is shut off,

When the common transfer chamber and the medium cleanliness processing chamber are in communication with each other, the communication between the common transfer chamber and the high cleanliness processing chamber is shut off.

[4] The high cleanliness processing is physical vapor deposition, and the medium cleanliness processing is chemical vapor deposition.

4. The method for operating a vacuum processing apparatus according to claim 3, wherein: