JP4983745B2 - Pressure adjusting device, treatment system using the same, and pressure adjusting method - Google Patents

Description

  The present invention relates to a pressure adjusting device for adjusting a pressure between processing chambers (chambers) in a multi-chamber type processing system, for example, clustered to process a semiconductor wafer or the like, and a processing system using the same.

  In general, in order to manufacture a semiconductor integrated circuit, various processes such as a film forming process, an oxidation diffusion process, an annealing process, and an etching process are repeatedly performed on a semiconductor wafer made of, for example, a silicon substrate. When performing the above-described series of processes, for example, in order to improve the efficiency of the process and avoid atmospheric transfer of the semiconductor wafer, for example, a single-wafer type of the same or different processing chamber for performing the above-described series of processes. A plurality of semiconductor wafers are combined and clustered to form a cluster so that a semiconductor wafer which has been subjected to one process is transferred to a processing chamber where a different process is performed without being exposed to the atmosphere, and is continuously processed one after another. A clustered multi-chamber processing system is known (for example, Patent Documents 1 and 2).

  For example, in this type of multi-chamber processing system, a film processing chamber and an etching processing chamber are commonly connected to a common transfer chamber that is always kept in a vacuum state via a gate valve. The load lock chamber is connected to the transfer chamber through a gate valve with a small capacity and in a vacuum state or an atmospheric pressure state as necessary, and the load lock chamber can be connected to the transfer chamber without breaking the vacuum state of the transfer chamber. It is possible to carry in and out semiconductor wafers.

In addition, in this load lock chamber, an inert gas atmosphere such as N ₂ gas is used to prevent natural oxidation of the semiconductor wafer surface. The atmosphere-side transfer chamber that is in the state is connected, and the semiconductor wafer taken into the apparatus can be transferred into and out of the load lock chamber.

JP-A-8-291384 JP-A-11-186355

  By the way, in the manufacturing process of a semiconductor wafer, even if a very small amount of dust, that is, particles are present, it becomes a defective product easily due to processing of a line width of micron order. How to eliminate particles is a big issue.

Under such circumstances, a major problem is that when the semiconductor wafer is transferred between the chambers, the pressure difference is generated when the two chambers are communicated with each other due to the pressure difference generated between the chambers. As a result, the airflow flows into one chamber, which causes particles to roll up and adhere to the semiconductor wafer, and that particles and contaminants in one chamber flow into the other chamber and diffuse. Is a point. Therefore, in order to eliminate the pressure difference, when the load lock chamber that is repeatedly maintained in the vacuum state and the atmospheric pressure state and the atmosphere-side transfer chamber that is always maintained at the substantially atmospheric pressure state are communicated, so that the communicating both chambers by opening the gate valve which divides the two chambers where the pressure gauge is provided in the load lock chamber by supplying N ₂ gas is substantially detects the atmospheric pressure.

  However, the airflow easily moves with a slight pressure difference under a pressure of about atmospheric pressure, but the pressure gauge covering the pressure range of about atmospheric pressure is very expensive with high accuracy, and Even if the pressure gauge detects zero differential pressure, there is a risk that the air current flows and rolls up particles every time the two chambers communicate with each other due to the pressure difference due to this measurement error.

As another conventional communication method, a method as shown in FIG. 10 is also known. That is, a communication pipe 8 having an on-off valve 6 is provided in the middle so that the transfer chamber 2 on the atmosphere side and the load lock chamber 4 communicate with each other. When N ₂ gas is introduced into the chamber 4 and the pressure gauge 10 provided therein detects a substantially atmospheric pressure, the valve control unit 12 opens the on-off valve 6. As a result, the gas slightly moves from the high pressure chamber to the low pressure chamber via the communication pipe 8, so that the slight pressure difference between the two chambers 2 and 4 can be eliminated. The gate valve 14 that partitions the space is opened (for example, Patent Document 2).

  However, in this case as well, it is difficult to avoid the atmosphere in one room from moving to the other room via the communication pipe 8 due to the error of the pressure gauge 10 and the like. There is also a problem here that the atmosphere in the transfer chamber 2 on the atmosphere side that is likely to occur may enter the load lock chamber 4 to cause the diffusion of particles.

  Such a problem occurs not only between the above-described atmospheric-side transfer chamber 2 and the load lock chamber 4, but also between the load lock chamber and the vacuum transfer chamber, and between the vacuum transfer chamber and each processing chamber. There were some differences between them.

  In particular, as semiconductor integrated circuits are now becoming increasingly dense and highly miniaturized, the presence of a small number of particles can cause a decrease in yield, and an early solution of the above problems is desired.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to use a pressure adjusting device capable of reducing the differential pressure between two rooms to zero without causing the atmosphere of one room to flow into the other room when the two rooms communicate with each other. It is to provide a processing system and a pressure adjusting method.

  According to the first aspect of the present invention, there is provided a pressure adjusting device for a first chamber and a second chamber, which are communicated via an openable / closable opening / closing door and in which a pressure difference is generated. Between the communication passage communicating with the second chamber, the first and second on-off valves interposed in the middle of the communication passage, and the first and second on-off valves of the communication passage A gas supply passage connected to supply a clean gas having a predetermined pressure to the communication passage, a gas on-off valve interposed in the middle of the gas supply passage, and the first and In order to store the clean gas in the communication passage with the second on-off valve closed, and then supply the stored clean gas to the first and second chambers. And a valve control unit that controls to open the second on-off valve. A pressure adjustment device for.

  As described above, the communication path communicating the first room and the second room, the first and second opening / closing valves interposed in the middle of the communication path, and the first and second opening / closing of the communication path. A gas supply passage connected between the valve and supplying clean gas having a predetermined pressure to the communication passage; a gas on-off valve interposed in the middle of the gas supply passage; The first and second on-off valves store the clean gas in the communication passage with the second on-off valve closed and then supply the stored clean gas to the first and second chambers. And a valve control unit that controls to open the chamber, and immediately before opening the open / close door, for example, the gate valve, to communicate the two chambers, the clean gas stored in the communication passage is supplied to both chambers to increase the pressure. Since it was made to equilibrate, when two rooms communicate, the atmosphere of one room flows into the other room A differential pressure of both the room can be reduced to zero without.

  Therefore, when opening and closing doors and communicating with both rooms, not only can the particles be prevented from rolling up, but also particles and contaminants in one room can be prevented from diffusing into other rooms. Can do.

According to a second aspect of the present invention, in the first aspect of the invention, the valve control unit controls the open / close door to open when a predetermined time elapses after the first and second open / close valves are opened. It is characterized by.
According to a third aspect of the present invention, in the first or second aspect of the present invention, after the first and second on-off valves are opened, the valve control unit does not open the first and second doors until the open / close door is opened. Control is performed to maintain the open state of the on-off valve.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the valve control unit controls the first on-off valve and the second on-off valve to open simultaneously. It is characterized by that.
The invention of claim 5 is the invention according to any one of claims 1 to 4, wherein a pressure gauge is provided in at least one of the first room and the second room. The valve control unit controls the valve opening based on the detected value of the front air pressure gauge.

The invention of claim 6 is the invention according to any one of claims 1 to 5, wherein the predetermined pressure of the clean gas is the first and second before the first and second on-off valves are opened. It is characterized by being set higher than each pressure in the second room.
The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the communication passage has a volume increasing tank between the first on-off valve and the second on-off valve. It is connected.

The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein a volume increasing tank is connected to the gas supply passage downstream of the gas on-off valve. And
The invention according to claim 9 is the invention according to any one of claims 1 to 8, wherein the first chamber and the second chamber are for performing processing in a reduced-pressure atmosphere on the object to be processed. An atmosphere-side transfer chamber in the processing system and a load-lock chamber that is connected to the atmosphere-side transfer chamber and repeats an atmospheric pressure atmosphere and a reduced-pressure atmosphere.

The invention according to claim 10 is the invention according to any one of claims 1 to 8, wherein the first chamber and the second chamber are used for processing the object to be processed in a reduced pressure atmosphere. A decompression-side transfer chamber in the processing system, and a load-lock chamber that is connected to the decompression-side transfer chamber and repeats an atmospheric pressure atmosphere and a reduced-pressure atmosphere.
The invention of claim 11 is the invention according to any one of claims 1 to 8, wherein the first chamber and the second chamber are for performing processing in a reduced-pressure atmosphere on the object to be processed. A decompression-side transfer chamber in the processing system, and a processing chamber that is connected to the decompression-side transfer chamber and that actually processes the object to be processed in a reduced-pressure atmosphere.

According to a twelfth aspect of the present invention, in the invention according to any one of the first to eleventh aspects, the open / close door is a gate valve.
The invention of claim 13 is the invention according to any one of claims 1 to 12, wherein the clean gas is one or more of clean air, N ₂ gas, and rare gas. .

  The invention according to claim 14 is a processing system for performing processing on an object to be processed, one or a plurality of processing chambers that actually perform processing on the object to be processed, and an opening / closing door that can be opened and closed in the processing chamber. A decompression-side transfer chamber commonly connected via an opening provided with an opening, and an atmospheric pressure atmosphere and a reduced-pressure atmosphere connected to the decompression-side transfer chamber via an opening provided with an openable / closable door. A load lock chamber repeated; an atmosphere-side transfer chamber connected to the load lock chamber through an opening provided with an openable / closable door; and the decompression-side transfer chamber provided with the object to be processed. A first transfer mechanism that transfers, a second transfer mechanism that is provided in the atmosphere-side transfer chamber and transfers the object to be processed, and the pressure adjusting device according to any one of claims 1 to 13; System that controls the operation of the entire system And control unit, a processing system comprising the.

  A fifteenth aspect of the present invention is a pressure adjusting device for a first chamber and a second chamber, which are communicated via an openable / closable door, and in which a pressure difference is generated, wherein the first chamber A communication passage that communicates with the second chamber, first and second on-off valves interposed in the middle of the communication passage, and the first and second on-off valves of the communication passage It is performed using a pressure regulator having a gas supply passage that is connected between the gas supply passage and supplies a clean gas having a predetermined pressure to the communication passage, and a gas on-off valve that is provided in the middle of the gas supply passage. In the pressure adjusting method, the step of storing the clean gas in the communication passage in a state where the first and second on-off valves are closed, and the first and second on-off valves are opened and stored. Supplying clean gas to the first and second chambers. Which is a pressure adjusting method characterized.

According to the pressure adjusting device, the processing system using the pressure adjusting device, and the pressure adjusting method according to the present invention, the following excellent effects can be obtained.
In the pressure regulators of the first and second rooms that are connected to each other through the openable / closable door and that may cause a pressure difference, the communication between the first room and the second room is established. A clean gas having a predetermined pressure is connected between the passage, the first and second on-off valves provided in the middle of the communication passage, and the first and second on-off valves of the communication passage. A gas supply passage for supplying gas, a gas on-off valve interposed in the middle of the gas supply passage, and a clean gas in the communication passage with the first and second on-off valves closed immediately before opening the opening / closing door And a valve control unit for controlling the opening of the first and second on-off valves to supply the stored clean gas to the first and second chambers, and an open / close door such as a gate Immediately before opening the valve to connect the two rooms, the clean gas stored in the communication passage is sent to both rooms. Since so as to balance the pressure and supplies, when communicating two rooms, the pressure difference between both chambers without flowing the atmosphere of one room to the other room can be made zero.

  Therefore, when opening and closing doors and communicating with both rooms, not only can the particles be prevented from rolling up, but also particles and contaminants in one room can be prevented from diffusing into other rooms. Can do.

Hereinafter, a preferred embodiment of a pressure adjusting device, a processing system using the pressure adjusting device, and a pressure adjusting method according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing an example of a processing system according to the present invention, FIG. 2 is a diagram showing a pressure adjusting device provided between an atmosphere side transfer chamber and a load lock chamber, and FIG. 3 is a pressure reduction side transfer chamber and a load. FIG. 4 is a view showing a pressure adjusting device provided between the lock chamber and FIG. 4 is a view showing a pressure adjusting device provided between the decompression side transfer chamber and the processing chamber.

<Description of processing system>
First, the processing system will be described.
As shown in FIG. 1, this processing system 22 has a plurality of, for example, first to fourth four processing chambers 24a, 24b, 24c, 24d, a substantially hexagonal decompression-side transfer chamber 26, and a load lock function. The first and second load lock chambers 28a and 28b and the elongated atmosphere-side transfer chamber 30 are mainly included.

  Specifically, the processing chambers 24a to 24d are joined to four sides of the substantially hexagonal decompression-side transfer chamber 26, and the first and second load lock chambers 28a and 28b are joined to the remaining two sides. Are joined together. The atmosphere-side transfer chamber 30 is commonly connected to the first and second load lock chambers 28a and 28b. Here, the first processing chamber 24a, the second processing chamber 24b, the third processing chamber 24c, and the fourth processing chamber 24d are performed in a reduced pressure atmosphere such as a film forming process, an etching process, and an oxidation diffusion process. The same type or different types of processing are performed on a target object that is a semiconductor wafer.

  The decompression-side transfer chamber 26 and the four processing chambers 24a to 24d are joined via gate valves G1, G2, G3, and G4 that are open / close doors that can be opened and closed in an airtight manner, respectively. A cluster tool is formed so that it can communicate with the inside of the decompression side transfer chamber 26 as necessary. Further, the decompression-side transfer chamber 26 and the first and second load lock chambers 28a and 28b are also joined via gate valves G5 and G6 which are open / close doors that can be opened and closed in an airtight manner. Thus, it can communicate with the inside of the decompression side transfer chamber 26 as necessary.

Here, the inside of the decompression side transfer chamber 26 is always evacuated and maintained in a predetermined decompression atmosphere of an inert gas, for example, N ₂ gas. Gate valves G7 and G8, which are open / close doors that can be opened and closed in an airtight manner, are interposed between the first and second load lock chambers 28a and 28b and the atmosphere-side transfer chamber 30, respectively. . In the first and second load lock chambers 28a and 28b, a reduced-pressure atmosphere by evacuation and an atmospheric atmosphere are repeated as the semiconductor wafer is carried in and out. The semiconductor wafer W is loaded and unloaded with the gate valves G1 to G8 opened.

  Further, in each of the first to fourth processing chambers 24a to 24d, mounting tables 34a, 34b, 34c and 34d for mounting the semiconductor wafer W are provided, respectively, and the first and second loads are provided. In the lock chambers 28a and 28b, mounting tables 36a and 36b for temporarily mounting the semiconductor wafer W are provided, respectively.

  The first to fourth processing chambers 24a to 24d are supplied with a gas necessary for processing, for example, a gas introduction section (not shown) such as a shower head or a vacuum exhaust system (see FIG. (Not shown), heating means (not shown) for heating the semiconductor wafer, and the like are provided as necessary.

  Furthermore, each of the first to fourth processing chambers 24a to 24d is provided with pressure gauges 38a, 38b, 38c and 38d for detecting the pressure in the chamber, and the first and second load lock chambers. Pressure gauges 40a and 40d for detecting the pressure in the room are also provided on 28a and 28b, respectively. The pressure reducing side transfer chamber 26 is also provided with a pressure gauge 42 for detecting the pressure in the chamber.

Further, in the first and second load lock chambers 28a and 28b, gas introduction systems 44a and 44b each provided with an on-off valve for introducing, for example, N ₂ gas as an inert gas when returning to atmospheric pressure, Exhaust systems 46a and 46b provided with on-off valves are connected to evacuate the atmosphere in each room when necessary.

  In the decompression-side transfer chamber 26, the second load lock chambers 28a and 28b and the four processing chambers 24a to 24d can be accessed at positions where the articulated arms can be bent and extended. One transport mechanism 50 is provided, which has two picks 50a and 50b that can bend and stretch independently in opposite directions, and can handle two semiconductor wafers at a time. ing. Note that the first transport mechanism 50 having only one pick can be used.

  The atmosphere-side transfer chamber 30 is formed by a horizontally long box, and one or a plurality of, in the illustrated example, three carry-in portions for introducing a semiconductor wafer to be processed are provided on one side of the horizontally long. An opening is provided, and an opening / closing lid 52 that can be opened and closed is provided at each carry-in entrance. An introduction port 54 is provided corresponding to each of the carry-in ports, and a cassette container 56 can be placed one by one here. Each cassette container 56 can accommodate a plurality of, for example, 25 semiconductor wafers W placed in multiple stages at equal pitches. In the atmosphere-side transfer chamber 30, a downflow is formed by taking in clean air in a clean room in which the processing system is installed, and a substantially atmospheric pressure state is maintained.

  In the atmosphere-side transfer chamber 30, a second transfer mechanism 58, which is an atmosphere-side transfer mechanism for transferring the semiconductor wafer W along its longitudinal direction, is provided. The second transport mechanism 58 has two picks 58a and 58b that can be bent and stretched and swiveled, and can handle two semiconductor wafers W at a time. The second transfer mechanism 58 is slidably supported on a guide rail 60 provided on the introduction port side in the atmosphere-side transfer chamber 30 so as to extend along the length direction.

  Further, an orienter 62 for aligning the semiconductor wafer is provided at one end of the atmosphere-side transfer chamber 30. The orienter 62 has a turntable 62a that is rotated by a drive motor, and rotates with the semiconductor wafer W mounted thereon. An optical sensor 62b for detecting the peripheral edge of the semiconductor wafer W is provided on the outer periphery of the turntable 62a. Thereby, the positioning notch of the semiconductor wafer W, for example, the position direction of the notch or the orientation flat, the position of the semiconductor wafer W, or the like. The amount of misalignment at the center can be detected.

  And the pressure regulator which concerns on this invention is provided in the part of each gate valve of the processing system formed as mentioned above so that this may be straddled. Specifically, the pressure regulators A1, A2, A3 corresponding to the gate valves G1-G4 interposed between the decompression-side transfer chamber 26 and the first to fourth processing chambers 24a-24d. , A4 are respectively provided, and the pressure adjusting device A5 corresponds to the gate valves G5, G6 interposed between the decompression side transfer chamber 26 and the first and second load lock chambers 28a, 28b. , A6 are provided respectively, and pressure regulators A7, A7, corresponding to gate valves G7, G8 interposed between the atmosphere-side transfer chamber 30 and the first to second load lock chambers 28a, 28b, A8 is provided.

  Here, the pressure adjusting devices A1 to A8 basically have substantially the same configuration. In particular, the pressure regulators A1 to A4 provided corresponding to the gate valves G1 to G4 have the same configuration, and the pressure regulators A5 and A6 provided corresponding to the gate valves G5 and G6. The pressure regulators A7 and A8 provided in correspondence with the gate valves G7 and G8 have the same configuration.

  Therefore, here, the four pressure regulators A1 to A4 will be described by taking one pressure regulator A1 as an example, and the two pressure regulators A5 and A6 will be explained by taking one pressure regulator A5 as an example. The remaining two pressure adjusting devices A7 and A8 will be described by taking one pressure adjusting device A7 as an example. These pressure adjusting devices A1 to A4, A5 and A6, and A7 and A8 each have the same action (operation).

  First, FIG. 2 schematically shows a pressure adjusting device A7 provided corresponding to a gate valve G7 interposed between the atmosphere-side transfer chamber 30 and the first load lock chamber 28a, and FIG. FIG. 4 schematically shows a pressure adjusting device A5 provided corresponding to a gate valve G5 interposed between the side transfer chamber 26 and the first load lock chamber 28a. 1 schematically shows a pressure adjusting device A1 provided in correspondence with a gate valve G1 interposed between one processing chamber 24a. 2 to 4, the same reference numerals are given to the same components, and the description thereof is omitted.

<Configuration of pressure adjusting device A7>
First, as shown in FIG. 2, the pressure adjusting device A7 is provided so as to straddle the atmosphere-side transfer chamber 30 that is the first chamber and the first load lock chamber 28a that is the second chamber. Yes. That is, the pressure adjusting device A7 includes a communication path 66 that connects the atmosphere-side transfer chamber 30 that is the first room and the first load lock chamber 28a that is the second room, and a midway in the communication path 66. A clean gas having a predetermined pressure is connected between the first and second on-off valves 68, 70 provided between the first on-off valve 68 and the second on-off valve 70 of the communication passage 66. A gas supply passage 72 for supplying the gas, a gas on-off valve 74 provided in the middle of the gas supply passage 72, and a valve control unit comprising, for example, a computer for controlling the on-off valves 68, 70, 74, etc. 76.

  Here, the names of the first room and the second room are simply used to represent each room such as a load lock room and a transfer room in an abstract manner, and this point is also applied to other pressure adjusting devices. It is. Specifically, the communication passage 66 is made of piping or the like having a predetermined inner diameter, and gas outlets at both ends thereof face the atmosphere-side transfer chamber 30 and the first load lock chamber 28a, respectively. The gas can be released. The first on-off valve 68 is provided close to the atmosphere-side transfer chamber 30 side, and the second on-off valve 70 is provided close to the first load lock chamber 28a side.

Further, the gas supply passage 72 is also made of a pipe or the like having a predetermined inner diameter, and here, N ₂ gas having a predetermined pressure can be supplied as a clean gas. The pressure of the N ₂ gas is set to a pressure higher than the pressure in the atmosphere-side transfer chamber 30 and the first load lock chamber 28a. For example, in the first load lock chamber 28a, the reduced-pressure atmosphere and the atmospheric pressure atmosphere are alternately repeated as the semiconductor wafer W is loaded and unloaded, whereas the atmosphere-side transfer chamber 30 takes in clean air from the clean room. Therefore, the N ₂ gas pressure is set to be higher than the atmospheric pressure, for example, about 0.2 MPa.

Further, the valve control unit 76 inputs the detection value of the pressure gauge 40a provided in the first load lock chamber 28a, and immediately before opening the gate valve G7 which is an opening / closing door, the first control unit 76a. The N ₂ gas is stored in the communication passage 66 with the second on-off valves 68 and 70 closed, and the pressure difference between the atmosphere side transfer chamber 30 and the first load lock chamber 28a is When it becomes zero or very small based on the detected value, the first and second on-off valves 68 and 70 are simultaneously opened while the gas on-off valve 74 is closed, and the stored N ₂ gas is transferred to the atmosphere-side transfer chamber. 30 and the first load lock chamber 28a.

As a result, the atmospheric gas can be prevented from flowing from one of the chambers to the other chamber. In this case, in the gas supply passage 72, the N ₂ gas is stored in the passage portion on the downstream side of the gas on-off valve 74 interposed therebetween. Accordingly, the volume in the communication passage 66 (between the first and second on-off valves 68 and 70), the volume in the gas supply passage 72 (downstream from the gas on-off valve 74), and the pressure of N ₂ gas are as described above. When the first and second on-off valves 68 and 70 are both opened to communicate with each other, the atmosphere does not flow out from the atmosphere-side transfer chamber 30 to the first load-lock chamber 28a side or vice versa. Each is set.

<Configuration of pressure adjusting device A5>
Next, as shown in FIG. 3, the pressure adjusting device A5 is an open / close door provided between the decompression-side transfer chamber 26 that is the first chamber and the first load lock chamber 28a that is the second chamber. It is provided so as to straddle a certain gate valve G5. The basic structure of the pressure adjusting device A5 is the same as the pressure adjusting device A7 described above with reference to FIG. Here, since the pressure gauges 42 and 40a are provided in the decompression side transfer chamber 26 and the first load lock chamber 28a, the detected values of both the pressure gauges 42 and 40a are both sent to the valve controller 76. Have been entered.

  Then, after confirming that the detected values of the two pressure gauges 42 and 40a are the same or slightly different, the above-described operation is performed in order to communicate the inside of the decompression side transfer chamber 26 and the inside of the first load lock chamber 28a. The valve operations of the first and second on-off valves 68 and 70 as described above are performed.

<Configuration of pressure adjusting device A1>
Next, as shown in FIG. 4, the pressure adjusting device A1 is an open / close door provided between the decompression-side transfer chamber 26 that is the first chamber and the first processing chamber 24a that is the second chamber. It is provided so as to straddle the gate valve G1. The basic structure of the pressure adjusting device A1 is the same as the pressure adjusting device A7 described above with reference to FIG. Here, since the pressure gauges 42 and 38a are provided in the decompression-side transfer chamber 26 and the first processing chamber 24a, both detected values of the pressure gauges 42 and 38a are input to the valve controller 76. Has been.

  Then, after confirming that the detected values of the two pressure gauges 42 and 38a are the same or slightly different, the above-described operation is performed in order to communicate the inside of the decompression side transfer chamber 26 and the inside of the first processing chamber 24a. Such valve operations such as the first and second on-off valves 68 and 70 are performed.

  Returning to FIG. 1, the overall operation of the processing system 22 configured as described above, for example, various processes for semiconductor wafers in the first to fourth processing chambers 24 a to 24 d, and loading / unloading operations of the semiconductor wafer W, etc. Is controlled by a system control unit 80 formed of, for example, a computer, and each valve control unit 76 of each pressure adjusting device A1 to A8 operates under the control of the system control unit 80. In this case, each of the gate valves G1 to G8 may be configured such that the valve control unit 76 performs an opening / closing operation, or when the valve control unit 76 notifies the system control unit 80 of a valve operation completion signal. The system control unit 80 may perform this.

  A computer-readable program necessary for controlling the processing system 22 is stored in the storage medium 82. The storage medium 82 includes, for example, a flexible disk, a CD (Compact Disc), a CD-ROM, a hard disk, a flash memory, or a DVD.

  Next, a schematic operation in the processing system 22 configured as described above and an operation of the pressure adjusting device of the present invention will be described. First, from the cassette container 56 installed in the introduction port 54, the unprocessed semiconductor wafer W is taken into the atmospheric-side transfer chamber 30 which is in the atmospheric pressure state by the second transfer mechanism 58, and is taken in. The semiconductor wafer W is transferred to an orienter 62 provided at one end of the atmosphere-side transfer chamber 30, where it is positioned.

  The semiconductor wafer W that has been positioned is transferred again by the second transfer mechanism 58, and either one of the first and second load lock chambers 28a and 28b using the gate valve G7 or the gate valve G8. It is carried into the load lock room. After the load lock chamber is evacuated, the gate valve G5 or the gate valve G6 of the load lock chamber is opened, and the load is applied using the first transfer mechanism 50 in the decompression side transfer chamber 26 that has been evacuated in advance. The semiconductor wafer W in the lock chamber is taken into the decompression side transfer chamber 26.

  Then, the unprocessed semiconductor wafer taken into the decompression-side transfer chamber 26 is transferred while being repeatedly loaded and unloaded from the first process chamber 24a to the fourth process chamber 24d, and in each process chamber, each time. Necessary predetermined processing is performed. When the semiconductor wafer W is loaded / unloaded between the decompression-side transfer chamber 26 and the first to fourth processing chambers 24a to 24d, the gate valves G1 to G4 are opened / closed each time. Become.

  As described above, if a predetermined process is performed on the semiconductor wafer W in each of the first to fourth processing chambers 24a to 24d, the processed semiconductor wafer W is loaded on any one of the loads. It is accommodated in the cassette container 56 for processed semiconductor wafers in the introduction port 54 via the lock chamber 28 a or 28 b and the atmosphere-side transfer chamber 30. Also, when the processed semiconductor wafer W is unloaded as described above, each gate valve in the unloading path is opened and closed.

  Now, as described above, when the unprocessed semiconductor wafer W is taken in and loaded into the processing system 22 and the processed semiconductor wafer W is unloaded, it exists in the middle of the path of the semiconductor wafer W. The gate valve is opened and closed each time the semiconductor wafer W passes. At that time, the pressure between the chambers (chambers) located on both sides of the gate valve is adjusted using the pressure regulator of the present invention. , Preventing the rolling of particles and the spread of contamination.

  A pressure adjusting method performed using the pressure adjusting device of the present invention will be described below with reference to FIGS. FIG. 5 is a flowchart showing an example of a pressure adjustment method when the gate valve between the atmosphere-side transfer chamber and the load lock chamber is opened, and FIG. 6 is when the gate valve between the decompression-side transfer chamber and the load lock chamber is opened. 7 is a flowchart showing an example of the pressure adjustment method, FIG. 7 is a flowchart showing an example of the pressure adjustment method when the gate valve between the decompression side transfer chamber and the processing chamber is opened, and FIG. It is a graph which shows typically an example of the pressure change of each of the 1st and 2nd room when two on-off valves are opened.

<Pressure adjustment between the atmosphere side transfer chamber and the load lock chamber>
First, referring to FIG. 2 and FIG. 5, a pressure adjustment method when opening the gate valve G7 between the first load lock chamber 28a in a reduced pressure atmosphere and the atmospheric-side transfer chamber 30 in the atmospheric pressure state. Will be described. In addition, valve operation of each valve is performed by the command from the valve control part 76 as mentioned above.

First, at the time of normal standby, both the first and second on-off valves 68 and 70 provided in the middle of the communication passage 66 of the pressure adjusting device A7 are closed, and the gas supply passage 72 The gas on-off valve 74 provided in the middle is opened. Therefore, the N ₂ gas, which is a clean gas set at a high pressure, is not only filled in the gas supply passage 72 but also in the communication passage 66, the first and second on-off valves 68, 70. Up to this, it is in a state filled with N ₂ gas.

Before opening the gate valve G7 in such a state, first, in step S1, first, the closed state of the first and second on-off valves 68 and 70 is confirmed and the gas supply is performed. The open state of the gas on-off valve 74 in the passage 72 is confirmed, and it is confirmed that the N ₂ gas, which is a clean gas, reaches the communication passage 66 and is filled in the communication passage 66 as described above.

Next, if it is confirmed that the communication passage 66 is filled with N ₂ gas, the gas on-off valve 74 is closed (S2). As a result, the high pressure N ₂ gas is stored between the first and second on-off valves 68 and 70 and the gas on-off valve 74. Specifically, the N ₂ gas is isolated in the communication passage 66 in the upstream portion of the first and second on-off valves 68 and 70 and in the gas supply passage 72 in the downstream portion of the gas on-off valve 74. Will be saved.

Next, the on-off valve 44a ′ of the gas introduction system 44a is opened in the low pressure side chamber, that is, the first load lock chamber 28a in this case, and N ₂ gas is gradually introduced to increase the internal pressure ( S3). The same gas source may be used as the N ₂ gas source of the gas introduction system 44a and the N ₂ gas source of the gas supply passage 72.

  The increase in the internal pressure is detected in real time by a pressure gauge 40a provided in the first load lock chamber 28a, and this detected value is input to the system control unit 80 (see FIG. 1), while the valve It is also input to the controller 76, and it is checked whether or not the detected value of the pressure gauge 40a has reached substantially atmospheric pressure (S4). Accordingly, the pressure in the first load lock chamber 28a, which is the low pressure side chamber, is continuously increased until the detected value reaches substantially atmospheric pressure (NO in S4).

  If the detected value of the pressure gauge 40a reaches substantially atmospheric pressure (YES in S4), the on-off valve 44a 'of the gas introduction system 44a is then closed to stop the pressure increase (S5). In this case, it is preferable to stop the pressure increase when the detected value is slightly lower than the atmospheric pressure. The on-off valve operation may be performed by a command from the valve control unit 76, but actually, for example, a command from the system control unit 80 is performed.

  As a result, the pressure in the atmosphere-side transfer chamber 30 and the first load lock chamber 28a are approximately the same pressure, that is, approximately atmospheric pressure, and the differential pressure between both chambers should be approximately zero. Actually, there are many cases where a certain amount of differential pressure is generated due to an error of the pressure gauge 40a, etc. When the gate valve G7 is opened in this state, there is a risk that particles are wound up due to gas movement caused by the differential pressure. There is a risk of contamination spreading.

Therefore, in the present invention, if the pressure increase is stopped as described above, then the first and second on-off valves 68 and 70 are simultaneously opened (S6), whereby the communication passage 66 and the gas on-off valve are thereby opened. The high-pressure N ₂ gas, which is a clean gas stored in the gas supply passage 72 at the downstream side of 74, is released and simultaneously supplied into the atmosphere-side transfer chamber 30 and the first load lock chamber 28a. . The pressures in the two chambers 30 and 28a become the same and become an equilibrium state, and a predetermined time elapses with the first and second on-off valves 68 and 70 opened until the gas flow is stabilized (NO in S7). ).

At this time, the pressure of the stored N ₂ gas is the pressure in the atmosphere-side transfer chamber 30 or the pressure in the first load lock chamber 28a just before opening the first and second on-off valves 68 and 70. And the volume of the communication passage 66 and the volume of the gas supply passage 72 at the downstream side of the gas on-off valve 74 are set sufficiently large. It does not flow into the other room through the passage 66. In particular, it is possible to reliably prevent the atmosphere in the atmosphere-side transfer chamber 30 where particles are likely to be generated in the load lock chamber from flowing through the communication path 66 toward the first load lock chamber 28a.

Here, the relationship between the volume of each chamber and the like and the pressure will be described. In FIG. 2, the pressure and volume in the atmosphere-side transfer chamber 30 before pressure adjustment, that is, immediately before opening the first and second on-off valves 68 and 70, are P1 and V1, respectively, and the inside of the first load lock chamber 28a. And the pressure of N ₂ gas, which is a clean gas, is P3, and the downstream side of the volume of the communication passage 66 between the first and second on-off valves 68 and 70 and the gas on-off valve 74 is P2 and V2. The sum total with the volume of the partial gas supply passage 72 is V3.

  Then, when the pressure when the first and second on-off valves 68 and 70 are simultaneously opened and adjusted to be in an equilibrium state is P, the following equation is established. Strictly speaking, V1 includes the volume of the communication passage 66 in the downstream portion of the first opening / closing valve 68, and V2 includes the volume of the communication passage 66 in the downstream portion of the second opening / closing valve 70. Is included.

P1 · V1 + P2 · V2 + P3 · V3 = P (V1 + V2 + V3)
(However, P> P1, P> P2, preferably P1> P2)
P = (P1 · V1 + P2 · V2 + P3 · V3) / (V1 + V2 + V3)
Therefore, since V1 and V2 are determined at the design stage of the system, the pressure P and the volume V3 are determined so as to satisfy the relational expression when the pressure regulator is designed.

  An example of the pressure change after the first and second on-off valves 68 and 70 are opened is shown in FIG. 8, and as shown in FIG. The pressure in the first load lock chamber 28a increases toward the equilibrium pressure P simultaneously with the opening of the valve. However, since the inside of the atmosphere-side transfer chamber 30 takes in the clean air in the clean room as described above to form a downflow, the pressure in the atmosphere-side transfer chamber 30 eventually becomes large over a certain period of time. It will return to atmospheric pressure. In this case, in order to prevent the atmosphere in the first load lock chamber 28a from flowing into the atmosphere-side transfer chamber 30 through the communication path 66, the difference between the pressure P and the pressures P1 and P2 is larger than necessary. Do not set.

In this case, preferably, as described above, P1> P2 is set so that the pressure in the first load lock chamber 28a is set slightly lower than that in the atmosphere-side transfer chamber 30. Since only a small amount of N ₂ gas is supplied into the first load lock chamber 28 a and the pressure here becomes substantially atmospheric pressure, the atmosphere in the first load lock chamber 28 a is aired through the communication path 66. Backflow into the side transfer chamber 30 can be reliably prevented. Further, the time T1 from when the first and second on-off valves 68 and 70 are opened to when the pressure P is brought into an equilibrium state depends on the inner diameter of the communication path 66, but is, for example, about several seconds, step S7. Then, it will wait until this time T1 passes.

  In step S6, the first and second on-off valves 68 and 70 are set to open at the same time. However, this "simultaneous" does not require simultaneity in a strict sense in terms of time. Even if there is a slight time difference in the opening operation of the valves 68 and 70, the synchronism is ensured. For example, the opening operation of both the on-off valves 68 and 70 is about ½ of the time T1 until the above-described equilibrium. If it is within the time difference, simultaneity is ensured.

  As described above, when the pressure in the atmosphere-side transfer chamber 30 and the pressure in the first load lock chamber 28a are in an equilibrium state, the gate valve G7 which is an open / close door is opened, and both chambers are communicated. (S8). Thereafter, the semiconductor wafer W is transferred from the atmosphere-side transfer chamber 30 side into the first load lock chamber 28a or in the opposite direction. At this time, the first and second on-off valves 68 and 70 are also closed. As described above, a series of pressure adjustment methods is completed.

  As described above, the communication path 66 that connects the first chamber, for example, the atmosphere-side transfer chamber 30 and the second chamber, for example, the first load lock chamber 28a, and the first path that is provided in the middle of the communication path 66. And a gas supply passage that is connected between the second on-off valves 68 and 70 and the first and second on-off valves 68 and 70 of the communication passage 66 and supplies clean gas having a predetermined pressure to the communication passage 66. 72, a gas on-off valve 74 provided in the middle of the gas supply passage 72, and a communication passage in a state where the first and second on-off valves 68 and 70 are closed immediately before opening the on-off door, for example, the gate valve G7. The clean gas is stored in 66, and then the first and second on-off valves 68 and 70 are controlled to open in order to supply the stored clean gas to the first and second chambers 30 and 28a. A valve control unit 76, and an open / close door such as a gate valve G7 is opened Immediately before communicating the house, the clean gas stored in the communication passage was supplied to both rooms so that the pressures were balanced, so when communicating between the two rooms, the atmosphere in one room was changed to the other. The differential pressure between the two rooms can be made zero without flowing into the room.

  Therefore, when the open / close door, for example, the gate valve G7 is opened and the two rooms communicate with each other, not only the particles can be prevented from being rolled up, but also the particles and contaminants existing in one room diffuse into the other room. This can be prevented.

<Pressure adjustment between load lock chamber and decompression side transfer chamber>
Next, a pressure adjustment method when opening the gate valve G5 between the first load lock chamber 28a under atmospheric pressure and the decompression-side transfer chamber 26 under low pressure will be described with reference to FIGS. . In addition, valve operation of each valve is performed by the command from the valve control part 76 as mentioned above. The basic operation here is the same as the method described in FIG. Here, the pressure adjusting device A5 is used. In FIG. 3, the decompression-side transfer chamber 26 is provided with an exhaust system 88 for exhausting the internal atmosphere and a gas supply system 90 for supplying an inert gas, for example, N ₂ gas.

First, during normal standby, the first and second on-off valves 68 and 70 provided in the middle of the communication passage 66 of the pressure adjusting device A5 are both closed, and the gas supply passage 72 The gas on-off valve 74 provided in the middle is opened. Therefore, the N ₂ gas, which is a clean gas set at a high pressure, is not only filled in the gas supply passage 72 but also in the communication passage 66, the first and second on-off valves 68, 70. Up to this, it is in a state filled with N ₂ gas.

Before opening the gate valve G5 in such a state, first, in step S11, the closed state of the first and second on-off valves 68 and 70 is confirmed and the gas supply is performed. The open state of the gas on-off valve 74 in the passage 72 is confirmed, and it is confirmed that the N ₂ gas, which is a clean gas, reaches the communication passage 66 and is filled in the communication passage 66 as described above.

Next, if it is confirmed that the communication passage 66 is filled with N ₂ gas, the gas on-off valve 74 is closed (S12). As a result, the high pressure N ₂ gas is stored between the first and second on-off valves 68 and 70 and the gas on-off valve 74. Specifically, the N ₂ gas is isolated in the communication passage 66 in the upstream portion of the first and second on-off valves 68 and 70 and in the gas supply passage 72 in the downstream portion of the gas on-off valve 74. Will be saved.

Next, the atmosphere in the high pressure side chamber, that is, the first load lock chamber 28a in this case, is gradually evacuated by opening the on-off valve 46a ′ of the exhaust system 46a to reduce the internal pressure (S13). . It is also possible to use the same gas source and N ₂ gas source of the N ₂ gas source and the gas supply passage 72 of the gas supply system 90.

  The above-described drop in internal pressure is detected in real time by a pressure gauge 40a provided in the first load lock chamber 28a, and at the same time, a pressure gauge 42 provided in the decompression side transfer chamber 26 simultaneously detects this internal pressure drop. Pressure is also detected in real time. While these detection values are input to the system control unit 80 (see FIG. 1), they are also input to the valve control unit 76 to check whether the detection values of both pressure gauges 40a and 42 are substantially the same. (S14). Therefore, the pressure in the first load lock chamber 28a, which is the low pressure side room, is continuously reduced until the two detection values are substantially the same (NO in S14). As is well known, the decompression-side transfer chamber 26 has a larger capacity than other chambers, so that it takes time to increase and decrease the pressure. The inside 26 is maintained in a reduced pressure atmosphere at a constant pressure.

  If the detected values of the two pressure gauges 40a and 42 are substantially the same (YES in S14), the on-off valve 46a 'of the exhaust system 46a is closed to stop the pressure reduction (S15). The on-off valve operation may be performed by a command from the valve control unit 76, but actually, for example, a command from the system control unit 80 is performed.

  As a result, the pressure in the decompression side transfer chamber 26 and the first load lock chamber 28a are in a reduced pressure atmosphere of substantially the same pressure, and the differential pressure between the two chambers should be close to zero. In many cases, a certain amount of differential pressure is generated due to an error in the pressure gauges 40a and 42. When the gate valve G5 is opened in this state, there is a risk that particles are wound up due to gas movement caused by the differential pressure. There is a risk of causing diffusion of contamination.

Therefore, in the present invention, if the pressure reduction is stopped as described above, then the first and second on-off valves 68 and 70 are simultaneously opened (S16), whereby the communication passage 66 and the gas on-off valve are opened. The high-pressure N ₂ gas, which is a clean gas stored in the gas supply passage 72 in the downstream portion of the cylinder 74, is opened and supplied simultaneously into the decompression-side transfer chamber 26 and the first load lock chamber 28a. . The pressures in the two chambers 26 and 28a become the same and become an equilibrium state, and a predetermined time elapses with the first and second on-off valves 68 and 70 opened until the gas flow is stabilized (NO in S17). ).

At this time, the pressure of the stored N ₂ gas is the pressure in the decompression-side transfer chamber 26 just before opening the first and second on-off valves 68 and 70 or the pressure in the first load lock chamber 28a. And the volume of the communication passage 66 and the volume of the gas supply passage 72 at the downstream side of the gas on-off valve 74 are set sufficiently large. It does not flow into the other room through the passage 66. This point is substantially the same as the case described with reference to FIG.

Here, the relationship between the volume of each chamber and the like and the pressure will be described. This point is substantially the same as the case described with reference to FIG. That is, in FIG. 3, the pressure and volume in the decompression-side transfer chamber 26 before pressure adjustment, that is, immediately before opening the first and second on-off valves 68 and 70 are P1 and V1, respectively. The pressure and volume in 28a are P2 and V2, the pressure of N ₂ gas, which is a clean gas, is P3, and the volume of the communication passage 66 between the first and second on-off valves 68 and 70 is larger than the gas on-off valve 74. The sum total with the volume of the gas supply passage 72 in the downstream portion is V3.

  Then, when the pressure when the first and second on-off valves 68 and 70 are simultaneously opened and adjusted to be in an equilibrium state is P, the following equation is established. Strictly speaking, V1 includes the volume of the communication passage 66 in the downstream portion of the first opening / closing valve 68, and V2 includes the volume of the communication passage 66 in the downstream portion of the second opening / closing valve 70. Is included.

P1 · V1 + P2 · V2 + P3 · V3 = P (V1 + V2 + V3)
(However, P> P1, P> P2, preferably P1> P2)
P = (P1 · V1 + P2 · V2 + P3 · V3) / (V1 + V2 + V3)
Therefore, since V1 and V2 are determined at the design stage of the system, the pressure P and the volume V3 are determined so as to satisfy the relational expression when the pressure regulator is designed.

  An example of the pressure change after the first and second on-off valves 68 and 70 are opened is shown in FIG. 8, and as shown in FIG. The pressure in the first load lock chamber 28a increases toward the equilibrium pressure P simultaneously with the opening of the valve. In this case, although it depends on the volume of the communication path 66, the rising pressure is very small. In this case, in order to prevent the atmosphere in the first load lock chamber 28a from flowing into the decompression-side transfer chamber 26 via the communication path 66, the difference between the pressure P and the pressures P1 and P2 is larger than necessary. Do not set.

  Further, the time T1 from when the first and second on-off valves 68 and 70 are opened to when the pressure P is brought into an equilibrium state depends on the inner diameter of the communication path 66, but is, for example, about several seconds, step S17. Then, it will wait until this time T1 passes.

  In step S16, the first and second on-off valves 68 and 70 are set to open simultaneously. As described above, this “simultaneous” means simultaneity in terms of time. This is not a requirement, and even if there is a slight time difference between the opening operations of the two on-off valves 68, 70, the synchronism is ensured. As long as the time difference is about ½ of the time T1, simultaneity is ensured.

  As described above, when the pressure in the decompression side transfer chamber 26 and the pressure in the first load lock chamber 28a are in an equilibrium state, the gate valve G5 which is an open / close door is opened, and both chambers are communicated. (S18). Thereafter, the semiconductor wafer W is transferred from the decompression side transfer chamber 26 side into the first load lock chamber 28a or in the opposite direction. At this time, the first and second on-off valves 68 and 70 are also closed. As described above, a series of pressure adjustment methods is completed. Also in this case, the same effects as those described with reference to FIGS. 2 and 5 can be exhibited.

<Pressure adjustment between the processing chamber and the decompression side transfer chamber>
Next, a pressure adjustment method when opening the gate valve G1 between the first processing chamber 24a under a low-pressure atmosphere and the decompression-side transfer chamber 26 under a low-pressure atmosphere will be described with reference to FIGS. In addition, valve operation of each valve is performed by the command from the valve control part 76 as mentioned above. The basic operation here is the same as the method described in FIG. In addition, the pressure adjusting device A1 is used here.

Further, in FIG. 4, an exhaust system 94 for exhausting the internal atmosphere and a gas supply system 96 (for supplying gas necessary for processing) are provided in the first processing chamber (the same applies to other processing chambers) 24a. In general, a shower head is used) from which an inert gas, for example, N ₂ gas can be supplied.

First, at the time of normal standby, both the first and second on-off valves 68 and 70 interposed in the middle of the communication passage 66 of the pressure adjusting device A1 are closed, and the gas supply passage 72 The gas on-off valve 74 provided in the middle is opened. Therefore, the N ₂ gas, which is a clean gas set at a high pressure, is not only filled in the gas supply passage 72 but also in the communication passage 66, the first and second on-off valves 68, 70. Up to this, it is in a state filled with N ₂ gas.

Before opening the gate valve G1 in such a state, first, in step S21, the closed state of the first and second on-off valves 68 and 70 is confirmed and the gas supply is performed. The open state of the gas on-off valve 74 in the passage 72 is confirmed, and it is confirmed that the N ₂ gas, which is a clean gas, reaches the communication passage 66 and is filled in the communication passage 66 as described above.

Next, if it is confirmed that the communication passage 66 is filled with N ₂ gas, the gas on-off valve 74 is closed (S22). As a result, the high pressure N ₂ gas is stored between the first and second on-off valves 68 and 70 and the gas on-off valve 74. Specifically, the N ₂ gas is isolated in the communication passage 66 in the upstream portion of the first and second on-off valves 68 and 70 and in the gas supply passage 72 in the downstream portion of the gas on-off valve 74. Will be saved.

Next, the atmosphere in the processing chamber side, that is, the first processing chamber 24a in this case, is gradually evacuated by opening the on-off valve 94a of the exhaust system 94 to reduce the internal pressure, or the gas supply system 96 is turned on. The N ₂ gas is gradually supplied to increase the pressure to approach the pressure in the decompression side transfer chamber 26 (S23). It is also possible to use the same gas source and N ₂ gas source of the N ₂ gas source and the gas supply passage 72 of the gas supply system 96.

  The above-described drop or rise in the internal pressure is detected in real time by a pressure gauge 38a provided in the first processing chamber 24a, and at the same time, the internal pressure is detected by a pressure gauge 42 provided in the decompression side transfer chamber 26. The pressure is also detected in real time. While these detected values are input to the system control unit 80 (see FIG. 1), they are also input to the valve control unit 76 to check whether the detected values of both pressure gauges 38a and 42 are substantially the same. (S24). Therefore, the pressure reduction or pressure increase in the first processing chamber 24a is continuously performed until both detection values are substantially the same (NO in S24). As described above, since the capacity of the decompression side transfer chamber 26 is larger than that of the other chambers, it takes time to increase and decrease the pressure. The inside 26 is maintained in a reduced pressure atmosphere at a constant pressure.

  If the detected values of the two pressure gauges 38a and 42 are substantially the same (YES in S24), then the step-down or pressure increase is stopped (S25). The on-off valve operation may be performed by a command from the valve control unit 76, but actually, for example, a command from the system control unit 80 is performed.

  As a result, the pressure in the decompression-side transfer chamber 26 and the first processing chamber 24a is a reduced-pressure atmosphere of substantially the same pressure, and the differential pressure between the two chambers should be nearly zero, In many cases, a certain amount of differential pressure is generated due to errors in the pressure gauges 38a and 42. If the gate valve G1 is opened in this state, there is a risk of rolling up particles due to gas movement due to the differential pressure or contamination. There is a risk of causing diffusion.

Therefore, in the present invention, if the pressure increase is stopped as described above, then the first and second on-off valves 68 and 70 are simultaneously opened (S26), whereby the communication passage 66 and the gas on-off valve are opened. The high-pressure N ₂ gas, which is a clean gas stored in the gas supply passage 72 at the downstream side of 74, is released and simultaneously supplied into the decompression-side transfer chamber 26 and the first processing chamber 24a. The pressures in the two chambers 26 and 24a become the same and become an equilibrium state, and a predetermined time elapses with the first and second on-off valves 68 and 70 opened until the gas flow is stabilized (NO in S27). ).

At this time, the pressure of the stored N ₂ gas is higher than the pressure in the decompression-side transfer chamber 26 just before opening the first and second on-off valves 68 and 70 or the pressure in the first processing chamber 24a. Is sufficiently high, and the volume of the communication passage 66 and the volume of the gas supply passage 72 at the downstream side of the gas on-off valve 74 are set sufficiently large. 66 does not flow into the other room. This is substantially the same as the case described with reference to FIGS.

Here, the relationship between the volume of each chamber and the like and the pressure will be described. This is substantially the same as the case described with reference to FIGS. That is, in FIG. 4, the pressure and volume in the decompression-side transfer chamber 26 before pressure adjustment, that is, immediately before opening the first and second on-off valves 68 and 70 are P1 and V1, respectively, and the first processing chamber 24a. The internal pressure and volume are P2 and V2, the pressure of the clean gas N ₂ gas is P3, and the volume of the communication passage 66 between the first and second on-off valves 68 and 70 is downstream of the gas on-off valve 74. The sum total with the volume of the gas supply passage 72 in the side portion is V3.

  Then, when the pressure when the first and second on-off valves 68 and 70 are simultaneously opened and adjusted to be in an equilibrium state is P, the following equation is established. Strictly speaking, V1 includes the volume of the communication passage 66 in the downstream portion of the first opening / closing valve 68, and V2 includes the volume of the communication passage 66 in the downstream portion of the second opening / closing valve 70. Is included.

P1 · V1 + P2 · V2 + P3 · V3 = P (V1 + V2 + V3)
(However, P> P1, P> P2, preferably P1> P2)
P = (P1 · V1 + P2 · V2 + P3 · V3) / (V1 + V2 + V3)
Therefore, since V1 and V2 are determined at the design stage of the system, the pressure P and the volume V3 are determined so as to satisfy the relational expression when the pressure regulator is designed.

  An example of the pressure change after the first and second on-off valves 68 and 70 are opened is shown in FIG. 8, and as shown in FIG. The pressure in the first processing chamber 24a increases toward the pressure P in the equilibrium state simultaneously with the opening operation of the valve. In this case, although it depends on the volume of the communication path 66, the rising pressure is very small. In this case, in order to prevent the atmosphere in the first processing chamber 24a from flowing into the decompression-side transfer chamber 26 through the communication path 66, the difference between the pressure P and the pressures P1 and P2 is set larger than necessary. Do not.

  Further, the time T1 from when the first and second on-off valves 68 and 70 are opened to when the pressure P is balanced is a few seconds, for example, depending on the inner diameter of the communication path 66, and step S27. Then, it will wait until this time T1 passes.

  In step S26, the first and second on-off valves 68 and 70 are set to open at the same time. As described above, this "simultaneous" means simultaneity in terms of time. This is not a requirement, and even if there is a slight time difference between the opening operations of the two on-off valves 68, 70, the synchronism is ensured. As long as the time difference is about ½ of the time T1, simultaneity is ensured.

  As described above, when the pressure in the decompression-side transfer chamber 26 and the pressure in the first processing chamber 24a are in an equilibrium state, the gate valve G1, which is an open / close door, is opened, and the two chambers communicate with each other ( S28). Thereafter, the semiconductor wafer W is transferred from the decompression side transfer chamber 26 side into the first processing chamber 24a or in the opposite direction. At this time, the first and second on-off valves 68 and 70 are also closed. As described above, a series of pressure adjustment methods is completed. Also in this case, the same effects as those described above with reference to FIGS. 2, 3, 5, and 6 can be exhibited.

In each of the above embodiments, when the volume of the N ₂ gas stored in the communication passage 66 or the gas supply passage 72 is small, the first on-off valve 68 and the second on-off valve are opened as shown in FIG. A volume increasing tank 100 may be provided between the valve 70 and the valve 70. The volume increasing tank 100 may be provided in the gas supply passage 72 on the downstream side of the gas opening / closing valve 74. According to this, the supply pressure “P” of the N ₂ gas can be lowered by the increase of the volume “V3” in the above formula.

Further, in the above embodiment, the N ₂ gas as a clean gas is not limited thereto, the cleaning gas may be one or more gases of the clean air, N ₂ gas and a rare gas. Furthermore, the structure of the processing system described above is merely an example, and the present invention can be applied to all processing systems or processing apparatuses using a gate valve or the like.

  Although the semiconductor wafer is described as an example of the object to be processed here, the semiconductor wafer includes a silicon substrate and a compound semiconductor substrate such as GaAs, SiC, GaN, and the like, and is not limited to these substrates. The present invention can also be applied to glass substrates, ceramic substrates, and the like used in display devices.

It is a schematic block diagram which shows an example of the processing system which concerns on this invention. It is a figure shown with the pressure regulator provided between the atmosphere side conveyance chamber and the load lock chamber. It is a figure which shows the pressure regulator provided between the pressure reduction side conveyance chamber and the load lock chamber. It is a figure which shows the pressure regulator provided between the pressure reduction side conveyance chamber and the process chamber. It is a flowchart which shows an example of the pressure adjustment method when opening the gate valve between an atmosphere side conveyance chamber and a load lock chamber. It is a flowchart which shows an example of the pressure adjustment method when opening the gate valve between a pressure reduction side conveyance chamber and a load lock chamber. It is a flowchart which shows an example of the pressure adjustment method when opening the gate valve between the pressure reduction side conveyance chamber and a process chamber. It is a graph which shows typically an example of pressure change of the 1st and 2nd room when the 1st and 2nd on-off valve of a pressure regulator is opened. It is a figure which shows the deformation | transformation embodiment of the pressure regulator which provided the volume increase tank. It is a block diagram which shows an example of the conventional pressure regulator.

Explanation of symbols

22 processing system 24a-24d processing chamber 26a, 26b load lock chamber 30 atmosphere side transfer chamber 50 first transfer mechanism 58 second transfer mechanism 66 communication path 68 first on-off valve 70 second on-off valve 72 gas supply path 74 Gas On / Off Valve 76 Valve Control Unit 80 System Control Unit 82 Storage Medium 100 Volume Increasing Tank A1-A8 Pressure Regulator G1-G8 Gate Valve (Open / Close Door)
W Semiconductor wafer (object to be processed)

Claims (15)

In the pressure regulators of the first chamber and the second chamber, which are communicated via an openable / closable door, and in which a pressure difference may occur,
A communication path communicating the first room and the second room;
First and second on-off valves interposed in the middle of the communication path;
A gas supply passage that is connected between the first and second on-off valves of the communication passage and supplies clean gas having a predetermined pressure to the communication passage;
A gas on-off valve interposed in the middle of the gas supply passage;
Immediately before opening the open / close door, the clean gas is stored in the communication passage with the first and second open / close valves closed, and then the stored clean gas is stored in the first and second open doors. A valve controller for controlling the first and second on-off valves to open to supply to the second room;
A pressure adjusting device comprising: a pressure adjusting device. 2. The pressure regulator according to claim 1, wherein the valve control unit performs control to open the opening / closing door when a predetermined time has elapsed after opening the first and second opening / closing valves. The valve control unit controls the first and second on-off valves to remain open after the first and second on-off valves are opened until the on-off door is opened. The pressure adjusting device according to claim 1 or 2. The pressure control device according to any one of claims 1 to 3, wherein the valve control unit controls the first on-off valve and the second on-off valve to open simultaneously. A pressure gauge is provided in at least one of the first room and the second room, and the valve control unit controls the valve opening based on the detected value of the front air pressure gauge. The pressure regulator according to any one of claims 1 to 4, wherein 6. The predetermined pressure of the clean gas is set higher than each pressure in the first and second chambers before the first and second on-off valves are opened. The pressure adjusting device according to any one of the above. The pressure according to any one of claims 1 to 6, wherein a volume increasing tank is connected to the communication path between the first on-off valve and the second on-off valve. Adjustment device. The pressure regulator according to any one of claims 1 to 7, wherein a volume increasing tank is connected to the gas supply passage downstream of the gas on-off valve. The first chamber and the second chamber include an atmosphere-side transfer chamber in a processing system for performing processing in a reduced-pressure atmosphere on an object to be processed, and an atmospheric pressure atmosphere connected to the atmosphere-side transfer chamber. The pressure adjusting device according to claim 1, wherein the pressure adjusting device is a load lock chamber that repeats a reduced-pressure atmosphere. The first chamber and the second chamber are a decompression-side transfer chamber in a processing system for performing processing in a reduced-pressure atmosphere on an object to be processed, and an atmospheric pressure atmosphere connected to the reduced-pressure-side transfer chamber. The pressure adjusting device according to claim 1, wherein the pressure adjusting device is a load lock chamber that repeats a reduced-pressure atmosphere. The first chamber and the second chamber are connected to the decompression-side transfer chamber in the processing system for processing the object to be processed in a decompressed atmosphere, and are connected to the decompression-side transport chamber and are in a decompressed atmosphere. The pressure adjusting device according to claim 1, wherein the pressure adjusting device is a processing chamber that actually performs processing on the object to be processed. The pressure regulator according to claim 1, wherein the opening / closing door is a gate valve. The pressure regulator according to any one of claims 1 to 12, wherein the clean gas is at least one of clean air, N ₂ gas, and rare gas. In a processing system for processing a workpiece,
One or a plurality of processing chambers for actually processing the object to be processed;
A decompression-side transfer chamber that is commonly connected to the processing chamber via an opening provided with an openable / closable door;
A load-lock chamber connected to the decompression-side transfer chamber through an opening provided with an openable / closable door, wherein an atmospheric pressure atmosphere and a decompression atmosphere are repeated;
An atmosphere-side transfer chamber connected to the load lock chamber via an opening provided with an openable / closable door;
A first transport mechanism that is provided in the decompression-side transport chamber and transports the workpiece;
A second transfer mechanism provided in the atmosphere-side transfer chamber for transferring the object to be processed;
A pressure regulator according to any one of claims 1 to 13,
A system controller that controls the operation of the entire system;
A processing system comprising: A pressure regulating device for a first chamber and a second chamber, which are communicated via an opening / closing door that can be opened and closed, and in which a pressure difference is generated,
A communication path communicating the first room and the second room;
First and second on-off valves interposed in the middle of the communication path;
A gas supply passage that is connected between the first and second on-off valves of the communication passage and supplies clean gas having a predetermined pressure to the communication passage;
A gas on-off valve interposed in the middle of the gas supply passage;
In a pressure adjusting method performed using a pressure adjusting device having
Storing the clean gas in the communication path with the first and second on-off valves closed;
Supplying the clean gas stored by opening the first and second on-off valves to the first and second chambers;
A pressure adjusting method characterized by comprising:

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