JP2018181871A - Semiconductor manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing device that comprises a high vacuum chamber and a front chamber, and that decompresses the high vacuum chamber from an atmospheric pressure to a predetermined low pressure in a short time.SOLUTION: A semiconductor manufacturing device 2 comprises a high vacuum chamber 3, a front chamber 5, a first turbo-molecular pump 11, a second turbo-molecular pump 12, a first roughing pump 14, an on-off valve 21, and a three-way valve 23. The first turbo-molecular pump 11 is connected with the high vacuum chamber 3. The second turbo-molecular pump is connected with the front chamber 5. The roughing pump 14 is connected with an air exhaustion port 12b of the second turbo-molecular pump 12. A first flow channel 31 connects an air exhaustion port 11b of the first turbo-molecular pump 11 with a suction port 12a of the second turbo-molecular pump 12 and a suction port 14a of the roughing pump 14. In the first flow channel 31, a connection destination of the air exhaustion port 11b of the first turbo-molecular pump 11 is switched to any one of the suction port 12a of the second turbo-molecular pump 12 and the suction port 14a of the roughing pump 14.SELECTED DRAWING: Figure 1

Description

  The technology disclosed herein relates to a semiconductor manufacturing apparatus. In particular, the present invention relates to a semiconductor manufacturing apparatus including a high vacuum chamber for providing a vacuum space for processing a semiconductor workpiece, and a front chamber for temporarily storing the semiconductor workpiece before placing the semiconductor workpiece in the high vacuum chamber. In the present specification, an object to be processed by the semiconductor manufacturing apparatus is referred to as a semiconductor work.

When a predetermined thin film is grown on a semiconductor wafer (semiconductor work), a high vacuum environment is required to process the semiconductor work, and the semiconductor manufacturing apparatus includes a high vacuum chamber. For example, a turbo molecular pump is used to lower the internal pressure of the high vacuum chamber to, for example, about 10 ^-7 [Pa]. Since the turbo molecular pump does not operate properly when the pressure difference between the intake and exhaust sides is large, a roughing pump is connected to the exhaust port of the turbo molecular pump as an auxiliary pump. For example, an oil rotary vacuum pump, a dry pump or the like is used as the roughing pump (for example, Patent Document 1).

Japanese Patent Application Publication No. 06-275600

When starting up the semiconductor device, it is necessary to lower the internal pressure of the high vacuum chamber from atmospheric pressure to a predetermined low pressure state suitable for processing a semiconductor workpiece. In order to lower the internal pressure of the high vacuum chamber from atmospheric pressure to a predetermined low pressure state in a short time, a powerful roughing pump is required. The present specification provides a semiconductor manufacturing apparatus capable of reducing the internal pressure of the high vacuum chamber from atmospheric pressure to a predetermined low pressure suitable for processing a semiconductor workpiece in a short time without providing a strong roughing pump. In the following, for the sake of convenience, a predetermined low pressure suitable for processing a semiconductor workpiece is referred to as "processing environmental pressure". An example of the processing environment pressure is about 10 ^-7 [Pa] as described above.

  Generally, in a semiconductor manufacturing apparatus provided with a high vacuum chamber, a small chamber called a front chamber (or a load lock chamber) for carrying a load (semiconductor work) from the outside under atmospheric pressure into the high vacuum chamber is attached. The front chamber is provided with a first partition that can be opened and closed between the front chamber and the semiconductor chamber, and is provided with a second partition that can be opened and closed between the front chamber and the outside. When the semiconductor workpiece is carried in from the outside, the first partition wall on the high vacuum chamber side is closed. When the semiconductor work is carried into the front room, close both bulkheads. After lowering the internal pressure of the front chamber to a low pressure close to the possible environmental pressure, the first partition on the high vacuum chamber side is opened to move the semiconductor workpiece to the high vacuum chamber. A vacuum pump is also required for the front room. The semiconductor manufacturing apparatus disclosed herein uses the vacuum pump for the front chamber as an auxiliary pump so that the high vacuum chamber can be quickly lowered from atmospheric pressure to the processing ambient pressure.

  The semiconductor manufacturing apparatus disclosed in the present specification includes a high vacuum chamber, an antechamber, a first turbo molecular pump, a second turbo molecular pump, a roughing pump, a first flow path, and a second flow path. , An on-off valve, and a switching valve. The high vacuum chamber is a chamber that provides a high vacuum state necessary for processing a semiconductor workpiece. The front chamber is provided with a first partition that can be opened and closed with the high vacuum chamber and a second partition that can be opened and closed with the outside. The front chamber is sealed by closing the first partition and the second partition. The first turbo molecular pump is connected to the high vacuum chamber, and the chamber of the high vacuum chamber can be depressurized. The second turbo molecular pump is connected to the front chamber, and the pressure in the front chamber can be reduced. The roughing pump is connected to the outlet of the second turbo molecular pump. The first flow path connects the outlet of the first turbo molecular pump to the inlet of the second turbo molecular pump and the inlet of the roughing pump. The first flow path is provided with a switching valve. The switching valve switches the connection destination of the exhaust port of the first turbo molecular pump to either the intake port of the second turbo molecular pump or the intake port of the roughing pump. The on-off valve opens and closes the second flow passage between the front chamber and the second turbo molecular pump. In addition, it is necessary to lower the internal pressure of the high vacuum chamber to some extent by another pump prior to the start of the turbo molecular pump, but here, for the convenience of explanation, the turbo molecular pump reduces the pressure from atmospheric pressure to processing environment pressure It will be expressed as

  In the above semiconductor manufacturing apparatus, when the internal pressure of the high vacuum chamber is lowered from atmospheric pressure to processing environment pressure, the on-off valve is closed and the switching valve is controlled to set the exhaust port of the first turbo molecular pump to the second turbo molecular pump Connect to the air intake. That is, the first turbo molecular pump and the second turbo molecular pump are connected in series, and the high vacuum chamber is depressurized by the three-stage pump together with the roughing pump connected to the exhaust port of the second turbo molecular pump in the latter stage . By connecting the pumps to three stages and depressurizing the high vacuum chamber, it becomes possible to quickly depressurize the high vacuum chamber to the processing environment pressure in a short time. After the internal pressure of the high vacuum chamber reaches the processing ambient pressure, the switching valve is switched to connect the exhaust port of the first turbo molecular pump to the suction port of the roughing pump. During processing of the semiconductor workpiece, a roughing pump is used as an auxiliary pump for the first turbo molecular pump. On the other hand, when the internal pressure of the front chamber is lowered to a low pressure close to the processing environment pressure, the on-off valve is opened and the front chamber is depressurized by the second turbo molecular pump and the roughing pump. When the internal pressure of the antechamber is lowered, the roughing pump can be used as an auxiliary pump dedicated to the second turbo molecular pump by stopping the first turbo molecular pump.

  The details and further improvement of the technology disclosed in the present specification will be described in the following "Forms for Carrying Out the Invention".

It is a block diagram of the semiconductor manufacturing apparatus of an Example. It is a figure which shows the flow path at the time of installation start-up. It is a figure which shows the flow path at the time of semiconductor work processing. It is a block diagram of the semiconductor manufacturing apparatus of a modification.

  The semiconductor manufacturing apparatus 2 of the embodiment will be described with reference to the drawings. FIG. 1 shows a block diagram of the semiconductor manufacturing apparatus 2. The semiconductor manufacturing apparatus 2 includes a high vacuum chamber 3, a vacuum transfer chamber 4, and a front chamber 5 as a room which can be isolated from the outside. The semiconductor manufacturing apparatus 2 further includes a first turbo molecular pump 11, a second turbo molecular pump 12, a third turbo molecular pump 13, a first roughing pump 14, and a second roughing pump 15. The semiconductor manufacturing apparatus 2 further includes a first on-off valve 21, a second on-off valve 22, and a three-way valve 23. Furthermore, the semiconductor manufacturing apparatus 2 includes a controller 16 and a vacuum gauge 24 as other facilities.

  The high vacuum chamber 3 is a small room which provides a place for processing a semiconductor work such as film formation on a semiconductor wafer (semiconductor work). Although not shown, the high vacuum chamber 3 is provided with a processing apparatus such as a film forming apparatus. A high vacuum environment is required to process semiconductor workpieces. The high vacuum chamber is sealed and can maintain high vacuum.

  A vacuum transfer chamber 4 is adjacent to the high vacuum chamber 3. The vacuum transfer chamber 4 is a small chamber for preparing a semiconductor workpiece before processing, and is provided with a bellows 8 and a stage 6 which move up and down. The bellows 8 is an actuator that moves up and down (expands and contracts) with the gas inside, but the inside and the outside of the bellows 8 are completely shut off, and the gas inside does not leak outside. The semiconductor work in the vacuum transfer chamber 4 is placed on the stage 6 and transferred to the high vacuum chamber 3 by the bellows 8. Note that some small circles in FIG. 1 represent seals (gaskets) that seal between the rooms or between the rooms and the pump.

  A front chamber 5 is associated with the vacuum transfer chamber 4. The front chamber 5 includes a first partition 51 and a second partition 52. Both the first partition 51 and the second partition 52 can be opened and closed. The first partition wall 51 is provided between the vacuum transfer chamber 4 and the first partition wall 51. Since the vacuum transfer chamber 4 is connected to the high vacuum chamber 3, the first partition 51 can be expressed as a partition between the front chamber 5 and the high vacuum chamber 3. The second partition 52 is provided between the second partition 52 and the outside. When the first partition 51 and the second partition 52 are closed, the front chamber is sealed. The external semiconductor work is temporarily stored in the front chamber 5 and thereafter transferred to the vacuum transfer chamber 4 and further to the high vacuum chamber 3. When the semiconductor work is put into the front chamber 5 from the outside, the first partition wall 51 is closed, and the second partition wall 52 is opened while the internal space of the front chamber 5 is shut off from the vacuum transfer chamber 4. The semiconductor work is carried in with the internal space of the front chamber 5 at atmospheric pressure. After the semiconductor work is put into the front chamber 5, the second partition wall 52 is closed, and the internal pressure of the front chamber 5 is lowered. When the internal pressure of the front chamber 5 becomes almost the same as the internal pressure of the vacuum transfer chamber 4, the first partition 51 is opened while the second partition 52 is closed. Then, the semiconductor work is transferred to the vacuum transfer chamber 4. The semiconductor work is transferred to the high vacuum chamber 3 via the vacuum transfer chamber 4. The processed semiconductor workpiece is unloaded from the semiconductor manufacturing apparatus 2 to the outside in the reverse procedure of the above-described procedure.

  The pump for reducing the pressure in each room will be described. An intake port 11 a of the first turbo molecular pump 11 is connected to the high vacuum chamber 3. The suction port 13 a of the third turbo molecular pump 13 is connected to the vacuum transfer chamber 4. The intake port 12 a of the second turbo molecular pump 12 is connected to the front chamber 5 via the second flow path 32, and the intake port 15 a of the second roughing pump 15 is connected via the third flow path 33. It is connected. An intake port 14 a of the first roughing pump 14 is connected to the exhaust port 12 b of the second turbo molecular pump 12.

  The exhaust port 11 b of the first turbo molecular pump 11 and the exhaust port 13 b of the third turbo molecular pump 13 are connected to the intake port 12 a of the second turbo molecular pump 12 and the first roughing pump 14 via the first flow path 31. It is connected to the intake port 14a. The first flow path 31 is provided with a three-way valve 23. The three-way valve 23 connects the exhaust port 11 b of the first turbo molecular pump 11 and the exhaust port 13 b of the third turbo molecular pump 13 to the intake port 12 a of the second turbo molecular pump 12 and the suction of the first roughing pump 14 Switch to one of the ports 14a.

  The second flow path 32 is provided with a first on-off valve 21, and the third flow path 33 is provided with a second on-off valve 22. A vacuum gauge 24 is connected to a side closer to the front chamber 5 than the second on-off valve 22 of the third flow path 33. The vacuum gauge 24 measures the internal pressure of the front chamber 5.

  The first on-off valve 21, the second on-off valve 22, and the three-way valve 23 are controlled by the controller 16. The dashed arrows in FIG. 1 indicate control signal lines. The controller 16 also controls the first turbo molecular pump 11, the second turbo molecular pump 12, the third turbo molecular pump 13, the first roughing pump 14, and the second roughing pump 15. The control signal lines connecting the pumps and the controller 16 are not shown.

The first turbo molecular pump 11, the second turbo molecular pump 12, and the third turbo molecular pump 13 have an ultimate pressure of about 10 ⁻⁷ [Pa], but do not operate properly when the exhaust side is at atmospheric pressure. Therefore, an auxiliary pump is connected to the exhaust port of the turbo molecular pump, and the exhaust side of the turbo molecular pump is depressurized. By doing so, the turbo molecular pump can be operated properly, and a predetermined low pressure (processing environment pressure) suitable for processing a semiconductor workpiece can be realized. The first roughing pump 14 and the second roughing pump 15 are, for example, an oil rotary vacuum pump and a dry pump, and the exhaust side operates even at atmospheric pressure, but its ultimate pressure is higher than the ultimate pressure of the turbo molecular pump (Close to atmospheric pressure).

  Before starting the semiconductor manufacturing apparatus 2, the internal pressure of the high vacuum chamber 3 and the internal pressure of the vacuum transfer chamber 4 are equal to the atmospheric pressure. When the semiconductor manufacturing apparatus 2 is started up, it is necessary to reduce the internal pressure of the high vacuum chamber 3 to the processing environmental pressure and to reduce the internal pressure of the vacuum transfer chamber 4 to near the processing environmental pressure. The high vacuum chamber 3 is depressurized by the first turbo molecular pump 11, and the vacuum transfer chamber 4 is depressurized by the third turbo molecular pump 13. However, when the first turbo molecular pump 11 and the second turbo molecular pump 13 are started. In advance, the second roughing pump 15 is operated in a state where the first partition 51 of the front chamber 5 is opened, and the high vacuum chamber 3 and the vacuum transfer chamber 4 are depressurized to about several pascals. However, in the following description, in order to simplify the description, it is expressed that the high vacuum chamber 3 is depressurized from the atmospheric pressure to the processing environment pressure by the first turbo molecular pump 11, and similarly, the vacuum transport by the third turbo molecular pump 13 It is expressed that the pressure in the chamber 4 is reduced from the atmospheric pressure to the processing environmental pressure.

  In the semiconductor manufacturing apparatus 2, the intake port 12 a of the second turbo molecular pump 12 is connected to the exhaust port 11 b of the first turbo molecular pump 11 in order to lower the internal pressure of the high vacuum chamber 3 in a short time at startup. An intake port 14 a of the first roughing pump 14 is connected to the exhaust port 12 b of the second turbo molecular pump 12. According to this configuration, the high vacuum chamber 3 can be depressurized by the three-stage set of two turbo molecular pumps 11, 12 and the first roughing pump 14. The exhaust port 12 b of the first turbo molecular pump 11 for drawing gas from the high vacuum chamber 3 is strongly depressurized by the second turbo molecular pump 12, so the first turbo molecular pump 11 quickly depressurizes the high vacuum chamber 3. can do. In addition, since the discharge side (the exhaust port 12b) of the second turbo molecular pump 12 is depressurized by the first roughing pump 14, both the first turbo molecular pump 11 and the second turbo molecular pump 12 operate properly. Can. The semiconductor manufacturing apparatus 2 of FIG. 1 has a total of three stages of pump groups: a two-stage turbo molecular pump (first and second turbo molecular pumps 11 and 12) and a single-stage roughing pump (first roughing pump 14) Thus, the high vacuum chamber 3 can be depressurized from the atmospheric pressure to the processing environment pressure in a short time.

  The exhaust port 13 b of the third turbo molecular pump 13 for depressurizing the vacuum transfer chamber 4 is connected to the three-way valve 23 in parallel with the exhaust port 11 b of the first turbo molecular pump 11. Therefore, the vacuum transfer chamber 4 is also depressurized to a predetermined pressure in a short time by the three-stage pump group.

  When the high vacuum chamber 3 and the vacuum transfer chamber 4 are depressurized from the atmospheric pressure, the controller 16 closes the first on-off valve 21 and controls the three-way valve 23 so that the exhaust port 11 b of the first turbo molecular pump 11 and the third The connection destination of the exhaust port 13 b of the turbo molecular pump 13 is switched to the intake port 12 a of the second turbo molecular pump 12. FIG. 2 shows a diagram showing the intake path at that time. A thick arrow indicates a flow path, and a cross indicates a blocked flow path.

  By closing the first on-off valve 21, the second turbo molecular pump 12 and the antechamber 5 are shut off. The exhaust of the first turbo molecular pump 11 and the exhaust of the third turbo molecular pump 13 are further sucked by the second turbo molecular pump 12 through the three-way valve 23. An intake port 14 a of a first roughing pump 14 is connected to an exhaust port 12 b of the second turbo molecular pump 12. The high vacuum chamber 3 is depressurized by two turbo molecular pumps 11 and 12 connected in series and a first roughing pump 14 for further aspirating the exhaust gas. The internal pressure of the high vacuum chamber 3 is rapidly reduced in a short time by the total of three stages of pressure reduction systems. The vacuum transfer chamber 4 is also the same, and the pressure is reduced by the two turbo molecular pumps 13 and 12 connected in series and the first roughing pump 14 that sucks in the exhaust gas. The internal pressure of the vacuum transfer chamber 4 is also rapidly decreased in a short time by the pressure reduction mechanism of three stages in total.

  When the high vacuum chamber 3 is depressurized to the processing environmental pressure and the vacuum transfer chamber 4 is depressurized to a pressure close to the processing environmental pressure, the semiconductor workpiece is ready for processing. The figure showing the flow path at that time is shown in FIG. After loading the semiconductor workpiece from the outside into the front chamber 5, the controller 16 opens the second on-off valve 22 and operates the second roughing pump 15. At this time, the first on-off valve 21 remains closed. The second roughing pump 15 lowers the internal pressure of the front chamber 5 below atmospheric pressure. After the internal pressure of the front chamber 5 drops to a predetermined low pressure, the controller 16 stops the second roughing pump 15 and closes the second on-off valve 22. Next, the controller 16 opens the first on-off valve 21 and operates the second turbo molecular pump 12 and the first roughing pump 14. The front chamber 5 is depressurized to a pressure close to the processing environment pressure by the second turbo molecular pump 12 and the first roughing pump 14. When the pressure in the front chamber 5 is reduced to near the processing environment pressure, the controller 16 stops the second turbo molecular pump 12 and the first roughing pump 14 and closes the first on-off valve 21. When the internal pressure of the front chamber 5 drops to near the processing environment pressure, the first partition wall 51 is opened to transfer the semiconductor workpiece from the front chamber 5 to the vacuum transfer chamber 4. The semiconductor work is transferred from the vacuum transfer chamber 4 to the high vacuum chamber 3 at a predetermined timing and processed.

  When maintaining the internal pressure of the high vacuum chamber 3 and the vacuum transfer chamber 4 at the processing environment pressure, the controller 16 controls the three-way valve 23 so that the exhaust port 11 b of the first turbo molecular pump 11 and the exhaust of the third turbo molecular pump 13 The connection destination of the port 13 b is switched to the intake port 14 a of the first roughing pump 14. The controller 16 operates the first turbo molecular pump 11, the third turbo molecular pump 13 and the first roughing pump 14 to decompress the high vacuum chamber 3 and the vacuum transfer chamber 4.

  As described above, the semiconductor manufacturing apparatus 2 of the embodiment uses the second turbo molecular pump 12 and the first roughing pump 14 for reducing the pressure in the front chamber 5 also for reducing the pressure in the high vacuum chamber 3 and the vacuum transfer chamber 4. Thus, the high vacuum chamber 3 and the vacuum transfer chamber 4 can be depressurized from the atmospheric pressure to the processing environment pressure in a short time. The second turbo molecular pump 12 and the first roughing pump 14 are used as auxiliary pumps of the first turbo molecular pump 11 for drawing gas from the high vacuum chamber 3. In addition, the second turbo molecular pump 12 and the first roughing pump 14 are also used as an auxiliary pump of the third turbo molecular pump 13 for drawing a gas from the vacuum transfer chamber 4.

  There is no need to simultaneously depressurize the front chamber 5 and the high vacuum chamber 3. Therefore, the second turbo molecular pump 12 and the first roughing pump 14 may be used as a pump for depressurizing the front chamber 5 or for depressurizing the high vacuum chamber 3 and the vacuum transfer chamber 4 depending on the situation. It may be used as an auxiliary pump.

  Points to note regarding the technology described in the embodiment will be described. The three-way valve 23 of the embodiment corresponds to an example of the “switching valve”. The switching valve may be realized by two on-off valves instead of the three-way valve. FIG. 4 shows a block diagram of a semiconductor manufacturing apparatus 2a of a modification. The semiconductor manufacturing apparatus 2a includes two on-off valves 123a and 123b instead of the three-way valve 23 of the embodiment. The on-off valve 123 a is provided in the partial flow path 31 a from the branch point 31 p of the first flow path 31 to the intake port 12 a of the second turbo molecular pump 12. The on-off valve 123 b is provided in the partial flow path 31 b from the branch point 31 p to the inlet 14 a of the first roughing pump 14. When the on-off valve 123a is opened and the on-off valve 123b is closed, a flow passage equivalent to the flow passage in FIG. 2 is realized. When the on-off valve 123a is closed and the on-off valve 123b is opened, a flow path equal to the flow path in FIG. 3 is realized.

  The first roughing pump 14 of the embodiment corresponds to an example of “roughing pump connected to the exhaust port 12 b of the second turbo molecular pump 12”. The first on-off valve 21 corresponds to an example of the “on-off valve for opening and closing the second flow path 32 between the front chamber 5 and the second turbo molecular pump 12”.

  As mentioned above, although the specific example of this invention was described in detail, these are only an illustration and do not limit a claim. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above. The technical elements described in the present specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the techniques exemplified in the present specification or the drawings can simultaneously achieve a plurality of purposes, and achieving one of the purposes itself has technical utility.

2, 2a: semiconductor manufacturing apparatus 3: high vacuum chamber 4: vacuum transfer chamber 5: front chamber 6: stage 8: bellows 11: first turbo molecular pump 11a, 12a, 13a, 14a, 15a: inlet 11b, 12b, 13b: exhaust port 12: second turbo molecular pump 13: third turbo molecular pump 14: first roughing pump 15: second roughing pump 16: controller 21: first on-off valve 22: second on-off valve 23: three-way Valve 24: vacuum gauge 31: first flow path 31a: partial flow path 31b: partial flow path 31p: branch point 32: second flow path 33: third flow path 51: first partition 52: second partition 123a, 123b : On-off valve

Claims (1)

A high vacuum chamber in which semiconductor workpieces are processed in the interior space;
A first partition that can be opened and closed between the high vacuum chamber and a second partition that can be opened and closed between the outside and the high vacuum chamber, and sealed by closing the first partition and the second partition And the front room,
A first turbo molecular pump connected to the high vacuum chamber and configured to decompress the high vacuum chamber;
A second turbo-molecular pump connected to the front chamber for decompressing the front chamber;
A roughing pump connected to an exhaust port of the second turbo molecular pump;
A first flow path connecting an exhaust port of the first turbo molecular pump to an intake port of the second turbo molecular pump and an intake port of the roughing pump;
An on-off valve for opening and closing a second flow passage between the front chamber and the second turbo molecular pump;
A switching valve provided in the first flow path, for switching the connection destination of the exhaust port of the first turbo molecular pump to any one of the intake port of the second turbo molecular pump and the intake port of the roughing pump;
Semiconductor manufacturing equipment equipped with.

Images