JP5867204B2 - Vacuum processing equipment - Google Patents

Description

  The present invention relates to a vacuum processing apparatus, and more specifically, a space for performing predetermined vacuum processing on a processing object is a first space, and a space adjacent to the first space is a second space, and the first communicates with each other. The present invention relates to a configuration in which a gas atmosphere can be separated by providing a pressure difference between the space and the second space (with other space).

  For example, a long and resin sheet-like base material has flexibility and good workability, so a predetermined thin film such as a predetermined metal film or oxide film is formed on its surface, or heat treatment It is generally known that it is applied to make an electronic component or an optical component. Conventionally, a long sheet-like base material is wound around a drum that is rotatably provided in a vacuum chamber, and a vacuum is applied to one surface of the sheet-like base material while the sheet-like base material is driven by rotation of the drum. For example, Patent Document 1 discloses that a film is formed by a plasma CVD method as a treatment.

  The above-mentioned conventional example includes a feeding means for feeding a sheet-like base material in a vacuum chamber connected to a vacuum pump, and a winding means for winding the processed sheet-like base material. A discharge space (film formation chamber) for forming a film by the plasma CVD method is defined using the peripheral surface portion of the drum around which the sheet-like base material that has been fed is wound. And it selects according to the composition of the thin film which is going to form into a film-forming chamber through the shower electrode arrange | positioned facing the peripheral surface part of the drum by which the sheet-like base material is wound so that the discharge space may be faced A raw material gas is introduced, and high frequency power for plasma generation (for example, 13.56 MHz) is input to the shower electrode, thereby forming plasma in the discharge space and decomposing the raw material gas to one side of the substrate. Is deposited and deposited on the film.

  Here, when a predetermined vacuum treatment is performed on the sheet-like base material to obtain a product, a multilayer film may be formed on the base material, or etching or plasma processing may be performed after the film formation processing is performed. . In such a case, a plurality of spaces for providing various processes along the circumferential direction of the drum by providing an isolation plate in the vacuum chamber are provided. Thus, when a plurality of isolated spaces are provided in a single vacuum chamber, it is impossible to completely isolate each space due to the configuration of the apparatus. It is not necessarily performed with the same gas component. For this reason, there is a problem that gas (process gas or the like) is mixed from a relatively high pressure space to a relatively low pressure space, so-called gas contamination occurs, which adversely affects the film quality during film formation.

In order to solve the above problem, it is known that a differential pressure chamber is interposed between the processing spaces arranged around the drum, and each processing space is separated into a gas atmosphere (see, for example, Patent Document 1). ). By the way, for example, when performing a film forming process by a CVD method or a sputtering method, for example, to prevent the film quality from being changed due to the influence of residual gas, the background pressure in the space in which the film is formed and thus the vacuum chamber is kept low (For example, 10 ⁻⁵ Pa) is desirable. For this reason, it is preferable to connect a vacuum pump for high vacuum such as a turbo molecular pump or a cryopump to each space arranged around the drum, and among them, the turbo molecular pump is relatively easy to use. Therefore, this type of vacuum processing apparatus is widely used.

  Here, a vacuum pump that compresses and exhausts gas with a pressure difference generated before and after the rotor blade, such as a turbo molecular pump, is a so-called back that can be evacuated from atmospheric pressure to the back pressure side in order to create a pressure difference. A pump (eg, a rotary pump) is connected. However, in the configuration in which the turbo molecular pump and the back pressure side back pump are provided for each space, as the space to be evacuated increases, the number of back pumps also needs to be increased. Not only does the maintenance cost increase, but the apparatus configuration becomes complicated.

JP 2011-42848 A

  In view of the above points, it is an object of the present invention to provide a low-cost vacuum processing apparatus that can reduce the number of vacuum pumps to be used without impairing the function of providing a pressure difference in spaces communicating with each other. To do.

In order to solve the above-mentioned problem, a space for performing a predetermined vacuum process on a processing object is a first space, a space interposed between the two first spaces is a second space, and the first space and the second space The vacuum processing apparatus of the present invention configured to create a pressure difference between the first space and the first space communicating with each other via the second space, the first atmosphere and the second space. The vacuum pumps are connected to each other and evacuate the inside, and each vacuum pump includes an intake port and an exhaust port, and compresses gas by a pressure difference generated between the intake port and the exhaust port to exhaust It is characterized by further comprising a connecting pipe for connecting one of the first space and the second space to the other of the exhaust ports of a vacuum pump that evacuates one of the first and second spaces. To do.

  According to the present invention, the suction side of the vacuum pump connected to the relatively low pressure space by the connecting pipe is connected to the relatively high pressure space, and is mixed into the relatively low pressure space (leakage). It is possible to reliably generate a pressure difference between the first space and the second space by pumping the gas back into the relatively high pressure space. In this case, as a vacuum pump, for example, a turbo molecular pump that has a rotating blade and compresses and exhausts gas with a pressure difference generated between a gas inlet and a gas outlet before and after the rotor is used. When the back pump for generating the pressure difference is prepared only at the exhaust port on the back pressure side of the vacuum pump connected to the relatively high pressure space, the back pump is required in the other space And not. For this reason, the number of back pumps to be used can be reduced to reduce the cost, and the complexity of the apparatus can also be suppressed. This is more advantageous when the number of spaces providing the pressure difference increases. Depending on the process execution pressure, it is also effective to separate the gas atmosphere using a pump that requires a back pump by creating a differential pressure, such as a mechanical booster pump, instead of a turbo molecular pump.

  The present invention includes a vacuum chamber, a drum around which a sheet-like base material is wound is disposed in the vacuum chamber, and the first space and the second space are continuously provided along the circumferential direction of the drum. This is particularly advantageous when a plurality of processing spaces for performing a predetermined vacuum processing and a plurality of differential pressure chambers are alternately arranged along the circumferential direction of the drum.

  In the present invention, there is further provided an adjusting means for adjusting an effective exhaust speed of a vacuum pump that evacuates one of the relatively low pressures, and a pressure difference generated between the first space and the second space is reduced. It is preferable that adjustment is possible. Thereby, the structure which adjusts the pressure of a differential pressure chamber according to the pressure at the time of the vacuum processing implemented in each space, and performs gas atmosphere separation in each processing space reliably is realizable.

The typical sectional view explaining the composition of the vacuum processing device of the embodiment of the present invention.

  Hereinafter, with reference to the drawings, an embodiment of the present invention will be described by taking a vacuum processing apparatus as a plasma CVD apparatus and forming a multilayer film on one surface of a resin sheet-like substrate S as an example. . In the following, with reference to FIG. 1, the mounting direction of the electrode unit CU provided on the side surface of the vacuum chamber is defined as left, right, and terms indicating directions such as up and down.

  Referring to FIG. 1, PM is a plasma CVD apparatus according to this embodiment in which film forming processing by plasma CVD method can be performed on a substrate S at two positions. The plasma CVD apparatus PM includes a vacuum chamber 1. The upper and lower spaces are divided into upper and lower spaces by partition plates 2 provided on the upper inner wall of the vacuum chamber 1 so as to be inclined, and a sheet-like base material S is wound around the upper space 1a. A feeding roller 3 for feeding the material S and a take-up roller 4 for winding the film-formed sheet-like substrate S are accommodated, and the lower space has a base so that the upper portion is located in the upper space. A drum 5 around which the material S is wound is rotatably provided. In addition, since a well-known thing can utilize the mechanism until it unwinds and winds up the base material S, detailed description is abbreviate | omitted here. Then, after the base material S fed from the feed roller 3 is drawn through the gap between the partition plate 2 and the peripheral surface of the drum 5 through the guide roller 31 and wound around the drum 5. Then, it is wound around the winding roller 4 through the guide roller 41 through another gap between the partition plate 2 and the peripheral surface of the drum 5. The drum 5 may incorporate a means for heating or cooling the substrate S.

  A rectangular through hole 11 having a width (longitudinal direction in FIG. 1) longer than the length in the generatrix direction of the drum 5 is formed on the left side surface and the right side surface of the vacuum chamber 1, and surrounds the outer peripheral edge of the through hole 11. In this way, the electrode units CU having the same structure are detachably mounted on both side surfaces of the vacuum chamber 1. The electrode unit CU attached to the left side surface of the vacuum chamber 1 will be described as an example. The electrode unit CU includes an electrode holder 6 formed by forming a conductive plate into a dish shape in cross-section. The electrode holder 6 is attached by being brought into contact with the left side surface of the vacuum chamber 1 through a vacuum seal such as an O-ring (not shown) on the right end flange 61 and fastened with a bolt or the like not shown in this state. The electrode holder 6 holds a first electrode (cathode electrode) 7 that is opposed to the peripheral surface portion of the drum 5 around which the base material S is wound with the discharge space CS interposed therebetween.

The first electrode 7 is composed of a bottomed cylindrical member 71 having conductivity, and a shower plate 72 made of the same material and provided with a plurality of gas injection ports 72a attached to the right opening surface. A gas supply pipe 73 is connected to the bottom. In this case, the gas supply pipe 73 extends to the wall surface of a matching box described later, and the gas pipe 74 from the gas source can be detachably connected. When a predetermined source gas is supplied from the gas supply pipe 73, it is once diffused in the cylindrical member 71, and the source gas is introduced into the discharge space CS through each gas injection port 72a. As the source gas, for example, when a silicon nitride film or a silicon oxide film is formed, a gas such as SiH ₄ , NH ₃ , N ₂ O, Ar, H ₂ or N ₂ is used.

  In the electrode holder 6, a connection member 8 is provided concentrically around the first electrode 7. The connecting member 8 is formed of a cylindrical member having conductivity, and the first electrode 7 is held on the inner peripheral surface of the connecting member 8 via a cylindrical insulator I. In addition, as a holding method of the 1st electrode 7, well-known methods, such as fastening with a screw and fitting, can be used. In this case, a flange 81 is formed at the left end of the connection member 8 so as to extend radially inward (vertical direction in FIG. 1), and is fixed to the inner surface of the electrode holder 6 via the flange 81. . As a result, the electrode holder 6 is simply mounted on the left side surface of the vacuum chamber 1, so that the discharge space CS is opposed to the peripheral surface portion of the drum 5 around which the sheet-like substrate S is wound. One electrode 7, specifically, the shower plate 72 is positioned and held.

  A matching box MB is fixed to the left side surface of the electrode holder 6. A matching circuit (not shown) having a known configuration, such as a matching variable capacitor, a tuning variable capacitor, and a coil, is provided in the grounding matching box MB. A feeder line MW from the matching circuit is connected to the electrode holder 6. And connected to the first electrode 7 through the connection member 8. In this case, the power supply line MW is made of, for example, a metal bus bar, and is supported by an insulator MG that also serves as a vacuum seal provided on the electrode holder 6 and the connection member 8. The gas supply pipe 73 is also supported by the insulator MG. The matching box MB is connected to a high-frequency power supply HE having a known structure so that high-frequency power can be supplied to the first electrode 7.

  In the vacuum chamber 1, there are a pair of upper and lower second electrodes 9 (anode electrodes) that cover the circumferential surface portions of the drum 5 with gaps on both sides of the discharge space CS in the circumferential direction (vertical direction in FIG. 1). Is provided. The second electrode 9 is made of a conductive plate material having a lateral width longer than the length of the drum 5 in the generatrix direction, and is curved corresponding to the peripheral surface of the drum 5. The insulator is fixed on the inner wall surface. In this case, the area of the second electrode 9 is set so that a large amount of return current can be recovered in consideration of the frequency of input power and the like. Further, the gap is set so that the space defined by the peripheral surface of the drum 5 and the second electrode 9 becomes a non-discharge space US in which plasma does not enter when plasma is formed in the discharge space. . In this case, a gap as the non-discharge space US extending in a radial direction of the drum 5 is formed between the second electrode 9 and the drum 5, so that the exhaust conductance from the discharge space CS is increased. It is also effective for gas atmosphere separation. When the electrode holder 6 is mounted on the left side wall of the vacuum chamber 1, the second electrode 9 is directly connected to the connection member 8.

  A plurality of pin members 91 extending in the left direction are provided upright at the end of the second electrode 9 on the discharge space CS side. In this case, the pin member 91 is configured to have a so-called other surface contact type contact having a low contact resistance like a banana plug. On the other hand, the right side surface of the connecting member 8 extends toward the outer side in the circumferential direction (vertical direction in FIG. 2) and is curved corresponding to the end of the second electrode 9 on the discharge space CS side. A portion 82 is provided. The extension 82 is formed with a receiving recess 83 into which the pin member 91 is fitted in correspondence with the position of the pin member 91. In this case, although not specifically illustrated and described, the extending portion 82 of the connecting member 8 has an endless contact (not shown) having elasticity on the contact surface between the extending portion 82 and the second electrode 9. Z). As such a contact, for example, a rubber O-ring whose surface is covered with a mesh metal can be used.

  By the way, in the plasma CVD apparatus PM, when forming a multilayer film on the substrate S, for example, films having different compositions may be formed. For this reason, a plurality of isolation plates 10a to 10d for partitioning the space are provided in the lower space in the vacuum chamber 1, and as a processing space including the discharge space CS that is isolated from each other counterclockwise from the upper space 1a. The first film forming chamber 11a, the first to third differential pressure chambers 11b to 11d, and the second film forming chamber 11e as a processing space including the other discharge space CS are connected. I have to. Here, the upper space 1a of the vacuum chamber 1, the first film formation chamber 11a, the first to third differential pressure chambers 11b to 11d, and the second film formation chamber 11e are completely isolated (see FIG. That is, it is impossible to make each chamber an airtight space due to the configuration of the apparatus, and the film forming process performed in both the film forming chambers 11a and 11e is performed with the same gas pressure and the same gas component. Not limited. For this reason, it is necessary that gas (process gas, etc.) is mixed from a relatively high pressure space into a relatively low pressure space, so-called gas contamination occurs, and the film quality during film formation is not adversely affected. is there.

  In the present embodiment, the exhaust ports 12a to 12a are formed on the wall surface of the vacuum chamber 1 that communicates with the first film forming chamber 11a, the first to third differential pressure chambers 11b to 11d, and the second film forming chamber 11e. 12e was opened, and exhaust ports 12f and 12g were opened on the wall surface of the vacuum chamber 1 leading to the upper space 1a. In addition, a rotary blade is provided in the first film forming chamber 11a and the second film forming chamber 11e as the first space through the exhaust pipe EP1 and becomes a relatively high pressure by introducing a predetermined source gas at the time of film formation. Then, a turbo molecular pump TMP1 serving as a vacuum pump that compresses and exhausts gas by a pressure difference generated between the intake port P1 and the exhaust port P2 before and after the rotor blades and a rotary pump RP serving as a back pump on the back pressure side are connected. did. In addition, the upper space 1a, the first differential pressure chamber 11b, and the third differential pressure chamber 11d as the second space communicating adjacent to both the film forming chambers 11a and 11e are connected to the above-mentioned through the exhaust pipe EP2. Similarly, a turbo molecular pump TMP2 serving as a vacuum pump for compressing and exhausting gas with a pressure difference generated between the intake port P1 and the exhaust port P2 was connected. Note that a turbo molecular pump TMP3 and a rotary pump RP on the back pressure side may be connected to the second differential pressure chamber 11c.

  The exhaust pipes EP1 and EP2 are each provided with a conductance valve CV having a closing function as an adjusting means so that the effective exhaust speed of the turbo molecular pumps TMP1 and TMP2 can be changed. In addition, as the turbo molecular pumps TMP1, TMP2, and TMP3, those having the same exhaust capability according to the vacuum chamber 1 and the volume of the space can be used. The back pressure side of the turbo molecular pump TMP2 that exhausts the upper space 1a, the first differential pressure chamber 11b, and the third differential pressure chamber 11d is connected to both the first and second film formation chambers 11a, 11e, respectively.

  According to the above embodiment, when the source gas is introduced into both the first and second film forming chambers 11a and 11e and the film is formed by the plasma CVD method, the gas leaking from both the film forming chambers 11a and 11e is After mixing into the upper space 1a, the first differential pressure chamber 11b and the third differential pressure chamber 11d, which are relatively pressured, and exhausted to the turbo molecular pump TMP2, the first film formation chamber 11a and the second component Pumped back into the membrane chamber 11e. As a result, it is possible to reliably generate a pressure difference between the film forming chambers 11a and 11e and the upper space 1a, the first differential pressure chamber 11b, and the third differential pressure chamber 11d. , 11e can be separated into a gas atmosphere. In this case, the rotary pump RP only needs to be connected to the exhaust port on the back pressure side of the turbo molecular pump TMP1 connected to both the first and second film forming chambers 11a and 11e. The cost can be reduced by reducing the number, and the complexity of the apparatus can also be suppressed. Further, by providing the conductance valve CV, the effective pumping speeds of the turbo molecular pumps TMP1 and TMP2 are adjusted, respectively, and both the first and second film forming chambers 11a and 11e, the upper space 1a, and the first differential pressure chamber. It may be possible to change the pressure difference generated between 11b and the third differential pressure chamber 11d.

  As mentioned above, although embodiment of this invention was described, this invention is not limited above. In the above-described embodiment, the sheet-like base material S is wound around the drum 5 and the multilayer film is formed while the sheet-like base material S is run. However, in a so-called in-line type film forming apparatus in which a processing substrate such as a silicon wafer is sequentially (intermittently) transferred by a transfer means such as a conveyor, and a film forming process is performed in a vacuum atmosphere by a film forming source provided in the transfer path of the conveyor. Gas atmosphere separation can also be performed by applying the present invention.

  In the above embodiment, the first space and the second space are alternately arranged around the drum 5 as an example. However, there are at least two spaces communicating with each other, and pressure is applied to both spaces. If it is desired to make a difference, the present invention can be widely applied, and the number of spaces is not limited. Furthermore, in the above embodiment, since the film forming chambers 11a and 11e have a relatively high pressure, the back pressure side of the turbo molecular pump TMP2 adjacent to the upper space 1a and the differential pressure chambers 11b and 11d is formed by the connecting pipe CP. Although an example of connecting to the chambers 11a and 11e is taken as an example, when it is desired to make the film forming chambers 11a and 11e relatively low in pressure, the back pressure side of the turbo molecular pump TMP1 of the film forming chambers 11a and 11e is connected by a connecting pipe CP. What is necessary is just to connect to a differential pressure chamber etc.

  Further, in the above-described embodiment, the example in which the adjusting means is configured by the conductance valve CV provided in the exhaust pipes EP1 and EP2 has been described as an example. However, the present invention is not limited to this. The adjusting means may be configured by selecting pumps having different capacities. Furthermore, in the above embodiment, the turbo pump provided as a vacuum pump has been described as an example. However, the suction pump and the exhaust port are provided, and the gas is compressed by the pressure difference generated between the intake port and the exhaust port. For example, a vacuum pump provided with a swinging piston can be used.

  Furthermore, in the above-described embodiment, the film formation by the plasma CVD method has been described as an example of the vacuum processing. However, the vacuum processing is not limited to the above, for example, film formation by the sputtering method, reactive ion etching, or vacuum heating. Alternatively, the first film formation chamber may be formed by plasma CVD, and the second film formation chamber may be formed by sputtering.

  PM ... plasma CVD apparatus (vacuum processing apparatus), 1 ... vacuum chamber, 1a ... upper space, 10a to 10d ... isolation plate, 11a, 11e ... deposition chamber (first space), 11b, 11c, 11d ... differential pressure chamber (Second space), TMP1, TMP2 ... turbo molecular pump (vacuum pump), RP ... rotary pump (back pump), CP ... connecting pipe, EP ... exhaust pipe, CV ... conductance valve (adjusting means), 5 ... drum, S: Sheet-like substrate.

Claims (3)

A space for performing a predetermined vacuum process on the object to be processed is a first space, a space interposed between the two first spaces is a second space, and a pressure difference is generated between the first space and the second space. A vacuum processing apparatus configured to separate the gas atmosphere between the first spaces communicating with each other via the second space ,
A vacuum pump connected to each of the first space and the second space and evacuating the inside is provided, and each vacuum pump includes an intake port and an exhaust port, and a pressure difference generated between the intake port and the exhaust port. A connecting pipe that connects an exhaust port of a vacuum pump that evacuates either one of the first space and the second space to a relatively low pressure to either one of the first space and the second space. The vacuum processing apparatus further comprising:
  2. The vacuum processing apparatus according to claim 1, further comprising a vacuum chamber, wherein a drum around which a sheet-like base material is wound is disposed in the vacuum chamber, and the first space and the second space are arranged in a circumferential direction of the drum. Is a vacuum processing apparatus characterized by being provided continuously.   An adjusting means for adjusting an effective exhaust speed of a vacuum pump that evacuates one of the relatively low pressures is further provided, and a pressure difference generated between the first space and the second space can be adjusted. The vacuum processing apparatus according to claim 1, wherein:

Images