JP5307778B2 - Substrate heating / cooling system - Google Patents

Description

  The present invention relates to an apparatus for heating and cooling a substrate when performing surface treatment such as coating or etching the surface of a substrate such as a semiconductor wafer by a vacuum deposition method, a sputtering method, or the like. More specifically, the present invention relates to a substrate heating / cooling apparatus capable of easily and speeding up cooling after heating the substrate.

  When a thin film is formed on a substrate such as a semiconductor wafer by sputtering or vacuum evaporation, molecules of the film forming material are released from a molecular beam source in a vacuum chamber and deposited on the substrate. Film. In such a film forming process, the substrate is mounted on a substrate holder, and is placed at a film forming position in the vacuum chamber with the film forming surface facing the molecular beam source. At the time of film formation, the substrate is heated to a temperature necessary for film formation. After film formation is completed, the substrate holder is removed from the film formation position, and the next substrate is newly installed at the film formation position. Thereafter, film formation is sequentially performed on the substrate while repeating this operation.

The heating temperature of the substrate at the time of film formation varies depending on the material to be formed, film formation conditions, and the like, but often reaches several hundred degrees Celsius. The substrate and substrate holder heated at the time of film formation need to be cooled to near room temperature at the time of replacement.
A conventional film forming apparatus has a structure in which a heater and a cooler are provided behind a holder holding a substrate, and the substrate and the substrate holder are heated and cooled via thermal radiation.

FIG. 6 shows an example of a substrate heating / cooling device that has been manufactured so far by the present applicant.
A ring plate-shaped port flange 25 is provided at a port portion opened to the upper side of the vacuum chamber 24, and a disk-shaped flange 23 is formed on the port flange 25 from above via a gasket (not shown) or the like. The flange 23 is fixed to the port flange 25 by means such as a screw (not shown).

  A disk ring-shaped holder support 27 is disposed under the flange 23 joined to the port flange 25. The substrate holder 1 is detachably attached to the holder support 27. The substrate holder 1 is attached to and detached from the holder support 27 by a transfer rod or the like (not shown) through a load lock chamber (not shown) provided on the side wall of the vacuum chamber 24. A substrate s such as a semiconductor wafer such as Si is mounted on the lower surface of the substrate holder 1 with a metal such as In.

  A heater 5 is attached to the rear surface of the substrate holder 1, that is, on the surface opposite to the surface on which the substrate s is mounted, with a desired distance from the substrate holder 1. The heater 5 is connected to a current introduction terminal 21 provided on the flange 20 via the wiring 10 inside the vacuum chamber 24, and further, a power source (external power supply) disposed outside the vacuum chamber 24 via the current introduction terminal 21. (Not shown). The heater 5 is heated by this power source. For example, a lamp heater is used as the heater 5.

  A reflector 7 for reflecting the heat generated by the heater 5 toward the substrate holder 1 is disposed behind and around the heater 5. Further, a refrigerant passage 29 is disposed so as to penetrate the reflector 7 and the center of the heater 5. The refrigerant passage 29 has an outer cylinder 30 and an inner cylinder 31, and a cooling section 32 provided at the lower end of the outer cylinder 30 is disposed close to the back surface, that is, the upper surface of the substrate holder 1. The refrigerant passage 29 is connected to a cooler (not shown) disposed outside the vacuum chamber 24 through a fluid joint 22 provided on the flange 23. As the coolant such as cooling water cooled by the cooler flows through the coolant passage 29, the substrate holder 1 and the substrate s attached thereto are cooled.

  A shutter 2 is provided so as to cover the bottom of the substrate s attached to the lower surface of the substrate holder 1. The shutter 2 is connected to a shaft 4 that hangs from a flange 23 into a vacuum chamber 24, and the shaft 4 is reciprocally rotated by a rotation introducing machine 20 provided on the flange 23, that is, outside the vacuum chamber 24. . By rotating the shutter 2 around the reciprocating shaft 4, the lower surface of the substrate s attached to the lower surface of the substrate holder 1, that is, the processing surface is opened and closed.

  Although not shown in FIG. 7, molecular beam sources and ion sources such as Knudsen cells and impact electron beam cells are arranged below the shutter 4, and one or more of these molecular beam sources and ions are arranged. Only when the shutter 2 is opened, molecules or ions emitted from the source enter the surface of the substrate s of the substrate holder 1. As a result, a thin film is formed on the surface of the substrate s or ions are implanted.

  However, in such a conventional thin film deposition apparatus, since the cooling section 32 provided at the lower end of the refrigerant passage 29 is disposed between the heater 5 and the substrate holder 1, the heating temperature of the substrate s is at most 500. ~ 600 ° C. Moreover, since the heating and cooling of the substrate and the substrate holder are performed by heat radiation in the vacuum chamber, there is a problem that it takes time. In particular, it takes longer to cool the substrate than to heat it, and this is a factor that increases the time for replacing the substrate.

  FIG. 7 shows the time elapsed immediately after the periphery of the substrate holder 1 is brought into contact with the lower edges of both sides of the reflecting mirror 6 from the state in which the substrate s is heated to 600 ° C. It is a graph which shows the relationship of substrate temperature. In this example, as apparent from the graph of FIG. 7, it takes 420 to 480 minutes from the start of cooling until the temperature of the substrate s drops to around 50 ° C., and the temperature drop is slow. As a result, there is a problem that the processing time per one substrate becomes long and the throughput is low.

JP 2010-214033 A JP 2006-190805 A JP 2005-220369 A Japanese Patent Laid-Open No. 10-83960

  In view of the above-described problems in the conventional substrate heating / cooling apparatus used for conventional thin film deposition, the present invention enables rapid cooling of the substrate and the substrate holder by a simple operation. It is an object of the present invention to reduce the time required for cooling the substrate and the substrate holder in the processing step and improve the throughput of the substrate processing.

  In order to achieve the above-mentioned object, the present invention arranges the heater 5 and the reflecting mirror 6 behind the substrate holder, and provides the reflecting mirror 6 with a cooling means, specifically, a refrigerant passage 8 through which the refrigerant flows. When the substrate holder 1 and the substrate s are cooled, the substrate holder 1 is brought into contact with the reflecting mirror 6 having the refrigerant passage 6 so that the heat of the substrate holder 1 and the substrate s attached thereto is absorbed by the reflecting mirror 6. I was able to cool quickly.

  That is, the substrate heating / cooling device according to the present invention includes a heater 5 that heats the substrate holder 1 and the substrate s attached thereto, and a reflecting mirror that reflects heat emitted from the heater 5 toward the substrate holder 1 and the substrate s. 6, a cooling mechanism is provided on the reflecting mirror 6, and a moving mechanism for moving the substrate holder 1 on which the substrate s is mounted to come into contact with and separate from the reflecting mirror 6 is provided. Is.

  More specifically, the substrate holder 1 is in contact with the reflecting mirror 6 at the peripheral portion of the back surface thereof. When the substrate holder 1 comes into contact with the reflecting mirror 6, the substrate holder 1 is pushed up via the elastic member 11. As a cooling means for the reflecting mirror 6, it is possible to provide a cooling medium passage 8 for circulating a cooling medium cooled outside the vacuum chamber 24 in which the substrate s is disposed inside the reflecting mirror 6.

  In such a substrate heating / cooling device according to the present invention, the substrate holder 1 is heated by the heater 5 while being separated from the reflecting mirror 6, thereby heating the substrate s held by the substrate holder 1 to a required temperature. I can do it. Subsequently, when the substrate s is cooled, the substrate holder 1 is moved by the moving mechanism, and the substrate holder 1 is brought into contact with the reflecting mirror 6 so that heat flows to the refrigerant flowing in the refrigerant passage 8 of the reflecting mirror 6. The substrate holder 1 and the substrate s held by the substrate holder 1 are rapidly cooled. By such a cooling means for the substrate holder 1 and the substrate s, the substrate holder 1 and the substrate s can be heated and cooled in a short time.

The substrate holder 1 causes the surrounding part behind the substrate holder 1 to abut the reflecting mirror 6. Thereby, since the substrate holder 1 can be cooled from the periphery, it can be rapidly cooled without giving a heat shock to the substrate s.
Furthermore, in the substrate heating / cooling device according to the present invention, the substrate holder 1 is elastically brought into contact with the reflecting mirror 6 by connecting the moving mechanism and the substrate holder 1 via the elastic member 11 that urges elasticity. I can do it. Thereby, the substrate holder 1 can be reliably adhered to the reflecting mirror 6 without giving an impact to the substrate s.

  As described above, in the substrate heating / cooling apparatus according to the present invention, the substrate holder 1 can be brought into contact with the reflecting mirror 6 to rapidly cool the substrate holder 1 and the substrate s held thereby. The cooling time after heating the substrate s held by the substrate s can be shortened. Thereby, the cycle time of the exchange, heating, film formation, and cooling of the substrate s can be shortened, and the throughput of the processing process of the substrate s can be improved.

It is a vertical front view which shows one Example of the board | substrate heating-cooling apparatus by this invention. It is a vertical front view which shows the film-forming apparatus containing one Example of the substrate heating / cooling apparatus by this invention. FIG. 3 is an enlarged view of a part of the substrate heating / cooling device according to the present invention in a state where the substrate holder is separated from the reflecting mirror. FIG. 3 is an enlarged view of a portion of the substrate heating / cooling device according to the present invention in a state where the substrate holder is in contact with the reflecting mirror. It is a graph which shows the temperature change of the board | substrate immediately after the board | substrate holder contact | abuts to a reflective mirror in one Example of the board | substrate heating-cooling apparatus by this invention. It is a vertical front view which shows the prior art example of a board | substrate heating-cooling apparatus. It is a graph which shows the temperature change of the board | substrate immediately after starting cooling of a substrate holder in the prior art example of a substrate heating / cooling apparatus.

In the present invention, in order to achieve the above-mentioned object, the substrate holder 1 is moved so that the substrate holder 1 separated from the reflecting mirror 6 at the time of heating is brought into contact with the reflecting mirror 6 having the refrigerant passage 8, thereby The refrigerant flowing in the refrigerant passage 8 in the reflecting mirror 6 absorbs the heat held by the substrate holder 1 so that the substrate holder 1 and the substrate s held by the substrate holder 1 are rapidly cooled.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  FIG. 1 shows an embodiment of a substrate heating / cooling apparatus according to the present invention, and FIG. 2 shows a thin film forming apparatus using the embodiment of the substrate heating / cooling apparatus. In FIG. 2, some symbols are omitted and will be described below with reference mainly to the symbols in FIG. The same parts as those in the conventional example shown in FIG.

  A ring plate-shaped port flange 25 is provided at a port portion opened to the upper side of the vacuum chamber 24, and a disk-shaped flange 23 is formed on the port flange 25 from above via a gasket (not shown) or the like. The flange 23 is fixed to the port flange 25 by means such as a screw (not shown).

  Support rods 17, 17 are suspended from the flange 23 joined to the port flange 25 into the vacuum chamber 24. Inside the vacuum chamber 24, the first frame 12 is disposed immediately below the flange 23, and slide bushes 18 and 18 are provided so as to penetrate the first frame 12 vertically. The support rods 17 and 17 are slidably fitted into the bushes 18 and 18. Accordingly, the first frame 12 disposed immediately below the flange 23 is slidable in the longitudinal direction, that is, in the vertical direction while being guided by the support rods 17 and 17.

  A screw hole penetrates the boss portion 16 at the center of the first frame 12 vertically, and the screw shaft 14 suspended from the flange 23 penetrates the screw hole of the boss portion 16 so as to form a screw pair. doing. The screw shaft 14 is rotated by a rotation introducing device 19 provided on the flange 23, that is, outside the vacuum chamber 24. When the screw shaft 14 is rotated in any direction by the rotation introducing machine 19, the first frame 12 is raised or lowered. The support rods 17 and 17 guide the vertical movement of the first frame 12.

  In addition to the slide bushes 18, 18, another set of slide bushes 15, 15 is provided in the first frame 12 so as to vertically penetrate the first frame 12. Support rods 13 and 13 are fitted into the slide bushes 15 and 15 so as to be slidable up and down. Elastic members 11, 11 made of compression springs are inserted between the tops of the support rods 13, 13 and the upper ends of the slide bushes 15, 15. The elastic members 11, 11 are provided on the first frame 12. When the slide bushes 15 and 15 are raised, the slide bushes 15 and 15 are compressed, and the elasticity accompanying the compression strain is urged.

  A disc ring-shaped second frame 28 is attached to the lower ends of the support rods 13 and 13. Further, support posts 26, 26 are suspended from the second frame 28, and a disk ring-shaped holder support 27 is attached to the lower ends of the support posts 26, 26. The substrate holder 1 is detachably attached to the holder support 27. The substrate holder 1 is attached to and detached from the holder support 27 by a transfer rod or the like (not shown) through a load lock chamber (not shown) provided on the side wall of the vacuum chamber 24. A substrate s such as a semiconductor wafer such as Si is mounted on the lower surface of the substrate holder 1 with a metal such as In.

  A heater 5 is attached to the rear surface of the substrate holder 1, that is, on the surface opposite to the surface on which the substrate s is mounted, with a desired distance from the substrate holder 1. The heater 5 is connected to a current introduction terminal 21 provided on the flange 20 via the wiring 10 inside the vacuum chamber 24, and further, a power source (external power supply) disposed outside the vacuum chamber 24 via the current introduction terminal 21. (Not shown). The heater 5 is heated by this power source. For example, a lamp heater is used as the heater 5.

The back of the heater 5 and its periphery are surrounded by a reflecting mirror 6. The periphery of the reflecting mirror 6 is further surrounded by a reflecting plate 7. The reflecting mirror 6 and the reflecting plate 7 are for reflecting the heat generated by the heater 5 to the substrate holder 1 side. The heater 5, the reflecting mirror 6 and the reflecting plate 7 are fixed to each other and fixed in the vacuum chamber 24 so that their positions do not fluctuate.
Further, a temperature measuring contact of the thermocouple 3 for measuring the temperature of the substrate s provided thereon is brought into contact with the center of the upper surface of the substrate holder 1.

  Inside the reflecting mirror 6 is formed a refrigerant passage 8 through which a refrigerant such as cooling water flows, and this refrigerant passage 8 is connected to an internal pipe 9 in the vacuum chamber 24 and a fluid joint 22 provided in the flange 23. It is connected to a cooler (not shown) disposed outside the vacuum chamber 24. As the coolant such as cooling water cooled by the cooler flows through the coolant passage 8 inside the reflector 6, the reflector 6 is cooled. The reflecting mirror 6 surrounding the heater 5 has a cup shape with an opening at the bottom. The peripheral portion of the reflecting mirror 6 has a cylindrical shape, and its lower edge surface is positioned below the heater 5.

  A shutter 2 is provided so as to cover the bottom of the substrate s attached to the lower surface of the substrate holder 1. The shutter 2 is connected to a shaft 4 that hangs from a flange 23 into a vacuum chamber 24, and the shaft 4 is reciprocally rotated by a rotation introducing machine 20 provided on the flange 23, that is, outside the vacuum chamber 24. . By rotating the shutter 2 around the reciprocating shaft 4, the lower surface of the substrate s attached to the lower surface of the substrate holder 1, that is, the processing surface is opened and closed.

  Although not shown in FIG. 1 and only shown in FIG. 2, a molecular beam source m such as a Knudsen cell or an impact electron beam cell or an ion source is disposed below the shutter 4. Molecules, ions, and the like emitted from the molecular beam source m and ion source arranged as described above enter the surface of the substrate s of the substrate holder 1 only when the shutter 2 is opened. As a result, a thin film is formed on the surface of the substrate s or ions are implanted.

  In such a substrate heating / cooling apparatus, when the substrate s mounted on the substrate holder 1 is heated, the peripheral portion of the substrate holder 1 is separated from the lower edges on both sides of the reflecting mirror 6 as shown in FIGS. ing. In this state, the substrate holder 1 is heated from the back surface by the heater 5, and the substrate s mounted thereon is heated to a predetermined temperature.

  Next, when the substrate s mounted on the substrate holder 1 is cooled from this state, the screw shaft 14 is rotated by the rotation introducing device 19 and the first frame 12 is raised. At this time, the first frame 12 is guided along support rods 17 and 17 slidably fitted into the slide bushes 18 and 18. As a result, the slide bush 15 provided on the first frame 12 rises, the elastic member 11 is compressed, and the elastic member 11 is urged by the compression strain in the compression direction by this compression strain. The support rods 13 and 13 are raised by the elastic force of the elastic member 11, and the holder support 27 is pushed up via the second frame 28 and the columns 26 and 26. Accordingly, the substrate holder 1 attached to the holder support 27 is raised. As a result, as shown in FIG. 4, the peripheral portion of the back surface of the substrate holder 1 comes into contact with the lower edges on both sides of the reflecting mirror 6.

  When the peripheral part of the substrate holder 1 comes into contact with the lower edges on both sides of the reflecting mirror 6, the heat of the substrate holder 1 is transmitted to the reflecting mirror 6, and this heat is transferred to the coolant passage 8 inside the reflecting mirror 6. Absorbed by refrigerant. The refrigerant that has absorbed the heat is sent to a cooler (not shown) disposed outside the vacuum chamber 24 through the internal pipe 9 in the vacuum chamber 24 and the fluid joint 22 provided on the flange 23, where the refrigerant is retained. Heat is dissipated. As a result, the substrate holder 1 is rapidly cooled, and the substrate s attached thereto is also rapidly cooled.

  As described above, since the substrate holder 1 is pushed up via the elastic member 11 and is brought into contact with the reflecting mirror 6 by the elasticity of the elastic member 11, the impact received by the substrate holder 1 at the time of contact is exerted on the elastic member 11. It is absorbed and relaxed by elasticity. In addition, the peripheral portion of the substrate holder 1 is surely brought into contact with the lower edges on both sides of the reflecting mirror 6 by the elastic force of the elastic member 11.

  After the cooling of the substrate holder 1 and the substrate s attached thereto is completed, the screw shaft 14 is reversed by the rotation introducing device 19 and the first frame 12 is lowered. As a result, the slide bush 15 provided on the first frame 12 is also lowered, the compression of the elastic member 11 is released, the support rods 13 and 13 are lowered, the second frame 28, the columns 26 and 26, and the holder support. 27 also descends. As a result, the substrate holder 1 attached to the holder support 27 is lowered, and the peripheral portion of the substrate holder 1 is separated from the lower edges on both sides of the reflecting mirror 6 as shown in FIGS.

  Thereafter, each time the heating and cooling of the substrate holder 1 and the substrate s attached thereto are repeated, the substrate holder 1 moves up and down. That is, the peripheral part of the substrate holder 1 is separated from the lower edges on both sides of the reflecting mirror 6 when the substrate s is heated, and the peripheral part of the substrate holder 1 is brought into contact with the lower edges on both sides of the reflecting mirror 6 when the substrate s is cooled. Thereby, in particular, the cooling time of the substrate holder 1 and the substrate s attached thereto can be shortened, and the heating-cooling cycle can be shortened.

  FIG. 5 shows the time elapsed immediately after the periphery of the substrate holder 1 is brought into contact with the lower edges of both sides of the reflecting mirror 6 from the state in which the substrate s is heated to 600 ° C. in the substrate heating / cooling device according to one embodiment of the present invention. It is a graph which shows the relationship of substrate temperature. In this example, as is apparent from the graph of FIG. 5, the temperature of the substrate s drops from 600 ° C. to 52 ° C. in 60 minutes immediately after the peripheral portion of the substrate holder 1 is brought into contact with the lower edges of both sides of the reflecting mirror 6. A sudden drop in temperature is observed. That is, rapid cooling is possible.

  INDUSTRIAL APPLICABILITY The present invention can be used as an apparatus for heating and cooling a substrate when coating the surface of a substrate such as a semiconductor wafer or performing a surface treatment such as etching the surface by a vacuum deposition method, a sputtering method, or the like. . Since the substrate can be rapidly cooled, the throughput can be improved in the surface treatment process with the substrate heated.

DESCRIPTION OF SYMBOLS 1 Substrate holder 5 Heater 6 Reflective mirror 8 Refrigerant passage 11 of reflective mirror Elastic member 24 Vacuum chamber s Substrate

Claims (4)

In a substrate heating / cooling apparatus that heats and cools a substrate (s) held by the substrate holder (1), a heater (5) that heats the substrate holder (1) and the substrate (s) attached thereto, The substrate (s) includes a substrate holder (1) and a reflecting mirror (6) that reflects the heat emitted from the heater (5) to the substrate (s) side. The reflecting mirror (6) is provided with cooling means, and the substrate (s A substrate heating / cooling device comprising: a moving mechanism for moving the substrate holder (1) mounted with the substrate holder (1) in contact with and separating from the reflecting mirror (6). The substrate heating / cooling device according to claim 1, wherein a peripheral portion of the back surface of the substrate holder (1) is brought into contact with the reflecting mirror (6). The substrate heating / cooling device according to claim 1 or 2, wherein the substrate holder (1) is pushed up via the elastic member (11) when the substrate holder (1) contacts the reflecting mirror (6). As a cooling means, a refrigerant passage (8) through which a refrigerant cooled outside the vacuum chamber (24) in which the substrate (s) is arranged is provided inside the reflecting mirror (6). Item 4. The substrate heating / cooling device according to any one of Items 1 to 3.

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