Plasma processing apparatus and plasma processing method

Abstract

The present invention provides a plasma processing apparatus and a plasma processing method capable of suppressing deposition of by-products into a region in a chamber that is not exposed to plasma and high-frequency power applied for generating the plasma. The chamber is used for plasma processing of a substrate. A heater is disposed in correspondence with a region in the chamber that is not exposed to plasma and high-frequency power applied for generating the plasma. A heater power source is configured to be capable of supplying pulse-shaped power to the heater.

Description

Technical Field

[0001] The present disclosure relates to a plasma processing apparatus and a plasma processing method. Background Art

[0002] Patent Document 1 discloses a technique in which a plasma processing chamber is insulated, plasma is generated from a fluorocarbon gas, and supplied to a space outside the plasma processing chamber, thereby removing deposits on non-plasma surfaces in the outer space.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-195817 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides a technology for suppressing the deposition of byproducts in a region within a chamber that is not exposed to plasma and high-frequency power.

[0008] Solutions for solving problems

[0009] A plasma processing apparatus according to one embodiment of the present disclosure includes a chamber, a heater, and a heater power supply. Plasma processing is performed on a substrate in the chamber. The heater is disposed in an area of ​​the chamber that is not exposed to the plasma and high-frequency power. The heater power supply is configured to supply pulsed power to the heater.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to suppress the deposition of byproducts in regions within the chamber that are not exposed to plasma and high-frequency power. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram schematically showing an example of a cross section of a plasma processing apparatus according to an embodiment.

[0013] Figure 2 This is a diagram showing an example of arrangement of heaters according to the embodiment.

[0014] Figure 3 This is a diagram showing an example of temperature change of the heater according to the embodiment.

[0015] Figure 4 This is a diagram showing an example of pulsed power supplied to the heater according to the embodiment.

[0016] Figure 5 This is a diagram showing an example of heating by the heater according to the embodiment.

[0017] Figure 6 This is a diagram showing an example of temperature changes on the front and back surfaces of a member according to the embodiment.

[0018] Figure 7 This is a diagram showing an example of a test body according to the embodiment.

[0019] Figure 8 It is a diagram for explaining an outline of an experiment according to the embodiment.

[0020] Figure 9 It is a diagram schematically showing the arrangement of heaters and test pieces according to the embodiment.

[0021] Figure 10 It is a diagram showing experimental results according to the embodiment.

[0022] Figure 11 This is a diagram schematically showing an example of a cross section of a plasma processing apparatus according to another embodiment.

[0023] Description of Reference Numerals

[0024] 10: plasma processing apparatus; 12: chamber; 13: support table; 48: partition; 51: exhaust port; 55: heater; 56: heater power supply; W: wafer. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the plasma processing apparatus and the plasma processing method disclosed in the present application will be described in detail with reference to the accompanying drawings. However, the disclosed plasma processing apparatus and the plasma processing method are not limited to these embodiments.

[0026] During plasma processing, byproducts are generated along with the treatment, and these byproducts scatter and adhere to the chamber. Therefore, there are technologies that use plasma to clean byproducts, such as Patent Document 1. However, areas within the chamber that are not exposed to the plasma and the high-frequency (RF) power applied to generate the plasma are areas where byproducts are easily deposited and difficult to remove even with plasma. Deposited byproducts need to be removed regularly using a scraper or the like, but there is a risk of generating harmful gases.

[0027] Therefore, a technology for suppressing the deposition of by-products in regions within a chamber that are not exposed to plasma and high-frequency power is desired.

[0028] [First embodiment]

[0029] [Structure of Plasma Processing Apparatus]

[0030] An example of a plasma processing apparatus according to an embodiment will be described. In this embodiment, a plasma processing apparatus is used to perform plasma etching on a substrate as a plasma process. The substrate is a wafer. Figure 1 This is a diagram schematically showing an example of a cross section of the plasma processing apparatus 10 according to the embodiment. Figure 1 The illustrated plasma processing apparatus 10 is a capacitively coupled plasma processing apparatus.

[0031] The plasma processing apparatus 10 includes a chamber 12. The chamber 12 is configured to be roughly cylindrical, for example, made of aluminum, and is airtight. The chamber 12 provides its internal space as a processing space 12c for performing plasma processing. A plasma-resistant coating is formed on the inner wall surface of the chamber 12. The coating can be an acid-resistant aluminum film or a film formed of yttrium oxide. The chamber 12 is grounded. An opening 12g is formed on the side wall of the chamber 12. When a wafer W is loaded into the processing space 12c from the outside of the chamber 12 and when a wafer W is unloaded from the processing space 12c to the outside of the chamber 12, the wafer W passes through the opening 12g. A gate valve 14 is installed on the side wall of the chamber 12 to open and close the opening 12g.

[0032] A support table 13 for supporting wafer W is disposed near the center of chamber 12. Support table 13 includes a support portion 15 and a workbench 16. Support portion 15 is substantially cylindrical and is disposed on the bottom of chamber 12. Support portion 15 is made of, for example, an insulating material. Support portion 15 extends from the bottom of chamber 12 upward within chamber 12. Workbench 16 is disposed within processing space 12c. Workbench 16 is supported by support portion 15.

[0033] The worktable 16 is configured to hold a wafer W placed thereon. The worktable 16 includes a lower electrode 18 and an electrostatic chuck 20. The lower electrode 18 includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of a metal such as aluminum and have a substantially disc shape. The second plate 18b is disposed on the first plate 18a and is electrically connected to the first plate 18a.

[0034] An electrostatic chuck 20 is disposed on the second plate 18b. The electrostatic chuck 20 includes an insulating layer and a film-shaped electrode disposed within the insulating layer. The electrodes of the electrostatic chuck 20 are electrically connected to a DC power supply 22 via a switch 23. A DC voltage is applied from the DC power supply 22 to the electrodes of the electrostatic chuck 20. When the DC voltage is applied to the electrodes of the electrostatic chuck 20, the electrostatic chuck 20 generates an electrostatic attraction, attracting the wafer W to the electrostatic chuck 20 and holding the wafer W. Furthermore, a heater may be built into the electrostatic chuck 20, or the heater may be connected to a heater power supply located outside the chamber 12.

[0035] A focus ring 24 is provided on the periphery of the second plate 18b. Focus ring 24 is a generally annular plate. Focus ring 24 is positioned to surround the edge of wafer W and electrostatic chuck 20. Focus ring 24 is provided to improve etching uniformity. Focus ring 24 can be formed of materials such as silicon or quartz.

[0036] A flow path 18f is provided inside the second plate 18b. A temperature adjustment fluid is supplied to the flow path 18f from a cooling unit provided outside the chamber 12 via a pipe 26a. The temperature adjustment fluid supplied to the flow path 18f is returned to the cooling unit via a pipe 26b. In other words, the temperature adjustment fluid circulates between the flow path 18f and the cooling unit. By controlling the temperature of the temperature adjustment fluid, the temperature of the workbench 16 (or electrostatic chuck 20) ​​and the temperature of the wafer W are adjusted. Furthermore, as an example of the temperature adjustment fluid, a heat transfer liquid GALDEN (registered trademark) is exemplified.

[0037] Plasma processing apparatus 10 is provided with gas supply line 28 . Gas supply line 28 is used to supply heat transfer gas, such as He gas, from a heat transfer gas supply mechanism between the upper surface of electrostatic chuck 20 and the back surface of wafer W.

[0038] The plasma processing apparatus 10 further includes a showerhead 30. The showerhead 30 is disposed above the workbench 16. The showerhead 30 is supported on the upper portion of the chamber 12 via an insulating member 32. The showerhead 30 may include an electrode plate 34 and a support 36. The lower surface of the electrode plate 34 faces the processing space 12c. The electrode plate 34 is provided with a plurality of gas ejection holes 34a. The electrode plate 34 may be formed of a material such as silicon or silicon oxide.

[0039] The support body 36 detachably supports the electrode plate 34 and is formed from a conductive material such as aluminum. A gas diffusion chamber 36a is provided within the support body 36. Multiple gas flow holes 36b extend downward from the gas diffusion chamber 36a and communicate with the gas ejection holes 34a. A gas inlet 36c is formed in the support body 36 for introducing gas into the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas inlet 36c.

[0040] The gas supply pipe 38 is connected to the gas source group 40 via the valve group 42 and the flow controller group 44. The gas source group 40 includes gas sources of various gases used for plasma etching. The valve group 42 includes a plurality of valves, and the flow controller group 44 includes a plurality of flow controllers such as a mass flow controller or a pressure-controlled flow controller. The plurality of gas sources of the gas source group 40 are connected to the gas supply pipe 38 via the corresponding valves in the valve group 42 and the corresponding flow controllers in the flow controller group 44. The gas source group 40 supplies various gases used for plasma etching to the gas diffusion chamber 36a of the support body 36 via the gas supply pipe 38. The gas supplied to the gas diffusion chamber 36a is dispersed and supplied to the chamber 12 in a spray-like manner from the gas diffusion chamber 36a via the gas ejection holes 34a and the gas flow holes 36b.

[0041] The lower electrode 18 is connected to the first high-frequency power supply 62 via the matching box 63. In addition, the lower electrode 18 is connected to the second high-frequency power supply 64 via the matching box 65. The first high-frequency power supply 62 is a power supply that generates high-frequency power for generating plasma. During plasma processing, the first high-frequency power supply 62 supplies high-frequency power of a predetermined frequency in the range of 27 to 100 MHz, for example, a frequency of 40 MHz, to the lower electrode 18 of the workbench 16. The second high-frequency power supply 64 is a power supply that generates high-frequency power for attracting ions (for generating bias). During plasma processing, the second high-frequency power supply 64 supplies high-frequency power of a predetermined frequency in the range of 400 kHz to 13.56 MHz, for example, 3 MHz, which is lower than that of the first high-frequency power supply 62, to the lower electrode 18 of the workbench 16. In this way, the workbench 16 is configured to be able to apply two high-frequency powers of different frequencies from the first high-frequency power supply 62 and the second high-frequency power supply 64. The shower head 30 and the workbench 16 function as a pair of electrodes (upper electrode and lower electrode).

[0042] The support body 36 of the showerhead 30 is connected to a variable DC power supply 68 via a low-pass filter (LPF) 66. The variable DC power supply 68 is configured to be able to supply and stop power via an on-off switch 67. The current and voltage of the variable DC power supply 68, as well as the on and off switching of the on-off switch 67, are controlled by a control unit 70, described later. Furthermore, when high-frequency power is applied from the first and second high-frequency power supplies 62 and 64 to the workbench 16 to generate plasma in the processing space, the control unit 70 turns on the on-off switch 67 as needed to apply a predetermined DC voltage to the support body 36.

[0043] An exhaust port 51 is provided at the bottom of the side of the support table 13 of the chamber 12. The exhaust port 51 is connected to an exhaust device 50 via an exhaust pipe 52. The exhaust device 50 includes a pressure controller such as a pressure regulating valve and a vacuum pump such as a turbomolecular pump. The exhaust device 50 exhausts the interior of the chamber 12 via the exhaust port 51 and the exhaust pipe 52, thereby reducing the pressure within the chamber 12 to a desired level.

[0044] In the chamber 12, a partition 48 is provided at a position upstream of the exhaust port 51 in the exhaust gas flow path to the exhaust port 51. The partition 48 is arranged between the support table 13 and the inner side surface of the chamber 12 in a manner surrounding the support table 13. The partition 48 is, for example, a plate-shaped member, which can be formed by covering the surface of an aluminum base material with ceramics such as Y2O3. The partition 48 is formed by a member having a plurality of slits, a mesh member, or a member having a plurality of punched holes, and is configured to allow exhaust gas to pass through. The internal space of the chamber 12 is divided into a processing space 12c and an exhaust space by the partition 48. The processing space 12c is used to perform plasma processing on the wafer W, and the exhaust space is connected to an exhaust system for exhausting the chamber 12 such as the exhaust pipe 52 and the exhaust device 50.

[0045] A heater 55 is arranged in an area of ​​the chamber 12 that is not exposed to the plasma and high-frequency power. In one example, the heater 55 is arranged in the exhaust space. The heater 55 is, for example, an infrared heater such as a carbon filament heater. The heater 55 is arranged so as to be spaced apart from the inner side surface of the chamber 12, the bottom of the chamber 12, the support table 13, and the partition 48 and to surround the support table 13. That is, the heater 55 is arranged along the side of the support table 13 so as to be spaced apart from the chamber 12, the support table 13, and the partition 48 without contacting the chamber 12, the support table 13, and the partition 48. The heater 55 is connected to a heater power supply 56 via wiring 57. The heater 55 generates heat based on the power supplied from the heater power supply 56, radiating infrared rays to heat the surrounding area. The heater power supply 56 supplies power to the heater 55 in a pulsed manner under the control of the control unit 70 described later. In addition, the heater power supply 56 can be either a DC power supply or a high-frequency power supply.

[0046] The plasma processing apparatus 10 further includes a control unit 70. The control unit 70 is, for example, a computer including a processor, a storage unit, an input device, a display device, and the like. The control unit 70 controls the various components of the plasma processing apparatus 10. In the control unit 70, an operator can use the input device to input commands and manage the plasma processing apparatus 10. Furthermore, the control unit 70 can visually display the operating status of the plasma processing apparatus 10 using the display device. The storage unit of the control unit 70 stores control programs and process data for controlling various processes performed by the plasma processing apparatus 10 using the processor. The processor of the control unit 70 executes the control program and controls the various components of the plasma processing apparatus 10 according to the process data, thereby causing the plasma processing apparatus 10 to perform the desired processes.

[0047] As mentioned above, plasma processing generates byproducts that scatter and adhere to chamber 12. Therefore, there are technologies that use plasma to clean these byproducts, such as those described in Patent Document 1. However, using plasma to clean areas within chamber 12 that are not exposed to plasma or high-frequency power is difficult to remove. For example, below partition 48 within chamber 12, the plasma and high-frequency power are shielded by partition 48, making it difficult for the plasma to reach the area. Consequently, byproducts are easily deposited below partition 48 within chamber 12.

[0048] Therefore, in the plasma processing apparatus 10 , the heater 55 is disposed in a region not exposed to the plasma or high-frequency power. For example, in the embodiment, the heater 55 is disposed below the partition plate 48 in the chamber 12 .

[0049] Figure 2 : is a diagram showing an example of the arrangement of the heater 55 according to the embodiment. Figure 2 , the vicinity of the lower portion of the partition plate 48 in the chamber 12 is shown. Below the partition plate 48 in the chamber 12, byproducts are easily deposited in an area 80 on the inner side surface of the chamber 12. Therefore, the heater 55 is disposed at a predetermined distance from the area 80 in the chamber 12 where byproducts are easily deposited.

[0050] When electric power is supplied from the heater power supply 56 to the heater 55 , the heater 55 generates heat. Figure 3 : is a diagram showing an example of temperature change of the heater 55 according to the embodiment. Figure 3 , the temperature change after power is supplied to the carbon filament heater as the heater 55 is shown. Figure 3 When the carbon filament heater is supplied with power, its temperature rises rapidly to 1000°C in about 3 seconds.

[0051] When power is supplied from the heater power supply 56 to the heater 55 , the heater 55 generates heat. The heat from the heater 55 heats the region 80 on the inner surface of the chamber 12 , thereby suppressing adhesion of by-products or removing by-products.

[0052] However, when power is continuously supplied from heater power supply 56 to heater 55 to suppress the adhesion of byproducts or to remove byproducts, heat from region 80 on the inner side of chamber 12 is also transferred to the outer surface, causing the outer surface temperature to rise. For example, the outer surface of chamber 12 corresponding to region 80 in chamber 12 becomes hot. If the outer surface temperature of chamber 12 becomes excessively high, measures to ensure the safety of the apparatus are necessary, such as installing a heat-insulating material on the outer surface of chamber 12. Therefore, it is preferable to maintain the outer surface of chamber 12 below a predetermined allowable temperature (e.g., 50°C) that is considered safe.

[0053] Therefore, the heater power supply 56 supplies pulsed power to the heater 55 . Figure 4 1 is a diagram showing an example of pulsed power supplied to the heater according to the embodiment. The controller 70 controls the heater power supply 56 to start and stop supplying power, thereby supplying pulsed power to the heater 55.

[0054] By arranging the heater 55 inside the chamber 12, the heating time can be shortened and the inner surface of the chamber 12 can be efficiently heated. Furthermore, by supplying pulsed power to the heater 55 and repeatedly heating and cooling the chamber 12, the temperature rise of the outer surface of the chamber 12 can be suppressed. The frequency of this pulsed power can be set to, for example, 0.05 Hz or less.

[0055] Figure 5 : is a diagram showing an example of heating by the heater 55 according to the embodiment. Figure 5 In FIG. 1 , a flat plate-shaped member 12h is shown that simulates the side wall of the chamber 12. The member 12h is made of the same metal as the chamber 12 (e.g., aluminum) and has a thickness of 10 mm. Figure 5 The right side of the component 12h is the front surface, and the left side is the back surface. Heater 55 is placed 50 mm from the surface of component 12h. Thus, the surface of component 12h corresponds to the inner wall surface of chamber 12. The back surface of component 12h corresponds to the outer wall surface of chamber 12.

[0056] When pulsed power is supplied to the heater 55, the surface of the component 12h is directly radiated with heat from the heater 55, causing the temperature to change as the power supply is turned on and off. Meanwhile, the temperature of the back surface of the component 12h changes due to heat transfer from the front surface, so the temperature change is not as significant as the temperature change on the front surface. Figure 6This diagram illustrates an example of temperature changes on the front and back surfaces of component 12h according to an embodiment. While power is being supplied, the surface temperature of component 12h rises sharply due to heat from heater 55. However, when power is stopped, heat diffuses into component 12h, causing the temperature to drop sharply. Meanwhile, radiant heat from heater 55 is stopped before the back surface of component 12h experiences a sharp rise in temperature due to heat transfer from the surface. Therefore, the back surface temperature of component 12h rises slowly before reaching its maximum value.

[0057] Therefore, by appropriately adjusting the periods during which power is supplied and stopped, the back surface of component 12h can be maintained below the permissible temperature, while the surface of component 12h is temporarily raised to a temperature sufficient to remove byproducts during the power supply period. The surface of component 12h corresponds to the inner wall of chamber 12. The back surface of component 12h corresponds to the outer wall of chamber 12. Therefore, the outer surface of chamber 12 can be maintained below the permissible temperature, while the inner surface of chamber 12 can be temporarily raised to a temperature sufficient to remove byproducts during the power supply period.

[0058] The control unit 70 controls the heater power supply 56 so that pulsed power, with the supply period and the supply stop period appropriately adjusted, is supplied to the heater 55. For example, an appropriate cycle of the supply period and the supply stop period can be determined through experiments. The control unit 70 controls the heater power supply 56 to supply pulsed power to the heater 55 at the determined cycle. The control unit 70 controls the heater power supply 56 to repeatedly supply power until the heat from the heater 55 causes a region 80 on the inner surface of the chamber 12 to a temperature that volatilizes byproducts adhering to the region 80 during plasma processing, and then stops the power supply. For example, the control unit 70 controls the heater power supply 56 to repeatedly supply and stop the power supply so that, during the power supply period, the region 80 reaches a temperature that volatilizes byproducts and the outer surface of the chamber 12 corresponding to the region 80 is kept below the permissible temperature. For example, when the byproducts generated by plasma processing are titanium-based byproducts, the controller 70 controls the heater power supply 56 to temporarily raise the temperature of the region 80 on the inner surface of the chamber 12 to 80° C. to 100° C. during the supply period.

[0059] Thus, plasma processing apparatus 10 can suppress deposition of byproducts in region 80 of the inner surface of chamber 12. In addition, plasma processing apparatus 10 can suppress the temperature of the outer surface of chamber 12 corresponding to region 80 to be below the permissible temperature.

[0060] Furthermore, in this embodiment, the case of suppressing the deposition of byproducts on the inner surface area 80 of the chamber 12 is described as an example, but the present invention is not limited thereto. The heater 55 can be placed in any area within the chamber 12 as long as it is located in the area where the deposition of byproducts is to be suppressed. By arranging the heater 55 in correspondence with the area within the chamber 12 that is not exposed to the plasma and the high-frequency power, and supplying pulsed power to the heater 55 from the heater power supply 56, the deposition of byproducts in the area within the chamber 12 that is not exposed to the plasma and the high-frequency power can be suppressed.

[0061] In addition, sometimes the chamber is cleaned by plasma. In one example, cleaning refers to performing plasma treatment in a manner where wafer W is not arranged in the chamber 12 or a wafer dummy is arranged in the chamber 12. The control unit 70 may also supply pulsed power from the heater power supply 56 to the heater 55 during such cleaning to promote the removal of byproducts. For example, when wafer W is subjected to plasma treatment, the control unit 70 controls the heater power supply 56 to supply power while the heater power supply 56 is on until the area not exposed to the plasma and high-frequency power reaches a first temperature. In one example, the first temperature is a temperature that can suppress the adhesion of byproducts. In addition, when cleaning the chamber 12 by plasma in a manner where wafer W is not arranged in the chamber 12 or a wafer dummy is placed in the chamber 12, the control unit 70 controls the heater power supply 56 to supply power while the heater power supply 56 is on until the area not exposed to the plasma and high-frequency power reaches a second temperature. In one example, the second temperature is a temperature that can promote the removal of byproducts. The second temperature may also be set to a higher temperature than the first temperature. For example, if titanium-based byproducts are produced as a byproduct of plasma processing, the temperature of region 80 on the inner surface of chamber 12 is temporarily raised to 80°C to 100°C while heater power 56 is on during plasma processing of wafer W. This prevents titanium-based byproducts produced as a result of plasma processing from adhering to region 80. Meanwhile, during cleaning, the temperature of region 80 on the inner surface of chamber 12 is temporarily raised to 100°C to 120°C while heater power 56 is on. This facilitates the removal of titanium-based byproducts adhering to region 80.

[0062] Next, a specific example will be described. Hereinafter, an experiment in which a temperature was measured using a flat plate-shaped test body simulating the side wall of the chamber 12 will be described as an example. Figure 7 : is a diagram showing an example of a test body according to an embodiment. Figure 7 In FIG, the structure of a flat plate-shaped test body 90 is shown. The test body 90 uses an aluminum (A5052) flat plate with a size of 360 mm × 200 mm and a thickness of 10 mm. Figure 9In the experiment, the upper side of the test piece 90 was set as the rear side, the lower side was set as the front side, the left side was set as the upper side, and the right side was set as the lower side. In the test piece 90, thermocouples for measuring temperature were set at a total of five positions: position F1 (surface center) near the center of the surface, and positions F2 (surface upper side), F3 (surface rear side), F4 (surface lower side), and F5 (surface front side) on the upper, lower, front, and rear sides 40 mm away from position F1. In addition, in the test piece 90, thermocouples for measuring temperature were set at a total of three positions: position B1 (back center) on the back side corresponding to position F1 on the surface, and positions B2 (back side) and B3 (back side) on the back side corresponding to positions F2 and F4 on the surface. Positions B2 and B3 were located at the front and rear sides, respectively, 40 mm away from position B1 near the center of the back side.

[0063] Figure 8 This figure illustrates an overview of an experiment according to an embodiment. In the experiment, a heater 55 was placed 50 mm from the surface of a test piece 90 to provide heating. A carbon filament heater was used as heater 55. Heater 55 passed through glass tube 91 and was positioned corresponding to the area on the surface of test piece 90 where a thermocouple was located. Figure 9 The figure schematically illustrates the arrangement of heater 55 and test piece 90 according to the embodiment. Heater 55 passes through a zigzag transparent glass tube 91 and is arranged facing the surface of test piece 90 at positions F1 to F5 at a distance of 50 mm.

[0064] In the experiment, the heater 55 was supplied with electric power at a current value of 20 A by turning on the power supply, and the current value was set to 0 A by turning off the power supply, thereby supplying and stopping electric power in a pulsed manner.

[0065] Figure 10 : is a graph showing the experimental results involved in the embodiment. Figure 10 In FIG, the change of the current value supplied to the heater 55 is shown at the bottom. Figure 10 , there are shown measurement results (F1 to F5) obtained by measuring five positions on the surface side using a thermocouple arranged on the surface of the test body 90, and measurement results (B1 to F3) obtained by measuring three positions on the back side using a thermocouple arranged on the back side of the test body 90.

[0066] like Figure 10As shown, the surface temperature of test object 90 can be changed in response to the supply and non-supply of power, and the surface of test object 90 can be temporarily raised to a temperature sufficient to remove byproducts during the power supply period. For example, during the conduction period, positions F1 (center of the surface), F2 (upper side of the surface), and F5 (front side of the surface) on the surface temporarily rise to a temperature sufficient to remove titanium-based byproducts, i.e., 80°C or higher. Meanwhile, the center, front, and rear sides of the back surface can be maintained below 50°C.

[0067] Therefore, the plasma processing apparatus 10 can suppress the deposition of by-products in the chamber 12 by appropriately arranging the heater 55 in the chamber 12 and supplying pulsed power to the heater 55 .

[0068] As described above, the plasma processing apparatus 10 according to this embodiment includes the chamber 12, the heater 55, and the heater power supply 56. Plasma processing is performed on the wafer W within the chamber 12. The heater 55 is arranged corresponding to an area within the chamber 12 that is not exposed to the plasma and the high-frequency power. The heater power supply 56 is configured to supply pulsed power to the heater 55. Thus, the plasma processing apparatus 10 can suppress the deposition of byproducts in areas within the chamber 12 that are not exposed to the plasma and the high-frequency power.

[0069] The plasma processing apparatus 10 also includes an exhaust port 51 and a partition 48. The exhaust port 51 is used to exhaust the interior of the chamber 12. The partition 48 is disposed upstream of the exhaust port 51 in the flow path of the exhaust gas flowing to the exhaust port 51 within the chamber 12. The heater 55 is disposed downstream of the partition 48 in the flow path of the exhaust gas flowing to the exhaust port 51. Thus, the plasma processing apparatus 10 can suppress the deposition of byproducts in areas downstream of the partition 48, where byproducts are more likely to deposit.

[0070] The plasma processing apparatus 10 further includes a support table 13 disposed within the chamber 12 and supporting the wafer W. A partition plate 48 is disposed between the support table 13 and the inner side surface of the chamber 12 so as to surround the support table 13. A heater 55 is disposed closer to the exhaust port 51 than the partition plate 48 so as to surround the support table 13. Thus, the plasma processing apparatus 10 according to this embodiment can suppress the deposition of byproducts in the area surrounding the support table 13 downstream of the partition plate 48.

[0071] The heater power supply 56 repeatedly supplies power until the area not exposed to the plasma and high-frequency power reaches a temperature at which the byproducts are volatilized by the heat from the heater 55, and then stops supplying power. Thus, the plasma processing apparatus 10 according to this embodiment can suppress the deposition of byproducts in areas not exposed to the plasma and high-frequency power.

[0072] Furthermore, the heater power supply 56 repeatedly turns on and off power during the power supply period to keep the temperature of the area not exposed to the plasma and the high-frequency power at a temperature that allows byproducts to volatilize, and to keep the outer surface of the chamber 12 corresponding to the unexposed area below the permissible temperature. Thus, the plasma processing apparatus 10 according to this embodiment can suppress the deposition of byproducts in the area not exposed to the plasma and the high-frequency power. Furthermore, the plasma processing apparatus 10 according to this embodiment can maintain the outer surface of the chamber 12 below the permissible temperature.

[0073] While the above describes the present embodiment, it should be understood that the disclosed embodiment is illustrative in all respects and not restrictive. In practice, the above embodiment can be embodied in a variety of ways. Furthermore, the above embodiment can be omitted, replaced, or modified in various ways without departing from the scope and spirit of the claims.

[0074] For example, in the above-described embodiment, the case where the period during which power is supplied from the heater power supply 56 to the heater 55 and the period during which power is stopped are appropriately adjusted and determined in advance is described as an example. However, the present invention is not limited to this. A temperature sensor may be used to measure the temperature, and the supply period and the supply stop period may be controlled based on the measured temperature. For example, the heater 55 may be arranged corresponding to a target area within the chamber 12 for suppressing the deposition of byproducts. In addition, a temperature sensor may be provided in the target area within the chamber 12 and on the outer surface of the chamber 12 corresponding to the location of the target area. The heater power supply 56 may also repeatedly supply power to the heater 55 in a pulsed manner until the temperature measured by the temperature sensor provided in the target area reaches a temperature at which the byproducts volatilize, and then stop supplying power. In addition, the closer the temperature measured by the temperature sensor provided on the outer surface of the chamber 12 is to the permissible temperature, the longer the heater power supply 56 stops supplying power.

[0075] In the above embodiment, the plasma processing apparatus 10 is described as a capacitively coupled plasma processing apparatus. However, the present invention is not limited thereto. The plasma processing method of this embodiment can be employed by any plasma processing apparatus. For example, the plasma processing apparatus 10 can be any type of plasma processing apparatus, such as an inductively coupled plasma processing apparatus or a plasma processing apparatus that excites a gas using surface waves such as microwaves.

[0076] In the above embodiment, the first and second high-frequency power supplies 62, 64 are connected to the lower electrode 18. However, the structure of the plasma source is not limited thereto. For example, the first high-frequency power supply 62 for generating plasma may be connected to the showerhead 30. Furthermore, the second high-frequency power supply 64 for attracting ions (for generating a bias voltage) may not be connected to the lower electrode 18.

[0077] Furthermore, in the above embodiment, the inter-electrode distance between the shower head 30, which functions as the upper and lower electrodes, and the stage 16 is fixed as an example. However, the present invention is not limited to this. In a parallel-plate plasma processing apparatus, the inter-electrode distance between the upper and lower electrodes affects the plasma processing characteristics of the substrate. Therefore, the plasma processing apparatus 10 may also be configured to be able to adjust the inter-electrode distance between the shower head 30 and the stage 16. Figure 11 This is a diagram schematically showing an example of a cross section of a plasma processing apparatus according to another embodiment. Figure 11 The plasma processing apparatus 10 shown in the figure includes a support table 13 and a shower head 30. The support table 13 is arranged near the center of the chamber 12 and supports the wafer W. The support table 13 is omitted in the figure, but has the same Figure 1The same structure is applied with high-frequency power when plasma is generated. The shower head 30 is arranged opposite to the support platform 13. The shower head 30 and the support platform 13 have the functions of an upper electrode and a lower electrode. In addition, the plasma processing device 10 also has a lifting mechanism 200 for lifting the shower head 30. The lifting mechanism 200 lifts and lowers the shower head 30 between the top of the chamber 12 and the support platform 13. The shower head 30 is provided with a bellows 210 in a manner surrounding the lifting mechanism 200. The bellows 210 is airtightly mounted on the top wall of the chamber 12 and the upper surface of the shower head 30. Inside the chamber 12, a cylindrical wall 220 is provided in a manner surrounding the shower head 30, the processing space 12c and the support platform 13. An exhaust port 51 is provided at the bottom of the side of the chamber 12. The exhaust port 51 is connected to the exhaust device 50 via an exhaust pipe 52. The exhaust device 50 exhausts the interior of the chamber 12 through the exhaust port 51 and the exhaust pipe 52 , thereby reducing the pressure in the chamber 12 to a desired pressure.

[0078] Within the chamber 12, a partition 48 is provided at a position upstream of the exhaust port 51 in the exhaust flow path leading to the exhaust port 51. The partition 48 is disposed between the inner side surface of the lower portion of the cylindrical wall 220 and the support table 13 so as to surround the periphery of the support table 13. The chamber 12 is divided by the partition 48 into a processing space 12c and an exhaust space. The processing space 12c is used to perform plasma processing on the wafers W and is connected to an exhaust system for exhausting the chamber 12, such as the exhaust pipe 52 and the exhaust device 50. The processing space 12c is formed by the lower surface of the shower head 30, the cylindrical wall 220, the partition 48, and the support table 13. For example, the processing space 12c is formed by the lower surface of the shower head 30, the inner wall surface of the cylindrical wall 220, the partition 48, and the support table 13. The exhaust space is, for example, a space formed by the inner wall surface of the chamber 12 , the outer wall surface of the cylindrical wall 220 , the outer circumferential upper portion of the shower head 30 , and the ceiling of the chamber 12 .

[0079] Here, it is difficult to remove byproducts by cleaning using plasma in areas within the chamber 12 that are not exposed to plasma or high-frequency power. Therefore, a heater 55 is arranged in an area within the chamber 12 that is not exposed to plasma or high-frequency power. In one example, the heater 55 is arranged in the exhaust space. For example, the heater 55 is arranged in the space 230 formed by the outer side of the cylindrical wall 220, the shower head 30, and the top of the chamber 12. As a result, the plasma processing apparatus 10 can suppress the deposition of byproducts in the space 230. In addition, the plasma processing apparatus 10 can suppress the temperature of the outer surface of the chamber 12 corresponding to the space 230 to below the allowable temperature.

[0080] The plasma processing apparatus 10 described above is a plasma processing apparatus that performs etching as a plasma process, but a plasma processing apparatus that performs any plasma process can be employed. For example, the plasma processing apparatus 10 can be a single-wafer deposition apparatus that performs chemical vapor deposition (CVD), atomic layer deposition (ALD), physical vapor deposition (PVD), or the like, or a plasma processing apparatus that performs plasma annealing, plasma implantation, or the like.

[0081] In the above-mentioned embodiment, the case where the substrate is a semiconductor wafer is described as an example, but the present invention is not limited thereto and the substrate may be another substrate such as a glass substrate.

Claims

1. A plasma processing apparatus comprising: a chamber for performing plasma processing on a substrate; a support table supporting the substrate; an exhaust port for exhausting gas in the chamber; and a partition plate disposed between an inner side surface of the chamber and the support table, dividing the chamber into a processing space for processing the substrate and an exhaust space including the exhaust port; a heater disposed in the exhaust space; a heater power supply capable of supplying pulsed power to the heater; and The control unit controls the heater power supply to supply power to the heater until the exhaust space reaches a temperature at which byproducts adhering to the exhaust space are volatilized.

2. The plasma processing apparatus according to claim 1, wherein The heater is arranged so as to surround the support table.

3. The plasma processing apparatus according to claim 1 or 2, wherein: The heater is an infrared heater.

4. The plasma processing apparatus according to claim 1 or 2, wherein: The frequency of the pulsed power is 0.05 Hz or less.

5. A plasma processing apparatus comprising: a chamber for performing plasma processing on a substrate; a support table supporting the substrate; an upper electrode disposed facing the support platform; a lifting mechanism for lifting the upper electrode between the top of the chamber and the support table; as well as a cylindrical wall provided in the chamber and surrounding the support table and the upper electrode; a heater disposed in a space formed by the outer side of the cylindrical wall, the upper electrode, and the top of the chamber; a heater power supply capable of supplying pulsed power to the heater; and The control unit controls the heater power supply to supply power to the heater until the space reaches a temperature at which byproducts adhering to the space are volatilized.

6. The plasma processing apparatus according to claim 5, wherein: The heater is an infrared heater.

7. The plasma processing apparatus according to claim 5 or 6, characterized in that: The frequency of the pulsed power is 0.05 Hz or less.

8. A plasma processing apparatus comprising: a chamber for performing plasma processing on a substrate; a heater disposed in a region of the chamber that is not exposed to the plasma and the high-frequency power; a heater power supply capable of supplying pulsed power to the heater; and a control unit that controls the heater power supply to execute a process including the following steps: (a) supplying power to the heater until the unexposed area reaches a temperature at which the by-products adhering to the unexposed area volatilize; Step (b), stopping the supply of the power; and Step (c) is to repeat the steps (a) and (b).

9. The plasma processing apparatus according to claim 8, wherein: A temperature sensor for measuring temperature is further provided on at least one of the unexposed region and the outer surface of the chamber.

10. The plasma processing apparatus according to claim 8 or 9, characterized in that: In the step (c), the control unit repeatedly performs the steps (a) and (b) so that the outer surface of the chamber becomes lower than a permissible temperature lower than the volatilization temperature.

11. The plasma processing apparatus according to claim 8 or 9, characterized in that: The heater is an infrared heater.

12. The plasma processing apparatus according to claim 8 or 9, characterized in that: The frequency of the pulsed power is 0.05 Hz or less.

13. A plasma processing apparatus comprising: a chamber for performing plasma processing on a substrate; a heater disposed in a region of the chamber that is not exposed to the plasma and the high-frequency power; a heater power supply capable of supplying pulsed power to the heater; and a control unit that controls the heater power supply. The control unit executes the following steps: placing the substrate on a support table that supports the substrate to perform plasma processing; and cleaning the chamber without placing the substrate on the support table. The process of performing plasma treatment includes the following steps: Step (a1) of supplying power to the heater until the unexposed area reaches a first temperature that suppresses adhesion of by-products; Step (b1), stopping the supply of the power; and Step (c1), repeating the steps (a1) and (b1), The cleaning process includes the following steps: Step (a2), supplying power to the heater until the unexposed area reaches a second temperature that promotes removal of by-products; Step (b2), stopping the supply of the power; and Step (c2): repeating the steps (a2) and (b2).

14. The plasma processing apparatus according to claim 13, wherein: The by-product is a titanium by-product, the first temperature is 80°C to 100°C, and the second temperature is 100°C to 120°C.

15. The plasma processing apparatus according to claim 13 or 14, wherein: The frequency of the pulsed power is 0.05 Hz or less.

16. The plasma processing apparatus according to claim 13 or 14, wherein: The heater is an infrared heater.

17. A plasma treatment method, the plasma treatment method being performed by the plasma treatment apparatus according to any one of claims 1 to 16, the method comprising the following steps: performing plasma processing on the substrate within the chamber; and Pulse power is supplied to a heater disposed in a region of the chamber that is not exposed to the plasma and the high-frequency power.

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