Plasma processing apparatus and control method thereof

Abstract

To provide a technique for suppressing deformation of an upper electrode portion due to heat input from plasma.SOLUTION: A plasma processing apparatus includes a substrate support part, an upper electrode part disposed opposite the substrate support part, and a control part, and the upper electrode part includes, in order from the substrate support part side, an electrode plate, a cooling plate through which a heat transfer fluid flows, and a heater, and the control part controls the output of the heater according to the amount of heat input from the plasma to the upper electrode part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a plasma processing apparatus and a method for controlling the plasma processing apparatus.

Background Art

[0002] For example, Patent Document 1 discloses an electrode unit disposed in a substrate processing apparatus including a processing chamber for processing a substrate by plasma, the electrode unit having an electrode layer, a heating layer, and a cooling layer that are sequentially arranged from the processing chamber side and exposed in the processing chamber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique for suppressing deformation of an upper electrode portion due to heat input from plasma.

Means for Solving the Problems

[0005] According to one aspect of the present disclosure, there is provided a plasma processing apparatus including a substrate support portion, an upper electrode portion provided to face the substrate support portion, and a control portion, wherein the upper electrode portion includes, in order from the side of the substrate support portion, an electrode plate, a cooling plate through which a heat transfer fluid flows inside, and a heater, and the control portion controls the output of the heater according to the amount of heat input from the plasma to the upper electrode portion.

Effects of the Invention

[0006] The present disclosure provides a technique for suppressing deformation of an upper electrode portion due to heat input from plasma.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

[0008] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. In the present specification and the drawings, substantially the same components are denoted by the same reference numerals, and redundant descriptions are omitted. Note that, for ease of understanding, the scales of the respective portions in the drawings may be different from the actual ones. In directions such as parallel, right angle, orthogonal, horizontal, vertical, up and down, left and right, a deviation that does not impair the effects of the embodiment is allowed. The shape of the corners is not limited to a right angle and may be rounded. Parallel, right angle, orthogonal, horizontal, and vertical may include substantially parallel, substantially right angle, substantially orthogonal, substantially horizontal, and substantially vertical.

[0009] <Plasma processing system> A configuration example of the plasma processing system will be described below. FIG. 1 is a diagram for explaining the configuration of a plasma processing system including a plasma processing apparatus 1 which is an example of the plasma processing apparatus according to the present embodiment.

[0010] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. Further, the plasma processing apparatus 1 includes a heat transfer fluid supply unit 50 and a heater power supply unit 60. Furthermore, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13 which is an example of an upper electrode unit. The substrate support unit 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support unit 11. The shower head 13 is provided facing the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, the side wall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas discharge port for discharging gas from the plasma processing space. The side wall 10a is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the plasma processing chamber 10 housing.

[0011] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region (substrate support surface) 111a for supporting a substrate (wafer) W and an annular region (ring support surface) 111b for supporting the ring assembly 112. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan view. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. In one embodiment, the main body portion 111 includes a base and an electrostatic chuck. The base includes a conductive member. The conductive member of the base functions as a lower electrode. The electrostatic chuck is disposed on the base. The upper surface of the electrostatic chuck has the substrate support surface 111a. The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Also, although not shown, the substrate support portion 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. Further, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0012] The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c. Further, the shower head 13 includes a conductive member. The conductive member of the shower head 13 functions as an upper electrode. The shower head 13 includes an electrode plate 13A, a cooling plate 13B, and a heater 13C. The cooling plate 13B includes a flow path 13r through which the heat transfer fluid supplied from the heat transfer fluid supply unit 50 flows. The heater 13C is supplied with power from the heater power supply unit 60. Note that the gas introduction unit may include, in addition to the shower head 13, one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0013] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one processing gas from the corresponding gas source 21 to the shower head 13 via the corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Further, the gas supply unit 20 may include one or more flow modulation devices that modulate or pulse the flow rate of at least one processing gas.

[0014] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to the conductive member of the substrate support 11 and / or the conductive member of the shower head 13. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Accordingly, the RF power supply 31 can function as at least a part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Also, by supplying a bias RF signal to the conductive member of the substrate support 11, a bias potential is generated on the substrate W, and the ion component in the formed plasma can be drawn into the substrate W.

[0015] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to the conductive member of the substrate support unit 11 and / or the conductive member of the shower head 13 via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support unit 11 and / or the conductive member of the shower head 13. The second RF generation unit 31b is coupled to the conductive member of the substrate support unit 11 via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a frequency lower than that of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to the conductive member of the substrate support unit 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0016] In addition, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to the conductive member of the substrate support unit 11 and is configured to generate a first DC signal. The generated first bias DC signal is applied to the conductive member of the substrate support unit 11. In one embodiment, the first DC signal may be applied to other electrodes such as the electrodes in the electrostatic chuck. In one embodiment, the second DC generation unit 32b is connected to the conductive member of the shower head 13 and is configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the shower head 13. In various embodiments, at least one of the first and second DC signals may be pulsed. Note that the first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0017] The exhaust system 40 can be connected to, for example, a gas outlet 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.

[0018] The heat transfer fluid supply unit 50 supplies the heat transfer fluid adjusted to the temperature set for the shower head 13. The heat transfer fluid supply unit 50 also recovers the heat transfer fluid that has passed through the shower head 13. Then, the heat transfer fluid supply unit 50 adjusts the recovered heat transfer fluid to the set temperature and supplies it to the shower head 13 again.

[0019] The heater power supply unit 60 supplies power to the heater 13C. The power supplied from the heater power supply unit 60 is controlled by the control unit 2.

[0020] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to execute various processes described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 so as to execute the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0021] <Plasma Processing Apparatus According to the Present Embodiment> The plasma processing apparatus according to the present embodiment will be described. The plasma processing apparatus according to the present embodiment includes a substrate support unit, an upper electrode unit provided to face the substrate support unit, and a control unit. The upper electrode unit in the plasma processing apparatus according to the present embodiment includes, in order from the side of the substrate support unit, an electrode plate, a cooling plate through which a heat transfer fluid flows inside, and a heater. The control unit in the plasma processing apparatus according to the present embodiment controls the output of the heater according to the amount of heat input from the plasma to the electrode plate.

[0022] The plasma processing apparatus according to the present embodiment will be described with reference to the drawings. FIG. 2 is a diagram for explaining a shower head 13 which is an example of the upper electrode unit in the plasma processing apparatus according to the present embodiment.

[0023] The shower head 13 includes an electrode plate 13A, a cooling plate 13B, and a heater 13C. The plasma processing apparatus 1 further includes a heat transfer fluid supply unit 50, a heater power supply unit 60, and a control unit 70 that controls the heat transfer fluid supply unit 50 and the heater power supply unit 60. Note that the control unit 70 may be included in the plasma processing apparatus 1, or the control unit 2 may perform the processing of the control unit 70.

[0024] (Electrode plate 13A) The electrode plate 13A functions as an upper electrode. The electrode plate 13A is provided on the plasma processing space 10s side in the shower head 13. The electrode plate 13A is formed of, for example, a semiconductor, such as silicon or silicon carbide. The electrode plate 13A is, for example, held on the outside by a holder and fixed to the cooling plate 13B. The electrode plate 13A is fixed so as to be in close contact with the cooling plate 13B in order to efficiently cool the electrode plate 13A by the cooling plate 13B.

[0025] (Cooling plate 13B) The cooling plate 13B cools the shower head 13, particularly the electrode plate 13A. The cooling plate 13B has a flow path 13r through which the heat transfer fluid RF supplied from the heat transfer fluid supply unit 50 flows.

[0026] The cooling plate 13B is formed of a metal, such as an aluminum alloy.

[0027] The heat transfer fluid RF supplied from the heat transfer fluid supply unit 50 is heated while passing through the flow path 13r. Then, the heat transfer fluid RF heated by passing through the flow path 13r is recovered by the heat transfer fluid supply unit 50. The heat transfer fluid RF recovered by the heat transfer fluid supply unit 50 is adjusted to a set temperature and then supplied to the cooling plate 13B again.

[0028] The heat transfer fluid supply unit 50 is controlled by the control unit 70. The control unit 70 controls, for example, the temperature and flow rate of the heat transfer fluid RF supplied from the heat transfer fluid supply unit 50 to the shower head 13.

[0029] The heat transfer fluid RF is a liquid, for example, brine, water, an aqueous solution of calcium chloride, an aqueous solution of ethylene glycol, alcohol, silicone oil, or the like. The heat transfer fluid RF may also be a gas, for example, air, helium gas, nitrogen gas, or the like.

[0030] Note that the shower head 13 may be provided with a heat transfer member that promotes heat transfer between the electrode plate 13A and the cooling plate 13B.

[0031] (Heater 13C) The heater 13C heats the shower head 13. The heater 13C is, for example, an electric heater. The heater 13C is provided on the side far from the plasma treatment space 10s in the cooling plate 13B.

[0032] The heater 13C is supplied with power from the heater power supply unit 60. The heater 13C generates heat by the power supplied from the heater power supply unit 60 and heats the cooling plate 13B.

[0033] The heater power supply unit 60 is controlled by the control unit 70. The control unit 70 controls, for example, the power HP supplied from the heater power supply unit 60 to the heater 13C.

[0034] [Deformation due to heat in the upper electrode portion] Next, the deformation due to heat in the upper electrode portion in the plasma processing apparatus according to the present embodiment will be described. Each of FIGS. 3 and 4 is a diagram for explaining the deformed state due to heat of a shower head 13 which is an example of the upper electrode portion in the plasma processing apparatus according to the present embodiment. FIG. 3 is a diagram showing the influence of heat from the heater 13C. FIG. 4 is a diagram showing the influence of heat from the plasma.

[0035] First, the influence of the heat from the heater 13C will be described. As shown in FIG. 3, when the heat Qh from the heater 13C enters the cooling plate 13B, due to the heat Qh from the heater 13C, as shown by the arrow Du1, the upper side of the shower head 13 expands due to heat. On the other hand, the lower side of the shower head 13 expands to a smaller degree compared to the upper side as shown by the arrow Dd1. Due to this difference in the amount of expansion between the upper and lower sides, the surface of the cooling plate 13B that contacts the electrode plate 13A is deformed so as to be convex upward as shown by the line LD1.

[0036] For example, due to the heat from the heater 13C, the cooling plate 13B deflects upward by about several hundred micrometers at the center compared to the outer side.

[0037] Next, the influence of the heat from the plasma will be described. As shown in FIG. 4, when heat enters the cooling plate 13B from the plasma through the electrode plate 13A, due to the heat Qp from the plasma, as shown by the arrow Dd2, the lower side of the shower head 13 expands due to heat. On the other hand, the upper side of the shower head 13 expands to a smaller degree compared to the lower side as shown by the arrow Du2. Due to this difference in the amount of expansion between the upper and lower sides, the surface of the cooling plate 13B that contacts the electrode plate 13A is deformed so as to be convex downward as shown by the line LD2.

[0038] For example, due to the heat from the plasma, the cooling plate 13B deflects downward by about several hundred micrometers at the center compared to the outer side.

[0039] When the cooling plate 13B is deformed by heat, the contact between the cooling plate 13B and the electrode plate 13A may become weak. When the contact between the cooling plate 13B and the electrode plate 13A becomes weak, the efficiency of cooling the electrode plate 13A with the cooling plate 13B decreases. When the efficiency of cooling the electrode plate 13A with the cooling plate 13B decreases, the cooling plate 13B may not be able to sufficiently cool the electrode plate 13A, and the temperature of the electrode plate 13A may rise.

[0040] As described above, the deformation of the cooling plate 13B due to the heat from the plasma is opposite in tendency to the deformation of the cooling plate 13B due to the heat from the heater 13C. Therefore, the inventors have found that the deformation of the cooling plate 13B due to the heat from the plasma can be suppressed by heating the cooling plate 13B from the plasma with the heater 13C.

[0041] In the plasma processing apparatus according to the present embodiment, the output of the heater is controlled according to the amount of heat input from the plasma to the upper electrode portion. By controlling the output of the heater according to the amount of heat input from the plasma to the upper electrode portion, the deformation of the cooling plate due to the heat from the plasma can be offset by the deformation due to the heat from the heater, and the deformation of the cooling plate can be suppressed.

[0042] In the plasma processing apparatus according to the present embodiment, since the plasma processing space is a vacuum environment and the outside of the plasma processing space is an atmospheric pressure environment, the upper electrode portion may be deformed so as to be convex downward. In the plasma processing apparatus according to the present embodiment, by providing the heater, the influence on the deformation of the upper electrode portion due to the atmospheric pressure can also be suppressed.

[0043] [Position of the flow path in the cooling plate] Regarding the upper electrode portion in the plasma processing apparatus according to the present embodiment, the position of the flow path in the cooling plate will be described. Each of FIGS. 5 to 7 is a diagram for explaining the position of the flow path with respect to the upper electrode portion in the plasma processing apparatus according to the present embodiment. For each of FIGS. 5 to 7, an explanation will be given using a model assuming the upper electrode portion.

[0044] (1) When the flow path is on the heater side The upper electrode portion MD1 in FIG. 5 is a model showing an example of the upper electrode portion in the plasma processing apparatus according to the present embodiment, and includes an electrode plate CEL, a cooling plate CP1, and a heater HTR.

[0045] The upper electrode part MD1 is provided with the flow path FP1 in the cooling plate CP1 on the side of the heater HTR. Let the distance from the heater HTR to the flow path FP1 in the cooling plate CP1 be the distance L11. Let the distance from the electrode plate CEL to the flow path FP1 in the cooling plate CP1 be the distance L12. In the upper electrode part MD1, as shown in Equation 1, it is assumed that the distance L12 is three times the distance L11.

[0046] L12 = 3×L11 ··· Equation 1

[0047] Heat of the calorific value Pw1 from the plasma enters the upper electrode part MD1 from the side of the electrode plate CEL. For the heater HTR, heat of the calorific value Hw1 enters the cooling plate CP1. As shown in Equation 2, it is assumed that the calorific value Pw1 is three times the calorific value Hw1.

[0048] Pw1 = 3×Hw1 ··· Equation 2

[0049] When plasma is generated, the temperature T12 on the side of the electrode plate CEL in the cooling plate CP1 becomes very high compared to the temperature T11 on the side of the heater HTR in the cooling plate CP1 (Equation 3).

[0050] T12 >>> T11 ··· Equation 3

[0051] Let the width of the cooling plate CP1 be L, and the coefficient of thermal expansion of the cooling plate CP1 be α. Then, the lower width of the cooling plate CP1 is L + α×T12×L, and the upper width is L + α×T11×L. Since Equation 4 holds from Equation 3, the cooling plate CP1 strongly bends downward.

[0052] L + α×T12×L >>> L + α×T11×L ··· Equation 4

[0053] (2) When the flow path is in the middle between the heater and the electrode plate The upper electrode part MD2 in FIG. 6 is a model showing an example of the upper electrode part in the plasma processing apparatus according to the present embodiment, and includes an electrode plate CEL, a cooling plate CP2, and a heater HTR.

[0054] The upper electrode part MD2 is provided with the flow path FP2 in the cooling plate CP2 in the middle between the heater HTR and the electrode plate CEL. Let the distance from the heater HTR to the flow path FP2 in the cooling plate CP2 be the distance L21. Let the distance from the electrode plate CEL to the flow path FP2 in the cooling plate CP2 be the distance L22. In the upper electrode part MD2, as shown in Equation 5, it is assumed that the distance L22 is equal to the distance L21.

[0055] L22 = L21 ··· Equation 5

[0056] Heat of the heat quantity Pw2 from the plasma enters the upper electrode part MD2 from the electrode plate CEL side. Heat of the heat quantity Hw2 enters the cooling plate CP2 from the heater HTR. As shown in Equation 6, it is assumed that the heat quantity Pw2 is three times the heat quantity Hw2.

[0057] Pw2 = 3×Hw2 ··· Equation 6

[0058] When plasma is generated, the temperature T22 on the electrode plate CEL side in the cooling plate CP2 becomes higher compared to the temperature T21 on the heater HTR side in the cooling plate CP2 (Equation 7).

[0059] T22 >> T21 ··· Equation 7

[0060] Let the width of the cooling plate CP2 be L, and the coefficient of thermal expansion in the cooling plate CP2 be α. Then, the lower width in the cooling plate CP2 is L + α×T22×L, and the upper width is L + α×T21×L. Since Equation 8 holds from Equation 7, the cooling plate CP2 is bent downward. On the other hand, the degree of downward bending is smaller than that of the cooling plate CP1.

[0061] L + α×T22×L >> L + α×T21×L ··· Equation 8

[0062] (3) When the flow path is on the electrode plate side The upper electrode portion MD3 in FIG. 7 is a model showing an example of the upper electrode portion in the plasma processing apparatus according to the present embodiment, and includes an electrode plate CEL, a cooling plate CP3, and a heater HTR.

[0063] The upper electrode portion MD3 provides a flow path FP3 in the cooling plate CP3 on the electrode plate CEL side. Let the distance from the heater HTR to the flow path FP3 in the cooling plate CP3 be the distance L31. Let the distance from the electrode plate CEL to the flow path FP3 in the cooling plate CP3 be the distance L32. In the upper electrode portion MD3, as shown in Equation 9, it is assumed that the distance L31 is three times the distance L32.

[0064] L31 = 3×L32 ··· Equation 9

[0065] Heat of the heat quantity Pw3 from the plasma enters the upper electrode portion MD3 from the electrode plate CEL side. Heat of the heat quantity Hw3 enters the cooling plate CP3 from the heater HTR. As shown in Equation 10, it is assumed that the heat quantity Pw3 is three times the heat quantity Hw3.

[0066] Pw3 = 3×Hw3 ··· Equation 10

[0067] When plasma is generated, the temperature T32 on the electrode plate CEL side of the cooling plate CP3 becomes slightly higher than the temperature T31 on the heater HTR side of the cooling plate CP3 (Equation 11).

[0068] T32 > T31 ··· Equation 11

[0069] Let the width of the cooling plate CP3 be L and the coefficient of thermal expansion of the cooling plate CP3 be α. Then, the lower width of the cooling plate CP3 is L + α×T32×L, and the upper width is L + α×T31×L. Since Equation 12 holds from Equation 11, the cooling plate CP3 bends downward. On the other hand, the degree of downward bending is smaller than that of the cooling plate CP2.

[0070] L + α×T32×L > L + α×T31×L ··· Equation 12

[0071] Therefore, in the above example, since the amount of heat by the plasma is three times the amount of heat by the heater, it is desirable that the distance from the heater to the flow path in the cooling plate is more than three times the distance from the electrode plate to the flow path in the cooling plate.

[0072] Also, from the above, it is desirable that the flow path in the cooling plate is provided closer to the electrode plate than the heater in the cooling plate.

[0073] In the above example, an example where the amount of heat by the plasma is three times the amount of heat by the heater has been described, but the amount of heat by the plasma is not limited to three times the amount of heat by the heater. When the amount of heat by the plasma is a predetermined constant multiple of the amount of heat by the heater, the distance from the heater to the flow path in the cooling plate may be more than the said constant multiple of the distance from the electrode plate to the flow path in the cooling plate. For example, when the amount of heat by the plasma is α times (α is a real number greater than 1) the amount of heat by the heater, the distance from the heater to the flow path in the cooling plate may be more than α times the distance from the electrode plate to the flow path in the cooling plate. In other words, the distance from the heater to the flow path in the cooling plate may be made longer than the distance obtained by multiplying the distance from the electrode plate to the flow path in the cooling plate by the ratio of the amount of heat from the plasma to the amount of heat from the heater.

[0074] [Operation of the Plasma Processing Apparatus According to the Present Embodiment] Next, the operation of the plasma processing apparatus according to the present embodiment will be described. By describing the operation of the plasma processing apparatus according to the present embodiment, the control method of the plasma processing apparatus according to the present embodiment will be described. FIG. 8 is a diagram for explaining the operation of a plasma processing apparatus 1 which is an example of the plasma processing apparatus according to the present embodiment. Also, for comparison, FIG. 9 shows a diagram for explaining the operation of the plasma processing apparatus of the reference example.

[0075] The horizontal axis in each of FIGS. 8 and 9 conceptually represents time, and the vertical axis represents measured values and the like. In FIGS. 8 and 9, tp on the horizontal axis indicates the time when plasma generation starts. The signs on the vertical axis in FIGS. 8 and 9 will be described. Tcp indicates the temperature of the cooling plate 13B. Qh indicates the power supplied from the heater power supply unit 60 to the heater 13C. Tce indicates the temperature of the electrode plate 13A. Qp indicates the heat input from the plasma. Vrf indicates the flow rate of the heat transfer fluid RF.

[0076] In the plasma processing apparatus according to the present embodiment shown in FIG. 8, when there is heat input from the plasma, the control unit 70 controls the heater power supply unit 60 to heat the cooling plate 13B with the heater 13C in order to reduce the warping of the cooling plate 13B. When the control unit 70 controls the heater power supply unit 60 to heat the cooling plate 13B with the heater 13C, the warping of the cooling plate 13B is reduced, and by efficiently cooling the electrode plate 13A, the temperature or the difference in in-plane temperature of the electrode plate 13A can be reduced.

[0077] The control unit 70 controls the heater power supply unit 60 to adjust the power supplied from the heater power supply unit 60 to the heater 13C so as to reduce the deformation of the cooling plate 13B. In FIG. 8, as indicated by the arrow B, based on the heat input of the plasma, the power supplied from the heater power supply unit 60 to the heater 13C is adjusted. After plasma generation, the control unit 70 controls to increase the output of the heater 13C. More specifically, when the amount of heat input to the shower head 13 increases, the control unit 70 controls the heater power supply unit 60 to increase the output of the heater 13C. Then, as indicated by the arrow A at Tcp, which is the temperature of the cooling plate 13B, the cooling plate 13B becomes higher.

[0078] On the one hand, by introducing heat from the heater 13C, the deformation of the cooling plate 13B is reduced. Since the deformation of the cooling plate 13B is small, the electrode plate 13A can be cooled while being in sufficient contact with the cooling plate 13B. Therefore, the temperature Tce indicating the temperature of the electrode plate 13A can be lowered as indicated by the arrow C.

[0079] Here, the plasma processing apparatus of the reference example will be described. In the plasma processing apparatus of the reference example shown in FIG. 9, the temperature of the cooling plate 13B is controlled to be constant as indicated by the arrow X at Tcp, which is the temperature of the cooling plate 13B. Therefore, in the plasma processing apparatus of the reference example, when plasma is generated, the power Qh supplied from the heater power supply unit 60 to the heater 13C is reduced as indicated by the arrow Y in a manner that cancels out the heat input from the plasma. As described above, without the heat input from the heater 13C, the cooling plate 13B is deformed convexly upward, so the contact between the electrode plate 13A and the cooling plate 13B becomes weak. Therefore, the temperature Tce indicating the temperature of the electrode plate 13A increases as indicated by the arrow Z.

[0080] When comparing Tce in FIG. 8 and Tce in FIG. 9, the portion indicated by the arrow C is lower than the portion indicated by the arrow Z. That is, according to the plasma processing apparatus according to the present embodiment, the deformation of the cooling plate can be reduced. And according to the plasma processing apparatus according to the present embodiment, by reducing the deformation of the cooling plate, the electrode plate can be cooled more efficiently.

[0081] According to the plasma processing apparatus according to the present embodiment, it is possible to suppress the deformation of the upper electrode portion due to the heat input from the plasma. The plasma processing apparatus according to the present embodiment can efficiently cool the electrode plate and reduce the temperature of the electrode plate by suppressing the deformation of the upper electrode portion due to the heat input from the plasma.

[0082] According to the plasma processing apparatus according to the present embodiment, by arranging the flow path in the cooling plate on the electrode plate side, it is possible to further suppress deformation due to heat input from the plasma of the cooling plate.

[0083] The plasma processing apparatus according to the present embodiment disclosed this time should be considered to be illustrative in all respects and not restrictive. The above embodiment can be modified and improved in various forms without departing from the scope and gist of the appended claims. Matters described in the above plurality of embodiments can also adopt other configurations and can be combined within a non - conflicting range.

Explanation of Reference Numerals

[0084] 1 Plasma processing apparatus 11 Substrate support part 13 Shower head 13A Electrode plate 13B Cooling plate 13C Heater 13r Flow path 50 Heat transfer fluid supply part 60 Heater power supply part 70 Control part

Claims

1. a substrate support section, an upper electrode section provided to face the substrate support section, a control section, and comprising, the upper electrode section includes, in order from the side of the substrate support section, an electrode plate, a cooling plate through which a heat transfer fluid flows inside, and a heater, the control section controls the output of the heater according to the amount of heat input from the plasma to the upper electrode section, a plasma processing apparatus.

2. the control section controls so as to increase the output of the heater when the amount of heat input from the plasma to the upper electrode section increases, the plasma processing apparatus according to Claim 1.

3. the cooling plate has a flow path through which the heat transfer fluid flows, the flow path is provided closer to the electrode plate than the heater in the cooling plate, the plasma processing apparatus according to Claim 2.

4. the distance from the heater to the flow path in the cooling plate is longer than the distance from the electrode plate to the flow path in the cooling plate multiplied by the ratio of the amount of heat from the plasma to the amount of heat from the heater, the plasma processing apparatus according to Claim 3.

5. the control section controls so as to increase the output of the heater after plasma generation, the plasma processing apparatus according to any one of Claims 1 to 4.

6. the cooling plate is formed of metal, the electrode plate is formed of semiconductor, the plasma processing apparatus according to any one of Claims 1 to 4.

7. a control method in a plasma processing apparatus comprising a substrate support section, an upper electrode section provided to face the substrate support section, and a control section, the upper electrode section including, in order from the side of the substrate support section, an electrode plate, a cooling plate through which a heat transfer fluid flows inside, and a heater, wherein the output of the heater is controlled according to the amount of heat input from the plasma to the upper electrode section, a control method of a plasma processing apparatus.

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