Holder temperature detection method, holder monitoring method, and substrate processing apparatus

Abstract

To provide a holder temperature detection method for measuring a temperature of a rotatable holder, a holder monitoring method and a substrate processing apparatus.SOLUTION: The present invention discloses a holder temperature detection method for measuring a temperature of a rotatable holder that holds a substrate. The method comprises a step of irradiating a fluorescent body thermally mounted on the holder with a light pulse having a first wavelength, a step of detecting fluorescence having a second wavelength emitted from the fluorescent body due to the light pulse and a step of estimating the temperature of the holder on the basis of, the detected fluorescence.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a holder temperature detection method, a holder monitoring method, and a substrate processing apparatus. [Background technology]

[0002] There is known a substrate processing apparatus in which a holder for holding a substrate is configured to be rotatable. Patent Document 1 discloses a movable body structure including a processing vessel configured to enable processing in a vacuum environment, a fixed part disposed in the processing vessel, a movable part provided movably relative to the fixed part, a transceiver module provided on the fixed part and having an airtight sealing structure, and a sensor module provided on the movable part and having an airtight sealing structure, in which the transceiver module and the sensor module transmit and receive signals in a non-contact manner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-178163 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the substrate processing apparatus, it is necessary to detect the temperature of a rotatable holder.

[0005] In response to the above-mentioned problems, an object of one aspect is to provide a holder temperature detection method for detecting the temperature of a rotatable holder, a holder monitoring method, and a substrate processing apparatus. [Means for solving the problem]

[0006] In order to solve the above problem, according to one aspect, there is provided a holder temperature detection method for measuring a temperature of a rotatable holder that holds a substrate, the holder comprising: the surface opposite to the surface for holding the substrate Thermally attached to a phosphor, a light source that irradiates a light pulse of a first wavelength, a detector that detects fluorescence of a second wavelength emitted from the phosphor, and an optical waveguide having one end disposed apart from the phosphor and the other end connected to the light source and the detector,To phosphor The above First wavelength The above A step of irradiating a light pulse and emitting light from the phosphor due to the light pulse. The above Second Wavelength The above A holder temperature detection method is provided, comprising the steps of detecting fluorescence and estimating a temperature of the holder based on the detected fluorescence. Effect of the Invention

[0007] According to one aspect, it is possible to provide a holder temperature detection method for detecting the temperature of a rotatable holder, a holder monitoring method, and a substrate processing apparatus. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an example of a substrate processing apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a vertical cross-sectional view showing an example of a substrate processing apparatus according to an embodiment of the present invention. [Diagram 3] 13 is an example of a flowchart illustrating a method for monitoring a holder. [Figure 4] 13 is a graph showing an example of temperature change when the thermal conductivity between the holder and the substrate is a reference value. [Diagram 5] 13 is a graph showing an example of temperature change when the thermal conductivity between the holder and the substrate is 50% of the reference value. [Figure 6] 1 is an example of a graph showing a change in temperature of a substrate. [Figure 7] 1 is an example graph showing a predicted time required to cool a substrate. [Figure 8] 13 is an example of a graph showing an increase in integral value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this specification and the drawings, substantially the same components are designated by the same reference numerals, and redundant description will be omitted.

[0010] <Substrate processing equipment> The substrate processing apparatus 100 according to this embodiment will be described with reference to Figs. 1 and 2. Figs. 1 and 2 are vertical cross-sectional views showing an example of the substrate processing apparatus 100 according to this embodiment. Fig. 1 shows a state in which the contact plate 37 of the refrigeration device 30 is separated from the holder 21. Fig. 2 shows a state in which the contact plate 37 of the refrigeration device 30 is in contact with the holder 21.

[0011] The substrate processing apparatus 100 shown in FIG. 1 is, for example, a PVD (Physical Vapor Deposition) apparatus that forms a film on a substrate W, such as a semiconductor wafer, which is a processing target, inside a processing vessel 10 that forms an ultra-high vacuum and extremely low temperature atmosphere and performs substrate processing using a processing gas. Here, the ultra-high vacuum is, for example, 10 -5 The term "extremely low temperature" refers to a pressure atmosphere of less than or equal to Pa, and "extremely low temperature" refers to a temperature atmosphere of less than -30°C, for example, about -200°C.

[0012] The substrate processing apparatus 100 includes a processing vessel 10, a holder 21 that holds a substrate W inside the processing vessel 10, a refrigeration device 30, a rotation support part 40 that rotatably supports the holder 21, a first lifting device 50 that lifts and lowers the holder 21, and a second lifting device 60 that lifts and lowers the refrigeration device 30. Although the substrate processing apparatus 100 shown in Figs. 1 and 2 will be described as including two lifting devices, the first lifting device 50 that lifts and lowers the holder 21 and the second lifting device 60 that lifts and lowers the refrigeration device 30, the holder 21 and the refrigeration device 30 may be lifted and lowered by a common lifting device.

[0013] Inside the processing vessel 10, a holder 21 is disposed at the bottom. Moreover, above the holder 21, a plurality of target holders 12 are fixed at a predetermined inclination angle θ with respect to the horizontal plane. A target T is attached to the bottom surface of each target holder 12. Note that in FIGS. 1 and 2, the number of target holders 12 may be one, or may be three or more. Moreover, the material of the target may be different for each target holder 12, or may be the same.

[0014] The processing vessel 10 is configured so that the inside thereof can be depressurized to an ultra-high vacuum by operating an exhaust device (not shown) such as a vacuum pump. Furthermore, a processing gas (e.g., a rare gas such as argon (Ar), krypton (Kr), or neon (Ne), or nitrogen (N2) gas) required for sputtering film formation is supplied to the processing vessel 10 through a gas supply pipe (neither of which is shown) that communicates with a processing gas supply device.

[0015] An AC or DC voltage is applied to the target holder 12 from a plasma generation power supply (not shown). When the AC voltage is applied from the plasma generation power supply to the target holder 12 and the target T, plasma is generated inside the processing vessel 10, the rare gas and the like inside the processing vessel 10 are ionized, and the target T is sputtered by the ionized rare gas elements and the like. The sputtered atoms or molecules of the target T are deposited on the surface of the substrate W held by the holder 21 facing the target T.

[0016] By tilting the target T with respect to the substrate W, the incident angle of the sputtered particles sputtered from the target T onto the substrate W can be adjusted, and the in-plane uniformity of the thickness of the film formed on the substrate W can be improved. Even if each target holder 12 is installed at the same tilt angle θ inside the processing vessel 10, the incident angle of the sputtered particles onto the substrate W can be changed by raising and lowering the holder 21 to change the distance between the target T and the substrate W. Therefore, the holder 21 is controlled to be raised and lowered for each target T to be applied so as to achieve a distance suitable for each target T.

[0017] The holder 21 is made of a material having high thermal conductivity (eg, Cu) and is formed into a disk shape.

[0018] An ESC plate 22 is provided on the upper surface side of the holder 21. The ESC plate 22 has a chuck electrode embedded in a dielectric. A predetermined potential is applied to the chuck electrode via wiring. With this configuration, the substrate W can be attracted by the electrostatic chuck and fixed to the upper surface of the holder 21.

[0019] A cylindrical stand 23 is provided on the lower surface side of the holder 21. The cylindrical stand 23 is made of a material with low thermal conductivity (e.g., austenitic stainless steel, ferritic stainless steel, etc.) and is formed into a cylindrical shape. The cylindrical stand 23 supports the holder 21. The cylindrical stand 23 divides a space 15a inside the cylindrical stand 23 and a space 15b outside the cylindrical stand 23. The holder 21, the ESC plate 22, and the cylindrical stand 23 form a rotating body 20 that rotates on a rotation axis CL. The cylindrical stand 23 may have a hollowed-out space in a cylindrical shape. This can further reduce the thermal conductivity of the cylindrical stand 23.

[0020] The refrigeration device 30 includes a cold head 31 , a cold link 32 , and a heat transfer plate assembly 33 .

[0021] The cold head 31 is supported by a support member 38. The cold head 31 is cooled by a refrigerator (not shown). From the viewpoint of cooling capacity, the refrigerator preferably uses a GM (Gifford-McMahon) cycle.

[0022] The cold link 32 is formed from the cold head 31 toward the holder 21. The cold link 32 is made of a material having high thermal conductivity (for example, Cu), and thermally connects the cold head 31 and the heat transfer plate assembly 33.

[0023] The heat transfer plate assembly 33 includes a plate 34, concentric bellows 35a and 35b, a plate 36, and a contact plate 37. The plate 34 is thermally connected to the cold link 32. The concentric bellows 35a and 35b thermally connect the plate 34 and the plate 36. The plate 36 is provided on its upper surface with a thermally connected contact plate 37.

[0024] With this configuration, the cold head 31 cools the contact plate 37 of the heat transfer plate assembly 33 to an extremely low temperature via the cold link 32 and the heat transfer plate assembly 33. In addition, by raising the support member 38 or lowering the holder 21, the contact plate 37 can be brought into contact with the rear surface of the holder 21. In addition, by lowering the support member 38 or raising the holder 21, the holder 21 and the contact plate 37 can be separated from each other.

[0025] The rotation support part 40 has an inner race member 41, a bearing 42, a bearing 43, and an outer race member 44. The bearing 42 is disposed between the inner race member 41 and the cylindrical stand 23. Furthermore, the bearing 43 is disposed between the outer race member 44 and the cylindrical stand 23. With this configuration, the cylindrical stand 23 is rotatably supported.

[0026] Furthermore, a bellows 45a is provided between the inner ring member 41 and the support member 38. A bellows 45b is provided between the outer ring member 44 and the bottom surface 11. The bearings 42, 43 rotatably support the cylindrical stand 23 and seal it with magnetic fluid. As a result, the space 15a in which the refrigeration device 30 is disposed is made airtight by the bearing 42 and the bellows 45a. Furthermore, the space 15b is made airtight by the bearing 43 and the bellows 45b.

[0027] Furthermore, the substrate processing apparatus 100 includes a rotation motor (not shown) that rotates the cylindrical stand 23. As a result, the rotation motor can rotate the holder 21 that rotates the cylindrical stand 23.

[0028] The first lifting device 50 lifts and lowers the cylindrical stand 23, the inner ring member 41, and the outer ring member 44, thereby lifting and lowering the holder 21.

[0029] The second lifting device 60 lifts and lowers the support member 38, thereby lifting and lowering the contact plate 37.

[0030] The vacuum pump 70 evacuates the space 15a through an opening (not shown) provided in the support member 38. In addition, the vacuum pump (not shown) evacuates the space 15a through an opening (not shown) provided in the support member 38.

[0031] The substrate processing apparatus 100 also includes a temperature detection unit that detects the temperature of the rotating holder 21. The temperature detection unit has phosphors 80a and 80b, a detection unit (one end of an optical waveguide) 81, an optical fiber (optical waveguide) 82, and a processing unit 83.

[0032] The phosphors 80a and 80b are provided on the surface of the holder 21. For example, the phosphors 80a and 80b are arranged in thermal connection to the rear side of the rotating holder 21 near the end. The phosphors 80a and 80b may be arranged on the rear side of the holder 21, as in the case of the phosphor 80a. The phosphors 80a and 80b may be arranged inside a recess formed on the rear side of the holder 21, as in the case of the phosphor 80b. The phosphors 80a and 80b may be formed on a metal pellet having high thermal conductivity, such as Cu or Al, and the metal pellet having the phosphor may be attached to the holder 21. The phosphors 80a and 80b may be arranged in a plurality of portions in the circumferential direction of the holder 21.

[0033] When irradiated with light of a first wavelength, the phosphors 80a and 80b are excited, emit light (fluorescence) of a second wavelength different from the first wavelength, and transition to the ground state. For example, YAG or the like can be used as the phosphors 80a and 80b.

[0034] The processing unit 83 is provided outside the processing vessel 10 and includes a light source (not shown) that irradiates pulsed light of a first wavelength and a detector (not shown) that detects light of a second wavelength. One end of an optical fiber (optical waveguide) 82 is connected to a detection section 81 in the processing vessel 10, and the other end is connected to the processing unit 83 (light source, detector) via a fitting 82a that penetrates the bottom surface 11 of the processing vessel 10. With this configuration, the light source of the processing unit 83 irradiates light 86a from the detection section 81 via the optical fiber 82. Also, light 86b incident on the detection section 81 is guided to the detection section of the processing unit 83 via the optical fiber 82.

[0035] The temperature detection unit also includes a position adjustment unit that adjusts the position of the detection unit 81. In the example shown in FIGS. 1 and 2, the position adjustment unit includes a support member 84 and an abutment member 85. The support member 84 stands upright from the outer ring member 44 and supports the detection unit 81 so as to be movable in the vertical direction. Specifically, the detection unit 81 is inserted into a hole 84a provided in the support member 84, and the detection unit 81 is supported so as to be movable in the vertical direction. The abutment member 85 stands upright from the bottom surface 11 of the processing vessel 10. As a result, in the state shown in FIG. 1, the enlarged diameter portion of the detection unit 81 engages with the edge of the hole 84a, so that the distance 87 from the phosphor 80a to the detection unit 81 is maintained. On the other hand, in the state shown in FIG. 2, the bottom of the detection unit 81 engages with the abutment member 85, so that the detection unit 81 is pushed up from the hole 84a, and the distance 87 from the phosphor 80b to the detection unit 81 is maintained. In this way, the position adjustment unit can maintain a constant distance 87 from the phosphors 80a, 80b to the detection unit 81 by adjusting the position of the detection unit 81. Note that the distance 87 is preferably 1 mm or more and 50 mm or less, and more preferably 5 mm or more and 20 mm or less.

[0036] The substrate processing apparatus 100 also includes a control unit 90 that controls the entire substrate processing apparatus 100. The temperature of the holder 21 detected by a temperature detection unit (processing unit 83) is input to the control unit 90. The control unit 90 also controls a rotation motor (not shown) that rotates the cylindrical stand 23, the first lifting device 50, the second lifting device 60, and the like.

[0037] <Holder temperature detection method> First, the temperature detection of the holder 21 during rotation will be described with reference to Fig. 1. In a deposition process for depositing sputtered particles on the substrate W, the holder 21 moves away from the contact plate 37 and rotates, as shown in Fig. 1. When the holder 21 rotates, the phosphor 80a also rotates.

[0038] When the rotating holder 21 reaches a predetermined angle and the phosphor 80a and the detection unit 81 are aligned (in other words, when the phosphor 80a reaches the irradiation direction and detection direction of the detection unit 81), the processing unit 83 irradiates the phosphor 80a with pulsed light of a first wavelength. Then, the processing unit 83 detects the fluorescence of a second wavelength from the phosphor 80a. Then, the processing unit 83 estimates the temperature of the holder 21 based on the detected fluorescence.

[0039] Here, the phosphor 80a irradiated with the pulsed light of the first wavelength radiates fluorescence of the second wavelength while the intensity is attenuating. The attenuation of the intensity of the fluorescence emitted by the phosphor 80a depends on the temperature of the phosphor 80a (in other words, the temperature of the holder 21). The processing unit 83 calculates a decay time constant based on the detected attenuation of the intensity of the fluorescence. The processing unit 83 also stores in advance a table that associates the decay time constant with the temperature of the holder 21. The processing unit 83 estimates (detects) the temperature of the holder 21 based on the table and the calculated attenuation time constant.

[0040] It is preferable that the phosphor 80a is made of a material whose fluorescence intensity decays in a short time (for example, 1 to 10 ms) at cryogenic temperatures. This can shorten the detection time. It is also possible to suppress changes in the optical path length from the phosphor 80a to the detection unit 81 caused by the movement of the phosphor 80a (rotation of the holder 21). The intensity of the detected fluorescence may be corrected based on the positional and angular relationship between the phosphor 80a and the detection unit 81.

[0041] Furthermore, by providing a plurality of phosphors 80a in the circumferential direction, the temperature of the holder 21 can be detected periodically according to the rotation speed of the holder 21 and the number of phosphors 80a.

[0042] Furthermore, a plurality of detectors 81 may be provided in an arc shape centered on the rotation axis CL. This allows the temperature of holder 21 to be suitably detected even in a configuration in which holder 21 rotates at a high speed or in which phosphor 80a whose fluorescence intensity decay time is long is used.

[0043] In addition, the processing unit 83 has been described as estimating the temperature based on the temperature dependence of the intensity attenuation of the fluorescent light, but this is not limiting. The temperature of the holder 21 may be estimated based on the temperature dependence of other optical properties of the fluorescent light (for example, the band edge of Si, etc.).

[0044] Next, the temperature detection of the holder 21 during cooling will be described with reference to Fig. 2. During the cooling process, the holder 21 descends L1 at a rotation angle at which the phosphor 80b and the detection unit 81 are aligned. As a result, the holder 21 comes into contact with the contact plate 37 as shown in Fig. 2, and is cooled.

[0045] The processing unit 83 irradiates the phosphor 80b with pulsed light of a first wavelength. Then, the processing unit 83 detects the fluorescence of a second wavelength from the phosphor 80b. Then, the processing unit 83 estimates the temperature of the holder 21 based on the detected fluorescence.

[0046] Here, the phosphor 80b is disposed in a recessed portion of the holder 21. This allows the temperature of the holder 21 to be measured at a position closer to the substrate W. Therefore, when estimating the temperature of the substrate W based on the detected temperature of the holder 21, the estimation accuracy can be improved.

[0047] Furthermore, the distance 87 from phosphor 80b to detection unit 81 shown in FIG. 2 is maintained at the distance 87 from phosphor 80a to detection unit 81 shown in FIG. 1 by the position adjustment unit (support member 84, contact member 85). This makes it possible to equalize the effect of intensity attenuation due to the optical path length from phosphors 80a, 80b to detection unit 81. Therefore, even in the state of FIG. 2, the temperature of holder 21 can be detected in the same way as in the state of FIG. 1.

[0048] As described above, according to the substrate processing apparatus 100 of this embodiment, the temperature of the holder 21 can be detected by using the temperature detection section (phosphors 80a, 80b, detection section 81, optical fiber 82, and processing unit 83).

[0049] Incidentally, as a method for measuring the temperature of a rotating body, a configuration is known in which an element for measuring the temperature is provided inside the rotating body, and the temperature is measured from the outside via a slip ring having a conductive ring and a sliding contact. However, in the substrate processing apparatus 100 according to this embodiment, since the diameter of the rotating body 20 is large, it is difficult to apply a slip ring. In addition, since the holder 21 is cooled to an extremely low temperature, it is also difficult to measure the temperature of the holder 21 using a pyrometer.

[0050] In contrast, the temperature detection unit of this embodiment can detect the temperature of the holder 21 without contact between the phosphors 80a, 80b provided on the rotating holder 21 and the detection unit 81. Furthermore, the temperature detection unit of this embodiment can detect the temperature of the holder 21 that is cooled to an extremely low temperature.

[0051] <Holder monitoring> Next, monitoring of the holder 21 will be described with reference to Fig. 3. Fig. 3 is an example of a flowchart illustrating a method for monitoring the holder 21. Here, a case will be described in which the control unit 90 monitors the heat transfer state between the holder 21 and the substrate W and performs a film formation process.

[0052] In step S101, the holder 21 is rotated to a rotation angle φ0. Here, the substrate processing apparatus 100 has an encoder (not shown) that detects the rotation angle of the holder 21. The angle detected by the encoder is input to the control unit 90. The control unit 90 controls a rotation motor (not shown) to rotate the holder 21 to the rotation angle φ0. The rotation angle φ0 is the rotation angle of the holder 21 at which the phosphor 80b is aligned with the detection unit 81.

[0053] In step S102, the contact plate 37 is brought into contact with the holder 21. Here, the control unit 90 controls the first lifting device 50 to lower the holder 21. This brings the state of the substrate processing apparatus 100 into the state shown in FIG.

[0054] In step S103, the temperature of the holder 21 is cooled to a predetermined temperature T0. The cold head 31 and the holder 21 are thermally connected via the cold link 32 and the heat transfer plate assembly 33, and cooling of the holder 21 begins. Here, the processing unit 83 irradiates the phosphor 80b with pulsed light, and measures (estimates) the temperature of the holder 21 based on the detected fluorescence of the phosphor 80b. When the temperature of the holder 21 becomes equal to or lower than the predetermined temperature T0, the processing of the control unit 90 proceeds to step S104.

[0055] In step S104, the substrate W is placed and a heat transfer gas is supplied. The high-temperature substrate W is placed on the placement surface of the holder 21 by a transport device (not shown). The control unit 90 controls a power supply (not shown) that applies power to the electrodes of the ESC plate 22 to adsorb the substrate W to the ESC plate 22. The control unit 90 also controls a heat transfer gas supply unit (not shown) to supply a heat transfer gas (e.g., He gas) between the back surface of the substrate W and the upper surface of the ESC plate 22. The upper surface of the ESC plate 22 has a recess and a protrusion that stands in contact with the bottom surface of the recess, and the upper surface of the protrusion contacts the back surface of the substrate W. The heat transfer gas is supplied to a space formed by the back surface of the substrate W and the recess.

[0056] In step S105, an integral value E of the temperature change of the holder 21 from when the substrate W is placed until a predetermined time is calculated. Here, the processing unit 83 irradiates the phosphor 80b with pulsed light, and detects the temperature of the holder 21 based on the detected fluorescence of the phosphor 80b. The processing unit 83 also obtains the time change T(t) of the temperature of the holder 21 by repeating the temperature measurement in a predetermined cycle. The control unit 90 calculates the integral value E (=(T(t)-T0)Δt) based on the time change T(t) of the temperature of the holder 21, the initial temperature T0, and the duration Δt. Note that the integral value E is a value that depends on the heat transfer state between the holder 21 and the substrate W. If the heat transfer state between the holder 21 and the substrate W deteriorates, the integral value E becomes smaller.

[0057] In step S106, the control unit 90 determines whether the integral value E is equal to or greater than the threshold value E0. If the integral value E is equal to or greater than the threshold value E0 (S106: Yes), the control unit 90 proceeds to step S107. If the integral value E is not equal to or greater than the threshold value E0 (S106: No), the control unit 90 proceeds to step S111.

[0058] In step S107, the control unit 90 performs a film formation process. The control unit 90 controls the first lifting device 50 to lift the holder 21. Then, the control unit 90 controls a rotation motor (not shown) to rotate the holder 21. This brings the state of the substrate processing apparatus 100 into the state shown in FIG. 1. Then, a film is formed on the substrate W by discharging sputtered particles from the target T. Note that, the processing unit 83 irradiates pulsed light at a timing when the phosphor 80a rotating together with the holder 21 is placed on the detection unit 81, and measures (estimates) the temperature of the holder 21 based on the detected fluorescence of the phosphor 80a.

[0059] In step S108, the holder 21 is rotated to a rotation angle φ0. Here, the substrate processing apparatus 100 has an encoder (not shown) that detects the rotation angle of the holder 21. The angle detected by the encoder is input to the control unit 90. The control unit 90 controls a rotation motor (not shown) to rotate the holder 21 to the rotation angle φ0. The rotation angle φ0 is the rotation angle of the holder 21 at which the phosphor 80b is aligned with the detection unit 81.

[0060] In step S109, the contact plate 37 is brought into contact with the holder 21. Here, the control unit 90 controls the first lifting device 50 to lower the holder 21. This brings the state of the substrate processing apparatus 100 into the state shown in FIG.

[0061] In step S110, the substrate W is unloaded. The control unit 90 controls a power source (not shown) that applies power to the electrodes of the ESC plate 22 to release the suction of the substrate W by the ESC plate 22. Then, the substrate W is unloaded from the mounting surface of the holder 21 by a transport device (not shown).

[0062] When the next substrate W is loaded into the substrate processing apparatus 100, the process of the control unit 90 repeats steps S104 to S110.

[0063] In addition, in step S106, if the integral value E is not equal to or greater than the threshold value E0 (S106: No), the process of the control unit 90 proceeds to step S111. In step S111, the control unit 90 issues a warning.

[0064] Here, a simulation of a temperature change when a high-temperature substrate W is placed on the holder 21 will be described with reference to FIGS.

[0065] Fig. 4 is an example of a graph showing temperature change when the thermal conductivity between the holder 21 and the substrate W is a reference value. Fig. 5 is an example of a graph showing temperature change when the thermal conductivity between the holder 21 and the substrate W is 50% of the reference value.

[0066] 4 and 5, the vertical axis indicates temperature (K) and the horizontal axis indicates time. The time on the horizontal axis is set to 0 at the time when the substrate W is brought into contact with the holder 21. The dashed line indicates the temperature of the cold head 31. The dashed line indicates the temperature of the substrate W. The temperature curves T1 to T12 indicated by solid lines indicate the temperatures of each slice obtained by slicing the holder 21 in the plate thickness direction at a predetermined interval. Note that T1 is the temperature curve for the slice on the front side, and T12 is the temperature curve for the slice on the back side. The temperature T0 of the holder 21 and the cold head 31 before the substrate W is placed is set to 100K. In addition, in the reference value of the thermal conductivity in FIG. 4, the pressure of the heat transfer gas (He gas) filled between the ESC plate 22 and the substrate W is set to 6 Torr.

[0067] When a high-temperature substrate W is placed on the holder 21, the temperature curve T1 of the slice closest to the substrate W shows the highest temperature rise compared to the temperatures of the other slices. Also, the temperature curve T12 of the slice in contact with the cold head 31 is cooled to 100 K or less in response to the heat load of the substrate W.

[0068] FIG. 6 is an example of a graph showing the temperature change of the substrate W. In FIG.

[0069] 6, the vertical axis indicates temperature (K) and the horizontal axis indicates time. The time on the horizontal axis is set to 0 at the time when the substrate W is brought into contact with the holder 21. The temperature drop of the substrate W before contact is heat dissipation due to radiant heat. The pressures of the heat transfer gas (He gas) filled between the ESC plate 22 and the substrate W are also shown for 2 Torr, 3 Torr, 4 Torr, and 6 Torr.

[0070] 6, the cooling efficiency of the substrate W is improved by the pressure of the heat transfer gas. Also, the time required to cool the substrate W is shorter as the pressure of the heat transfer gas is higher.

[0071] FIG. 7 is an example of a graph showing a predicted time required to cool the substrate W. In FIG.

[0072] 7, the vertical axis indicates the predicted time required to cool the substrate W from 498 K to 101 K, and the horizontal axis indicates the thermal conductivity between the holder 21 and the substrate W. Note that the horizontal axis is normalized with the thermal conductivity at the reference value set to 1.

[0073] The thermal conductivity between the holder 21 and the substrate W depends on the pressure of the heat transfer gas (see FIG. 6) and the contact conditions between the convex parts of the ESC plate 22 and the rear surface of the substrate W. For example, the cooling efficiency is affected if the placement position of the substrate W is misaligned or if particles are present between the ESC plate 22 and the substrate W. In this case, there is a risk that sputtered particles will be deposited at a temperature higher than the design temperature in the film formation process (step S107).

[0074] Here, it is difficult to directly measure the temperature of the substrate W. The control unit 90 detects the temperature of the holder 21 and estimates the thermal conductivity between the holder 21 and the substrate W. By estimating the thermal conductivity, it is possible to confirm whether the substrate W is appropriately positioned and whether the substrate W and the holder 21 are in appropriate thermal contact with each other.

[0075] Here, as shown by comparing Figures 4 and 5, the temperature of the slices of holder 21 close to the contact surface with the substrate W increases at different rates depending on the gas conductance and also depending on the conductance between the substrate W and holder 21.

[0076] Moreover, the sum of the product of the temperature rise of the holder 21 and time (integral value E in step S105) is proportional to the energy required to cool the substrate W. This corresponds to the area surrounded by the temperature curve and temperature T0. As an example, in Figs. 4 and 5, the integral value E of the temperature change up to a predetermined time (e.g., 20 seconds) on the temperature curve T3 is shown shaded. The temperature of each slice of the holder eventually converges to 100K by the refrigeration device 30.

[0077] Fig. 8 is an example of a graph showing an increase in the integral value E. In Fig. 8, the vertical axis represents ΔT×Δt (=integral value E) and the horizontal axis represents time. Also shown are cases where the thermal conductivity is a reference value (Ref), and 85%, 65%, and 50% of the reference value.

[0078] The curves converge at about 60 seconds, but differences in thermal conductivity can be distinguished in a shorter time. That is, the temperature of the holder 21 is recorded chronologically, and the integral value E is evaluated in a short time (e.g., 20 seconds) (see step S106). This makes it possible to evaluate the thermal conductivity between the substrate W and the holder 21 without directly measuring the temperature of the substrate W.

[0079] Moreover, by providing phosphor 80b in a recess (for example, in the slice of temperature curve T3 in the example of Figs. 4 and 5), the temperature detection position can be brought closer to the mounting surface of substrate W, which is preferable. This makes it possible to increase the temperature rise after high-temperature substrate W is mounted on holder 21, and also increases the change in integral value E due to the change in thermal conductivity. This makes it possible to improve the accuracy of evaluation of the thermal conductivity between substrate W and holder 21.

[0080] If the integral value E calculated in step S105 is not equal to or greater than the threshold value E0 (S106: No), it is determined that the thermal conductivity between the substrate W and the holder 21 is poor, and an alarm can be issued (see step S111). This makes it possible to prevent deposition of sputtered particles at a temperature higher than the design temperature in the film formation process (step S107).

[0081] Although the substrate processing apparatus has been described above by way of the above-mentioned embodiment, the substrate processing apparatus according to the present invention is not limited to the above-mentioned embodiment, and various modifications and improvements are possible within the scope of the present invention. The matters described in the above-mentioned embodiments can be combined to the extent that they are not inconsistent. [Explanation of symbols]

[0082] W substrate 100 Substrate processing apparatus 21 Holder 22 ESC plate 23 Cylindrical stand 30 Refrigeration equipment 40 Rotation support part 50 First lifting device 60 Second lifting device 70 Vacuum Pump 80a, 80b Phosphor 81 Detection unit (one end of optical waveguide) 82 Optical Fiber (Optical Waveguide) 83 Processing Unit 84 Support member (position adjustment part) 85 Contact member (position adjustment part) 86a Light (first wavelength pulsed light) 86b Light (second wavelength fluorescence) 90 Control section

Claims

1. A holder temperature detection method for measuring a temperature of a rotatable holder for holding a substrate, comprising: a phosphor thermally attached to a surface of the holder opposite to a surface of the holder that holds the substrate; a light source that irradiates a light pulse of a first wavelength; a detector for detecting fluorescence of a second wavelength emitted from the phosphor; an optical waveguide having one end disposed apart from the phosphor and the other end connected to the light source and the detector; irradiating the phosphor with the light pulse at the first wavelength; detecting the fluorescence of the second wavelength emitted from the phosphor due to the light pulse; and estimating a temperature of the holder based on the detected fluorescence. Holder temperature detection method.

2. The distance between one end of the optical waveguide and the phosphor is 1 mm or more and 50 mm or less. The holder temperature detection method according to claim 1 .

3. the holder is rotated, and when the phosphor and one end of the optical waveguide are aligned, the light pulse is irradiated and the fluorescence is detected. The holder temperature detection method according to claim 1 or 2.

4. the phosphor has a first phosphor thermally attached to a surface of the holder opposite to a surface that holds the substrate, and a second phosphor thermally attached to a surface closer to the surface that holds the substrate than the opposite surface, a position adjustment unit that moves one end of the optical waveguide so that a distance from one end of the optical waveguide to the second phosphor becomes a distance from one end of the optical waveguide to the first phosphor; The holder temperature detection method according to any one of claims 1 to 3.

5. The step of estimating the temperature of the holder comprises: estimating a temperature of the holder based on the intensity decay of the fluorescent light; The holder temperature detection method according to any one of claims 1 to 4.

6. The step of estimating the temperature of the holder comprises: Calculating a decay time constant based on the intensity decay of the fluorescence; estimating the temperature of the holder based on the calculated decay time constant and a table in which the decay time constant corresponds to the temperature of the holder; The holder temperature detection method according to claim 5.

7. 1. A holder monitoring method for monitoring a heat transfer state between a substrate and a holder that holds the substrate, comprising the steps of: placing the substrate on the holder and introducing a heat exchange gas between the holder and the substrate; 7. The holder temperature detection method according to claim 1, further comprising the steps of: detecting the temperature of the holder; and calculating an integral value of a temperature change of the holder up to a predetermined time. evaluating a thermal conductivity between the holder and the substrate based on the integral value; A holder monitoring method comprising:

8. issuing an alarm based on said evaluation; The holder monitoring method according to claim 7.

9. A rotatable holder for holding a substrate; a phosphor thermally attached to a surface of the holder opposite to a surface of the holder that holds the substrate; a light source that irradiates the phosphor with a light pulse of a first wavelength; a detector for detecting fluorescence of a second wavelength emitted from the phosphor due to the light pulse; an optical waveguide having one end disposed apart from the phosphor and the other end connected to the light source and the detector; and a temperature detection unit that estimates the temperature of the holder based on the detected fluorescence. Substrate processing equipment.

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