Plasma processing apparatus and plasma processing method

Abstract

A plasma processing apparatus that improves yield includes a processing chamber disposed inside a vacuum vessel and forming plasma inside; a sample stage disposed inside the processing chamber and resting a wafer that is a processing target on an upper surface; a metal base material having a circular plate or a cylindrical shape disposed inside the sample stage; a refrigerant flow path that is concentrically disposed multiple times around a center of the base material inside and circulating a refrigerant adjusted to a predetermined temperature inside; at least one temperature sensor disposed between the refrigerant flow path and an upper surface of the base material and detecting temperature; and a controller that detects temperature of the base material or the wafer being processed that is resting on the sample stage using output from the temperature sensor. The controller detects temperature of the base material or the wafer based on a linear function that represents a relationship between an error that is a difference between temperature obtained from the output of the temperature sensor and actual temperature of the base material or the wafer when the error is set, the linear function being different for each region of a plurality of continuous temperature ranges within a range of adjustable temperature of the refrigerant, a plurality of the linear functions containing the same coefficient and having a point at which the error is zero.

Description

TECHNICAL FIELD

[0001] The present application relates to a plasma processing apparatus and a plasma processing method. BACKGROUND

[0002] A plasma processing apparatus is known, which is provided with: a processing chamber arranged inside a vacuum container; and a sample stage of a substrate shape on which a sample such as a semiconductor wafer is placed on an upper surface thereof, arranged in a lower portion of the processing chamber, and which processes the sample using plasma formed in the processing chamber.

[0003] An example of such a plasma processing apparatus is disclosed in Patent Literature 1. In the disclosed plasma processing apparatus, inside a base material of a circular plate or a cylindrical shape made of metal, which constitutes a sample stage arranged inside a processing chamber of a vacuum container, a refrigerant flow path is arranged concentrically and in multiple layers, through which a refrigerant flows on the inside, and a plurality of temperature sensors that detect the temperature of the base material are arranged. The temperature sensors are inserted into the upper end portions of sensor holes, which extend from the bottom surface of the base material through the multiple refrigerant flow paths to the portions between the upper ends of the refrigerant flow paths and the upper surface of the base material, and the temperature of a sample placed on the upper surface of the base material or the upper surface of a dielectric film such as ceramic covering the upper surface of the base material can be detected based on the outputs detected by the temperature sensors at the portions of the upper ends of the holes.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: JP Patent Publication No. 2018-120881 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In the above-described prior art, the following problems arise.

[0009] Specifically, in order to achieve high integration of semiconductor devices in recent years, the processing conditions of semiconductor wafers used to manufacture the devices have become wider. For example, the types of materials of film layers that become the objects of processing have also increased, and in order to achieve temperatures suitable for processing of each material, the temperature conditions of a sample stage that holds a wafer inside a vacuum container are sought to be controlled in a wider range than in the past.

[0010] As such a temperature condition, in the past, as a process for manufacturing a semiconductor device that is difficult to mass-produce by increasing the etching speed (rate), it has been proposed to maintain a wafer at a region of 0°C or less (subzero) as a temperature for processing an oxide film that is not the object of processing. Further, an etching process that targets a film layer containing an organic material has been proposed, in which the temperature of the wafer during processing is 100°C or more.

[0011] Therefore, it is sought to control the temperature of a wafer and a sample stage that supports the wafer with high precision in a temperature range from subzero to near 100°C or more. On the other hand, in order to control the temperature of such a sample stage, a refrigerant flow path in which a refrigerant that is supplied at a given temperature and circulated is provided inside a metal member that constitutes a main part of the sample stage, and a heater that is supplied with electric current to generate heat. Then, in order to control the temperature of the desired wafer or sample stage for processing with high precision, the temperature of the wafer or sample stage is detected or estimated from the output of a temperature sensor disposed inside the sample stage, and this information is fed back to adjust the temperature of the refrigerant and the amount of heat generated by the heater.

[0012] However, if the temperature of the refrigerant is increased or decreased in order to achieve the temperature of the sample stage or wafer in a wide range, the amount of heat from the heater that is absorbed by the refrigerant flowing in the refrigerant flow path that is also disposed inside the sample stage will increase or decrease. Therefore, in the related art, the difference (detection error) between the value of the temperature indicated by the output of the temperature sensor and the actual temperature of the sample stage can increase as the temperature of the sample stage changes.

[0013] If the detection error increases in this way, the yield of the process for manufacturing a wafer for a semiconductor device will be impaired, and the efficiency of the process will decrease.

[0014] The present application has been made in view of the above-described problems, and provides a plasma processing apparatus and a plasma processing method that improve the yield by improving the temperature detection accuracy.

[0015] Means for solving the problems

[0016] To solve the above problems, one of the representative plasma processing apparatuses according to the present application is achieved as follows, and includes: a processing chamber disposed inside a vacuum container and forming plasma inside; a sample stage disposed inside the processing chamber and placing a wafer, which is a processing target, on an upper surface; a metal base disposed on the sample stage and having a coolant flow path in which a coolant having a regulated temperature flows inside; at least one temperature sensor disposed between the coolant flow path and the upper surface of the base to detect a temperature; and a controller that detects a temperature of the base or the wafer being processed on the sample stage using an output from the temperature sensor, and detects the temperature of the base or the wafer based on a linear function representing a relationship between an error, which is a difference between a temperature obtained from the output of the temperature sensor and an actual temperature of the base or the wafer, and a set temperature of the coolant, the linear function being different for each region of a plurality of continuous temperature ranges within a range of temperatures that can be regulated for the coolant, the plurality of linear functions including the same coefficient and having a point at which the error is zero.

[0017] Further, one of the representative plasma processing methods according to the present application is achieved as follows, and the plasma processing method uses a plasma processing apparatus including: a processing chamber disposed inside a vacuum container and forming plasma inside; a sample stage disposed inside the processing chamber and placing a wafer, which is a processing target, on an upper surface; a metal base disposed on the sample stage and having a coolant flow path in which a coolant having a regulated temperature flows inside; and at least one temperature sensor disposed between the coolant flow path and the upper surface of the base to detect a temperature, and in the plasma processing method, a temperature of the base or the wafer is detected based on a linear function representing a relationship between an error, which is a difference between a temperature obtained from an output of the temperature sensor and an actual temperature of the base or the wafer, and a set temperature of the coolant, the linear function being different for each region of a plurality of continuous temperature ranges within a range of temperatures that can be regulated for the coolant, the plurality of linear functions including the same coefficient and having a point at which the error is zero.

[0018] Effects of the Invention

[0019] According to the present application, a plasma processing apparatus and a plasma processing method that improve yield by improving temperature detection accuracy can be provided.

[0020] The above problems, structures, and effects other than the above will be apparent from the following description of the embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1is a schematic cross-sectional view schematically showing the structure of a plasma processing apparatus according to the embodiment of the present application.

[0022] Figure 2 is a schematic cross-sectional view schematically showing the structure of a plasma processing apparatus according to the embodiment of the present application. Figure 1 is a schematic longitudinal cross-sectional view schematically showing the structure of a main portion of the wafer mounting electrode according to the embodiment shown in FIG. 1.

[0023] Figure 3 is a schematic longitudinal cross-sectional view schematically showing the structure of a main portion of the wafer mounting electrode according to the embodiment shown in FIG. 1. Figure 1 is a schematic top view schematically showing the structure of a vacuum processing apparatus as a processing assembly according to the plasma processing apparatus according to the embodiment shown in FIG. 1.

[0024] Figure 4 is a schematic longitudinal cross-sectional view schematically showing the structure of a main portion of the wafer mounting electrode according to the embodiment shown in FIG. 1. Figure 2 is a schematic longitudinal cross-sectional view schematically showing the structure of a main portion of the wafer mounting electrode according to the embodiment shown in FIG. 1.

[0025] Figure 5 is a schematic longitudinal cross-sectional view schematically showing the structure of a main portion of the wafer mounting electrode according to the embodiment shown in FIG. 1. Figure 2 and Figure 4 is a graph showing the relationship between the detection result of the temperature sensor provided in the wafer mounting electrode and the actual temperature of the wafer mounting electrode with respect to the change in the temperature of the refrigerant of the refrigerant flow path according to the embodiment shown in FIG. 1. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described below with reference to the drawings.

[0027] Figure 1 is a schematic cross-sectional view schematically showing the structure of a plasma processing apparatus according to the embodiment of the present application. In particular Figure 1 An electron cyclotron resonance (ECR) plasma etching apparatus is shown, which uses a microwave electric field to form an electric field for forming a plasma, induces ECR of the electric field and the magnetic field of the above-mentioned microwave to form a plasma, and uses the above-mentioned plasma to perform etching processing on a substrate-shaped sample such as a semiconductor wafer.

[0028] The ECR plasma etching apparatus is provided with a microwave cavity Figure 1The illustrated plasma processing apparatus 100 is explained. The plasma processing apparatus 100 has a vacuum vessel 101 internally provided with a processing chamber 104 that forms a plasma. Above the upper end of the side wall of the upper portion of the vacuum vessel 101 having a cylindrical shape, a dielectric window 103 (for example, made of quartz) having a circular plate shape is carried as a cover member, constituting a portion of the vacuum vessel 101. In a state of being carried above the side wall of the cylindrical vacuum vessel 101, a seal member such as an O-ring is interposed between the back surface (lower surface) of the peripheral portion of the dielectric window 103 and the upper end of the side wall of the vacuum vessel 101 having a cylindrical shape, and is disposed. When the processing chamber 104 inside the vacuum vessel 101 is exhausted to reduce the pressure, the dielectric window 103 is pressed against the vacuum vessel 101, and the seal member is deformed. Thereby, the inside and outside of the vacuum vessel 101 or the processing chamber 104 are airtightly partitioned.

[0029] Further, in the lower portion of the vacuum vessel 101, a vacuum exhaust port 110 having a circular opening is disposed facing the processing chamber 104, and communicates with a vacuum exhaust device (not shown) disposed below the vacuum vessel 101 and connected thereto. Further, below the lower surface of the dielectric window 103 constituting the cover member of the upper portion of the vacuum vessel 101, a shower plate 102 constituting a circular top plate surface of the processing chamber 104 and facing the processing chamber 104 is provided. The shower plate 102 has a circular plate shape having a plurality of gas introduction holes 102a disposed therethrough in the central portion, and a gas for etching processing is introduced from above into the processing chamber 104 through the gas introduction holes 102a. The shower plate 102 of the present embodiment is made of a dielectric material such as quartz.

[0030] A portion of the upper side of the outer side of the upper portion of the vacuum vessel 101 is provided with an electric field / magnetic field forming portion 160 that forms an electric field and a magnetic field for generating a plasma 116 inside the processing chamber 104. The electric field / magnetic field forming portion 160 is provided with an electric field generating power source 106 and a waveguide 105. The waveguide 105 is disposed above the dielectric window 103, and internally transmits a high frequency electric field of a given frequency for generating the plasma 116 in order to introduce the electric field into the processing chamber 104. The cylindrical portion constituting the lower portion of the waveguide 105 has an axis in the vertical direction and communicates with the processing chamber 104 above the central portion of the dielectric window 103, and has a smaller diameter than the dielectric window 103. Further, the electric field generating power source 106 that oscillates and forms the high frequency electric field transmitted inside the waveguide 105 is provided at the other end portion of the waveguide 105. The given frequency of the electric field is not particularly limited, and a microwave of 2.45 GHz is used in the present embodiment.

[0031] The magnetic field generating coil 107 is disposed so as to surround the lower end portion of the cylindrical portion of the waveguide 105 located above the dielectric window 103 of the processing chamber 104 and the outer periphery of the side wall of the vacuum container 101 constituting the cylindrical portion of the processing chamber 104. The magnetic field generating coil 107 is composed of electromagnets disposed in multiple stages in the vertical direction to generate a magnetic field by supplying a direct current and a yoke.

[0032] In the above-described structure, in a state where the gas for processing is introduced into the processing chamber 104 from the gas introduction hole 102a of the shower plate 102, an electric field of microwaves oscillated by the electric field generating power source 106 propagates inside the waveguide 105 and is supplied to the processing chamber 104 from the upper portion to the lower portion through the dielectric window 103 and the shower plate 102. Further, a magnetic field generated by a direct current supplied to the magnetic field generating coil 107 is supplied to the processing chamber 104 to interact with the electric field of the microwaves to induce an ECR (Electron Cyclotron Resonance). By the ECR, atoms or molecules of the gas for processing are excited, dissociated, or ionized to generate a high-density plasma 116 in the processing chamber 104.

[0033] A wafer mounting electrode 120 constituting a sample stage is disposed in the lower portion of the processing chamber 104 below the space where the plasma 116 is formed. Figure 2 In the wafer mounting electrode 120, the central portion of the upper portion has a cylindrical protruding portion (convex portion) in which the upper surface is higher than the outer periphery, and a mounting surface 120a on which a semiconductor wafer (hereinafter, simply referred to as a wafer) 109 as a sample (processing target) is placed is provided on the upper surface of the convex portion. The mounting surface 120a is disposed so as to face the shower plate 102 or the dielectric window 103.

[0034] As shown in FIG. 1, the upper surface 120b of the convex portion of the upper central portion of the electrode base material (hereinafter, simply referred to as a base material) 108 constituting a part of the wafer mounting electrode 120 is covered with a dielectric film 140 constituting the mounting surface 120a. Figure 2 As shown in FIG. 1, the upper surface 120b of the convex portion of the upper central portion of the electrode base material (hereinafter, simply referred to as a base material) 108 constituting a part of the wafer mounting electrode 120 is covered with a dielectric film 140 constituting the mounting surface 120a. Figure 1 The conductive body film 111 is connected to a direct current power source 126 via a high-frequency filter 125 as shown in FIG. 1, and is a film of a plurality of conductive bodies for electrostatic chucking.

[0035] Here, the electrostatic adsorption electrode is included in the conductive film 111 in a film shape, and direct current power based on electrostatic adsorption of the semiconductor wafer is supplied to the inside thereof, and electrostatic adsorption for forming the wafer 109 is formed across the upper portion of the dielectric film 140 covering the same. The electrostatic adsorption electrode of the conductive film 111 of the present embodiment is a plurality of films having a circular or approximately circular shape when viewed from above and insulated from each other by being arranged at a given distance apart, and can be a bipolar type in which one of the plurality of film-shaped electrodes and the other are given different polarities, or can be a unipolar type in which the same polarity is given. In Figure 1 only a single conductive film 111 is disclosed, but the electrostatic adsorption electrode of the bipolar type of the present embodiment is configured with a plurality of film-shaped metal electrodes each given a different polarity inside the dielectric film 140.

[0036] In Figure 1 the electrode substrate 108 having a circular or cylindrical shape made of a conductive material arranged inside the wafer placement electrode 120 is connected to the high-frequency power source 124 via the matching device 129 and a power supply path including wiring such as a coaxial cable. These high-frequency power source 124 and matching device 129 are arranged at a position closer than the distance between the high-frequency filter 125 and the conductive film 111. Further, the high-frequency power source 124 is connected to the ground portion 112.

[0037] In the present embodiment, during processing of the wafer 109, the wafer 109 is adsorbed and held on the upper surface of the dielectric film 140 of the wafer placement electrode 120 by supplying high-frequency power of a given frequency from the high-frequency power source 124. A bias potential having a distribution corresponding to the difference in potential from the plasma 116 is formed above the held wafer 109. In other words, the above-described sample stage has the wafer placement electrode 120 to which high-frequency power is supplied from the high-frequency power source 124 during formation of the plasma 116.

[0038] Details will be described later, but the inside of the electrode substrate 108 is provided with a coolant flow path 152 for removing transferred heat to cool the wafer placement electrode 120, and multiple spiral or concentric arrangements are arranged around the center axis in the vertical direction of the electrode substrate 108 or wafer placement electrode 120, and a coolant having a temperature adjusted to a given range flows inside. The inlet and outlet of the wafer placement electrode 120 of the coolant flow path 152 are connected to a temperature adjuster by piping, and the temperature adjuster is provided with a refrigeration cycle not shown in the drawing, and the coolant is adjusted to a temperature within a given range by heat transfer. The coolant whose temperature changes by heat exchange during flow through the coolant flow path 152 flows out from the outlet, and after being adjusted to a given temperature range by the flow path inside the temperature adjuster via the piping and passing through the temperature adjuster, it returns to the coolant flow path 152 inside the electrode substrate 108, and circulates.

[0039] On the outer periphery side of the convex portion of the electrode substrate 108 of the wafer mounting electrode 120, which has a mounting surface 120a of the same circular shape as the wafer 109, a recessed portion 120d, which is annularly arranged as viewed from above, is arranged. On the annular upper surface of the recessed portion 120d, which is formed at a lower height than the mounting surface 120a of the sample stage, a pedestal ring 113 of an annular member made of a material of a dielectric such as quartz or alumina or the like is mounted. Figure 1 The pedestal ring 113 covers the bottom surface of the recessed portion 120d or the cylindrical side wall surface of the convex portion with respect to the plasma 116.

[0040] In the pedestal ring 113 of the present embodiment, as shown in Figure 1 , the cylindrical side wall portion of the outer periphery of the annular portion extends downward further than the recessed portion 120d at the lower end of the side wall portion in the state of being mounted on the recessed portion 120d, and has a size that covers the cylindrical side wall surface of the electrode substrate 108 or the insulating plate of the wafer mounting electrode 120. Further, in the state where the pedestal ring 113 is mounted on the recessed portion 120d and the bottom surface of the annular portion is in contact with the upper surface of the recessed portion 120d or the protective dielectric coating film covering the same, the flat upper surface of the pedestal ring 113 has a size that is higher than the mounting surface 120a.

[0041] The plasma processing apparatus 100 of the present embodiment is provided with devices that adjust the operation of the plasma processing apparatus 100, including devices that adjust the electric field and the magnetic field, such as the above-mentioned electric field generating power supply 106, the magnetic field generating coil 107, the high frequency power supply 124, the high frequency filter 125, the direct current power supply 126, the high frequency power supply 127, the matchers 128, 129, the load impedance variable box 130, or devices that constitute a pressure adjustment system, such as the vacuum exhaust device described later, the mass flow controller that adjusts the amount of gas supply, or a temperature adjustment mechanism such as a temperature adjuster that adjusts the amount of heat of the heater inside the wafer mounting electrode 120, the temperature of the coolant supplied to and circulated in the coolant flow path 152.

[0042] Each of these devices is provided with a detector that detects the state of the operation, such as the output, the flow rate, the pressure, and can communicate with the controller 170 by wired or wireless means. If a signal indicating the state of the operation from the detector provided in each of these devices is transmitted to the controller 170, the arithmetic unit of the controller 170 reads out the software stored in the storage device inside the controller 170, detects the amount of the state from the signal received from the detector based on the algorithm thereof, and calculates and transmits an instruction signal for adjusting it to an appropriate value. The devices included in the electric field / magnetic field adjustment system or the pressure adjustment system, etc. that receive the instruction signal adjust the operation in response to the instruction signal.

[0043] Details will be described later, but in a vacuum processing apparatus including such a plasma processing device 100, a robot for wafer transport is disposed in a vacuum transport chamber that is depressurized to the same pressure as the processing chamber 104 inside the vacuum transport vessel that is another vacuum vessel connected to the side wall of the vacuum vessel 101. When a gate valve disposed in the vacuum transport chamber is opened, the gate passage that communicates between the vacuum transport chamber and the processing chamber 104, a wafer 109 before processing is placed on the tip end of the robot arm and is transported inside the processing chamber 104 through the gate by the extension of the arm. Further, the wafer 109 transported above the wafer placement surface 120a of the wafer placement electrode 120 inside the processing chamber 104 is handed over to the lift pins by the up-and-down movement of the lift pins, and further, after being placed on the wafer placement surface 120a, is adsorbed and held on the wafer placement surface 120a of the wafer placement electrode 120 by electrostatic force generated by direct current power applied from the direct current power source 126.

[0044] After the transport robot is withdrawn from inside the processing chamber 104 to the vacuum transport chamber by the contraction of the arm, the gate valve hermetically occludes the gate from the vacuum transport chamber, and the inside of the processing chamber 104 is sealed. In this state, a gas for etching processing is supplied to the processing chamber 104 through a gas supply line composed of a pipe connecting a gas source and the vacuum vessel 101. A mass flow controller (not shown) as a flow path regulator is disposed on this pipe, and has a flow path through which the gas flows inside, and a valve disposed on the flow path and that increases or decreases the cross-sectional area of the flow path or opens and closes to regulate the flow rate to a value within a desired range. The gas whose flow rate or speed is regulated by the mass flow controller is introduced into the space of the gap between the dielectric window 103 and the quartz-made shower plate 102 from the flow path inside the vacuum vessel 101 connected to the end of the pipe. The introduced gas is diffused in this space, and is introduced into the processing chamber 104 through the gas introduction holes 102a of the shower plate 102.

[0045] The inside of the processing chamber 104 is exhausted of the gas and particles inside through the vacuum exhaust port 110 by the action of the vacuum exhaust device connected to the vacuum exhaust port 110. In correspondence with the balance between the supply amount of the gas from the gas introduction holes 102a of the shower plate 102 and the exhaust amount from the vacuum exhaust port 110, the inside of the processing chamber 104 is adjusted to a given value within a range suitable for the processing of the wafer 109.

[0046] Further, during the period when the wafer 109 is held by suction, a gas having heat transfer properties such as He (helium) is supplied from an unillustrated opening in the upper surface of the dielectric film 140 to the gap between the wafer 109 and the wafer placement electrode 120, i.e., the upper surface of the dielectric film 140, whereby heat transfer between the wafer 109 and the wafer placement electrode 120 is promoted. In addition, the temperature of the wafer placement electrode 120 or the electrode base material 108 is adjusted in advance before the wafer 109 is placed by circulating a coolant having a temperature adjusted to a given range in the coolant flow path 152 provided in the electrode base material 108 of the wafer placement electrode 120. Thus, by heat transfer between the wafer 109 and the wafer placement electrode 120 or the electrode base material 108 having a large heat capacity, the temperature of the wafer 109 is adjusted to be close to their temperatures before processing, and after the start of processing, heat from the wafer 109 is also transferred to adjust the temperature of the wafer 109.

[0047] The etching process will be described below. In the above state, the electric field and the magnetic field in the processing chamber 104 to which microwaves are supplied are used to generate plasma 116 using a gas. If the plasma 116 is formed, high-frequency (RF) power is supplied from the high-frequency power source 124 to the electrode base material 108, a bias potential is formed above the upper surface of the wafer 109, and charged particles such as ions in the plasma 116 are guided to the upper surface of the wafer 109 in correspondence with the potential difference between the potential of the plasma 116. Further, the above charged particles collide with the surface of the film layer of the above processing target film layer including the mask previously placed on the upper surface of the wafer 109 and the film structure of the film layer of the processing target to perform the etching process. In the etching process, the gas for processing introduced into the processing chamber 104 and the particles of reaction products generated in the processing are exhausted from the vacuum exhaust port 110.

[0048] The etching process of the film layer of the processing target proceeds, and if the process reaches a given etching amount or a remaining film thickness is detected by an unillustrated end point detector or a film thickness detector, the supply of high-frequency power from the high-frequency power source 124 is stopped, in addition, the supply of power to the electric field generating power source 106 and the magnetic field generating coil 107 is stopped, the plasma 116 is extinguished, and the etching process is stopped. Thereafter, a destaticizing process is performed in which the electrostatic suction electrode of the conductive film 111 of the wafer 109 is supplied with power from the direct current power source 126 so as to become a potential opposite to that in the processing.

[0049] Further, the inside of the processing chamber 104 is introduced with a dilution gas to replace the gas for processing. After that, the wafer 109 is lifted by the lift pins from the mounting surface 120a of the wafer mounting electrode 120, passes through the gate opened by the gate valve, and is handed over to the arm tip of the transport robot which enters the processing chamber 104, and is transported outside the processing chamber 104 by the contraction of the arm. In the case where there is another wafer 109 to be processed, the wafer 109 is transported in by the transport robot and processed in the same manner as above, and in the case where there is no other wafer 109, the gate valve hermetically closes the gate to seal the processing chamber 104, and the processing in the processing chamber 104 is ended.

[0050] Then, in the plasma processing apparatus 100 of the present embodiment, in the processing of the wafer 109, the conductor ring 131 disposed between the recessed portion 120d of the wafer mounting electrode 120 at the outer periphery of the mounting surface 120a and the susceptor ring 113 is supplied with the second high-frequency electric power from the high-frequency power source 127 as the second high-frequency power source. Further, the conductor ring 131 constitutes a power supply path of the second high-frequency electric power, and is disposed in a through-hole which penetrates the outer peripheral portion of the electrode base material 108 of the wafer mounting electrode 120, and is connected to the power supply connector 161 which is held so as to be pressed upward from below with respect to the conductor ring 131.

[0051] The high-frequency electric power output from the high-frequency power source 127 is supplied to the conductor ring 131 of the conductive body disposed on the inner side of the susceptor ring 113 along the power supply path which electrically connects between the high-frequency power source 127 and the conductor ring 131, through the matching box 128 and the load impedance variable box 130 which are disposed on the power supply path.

[0052] At this time, by adjusting the impedance on the power supply path in the load impedance variable box 130 to a value within an appropriate range, the value of the impedance with respect to the first high-frequency electric power from the high-frequency power source 127 through the electrode base material 108 to the outer peripheral edge portion of the wafer 109 with respect to the relatively high impedance portion of the upper portion of the susceptor ring 113 becomes relatively low. Thereby, the high-frequency electric power is effectively supplied to the outer peripheral side portion and the outer peripheral edge portion of the wafer 109, and the concentration of the electric field at the outer peripheral side portion or the outer peripheral edge portion of the wafer 109 is relaxed, the distribution of the height of the equipotential surface of the bias potential above these regions is within the desired range of the deviation of the direction of incidence of the charged particles such as ions in the plasma to the upper surface of the wafer 109, and the yield of the processing is improved.

[0053] In the present embodiment, the high-frequency power source 127 is electrically connected to the grounding portion 112. In addition, in the present example, the frequency of the second high-frequency electric power supplied from the high-frequency power source 127 to the conductor ring 131 is appropriately selected in correspondence with the conditions of the processing of the wafer 109, and is preferably the same as or a constant multiple of the value of the high-frequency power source 124.

[0054] Figure 2 is a schematic diagram Figure 1 is a schematic diagram of the main part of the structure of the wafer placement electrode of the embodiment shown. In Figure 2 In the present embodiment, the wafer placement electrode 120 of the plasma processing apparatus 100 includes an electrode base material 108 having a circular plate shape made of metal and supplied with high-frequency bias power, and a dielectric film 140 configured of a ceramic such as alumina or yttrium oxide disposed on the upper surface thereof. The main part of the structure of the wafer placement electrode 120 will be described in detail.

[0055] In the present drawing, the dielectric film 140 disposed on the upper portion of the electrode base material 108 made of metal as the base material of the wafer placement electrode 120 has a film-shaped conductive film 111 disposed so as to cover the upper surface of the convex portion disposed on the central portion of the upper portion of the electrode base material 108, and forms two layers in the inside in the vertical direction. The film-shaped electrode of the lower layer in the conductive film 111 is a heater electrode 202 occupying a plurality of regions (areas) of the upper surface of the convex portion or the dielectric film 140 as viewed from above. In the present embodiment, the heater electrode 202 is disposed so as to substantially occupy each of the central circular region including the center of the dielectric film 140 and the plurality of annular regions surrounding the same and concentrically disposed with respect to the center. The annular regions of the heater electrode 202 are divided into a plurality of (three or more in the present example) arc-shaped small regions around the above-mentioned center, and the heater electrode 202 is disposed so as to occupy each of the small regions. That is, the heater electrode 202 of the present embodiment is disposed so as to substantially occupy the same area as the central circular area and the plurality of arc-shaped areas around the same in the dielectric film 140, and cover the entire upper surface of the convex portion of the electrode base material 108.

[0056] On the other hand, the film-shaped electrode of the upper layer in the conductive film 111 is an electrostatic chucking electrode (ESC electrode) 201 occupying a circular region including the center of the dielectric film 140 and at least one annular region surrounding the same concentrically with respect to the center as viewed from above. With respect to the radial direction from the center of the wafer placement electrode 120 of the present example, the positions at which the two adjacent ESC electrodes are separated from each other also lie on the same specific radius position with respect to the center, and are concentrically separated. The positions at which the adjacent two annular regions in which the heater electrode 202 is disposed are concentrically separated from each other at the same specific radius position with respect to the center overlap each other as viewed from above, and one of the projected regions includes the other.

[0057] In the present embodiment, the plurality of ESC electrodes 201 are each connected to the direct current power supply 126, and a voltage determined in correspondence with an instruction signal from the controller 170 is applied thereto, and a polarity corresponding to the voltage is imparted thereto. In correspondence with the polarity corresponding to the voltage, electric charges are aggregated in a region above each electrode in the wafer 109 above, thereby inducing an electrostatic force. The plurality of ESC electrodes 201 in the present example are imparted with either one of a positive or negative polarity, and form a so-called bipolar type in which electrodes each constituting a pair of electrodes of a positive electrode and a negative electrode are mutually arranged. The ESC electrodes 201 each imparted with a positive or negative polarity are arranged in a shape in which the sum of the areas of the electrodes is set to have the same value or a value approximating to a value that can be regarded as the same value.

[0058] Further, in the wafer placement electrode 120 of the present embodiment, a plurality of temperature sensors 203 that detect the temperature of the electrode substrate 108 are arranged in each region into which a region or zone in which the heater electrode 202 is arranged in the dielectric film 140 inside the electrode substrate 108 is projected, as viewed from above. In addition, a refrigerant flow path 152 that is concentrically or spirally arranged around a central axis in the up-down direction of the wafer placement electrode 120 is arranged at a position inside the electrode substrate 108 that is lower than the tip portion that detects the temperature of the temperature sensor 203. Thus, the temperature of the electrode substrate 108 or the wafer placement electrode 120 is adjusted by the heat generated by the heater electrode 202, and by the refrigerant circulating inside the refrigerant flow path 152 that is adjusted to a given temperature.

[0059] In the present example, one temperature sensor 203 corresponding to each of the heater electrodes 202 in each zone can be inserted and stored inside a sensor hole 204 arranged inside the electrode substrate 108 below the zone, and thus arranged. Further, as shown in the present embodiment, the temperature sensor corresponding to each region in a circular or ring shape can be stored one in each of the sensor holes 204 at a position arranged in the projected range of the region.

[0060] The placement surface 120a above the ESC electrode 201 of the dielectric film 140 has a ring-shaped convex portion 206 arranged at the outermost peripheral portion and surrounding the inner side, and a plurality of convex portions 207 arranged on the upper portion of the dielectric film 140 on the inner side. The upper surfaces of these convex portions abut against and push against the back surface of the wafer 109 placed on the upper surface of the dielectric film 140 and electrostatically attracted thereto. If direct current power is supplied to the ESC electrode 201 inside the dielectric film 140 from the direct current power supply 126 to impart a specific potential thereto, molecules or atoms in the member including the back surface of the wafer 109 are polarized in correspondence with the electric charge inside the ESC electrode 201, thereby inducing electric charges. The dielectric material of the dielectric film 140 above the ESC electrode generates electrostatic force, whereby electrostatic force that attracts each other is generated between the wafer 109 and the ESC electrode 201, and as a result, the wafer 109 is attracted to the dielectric film 140 with a given attraction force.

[0061] On the other hand, below the bottom of the vacuum vessel 101, an exhaust device having a vacuum pump including a rough-pumping pump such as a turbo molecular pump and a rotary pump is connected to the bottom and is disposed in communication with the processing chamber 104 via a vacuum exhaust port 110 of the bottom of the vacuum vessel 101. By driving the vacuum pump, the pressure inside the processing chamber 104 in a state in which the wafer 109 is contained therein is maintained at a high vacuum degree. Normally, the pressure in the processing chamber 104 during processing of the wafer 109 is set to a value within a range suitable for processing of the wafer 109 by balancing the flow rate or speed of supply of a mixed gas of a processing gas from a processing gas supply path and a dilution gas and the flow rate or speed of exhaust from the vacuum exhaust port 110.

[0062] In such a plasma processing device 100, in a state in which the wafer 109 is guided and attracted to be held on the upper surface of the dielectric film 140, a gap (hereinafter also referred to as a slit) between the wafer 109 and the upper surface of the dielectric film 140 is supplied with a gas such as He gas having high heat transferability from a gas source via a gas passage not shown, to promote heat transfer between the refrigerant circulating and flowing in the refrigerant flow path 152 formed in the electrode base material 108 and the wafer 109.

[0063] The etching processing of the film layer that is the processing target on one wafer 109 implemented in the present embodiment has a plurality of processes (steps) having different processing conditions including a range of suitable implementation temperatures, and has a transition step for transitioning the temperature of the wafer 109 or the upper surface of the wafer placement electrode 120 or the dielectric film 140 on which the wafer 109 is placed and held from the condition of the preceding process to the condition of the subsequent process between the processes of the preceding and subsequent etching processing.

[0064] Reference Figure 3The structure of the vacuum processing apparatus 300 provided with the plasma processing apparatus according to the embodiment of the present application will be described. Figure 3 is a schematic top view showing the structure of the vacuum processing apparatus provided with the plasma processing apparatus according to the embodiment shown in Figure 1 is a schematic top view showing the structure of the vacuum processing apparatus provided with the plasma processing apparatus according to the embodiment shown in

[0065] The vacuum processing apparatus 300 shown in the figure is roughly divided into an atmospheric side block 301 and a vacuum side block 302. The atmospheric side block 301 is a portion that transports, stores, and positions a substrate-shaped wafer such as a semiconductor wafer under atmospheric pressure. The vacuum side block 302 is a block that transports a substrate-shaped wafer such as a wafer under a pressure reduced from atmospheric pressure and processes the wafer in a predetermined vacuum processing chamber. Further, between the portion of the vacuum side block 302 that performs the aforementioned transport and processing and the atmospheric side block 301, a device that links them and changes the pressure between atmospheric pressure and vacuum pressure with the wafer inside is provided.

[0066] The atmospheric side block 301 includes a housing 306 that is a substantially rectangular parallelepiped-shaped container provided with an atmospheric transport robot 309 inside, the pressure inside is set to be the same as or slightly higher than the pressure of the atmosphere around the vacuum processing apparatus 300, and an atmospheric transport chamber having a wafer inside before and after the wafer is processed is provided. The front side of the housing 306 is provided with a plurality of wafer cassette stages 307 on which wafer cassettes that store substrate-shaped wafers such as semiconductor wafers as processed objects for processing or cleaning are loaded.

[0067] The vacuum side block 302 is provided with one or more lock chambers 305 that are provided between the first vacuum transport chamber 304 and the atmospheric side block 301 and change the pressure between atmospheric pressure and vacuum pressure with the wafer inside being exchanged between the atmospheric side and the vacuum side.

[0068] The first vacuum transport chamber 304 and the second vacuum transport chamber 310 are each a component including a vacuum container that has a substantially rectangular shape in a plan view, and they are two components that have substantially the same degree of structural differences. The vacuum transport intermediate chamber 311 is a vacuum container that can be reduced to a vacuum degree equivalent to that of the other vacuum transport chambers or vacuum processing chambers and is linked to the vacuum transport chambers 304 and 310 so as to be in communication with each other. A gate valve 320 that communicates the chambers inside, opens and blocks the passage for transporting the wafer inside, and divides them is provided between the vacuum transport chambers 304 and 310. The vacuum transport intermediate chamber 311 and the vacuum transport chambers 304 and 310 are hermetically sealed by the gate valve 320.

[0069] Further, the chamber inside the vacuum transfer intermediate chamber 311 is provided with a storage section that holds a plurality of wafers with gaps between their faces, and holds them horizontally, and has the function of a relay chamber that temporarily stores wafers when transferring them between the vacuum transfer chambers 304, 310. That is, a wafer that is carried in by the vacuum transfer robot 308 in one of the vacuum transfer chambers and is placed in the storage section is carried out by the vacuum transfer robot 308 in the other of the vacuum transfer chambers, and is carried to the vacuum processing assembly 303 or the lock chamber 305 that is connected to that vacuum transfer chamber.

[0070] In the other face of the first vacuum transfer chamber 304 and the second vacuum transfer chamber 310 that is different from the face connected to the vacuum transfer intermediate chamber 311, a vacuum processing assembly 303 is connected. Figure 1 The vacuum processing assembly 303 of the plasma processing apparatus 100 shown in the drawing. In this embodiment, the vacuum processing assembly 303 is configured as described above, including the vacuum vessel 101, and is a component configured including a generation unit that supplies an electric field and a magnetic field for forming the plasma 116 in the processing chamber 104 inside the vacuum vessel 101, and a exhaust unit including a vacuum pump that exhausts the space inside the vacuum vessel 101, i.e., the processing chamber 104, that is reduced in pressure, and implements etching processing that utilizes the plasma 116 in the processing chamber 104 inside.

[0071] In the vacuum processing apparatus 300 of this example, two vacuum processing assemblies 303 are connected to each of the first vacuum transfer chamber 304 and the second vacuum transfer chamber 310. In these vacuum processing assemblies 303, not only etching processing of the wafer 109, but also ashing processing, or processing performed on other semiconductor wafers, can be performed. Further, in each vacuum processing assembly 303, a pipe that flows processing gas supplied to the processing chamber 104 inside the vacuum vessel 101 corresponding to the processing performed is connected.

[0072] The first vacuum transfer chamber 304 is configured to be able to connect up to two vacuum processing assemblies 303, and in this embodiment, two vacuum processing assemblies 303 are connected. On the other hand, the second vacuum transfer chamber 310 is configured to be able to connect up to three vacuum processing assemblies 303, but in this embodiment, up to two vacuum processing assemblies 303 are connected.

[0073] The first vacuum transfer chamber 304 and the second vacuum transfer chamber 310 have their interiors configured as transfer chambers. In the first vacuum transfer chamber 304, a vacuum transfer robot 308 that transfers wafers under vacuum between the lock chamber 305 and either of the vacuum processing assemblies 303 or the vacuum transfer intermediate chamber 311 is disposed in the central portion of the space inside. In the second vacuum transfer chamber 310, likewise, a vacuum transfer robot 308 is disposed in the central portion inside, and can transfer wafers between either of the vacuum processing assemblies 303 or the vacuum transfer intermediate chamber 311.

[0074] The vacuum transfer robot 308 places a wafer on its arm, and in the first vacuum transfer chamber 304, performs wafer transfer into or out of the lock chamber 305 or any of the vacuum transfer intermediate chambers 311, which are provided on the wafer stage (e.g., wafer placement electrode) of the vacuum processing assembly 303. Between these vacuum processing assemblies 303, the lock chamber 305, the vacuum transfer intermediate chambers 311, the first vacuum transfer chamber 304, and the second vacuum transfer chamber 310 and the transfer chambers, passages are provided that are connected by gate valves 320 that can be hermetically closed and opened.

[0075] In the vacuum processing apparatus of the embodiment, Figure 3 In the vacuum processing apparatus of the embodiment, the processing performed on the wafer is performed under the same conditions including the processing time for all of the vacuum processing assemblies 303. In addition, the number of wafers that can be transferred per unit time in the lock chamber 305 is less than the number of wafers that can be processed per unit time in the vacuum processing assemblies 303 and is the same as or slightly less than the number of wafers that can be transferred per unit time by the vacuum transfer robot 308 provided in each of the vacuum transfer chambers. This is because, when the processed wafer is transferred out of the lock chamber 305 to the atmospheric side block 301, a long time is required for the temperature of the wafer subjected to a heating process such as ashing to decrease to a level that does not interfere with transfer and storage into a cassette, and the wafer stays in the lock chamber 305 for a relatively long time.

[0076] The vacuum transfer robot 308 (provided as robot 1) provided in the first vacuum transfer chamber 304 is a mechanism that performs handover of a wafer between the lock chamber 305 and each of the vacuum processing assemblies 303 that perform a predetermined process before the wafer is transferred, with respect to a wafer introduced from the atmospheric side block 301 to the vacuum side block 302. On the other hand, the vacuum transfer robot 308 (provided as robot 2) provided in the second vacuum transfer chamber 310 is a mechanism that performs handover of a wafer between the vacuum transfer intermediate chamber 311 and any of the vacuum processing assemblies 303 connected to the second vacuum transfer chamber 310, with respect to a wafer transferred from the first vacuum transfer chamber 304 to the vacuum transfer intermediate chamber 311 by the robot 1.

[0077] In the present embodiment, after the processing of the wafer is completed in any of the vacuum processing assemblies 303, the processed wafer is transported from the vacuum processing assembly 303 to the lock chamber 305. Here, as described above, the time required for the wafer to be transported to the atmospheric block in the lock chamber 305, that is, the time from when the inside of the lock chamber 305 is depressurized in a state in which the wafer is accommodated, to the time when the wafer is left in the lock chamber 305 until the pressure is increased to the same or substantially the same as the atmospheric pressure and the gate valve of the vacuum side block 302 of the lock chamber 305 is opened to take out the wafer, is sufficiently longer than the time the wafer is left until the wafer is transported into the vacuum processing assembly 303 to be processed and then taken out. Therefore, in the present embodiment, the robot 1 generates a waiting time until the gate valve of the vacuum side block 302 of the lock chamber 305 is opened so as to become able to be transported in, while the processed wafer is held by the arm itself, because the robot 1 must return all the processed wafers to the lock chamber 305.

[0078] Reference Figure 4 to explain Figure 2 the configuration of the inside of the electrode base material 108 of the wafer placement electrode 120. Figure 4 is a cross-sectional view showing Figure 2 the structure of the inside of the metal base material of the wafer placement electrode according to the embodiment shown in the drawing. In particular, Figure 4 shows the cross section in the horizontal direction indicated by the A-A line shown in Figure 2

[0079] As shown in the drawing, the electrode base material 108 of the present embodiment is a metal such as aluminum or its alloy, or titanium or its alloy, and has a circular plate or a cylindrical shape, and has a refrigerant flow path 152 configured in multiple layers around the center or concentrically in the inside thereof. The refrigerant flow path 152 configured in multiple layers in the radial direction in the present example has an end portion having a flow inlet 401 into which the refrigerant flows in the inside at the outermost peripheral flow path portion, and the refrigerant flowing from the flow inlet 401 becomes a path that revolves to approach the center portion in the clockwise rotation direction around the center as viewed from above. In the example shown in Figure 4 the drawing, the refrigerant flow path 152 becomes a path in which the refrigerant flows about three turns in the clockwise direction along the flow path from the flow inlet 401 to reach the center portion of the electrode base material 108.

[0080] ​Furthermore, the refrigerant flow path 152 has a flow path that folds back counterclockwise at the center of the electrode substrate 108 and then rotates back, so that it approaches the outer periphery from the center in a counterclockwise direction. On the inner periphery side of the outermost flow path, there is another end located near the end with the inlet 401. The refrigerant outlet 402 is disposed at the other end. The refrigerant that flows from the inlet 401 through the interior of the refrigerant flow path 152 to the center flows counterclockwise around the folded portion of the flow path about 2 times to reach the other end of the refrigerant flow path 152, and then flows out of the refrigerant flow path 152 through the outlet 402.

[0081] Furthermore, in this embodiment, the electrode substrate 108 includes: through holes 403 for supplying power to connectors and cables for powering electrostatic adsorption electrodes 201 disposed within the dielectric film 140 of the wafer mounting electrode 120; through holes 404 for supplying power to heater electrodes 202; and sensor holes 204 for housing temperature sensors 203 disposed within the electrode substrate 108 between its upper surface and the refrigerant flow path 152. The refrigerant flow path 152 is configured to avoid these through holes, and therefore, in the vicinity of these through holes, it locally includes multiple portions that meander in the direction of the upper surface shown in the figure.

[0082] Furthermore, the electrode substrate 108 in this example has a circular plate shape with a radial (horizontal) dimension that is sufficiently large compared to its thickness (vertical) dimension. Therefore, the radial dimension is sufficiently large compared to the vertical dimension of the region where the refrigerant flow path 152 is located within the electrode substrate 108.

[0083] Next, use Figure 5 To explain Figure 1 The method for adjusting the temperature of the wafer mounting electrode 120 in the plasma processing apparatus shown. Figure 5 It is a schematic representation relative to the supply to Figure 2 And a graph showing the relationship between the temperature change of the refrigerant in the refrigerant flow path of the embodiment shown in 4 and the difference between the detection result of the temperature sensor in the wafer mounting electrode and the actual temperature of the wafer mounting electrode.

[0084] In the plasma processing apparatus of this embodiment, when the wafer is placed on the wafer mounting electrode 120 and adsorbed, the temperature of the wafer changes according to the temperature of the refrigerant supplied to the refrigerant flow path 152 and the amount of heat generated corresponding to the magnitude of the DC power supplied to the heater electrode 202. Therefore, the controller 170 receives the output from the temperature sensor 203 and sends a command signal corresponding to the detected temperature of the electrode substrate 108 or the estimated temperature of the wafer 109, thereby adjusting the temperature of the refrigerant and the amount of heat generated by the heater electrode 202. On the other hand, in the temperature sensor 203 provided in this example, for example, in a temperature sensor 203 utilizing a resistive element, the difference (error) between the detected temperature value and the actual temperature also increases or decreases. Therefore, in the controller 170, a predetermined amount is corrected based on the result obtained from the output of the temperature sensor 203, correcting the detection error of the temperature sensor 203 as described above, thereby detecting the temperature of the wafer mounting electrode 120 or the wafer 109 with high accuracy.

[0085] Therefore, in this example, before the processing of wafer 109, a process in manufacturing semiconductor devices, begins, the temperature of the coolant is pre-set to multiple values ​​within a given range by a coolant temperature regulator and supplied to the coolant flow path of the wafer mounting electrode 120, thereby adjusting the electrode substrate 108 to multiple different temperatures. While the electrode substrate 108 is adjusted to each temperature, the temperature is detected using a temperature sensor 203, and the error between the actual temperature of the upper surface of the electrode substrate 108 or the upper surface of the dielectric film 140 of the wafer mounting electrode 120 is calculated. Furthermore, the correlation between these error values ​​and the temperature setting value (the set coolant temperature) of the coolant temperature regulator is extracted, and coefficients representing these correlations are calculated. Figure 5 The diagrams showing these related information are provided.

[0086] As a result of the inventors' research, it is known that the temperature error obtained from the output of the temperature sensor 203 inside the electrode substrate 108 of the wafer mounting electrode 120 disposed in this example changes with a given tilt relative to the temperature set value of the refrigerant temperature regulator within the range envisioned as the actual processing conditions of the wafer 109, that is, it is essentially a linear function of the refrigerant's set temperature.

[0087] Therefore, in the plasma processing apparatus of this embodiment, as a process for manufacturing semiconductor devices, before starting the operation of processing the wafer 109, the temperature of the refrigerant is pre-set by the temperature regulator to multiple values ​​within a range of the temperature of the wafer 109 as the envisioned processing conditions. When the correlation between the error output of the temperature sensor 203 and the set temperature of the refrigerant is applied to a linear function (y = ax + b), the values ​​of its slope (coefficient a) and constant b are obtained as parameters. Then, the controller 170 estimates the value (y) of the function calculated based on these parameters and the set value (x) of the refrigerant temperature regulator, as an error. When estimating or calculating the temperature of the wafer mounting electrode 120 or the wafer 109 placed thereon in the wafer 109 processing process as a product manufacturing process, the estimated error is used to correct or adjust the temperature value detected based on the output from the temperature sensor 203. The corrected temperature value is used in the feedback control of the temperature regulator and the heater electrode.

[0088] Furthermore, in this embodiment, the temperature range of the wafer 109, which is the condition for the aforementioned processing, is divided into a series of consecutive ( Figure 5 In three regions (509, 510, and 511), different linear correlation functions 502, 503, and 504 are set as functions for error correction. These functions have the same (tilt) coefficient 'a' detected as the parameter used for correction and have error 0 (zero crossover) points 506, 507, and 508 in each temperature region. More specifically, correlation function 502 is represented by y = ax + b1 in the first region 509, correlation function 503 by y = ax + b2 in the second region 510, and correlation function 504 by y = ax + b3 in the third region 511. All functions pass through points where y = 0 within their respective regions. The coefficient 'a' is the same value as the coefficient 'a' of a single linear function representing the relationship between the error and the set temperature of the refrigerant, covering the entire range of temperatures where the refrigerant can be adjusted.

[0089] Furthermore, when the error between the temperature obtained from the output of a temperature sensor on a sample stage of another plasma processing apparatus having a substantially similar structure to this plasma processing apparatus and the actual temperature of the substrate or the wafer is taken as the substitution error, the coefficient 'a' can be set to the same value as the coefficient 'a' of a linear function representing the relationship between the substitution error and the set temperature of the refrigerant. Additionally, the heat output of the heater electrode 202 can be adjusted based on correlation functions 502, 503, and 504.

[0090] Errors in each of the multiple temperature regions are reduced by using different correction functions with the same coefficients in each of these divided temperature regions. For example...Figure 5 As shown, it is understood that, in comparison with the comparative example in which the correlation function 501 that uses a single function in which the range of temperatures in the processing assumed to be performed is set as a whole, the difference from the maximum value or the minimum value (corresponding to the correction amount of the error) is smaller in the functions 502, 503, 504 for correction of the present embodiment, and the accuracy of the detection of the temperature of the wafer 109 or the wafer mounting electrode 120 using the output of the temperature sensor 203 is improved.

[0091] As described above, according to the present embodiment, the processing of the wafer 109 can achieve the temperature of the wafer 109 with high accuracy throughout the range of temperatures assumed to be processed, and the yield of the processing can be improved.

[0092] Further, in the plasma processing apparatus of the present embodiment, the value of the coefficient of the linear function that represents the correlation between the error of the output of the temperature sensor 203 and the set temperature of the coolant detected by the temperature regulator that sets the temperature of the coolant to a plurality of values within the range of temperatures of the wafer 109 as a condition of the processing assumed to be performed is used in the correction or the calibration of the detection error of the wafer mounting electrode 120 of another plasma processing apparatus that has the same structure with respect to the wafer mounting electrode 120 including the temperature sensor 203 and the temperature regulator of the coolant supplied in connection therewith. In this case, as shown, the range of temperatures of the wafer 109 as a condition of the processing assumed to be performed can be divided into a plurality of (three in the present embodiment) regions that are continuous, and in each of the regions of the temperatures, a different linear function having the above-mentioned detected coefficient and having an error 0 (zero-crossing) point within the region of the temperature is used as a function for correction of the error. Figure 5 Figure 5 Figure 5 As shown, it is understood that, in comparison with the comparative example in which the correlation function 501 that uses a single function in which the range of temperatures in the processing assumed to be performed is set as a whole, the difference from the maximum value or the minimum value (corresponding to the correction amount of the error) is smaller in the functions 502, 503, 504 for correction of the present embodiment, and the accuracy of the detection of the temperature of the wafer 109 or the wafer mounting electrode 120 using the output of the temperature sensor 203 is improved.

[0093] Explanation of Reference Numerals

[0094] 100... plasma processing apparatus,

[0095] 101... vacuum chamber,

[0096] 102... shower plate,

[0097] 102a... gas introduction hole,

[0098] 103... dielectric window,

[0099] 104... processing chamber,

[0100] 105... waveguide,

[0101] 106... electric field generating power supply,

[0102] ​107...magnetic field generating coil,

[0103] 108...electrode substrate,

[0104] 109...wafer,

[0105] 110...vacuum exhaust port,

[0106] 111...conductor film,

[0107] 112...ground portion,

[0108] 113...base ring,

[0109] 116...plasma,

[0110] 120...wafer placement electrode,

[0111] 120a...placement surface,

[0112] 120b...upper surface,

[0113] 120d...recess,

[0114] 124...high frequency power supply,

[0115] 125...high frequency filter,

[0116] 126...direct current power supply,

[0117] 127...high frequency power supply,

[0118] 128, 129...matchers,

[0119] 130...load impedance variable box,

[0120] 201...electrostatic chuck (ESC) electrode,

[0121] 202...heater electrode,

[0122] 203...temperature sensor,

[0123] 204...sensor hole,

[0124] 301...atmosphere side block,

[0125] 302...vacuum side block,

[0126] 303...vacuum processing assembly,

[0127] 304...1st vacuum transfer chamber,

[0128] 305...lock chamber,

[0129] 306...housing,

[0130] 307...wafer cassette table,

[0131] 308...vacuum transfer robot,

[0132] 309...atmospheric transfer robot,

[0133] 310...second vacuum transfer chamber,

[0134] 311...vacuum transfer intermediate chamber,

[0135] 320...gate valve,

[0136] 401...flow inlet,

[0137] 402...flow outlet,

[0138] 403, 404...through holes.

Claims

1. A plasma processing device, characterized in that, have: A processing chamber configured inside a vacuum container and forming a plasma on its inner side; A sample stage disposed within the processing chamber and on the upper surface of which the wafer to be processed is placed; A metal substrate disposed on the sample stage and having a refrigerant flow path for temperature-controlled refrigerant inside; At least one temperature sensor is disposed between the refrigerant flow path and the upper surface of the substrate to detect temperature; and A controller that uses the output from the temperature sensor to detect the temperature of the substrate or the wafer being processed and placed on the sample stage. When the controller defines the difference between the temperature obtained from the output of the temperature sensor and the actual temperature of the substrate or the wafer as an error, it detects the temperature of the substrate or the wafer based on a linear function characterizing the relationship between the error and the set temperature of the refrigerant. The linear function corresponds to different regions of multiple consecutive temperature ranges within the adjustable temperature range of the refrigerant, and the multiple linear functions contain the same coefficients and have points where the error becomes 0.

2. The plasma treatment apparatus according to claim 1, characterized in that, The plasma processing apparatus includes a heater disposed between the upper surface of the sample stage and the refrigerant flow path. The output of the heater is adjusted according to the detected temperature.

3. The plasma treatment apparatus according to claim 1, characterized in that, The coefficient of the linear function is the same as the coefficient of the linear function that represents the relationship between the error and the set temperature of the refrigerant over the entire temperature range that the refrigerant can regulate.

4. The plasma treatment apparatus according to claim 1, characterized in that, When the temperature obtained from the output of the temperature sensor of the sample stage of another plasma processing apparatus having substantially the same structure as the plasma processing apparatus is set as the substitution error between the temperature of the substrate or the wafer and the actual temperature of the substrate or wafer, the coefficient of the first-order function is the same value as the coefficient of the first-order function representing the relationship between the substitution error and the set temperature of the refrigerant.

5. A plasma treatment method, utilizing a plasma treatment device, characterized in that, The plasma processing apparatus includes: A processing chamber configured inside a vacuum container and forming a plasma on its inner side; A sample stage disposed within the processing chamber and on the upper surface of which the wafer to be processed is placed; A metal substrate disposed on the sample stage and having a refrigerant flow path for temperature-controlled refrigerant inside; At least one temperature sensor is disposed between the refrigerant flow path and the upper surface of the substrate to detect temperature; and A controller that uses the output from the temperature sensor to detect the temperature of the substrate or the wafer being processed and placed on the sample stage. In the plasma treatment method described above. The controller detects the temperature of the substrate or wafer by defining the difference between the temperature obtained from the output of the temperature sensor and the actual temperature of the substrate or wafer as an error, based on a linear function characterizing the relationship between the error and the set temperature of the refrigerant. The linear function corresponds to different regions of multiple consecutive temperature ranges within the adjustable temperature range of the refrigerant, and the multiple linear functions contain the same coefficients and have points where the error becomes 0.

6. The plasma treatment method according to claim 5, characterized in that, The plasma processing apparatus includes a heater disposed between the upper surface of the sample stage and the refrigerant flow path. The output of the heater is adjusted according to the detected temperature.

7. The plasma treatment method according to claim 5, characterized in that, The coefficient of the linear function is the same as the coefficient of the linear function that represents the relationship between the error and the set temperature of the refrigerant over the entire temperature range that the refrigerant can regulate.

8. The plasma treatment method according to claim 5, characterized in that, When the temperature obtained from the output of the temperature sensor of the sample stage of another plasma processing apparatus having substantially the same structure as the plasma processing apparatus is set as the substitution error between the temperature of the substrate or the wafer and the actual temperature of the substrate or wafer, the coefficient of the first-order function is the same value as the coefficient of the first-order function representing the relationship between the substitution error and the set temperature of the refrigerant.

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