Plasma processing device and component temperature determination method

Abstract

The present invention provides a plasma processing apparatus and a component temperature determination method for accurately determining whether the temperature of a component within a processing container is saturated. The plasma processing apparatus comprises a processing container and an electrode, and further comprises: a pretreatment unit configured to perform pretreatment by igniting plasma to increase the temperature of the component within the processing container; a power application unit configured to apply RF power to the electrode after performing the pretreatment without igniting the plasma; a measurement unit configured to measure a physical quantity related to the RF power applied by the power application unit; and a determination unit configured to determine whether the temperature of the component within the processing container is saturated based on the physical quantity related to the RF power measured by the measurement unit.

Description

Technical Field

[0001] The present invention relates to a plasma processing device and a component temperature determination method. Background Art

[0002] Conventionally, there has been known a plasma processing apparatus that uses plasma to perform plasma treatment on a wafer or other object to be processed. Such a plasma processing apparatus, for example, includes a platform for holding the object to be processed, which also serves as an electrode, within a processing container capable of forming a vacuum space. The plasma processing apparatus performs plasma treatment on the object to be processed arranged on the platform by applying a predetermined high-frequency power (RF (Radio Frequency) power) to the platform. In addition, before performing plasma treatment on the object to be processed, the plasma processing apparatus performs a pre-treatment in which the plasma is ignited to increase the temperature of the components within the processing container. This pre-treatment is also referred to as a drying treatment. The drying treatment is achieved by igniting the plasma while the wafer dummy is placed on the platform. The drying treatment is repeated, for example, a predetermined number of times until the temperature of the components within the processing container is saturated.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2000-167385 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides a technology capable of accurately determining whether the temperature of a member in a processing container is saturated.

[0008] Solutions for solving problems

[0009] A plasma processing apparatus according to one embodiment of the present disclosure includes a processing container and an electrode. The plasma processing apparatus further includes: a pretreatment unit configured to perform pretreatment for igniting plasma to increase the temperature of a component within the processing container; a power application unit configured to apply RF power to the electrode without igniting plasma after performing the pretreatment; a measurement unit configured to measure a physical quantity related to the RF power applied by the power application unit; and a determination unit configured to determine whether the temperature of the component within the processing container is saturated based on the physical quantity related to the RF power measured by the measurement unit.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to accurately determine whether the temperature of the member in the processing container is saturated. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic cross-sectional view showing the structure of a plasma processing apparatus according to one embodiment.

[0013] Figure 2 This is a block diagram showing a schematic configuration of a control unit that controls a plasma processing apparatus according to one embodiment.

[0014] Figure 3 It is a diagram schematically showing components in a processing container.

[0015] Figure 4 This is a diagram showing an example of the electrical state of the plasma processing apparatus when RF power is applied to the mounting table using an equivalent circuit.

[0016] Figure 5 This is a diagram showing an example of the relationship between the temperature of the components in the processing container and the number of repetitions of the drying process.

[0017] Figure 6 This is a flowchart showing an example of a flow of a plasma processing method according to one embodiment.

[0018] Figure 7 This is a diagram illustrating a specific example of a flow in which plasma processing is started after the temperature of the components in the processing container is saturated.

[0019] Description of Reference Numerals

[0020] 1: Processing container; 2: Loading table; 10: Plasma processing apparatus; 100: Control unit; 121: Drying processing unit; 122: Plasma processing unit; 123: Power application unit; 124: Measurement unit; 125: Acquisition unit; 126: Determination unit; 141: Determination reference information; VM: Measuring device; W: Wafer. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the plasma processing apparatus and component temperature measurement method disclosed in the present application will be described in detail with reference to the accompanying drawings. However, the disclosed plasma processing apparatus and component temperature measurement method are not limited to these embodiments.

[0022] In addition, plasma processing apparatuses sometimes use the measurement results of a thermometer installed within the processing vessel to determine whether the temperature of components within the processing vessel has reached saturation. If the temperature of the components within the processing vessel has reached saturation, the repeated drying process is terminated. However, when the thermometer is installed within the processing vessel, the location of the thermometer becomes a temperature singularity, which reduces the accuracy of the thermometer's measurement results. As a result, it is difficult to accurately determine whether the temperature of components within the processing vessel has reached saturation. Furthermore, this affects the temperature uniformity of the components within the processing vessel.

[0023] Therefore, it is desired to accurately determine the saturation of the temperature of the components in the processing container without installing a thermometer in the processing container.

[0024] [Structure of Plasma Processing Apparatus]

[0025] Figure 1 This is a schematic cross-sectional view showing the structure of a plasma processing apparatus 10 according to one embodiment. The plasma processing apparatus 10 includes a processing container 1 that is airtightly constructed and is set to an electrical ground potential. The processing container 1 is cylindrical and is made of, for example, aluminum. The processing container 1 defines a processing space for generating plasma. A mounting table 2 for horizontally supporting a semiconductor wafer (hereinafter referred to as a "wafer") W serving as a workpiece is provided in the processing container 1. The mounting table 2 is configured to include a substrate (base) 2a and an electrostatic chuck (ESC: Electrostatic chuck) 6. The substrate 2a is made of a conductive metal, such as aluminum, and has a function as a lower electrode. The electrostatic chuck 6 has a function for electrostatically adsorbing the wafer W. The mounting table 2 is supported by a support table 4. The support table 4 is supported by a support member 3 made of, for example, quartz. In addition, a focusing ring 5 made of, for example, single crystal silicon is provided on the outer periphery above the mounting table 2. Furthermore, a cylindrical inner wall member 3 a made of, for example, quartz is provided in the processing chamber 1 so as to surround the mounting table 2 and the support table 4 .

[0026] A first RF power source 10a is connected to the substrate 2a via a first matching box 11a, and a second RF power source 10b is connected to the substrate 2a via a second matching box 11b. The first RF power source 10a is primarily used to generate plasma and is configured to supply high-frequency power at a predetermined frequency selected from the range of 150 MHz to 10 MHz to the substrate 2a on the mounting table 2. The second RF power source 10b is primarily used to attract ions (for biasing) and is configured to supply high-frequency power at a predetermined frequency selected from the range of 40 MHz to 100 kHz, which is lower than that of the first RF power source 10a, to the substrate 2a on the mounting table 2. In this manner, the mounting table 2 is configured to be capable of being applied with a voltage.

[0027] Furthermore, the frequency of the first RF power source 10a simultaneously generates plasma and has a significant ion attraction effect, with the lower the frequency, the greater the proportion of ion attraction effect. Furthermore, the frequency of the second RF power source 10b simultaneously attracts ions and has a significant plasma generation effect, with the higher the frequency, the greater the proportion of plasma generation effect.

[0028] Furthermore, a measuring device VM is provided in the first matching unit 11a. The measuring device VM measures Vpp (Voltage Peak to Peak), which is the RF voltage of the RF power output from the first RF power supply 10a and applied to the mounting table 2 via the first matching unit 11a. Vpp is an example of a physical quantity related to the RF power applied to the mounting table 2. The measuring device VM notifies the control unit 100 of RF voltage data indicating the measured Vpp.

[0029] On the other hand, a shower head 16 serving as an upper electrode is provided above the mounting table 2 in parallel with and facing the mounting table 2. The shower head 16 and the mounting table 2 function as a pair of electrodes (an upper electrode and a lower electrode).

[0030] Electrostatic chuck 6 is configured by sandwiching electrode 6a between insulators 6b, and electrode 6a is connected to DC power supply 12. When DC voltage is applied from DC power supply 12 to electrode 6a, wafer W is attracted by Coulomb force.

[0031] A refrigerant flow path 2d is formed inside the mounting table 2, and a refrigerant inlet pipe 2b and a refrigerant outlet pipe 2c are connected to the refrigerant flow path 2d. Moreover, the mounting table 2 is configured to be controlled to a specified temperature by circulating an appropriate refrigerant, such as cooling water, in the refrigerant flow path 2d. In addition, a gas supply pipe 30 is provided in a manner that passes through the mounting table 2, etc., and the gas supply pipe 30 is used to supply a gas (back side gas) such as helium for transferring heat and cold to the back side of the wafer W. The gas supply pipe 30 is connected to a gas supply source (not shown). Through these structures, the wafer W, which is adsorbed and held on the upper surface of the mounting table 2 by the electrostatic chuck 6, is controlled to a specified temperature.

[0032] The focus ring 5 provided on the outer periphery of the mounting table 2 is also controlled to a predetermined temperature. Alternatively, a heater may be provided inside the mounting table 2 or the electrostatic chuck 6 to heat the wafer W and the focus ring 5 to a predetermined temperature.

[0033] The mounting table 2 is provided with a plurality of, for example, three, pin through holes 200 (in Figure 1 Only one is shown in the figure. ), lift pins 61 are respectively provided inside these pin through holes 200. The lift pins 61 are connected to a drive mechanism 62 and are moved up and down by the drive mechanism 62.

[0034] The shower head 16 is mounted on the ceiling of the processing container 1. The shower head 16 includes a main body 16a and an upper top plate 16b forming an electrode plate, and is supported on the upper portion of the processing container 1 via an insulating member 95. The main body 16a is made of a conductive material, such as anodized aluminum, and is configured to detachably support the upper top plate 16b at the bottom of the main body 16a.

[0035] A gas diffusion chamber 16c is provided within the main body 16a. Furthermore, a large number of gas flow holes 16d are formed at the bottom of the main body 16a, positioned below the gas diffusion chamber 16c. Furthermore, gas inlet holes 16e are provided in the upper top plate 16b, extending through the thickness of the upper top plate 16b. These gas inlet holes 16e are arranged to overlap with the aforementioned gas flow holes 16d. This structure allows the processing gas supplied to the gas diffusion chamber 16c to be dispersed in a shower-like manner through the gas flow holes 16d and the gas inlet holes 16e and supplied into the processing vessel 1.

[0036] A gas inlet port 16g for introducing a processing gas into the gas diffusion chamber 16c is formed in the main body 16a. One end of a gas supply pipe 15a is connected to the gas inlet port 16g. A processing gas supply source (gas supply unit) 15 for supplying processing gas is connected to the other end of the gas supply pipe 15a. A mass flow controller (MFC) 15b and an opening and closing valve V2 are provided in sequence on the gas supply pipe 15a from the upstream side. Processing gas for plasma etching is supplied from the processing gas supply source 15 to the gas diffusion chamber 16c via the gas supply pipe 15a. Processing gas is dispersed and supplied into the processing container 1 in a spray-like manner from the gas diffusion chamber 16c via the gas flow hole 16d and the gas inlet port 16e.

[0037] The shower head 16, which serves as the upper electrode, is electrically connected to a variable DC power supply 72 via a low-pass filter (LPF) 71. The variable DC power supply 72 is configured to be able to be turned on / off by an on / off switch 73. The current / voltage of the variable DC power supply 72 and the on / off switching of the on / off switch 73 are controlled by a control unit 90, which will be described later. Furthermore, as will be described later, when a high frequency is applied from the first RF power supply 10a and the second RF power supply 10b to the mounting table 2 to generate plasma in the processing space, the control unit 90 turns on the on / off switch 73 as needed to apply a predetermined DC voltage to the shower head 16, which serves as the upper electrode.

[0038] A cylindrical ground conductor 1a is provided so as to extend from the side wall of the processing container 1 to a position above the height position of the shower head 16. The cylindrical ground conductor 1a has a ceiling at its upper portion.

[0039] An exhaust port 81 is formed at the bottom of the processing container 1. Exhaust port 81 is connected to a first exhaust unit 83 via an exhaust pipe 82. The first exhaust unit 83 includes a vacuum pump, which is configured to reduce the pressure within the processing container 1 to a predetermined vacuum level by operating the vacuum pump. Meanwhile, a wafer W loading / unloading port 84 is provided on a side wall of the processing container 1. A gate valve 85 is provided at this loading / unloading port 84 for opening and closing the port.

[0040] A sediment shield 86 is installed along the inner wall of the processing container 1. Sediment shield 86 prevents etching byproducts (sediments) from adhering to the processing container 1. A conductive member (GND block) 89, connected to a ground potential that can be controlled, is installed at the same height as the wafer W on sediment shield 86 to prevent abnormal discharge. Sediment shield 87 is also installed at the lower end of sediment shield 86, extending along the inner wall member 3a. Sediment shields 86 and 87 are detachable.

[0041] The operation of the plasma processing apparatus 10 having the above-described structure is centrally controlled by the control unit 100. The control unit 100 is, for example, a computer, and controls each unit of the plasma processing apparatus 10.

[0042] [Structure of the control unit]

[0043] Next, the control unit 100 will be described in detail. Figure 2 1 is a block diagram showing a schematic configuration of a control unit 100 that controls a plasma processing apparatus 10 according to an embodiment. The control unit 100 is, for example, a computer and includes an external interface 110 , a process controller 120 , a user interface 130 , and a storage unit 140 .

[0044] The external interface 110 is configured to communicate with various components of the plasma processing apparatus 10 and is used to input and output various data. For example, RF voltage data indicating RF power Vpp applied to the mounting table 2 is input from the measuring device VM to the external interface 110 .

[0045] The process controller 120 includes a CPU (Central Processing Unit) and controls various components of the plasma processing apparatus 10 .

[0046] The user interface 130 includes a keyboard for a process manager to input commands for managing the plasma processing apparatus 10 , a display for visually displaying the operating status of the plasma processing apparatus 10 , and the like.

[0047] The storage unit 140 stores a process recipe, which stores control programs (software), processing condition data, and the like for implementing various processes performed by the plasma processing apparatus 10 under the control of the process controller 120. For example, the storage unit 140 stores reference information 141. Reference information 141 is data that serves as a reference for determining whether the temperature of components within the processing vessel 1 is saturated when performing a drying process described later. It is data indicating the Vpp measured in advance when the temperature of the components within the processing vessel 1 is saturated. Details of reference information 141 will be described later. In addition, the control program and processing condition data may also be stored in a computer-readable recording medium (e.g., a hard disk, an optical disk such as a DVD, a floppy disk, a semiconductor memory, etc.). In addition, the control program, process recipe, and parameters may also be stored in other devices and read and utilized online, for example, via a dedicated line.

[0048] The process controller 120 has an internal memory for storing programs and data. The process controller 120 reads the control program stored in the storage unit 140 and executes the processing of the read control program. The process controller 120 functions as various processing units by executing the control program. For example, the process controller 120 has the functions of a drying processing unit 121, a plasma processing unit 122, a power application unit 123, a measurement unit 124, an acquisition unit 125, and a determination unit 126. In addition, in one embodiment, an example is given of the case where the process controller 120 functions as various processing units, but the present invention is not limited to this. For example, the functions of the drying processing unit 121, the plasma processing unit 122, the power application unit 123, the measurement unit 124, the acquisition unit 125, and the determination unit 126 can also be distributed to multiple controllers for implementation.

[0049] Furthermore, before performing plasma processing on wafer W, plasma processing apparatus 10 performs a pre-processing step in which plasma is ignited to raise the temperature of components within processing vessel 1. This pre-processing step is also referred to as a drying step. Drying is achieved, for example, by igniting plasma while a dummy wafer is placed on mounting table 2. The drying step is repeated, for example, a predetermined number of times until the temperature of components within processing vessel 1 reaches saturation. However, if the drying step is repeated too many times, the timing for starting plasma processing on wafer W is delayed, and the operating rate (productivity) of plasma processing apparatus 10 decreases.

[0050] Therefore, in the plasma processing apparatus 10, one approach is to use the measurement results of a thermometer installed in the processing vessel 1 to determine whether the temperature of the components in the processing vessel 1 has reached saturation. If the temperature of the components in the processing vessel 1 has reached saturation, the repeated drying process can be terminated. However, when a thermometer is installed in the processing vessel 1, the location of the thermometer becomes a temperature singularity, which reduces the accuracy of the thermometer's measurement results. As a result, it becomes difficult to accurately determine whether the temperature of the components in the processing vessel 1 has reached saturation. Furthermore, this affects the temperature uniformity of the components in the processing vessel 1.

[0051] Therefore, in the plasma processing apparatus 10 according to one embodiment, saturation of the temperature of the components in the processing container 1 is determined without providing a thermometer in the processing container 1. Specifically, the plasma processing apparatus 10 uses the Vpp of the RF power applied to the mounting table 2 to determine whether the temperature of the components in the processing container 1 has reached saturation.

[0052] Here, refer to Figure 3 and Figure 4 The relationship between the RF power Vpp applied to the mounting table 2 and the temperature of the components in the processing chamber 1 will be described.

[0053] Figure 3 This figure schematically illustrates the components within the processing vessel 1. A processing space for generating plasma is formed within the processing vessel 1. For example, the inner wall of the processing vessel 1, the mounting table 2 serving as the lower electrode, the support table 4, the focus ring 5, the showerhead 16 serving as the upper electrode, and the insulating member 95 face the processing space. For example, when generating plasma, RF power of a predetermined frequency is applied from the first RF power supply 10a to the mounting table 2.

[0054] Figure 4 1 is a diagram showing an example of the electrical state of the plasma processing apparatus 10 when RF power is applied to the mounting table 2 using an equivalent circuit. Figure 4 As shown, when RF power is applied to the mounting table 2, the plasma processing apparatus 10 is divided into a power supply 201, a matching device 202, and a processing space 203. The power supply 201 includes, for example, Figure 1 The first RF power supply 10a in the embodiment. The matching device 202 includes, for example Figure 1 The first matching device 11a in the embodiment includes variable capacitors C1 and C2 as a circuit structure of the first matching device 11a. In addition, the matching device 202 includes, for example, variable capacitors C1 and C2 as a circuit structure of the first matching device 11a. Figure 1 The measuring device VM in the process container 1 is used to measure Vpp, which is the RF voltage of the RF power output from the first RF power supply 10a and applied to the stage 2 via the first matching device 11a, and notifies the control unit 100 of RF voltage data representing Vpp. The processing space 203 includes, for example, the inner wall surface of the processing container 1, the stage 2 as a lower electrode, the support table 4, the focusing ring 5, the shower head 16 as an upper electrode, and the insulating member 95 as components arranged in the processing container 1. When RF power is applied to the stage 2, the inner wall surface of the processing container 1, the stage 2, and the focusing ring 5 are regarded as resistors R1, R2, and R5, for example. In addition, the support table 4 and the insulating member 95 are regarded as capacitors C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C19, C27, C19, C28, C29, C30, C31, C32, C33, C34, C35, C36, C37, C38, C39, C40, C41, C42, C5 95 In addition, the main body 16a and the upper top plate 16b of the shower head 16 are regarded as a resistor R 16a 、R 16b In addition, the gap between the shower head 16 and the mounting table 2 is regarded as a capacitor C GapThe combined impedance Z of the components within the processing container 1 changes as the temperature T of the components within the processing container 1 changes. Furthermore, according to Ohm's law, Vpp = Z·I holds true. Therefore, when the RF current I is constant, the RF power Vpp applied to the mounting table 2 changes as the combined impedance Z changes. In other words, Vpp changes as the temperature T of the components within the processing container 1 changes. Therefore, even if a thermometer is not installed within the processing container 1, it is possible to determine whether the temperature of the components within the processing container 1 is saturated by measuring Vpp.

[0055] When plasma is generated, the RF power output from the first RF power source 10a is absorbed by the load (plasma), resulting in no reflected wave or a small observed value. Furthermore, the magnitude of the reflected wave is determined by changes in the load impedance, and therefore varies with changes in the plasma state. Similarly to the reflected wave, the Vpp value also fluctuates due to changes in the load impedance caused by interference. Therefore, during plasma ignition, the reliability of the Vpp value is low, and temperature measurements using Vpp may be inaccurate.

[0056] On the other hand, when the RF radiation radiated from the mounting table 2, serving as the lower electrode, is totally reflected by the upper ceiling 16b of the shower head 16, serving as the upper electrode, the power provided without generating plasma returns to the mounting table 2 as a reflected wave. When the plasma is not ignited, the influence of conditions within the processing vessel 1, such as gas flow rate and pressure, can be reduced, suppressing impedance changes. Furthermore, the RF radiation is totally reflected rather than absorbed on the load side, thereby maintaining a constant magnitude of the reflected wave. Furthermore, the Vpp value when the RF radiation is totally reflected varies depending on the changes in the synthetic impedance Z associated with changes in the temperature T of the components within the processing vessel 1. Therefore, after performing a single drying process, the plasma processing apparatus 10 measures the Vpp value when the RF radiation is totally reflected, and determines whether the temperature of the components within the processing vessel 1 is saturated based on the measured Vpp value.

[0057] Return to Figure 2 The drying process section 121 controls the various components of the plasma processing apparatus 10 to perform a drying process. For example, the drying process section 121 reads out a process corresponding to the drying process to be performed from the storage section 140, and controls the various components of the plasma processing apparatus 10 based on the read-out process. The drying process is achieved, for example, by igniting plasma while the wafer dummy is placed on the mounting table 2. In one embodiment, the drying process section 121 repeats the drying process multiple times. As the drying process is repeated, the temperature of the components in the processing container 1 gradually rises.

[0058] The plasma processing unit 122 controls various components of the plasma processing apparatus 10 to perform plasma processing on the wafers W loaded into the processing container 1. For example, the plasma processing unit 122 reads a recipe corresponding to the plasma etching to be performed from the storage unit 140 and controls various components of the plasma processing apparatus 10 based on the read recipe. After the drying unit 121 stops repeatedly performing the drying process, the plasma processing unit 122 performs plasma processing on the wafers W.

[0059] After the drying process is performed, the power application unit 123 applies RF power to the mounting table 2 so as not to ignite plasma. Specifically, after the drying process is performed, the power application unit 123 applies RF power from the first RF power source 10a to the mounting table 2 at a level that causes total reflection and prevents plasma generation. For example, each time the drying process is completed, the power application unit 123 applies RF power to the mounting table 2 so as not to ignite plasma.

[0060] Furthermore, after the plasma processing is performed on the wafer W, the power application unit 123 applies RF power to the mounting table 2 so as not to ignite the plasma. That is, after the plasma processing is performed on the wafer W, the power application unit 123 applies RF power from the first RF power source 10 a to the mounting table 2 at a level that causes total reflection and prevents the generation of plasma.

[0061] The measuring unit 124 measures a physical quantity related to the RF power applied by the power applying unit 123. Specifically, the measuring unit 124 uses the RF power Vpp represented by the RF voltage data input to the external interface 110 as a physical quantity related to the RF power and measures Vpp. The measuring unit 124 measures Vpp each time a drying process is completed. Examples of timings for measuring Vpp include when the plasma disappears after a drying process is completed or when a predetermined time has elapsed since the plasma disappears. Preferably, the measurement timings are consistent with those corresponding to each drying process.

[0062] After the plasma processing is performed on the wafer W, the measuring unit 124 measures a physical quantity related to the RF power applied by the power applying unit 123. That is, after the plasma processing is performed on the wafer W, the measuring unit 124 measures Vpp, which is a physical quantity related to the RF power.

[0063] The acquisition unit 125 acquires reference information 141, which indicates the Vpp previously measured when the temperature of the components within the processing chamber 1 is saturated. For example, the acquisition unit 125 reads and acquires the reference information 141 from the storage unit 140. The timing for acquiring the reference information 141 can be arbitrary, and for example, it can be before the first drying process is performed. Furthermore, in one embodiment, the reference information 141 is pre-stored in the storage unit 140. However, if the reference information 141 is stored in another device, the acquisition unit 125 can also acquire the reference information 141 via a network.

[0064] Here, refer to Figure 5 The judgment criterion information 141 will be further described. Figure 5 This is a diagram showing an example of the relationship between the temperature of the components in the processing container 1 and the number of repetitions of the drying process. Figure 5 This is a result obtained by measuring the temperature of the components in the processing container 1 while the drying process is repeatedly performed.

[0065] like Figure 5 As shown, as the drying process is repeated, the temperature of the components in the processing container 1 gradually rises and reaches a fixed saturation point. In addition, an interval for replacing the dummy wafer is provided between one drying process and the next, so the temperature of the components in the processing container 1 temporarily decreases during this interval.

[0066] As described above, in plasma processing apparatus 10, as the drying process is repeated, the temperature of the components within processing vessel 1 rises, eventually reaching a fixed saturation point. Furthermore, Vpp changes in accordance with the temperature of the components within processing vessel 1. Therefore, when the temperature of the components within processing vessel 1 reaches a fixed saturation point, Vpp also reaches a fixed saturation point.

[0067] Therefore, for example, the drying process is repeatedly performed by experiments, and Vpp is measured in a state where the temperature of the components in the processing container 1 is saturated. The measured Vpp is stored in advance in the storage unit 140 as the judgment reference information 141. Figure 5 In the example, the temperature of the components in the processing container 1 after the sixth drying process has not changed compared to the temperature of the components in the processing container 1 after the fifth drying process. In this case, the temperature of the components in the processing container 1 is considered to be saturated. Therefore, the Vpp measured after the sixth drying process is stored in the storage unit 140 as the judgment reference information 141.

[0068] Return to Figure 2Description. The determination unit 126 determines whether the temperature of the component in the processing container 1 is saturated based on the Vpp measured by the measuring unit 124. That is, the determination unit 126 compares the Vpp measured by the measuring unit 124 with the Vpp indicated by the determination reference information 141 acquired by the acquisition unit 125 (hereinafter referred to as "reference Vpp" as appropriate), thereby determining whether the temperature of the component in the processing container 1 is saturated. In one embodiment, the determination unit 126 determines whether the Vpp measured by the measuring unit 124 is within the allowable range of the reference Vpp, thereby determining whether the temperature of the component in the processing container 1 is saturated. The allowable range of the reference Vpp refers to a range from an allowable value (lower limit value) lower than the reference Vpp to an allowable value (upper limit value) higher than the reference Vpp relative to the reference Vpp.

[0069] If the determination unit 126 determines that the temperature of the components in the processing container 1 is not saturated, the drying unit 121 continues to repeat the drying process. If the determination unit 126 determines that the temperature of the components in the processing container 1 is saturated, the drying unit 121 stops repeating the drying process.

[0070] Thus, in the plasma processing apparatus 10 , the saturation of the temperature of the components in the processing container 1 can be determined with high accuracy without installing a thermometer in the processing container 1 , and as a result, excessive repetition of the drying process can be suppressed.

[0071] In addition, when plasma processing is subsequently performed on the wafer W, a predetermined number of drying processes may be added before determining that the temperature of the components in the processing container 1 is saturated and stopping the repeated drying process to improve the reproducibility of the state in which the temperature of the components in the processing container 1 is saturated.

[0072] Alternatively, if the determination unit 126 determines that the temperature of the components within the processing vessel 1 is below the allowable temperature range, that is, below the lower limit of the allowable range of the reference Vpp, and that the temperature of the components within the processing vessel 1 is not saturated, then the determination unit 126 may further determine whether the drying process has been repeated a predetermined number of times. Furthermore, if the determination unit 126 determines that the temperature of the components within the processing vessel 1 is not saturated and that the drying process has not been repeated a predetermined number of times, then the drying process may continue to be repeated. Alternatively, if the determination unit 126 determines that the temperature of the components within the processing vessel 1 is not saturated and that the drying process has been repeated a predetermined number of times, then an alarm may be issued. Furthermore, if the temperature of the components within the processing vessel 1 is above the allowable temperature range, that is, above the upper limit of the allowable range of the reference Vpp, then an alarm may be issued. These alarms may be of any form as long as they can notify the administrator of the plasma processing apparatus 10 that the drying process is not proceeding normally due to a hardware failure or other reason. For example, the determination unit 126 may output a message to the user interface 130 to notify the user interface 130 of an abnormality in the drying process.

[0073] Thus, the plasma processing apparatus 10 can appropriately notify abnormalities in the drying process.

[0074] Furthermore, the determination unit 126 determines whether the temperature of the components within the processing container 1 is maintained at saturation based on the Vpp measured by the measurement unit 124 after the plasma treatment of the wafer W. Specifically, the determination unit 126 compares the Vpp measured by the measurement unit 124 after the plasma treatment of the wafer W with the reference Vpp to determine whether the temperature of the components within the processing container 1 is maintained at saturation. In one embodiment, the determination unit 126 determines whether the temperature of the components within the processing container 1 is maintained at saturation by determining whether the Vpp measured by the measurement unit 124 after the plasma treatment of the wafer W is within the allowable range of the reference Vpp.

[0075] Furthermore, if the determination unit 126 determines that the temperature of the components within the processing vessel 1 is not maintaining saturation, it issues an alarm. This alarm indicates that plasma processing is being performed while the temperature of the components within the processing vessel 1 is above or below the allowable temperature range due to a hardware failure or other reasons. This alarm may be in any form as long as it can notify the administrator of the plasma processing apparatus 10 that the plasma processing is not being performed normally on the wafer W. For example, the determination unit 126 may output a message to notify the user interface 130 of the abnormality in the plasma processing.

[0076] Thus, the plasma processing apparatus 10 can appropriately notify abnormalities in the plasma processing.

[0077] [Processing Flow]

[0078] Next, a flow of a plasma processing method will be described. The plasma processing method includes component temperature determination processing in which the plasma processing apparatus 10 determines whether the temperature of a component within the processing container 1 is saturated, and plasma processing of the wafer W is started based on the determination result of the component temperature determination processing. Figure 6 This is a flowchart showing an example of a flow of a plasma processing method according to one embodiment.

[0079] The acquisition unit 125 acquires the criterion information 141 (step S11), which indicates Vpp measured in advance when the temperature of the components in the processing container 1 is saturated. For example, the acquisition unit 125 acquires the criterion information 141 before the first drying process is performed.

[0080] The drying processing unit 121 performs a drying process (step S12) by igniting plasma, for example, while the dummy wafer is placed on the mounting table 2. After the drying process is performed, the dummy wafer is replaced with the plasma extinguished.

[0081] After the drying process is completed, the power application unit 123 applies RF power to the mounting table 2 so as not to ignite plasma (step S13). At this time, the power application unit 123 applies RF power while the dummy wafer is placed on the mounting table 2. By applying RF power while the dummy wafer is placed on the mounting table 2, the mounting table 2 can be protected from the plasma in the event that the plasma is accidentally ignited.

[0082] The measuring unit 124 measures Vpp, which is a physical quantity related to the applied RF power (step S14 ).

[0083] The determination unit 126 determines whether the measured Vpp is within the allowable range of the reference Vpp indicated by the determination reference information 141 , thereby determining whether the temperature of the components in the processing container 1 is saturated (step S15 ).

[0084] If it is determined that the measured Vpp is lower than the lower limit of the allowable range of the reference Vpp and the temperature of the components in the processing chamber 1 is not saturated (step S15: "Yes"), the determination unit 126 determines whether the drying process has been repeated a predetermined number of times (step S16). If it is determined that the drying process has not been repeated a predetermined number of times (step S16: "No"), the determination unit 126 returns the process to step S12 and continues to repeat the drying process.

[0085] On the other hand, when it is determined that the drying process has been repeated a predetermined number of times (step S16 : Yes), since the drying process is not performed normally, the determination unit 126 issues an alarm (step S17 ) and ends the process.

[0086] On the other hand, when it is determined that the measured Vpp is higher than the upper limit of the allowable range of the reference Vpp and the temperature of the components in the processing container 1 is higher than the allowable temperature range (step S15: "No", step S18: "Yes"), since the drying process is not performed normally, the determination unit 126 notifies the alarm (step S17) and ends the process.

[0087] On the other hand, if it is determined that the measured Vpp is within the allowable range of the reference Vpp and the temperature of the components within the processing container 1 is saturated (step S15: No, step S18: No), the determination unit 126 stops the repetition of the drying process (step S19). Furthermore, when plasma processing is subsequently performed on wafer W in step 20, a predetermined number of drying processes may be added before stopping the repetition of the drying process to improve the reproducibility of the state in which the temperature of the components within the processing container 1 is saturated.

[0088] After stopping the repetition of the drying process, the plasma processing unit 122 performs plasma processing on the wafer W (step S20 ). After the plasma processing is performed, the wafer W is replaced in a state where the plasma disappears.

[0089] After plasma processing is performed on wafer W, power application unit 123 applies RF power to mounting table 2 to prevent plasma ignition (step S21). At this time, power application unit 123 applies RF power while wafer W is mounted on mounting table 2. By applying RF power while wafer W is mounted on mounting table 2, mounting table 2 can be protected from the plasma in the event of unintentional plasma ignition.

[0090] The measuring unit 124 measures Vpp, which is a physical quantity related to the applied RF power (step S22 ).

[0091] The determination unit 126 determines whether the measured Vpp is within the allowable range of the reference Vpp indicated by the determination reference information 141, thereby determining whether the temperature of the components within the processing container 1 is maintained at saturation (step S23). If it is determined that the measured Vpp is within the allowable range of the reference Vpp and the temperature of the components within the processing container 1 is maintained at saturation (step S23: "Yes"), the determination unit 126 determines whether the number of wafers W that have completed the plasma treatment has reached a predetermined number (step S24). If it is determined that the number of wafers W that have completed the plasma treatment has not reached the predetermined number (step S24: "No"), the determination unit 126 returns the process to step S20 and repeats the plasma treatment.

[0092] On the other hand, when the determination unit 126 determines that the number of wafers W that have completed the plasma processing has reached the predetermined number (step S24 : Yes), the determination unit 126 ends the processing.

[0093] On the other hand, if the measured Vpp is not within the allowable range of the reference Vpp and the temperature of the components in the processing chamber 1 is not maintained at saturation (step S23: No), the plasma processing is not proceeding normally, so the determination unit 126 performs the following process. Specifically, the determination unit 126 issues an alarm (step S25) and terminates the process.

[0094] Next, a specific example will be described. Figure 7 This is a diagram illustrating a specific example of a flow in which plasma processing is started after the temperature of the components in the processing container 1 is saturated.

[0095] For example, Figure 7 As shown, as the drying process is repeated, the temperature of the components within the processing vessel 1 gradually rises, and is set to reach a fixed temperature near the saturation point after the fourth drying process. Furthermore, since Vpp changes according to the temperature of the components within the processing vessel 1, it is set that Vpp also reaches a value near the reference Vpp after the fourth drying process. In this case, since Vpp is within the allowable range of the reference Vpp, the plasma processing apparatus 10 determines that the temperature of the components within the processing vessel 1 is saturated and stops the repetition of the drying process. This can prevent excessive repetition of the drying process and reduce the delay in the timing of starting the first plasma process. As a result, the operating rate (productivity) of the plasma processing apparatus 10 can be improved.

[0096] As described above, a plasma processing apparatus 10 according to one embodiment includes a processing vessel 1 and a mounting table 2. The plasma processing apparatus 10 further includes a drying process unit 121, a power application unit 123, a measurement unit 124, and a determination unit 126. The drying process unit 121 performs a drying process to ignite plasma and thereby increase the temperature of components within the processing vessel 1. After performing the drying process, the power application unit 123 applies RF power to the mounting table 2 without igniting plasma. The measurement unit 124 measures a physical quantity related to the RF power applied by the power application unit 123. The determination unit 126 determines whether the temperature of the components within the processing vessel 1 has reached saturation based on the physical quantity related to the RF power measured by the measurement unit 124. Thus, the plasma processing apparatus 10 can accurately determine whether the temperature of the components within the processing vessel 1 has reached saturation without requiring a thermometer to be placed within the processing vessel 1.

[0097] Furthermore, the plasma processing apparatus 10 according to one embodiment includes an acquisition unit 125 that acquires determination reference information 141 indicating a physical quantity related to RF power, measured in advance, while the temperature of the components within the processing vessel 1 is saturated. The determination unit 126 compares the physical quantity related to RF power measured by the measurement unit 124 with the physical quantity related to RF power indicated by the determination reference information 131 acquired by the acquisition unit 125, thereby determining whether the temperature of the components within the processing vessel 1 is saturated. Thus, the plasma processing apparatus can accurately determine whether the temperature of the components within the processing vessel 1 is saturated using the physical quantity related to RF power measured in advance while the temperature of the components within the processing vessel 1 is saturated.

[0098] In addition, the drying process section 121 repeats the drying process multiple times. Each time the drying process is completed, the power application section 123 applies RF power to the mounting table 2 in a manner that does not ignite the plasma. Each time the drying process is completed, the measurement section 124 measures a physical quantity related to the RF power. When the determination section 126 determines that the temperature of the components in the processing container 1 is not saturated, the drying process section 121 continues to repeat the drying process. On the other hand, when the determination section 126 determines that the temperature of the components in the processing container 1 is saturated, the drying process section 121 stops repeating the drying process. Thus, the plasma processing apparatus 10 can suppress excessive repetition of the drying process, and as a result, the operating rate (productivity) of the plasma processing apparatus 10 can be improved.

[0099] Furthermore, the plasma processing apparatus 10 according to one embodiment includes a plasma processing unit 122 that performs plasma processing on wafers W loaded into the processing container 1. After the plasma processing, the power application unit 123 applies RF power to the mounting table 2 again without igniting the plasma. The measurement unit 124 measures a physical quantity related to the RF power applied by the power application unit 123 after the plasma processing. The determination unit 126 determines whether the temperature of components within the processing container 1 remains saturated based on the physical quantity related to the RF power measured by the measurement unit 124 after the plasma processing. Thus, when the plasma processing apparatus 10 performs plasma processing on wafers W after stopping the repeated drying process, it can accurately determine whether the temperature of components within the processing container 1 remains saturated.

[0100] Furthermore, the determination unit 126 issues an alarm when determining that the temperature of the components in the processing container 1 is not maintained at saturation. Thus, the plasma processing apparatus 10 can appropriately notify of abnormalities in the plasma processing.

[0101] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive, and the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope of the appended claims and the spirit thereof.

[0102] For example, in the above embodiment, the first RF power source 10a is connected to the substrate 2a via the first matching unit 11a, but the first RF power source 10a may be connected to the shower head 16 as the upper electrode via the first matching unit 11a. In this case, it is also possible to Figure 4 Since the plasma processing apparatus 10 is represented by such an equivalent circuit, the Vpp of the RF power applied to the shower head 16 can be measured.

[0103] In the above embodiment, the measuring device VM measures and outputs the Vpp of the RF power applied to the mounting table 2, that is, the RF voltage. However, the measuring device VM may also measure and output the RF current or the phase difference between the RF voltage and the RF power. Furthermore, the measuring device VM may output the impedance calculated by dividing the measured RF voltage by the RF current. Furthermore, the measuring device VM may output the RF power at the measurement location, which is the product of the measured RF voltage and the RF current. Furthermore, the measuring device VM may output the change in RF voltage from the initial state before the drying process is performed. Furthermore, the measuring device VM may output the change in RF current from the initial state before the drying process is performed. Furthermore, the measuring device VM may output the change in the phase difference between the RF voltage and the RF power from the initial state before the drying process is performed. Furthermore, the measuring device VM may output the change in impedance from the initial state before the drying process is performed. These values ​​output by the measuring device VM are examples of physical quantities related to the RF power applied to the mounting table 2.

Claims

1. A plasma processing apparatus comprising a processing container and an electrode, the plasma processing apparatus further comprising: a pretreatment unit configured to perform pretreatment by igniting plasma to increase the temperature of a member in the processing container; a power applying unit configured to apply radio frequency power to the electrode after performing the pretreatment so as not to ignite plasma; a measuring unit configured to measure a physical quantity related to the radio frequency power applied by the power applying unit; and a determination unit configured to determine whether the temperature of the member in the processing container is saturated based on the physical quantity related to the radio frequency power measured by the measurement unit, The physical quantity related to the RF power is at least any one of the following physical quantities: RF voltage, RF current, a phase difference between RF power and RF current, impedance, a change in RF voltage from an initial state in which the preprocessing has not been performed, a change in RF current from an initial state in which the preprocessing has not been performed, a change in the phase difference between RF power and RF current from an initial state in which the preprocessing has not been performed, and a change in impedance from an initial state in which the preprocessing has not been performed.

2. The plasma processing apparatus according to claim 1, wherein The apparatus further comprises an acquisition unit configured to acquire judgment reference information indicating a physical quantity related to the radio frequency power that is measured in advance in a state where the temperature of a component in the processing container is saturated. The determination unit is configured to compare the physical quantity related to the RF power measured by the measurement unit with the physical quantity related to the RF power indicated by the determination reference information acquired by the acquisition unit, thereby determining whether the temperature of the component in the processing container is saturated.

3. The plasma processing apparatus according to claim 1 or 2, wherein: The pre-processing unit is configured to repeatedly perform the pre-processing multiple times. The power applying unit is configured to apply radio frequency power to the electrode without igniting plasma each time the pre-treatment is completed. The measuring unit is configured to measure a physical quantity related to the radio frequency power each time the pre-processing is completed. The determination unit is configured to: cause the pretreatment unit to continue repeating the pretreatment when determining that the temperature of the component in the processing container is not saturated; and cause the pretreatment unit to stop repeating the pretreatment when determining that the temperature of the component in the processing container is saturated.

4. The plasma processing apparatus according to claim 3, wherein: The plasma processing unit is further provided, wherein the plasma processing unit is configured to perform plasma processing on the object to be processed which is loaded into the processing container after stopping the repetition of the pre-processing. The power application unit is configured to apply radio frequency power to the electrode again after the plasma treatment is performed without igniting plasma. The measuring unit is configured to measure a physical quantity related to the radio frequency power applied by the power applying unit after the plasma treatment is performed. The determination unit is configured to determine whether the temperature of the member in the processing container is maintained at saturation based on the physical quantity related to the radio frequency power measured by the measurement unit after the plasma processing is performed.

5. The plasma processing apparatus according to claim 4, wherein: The determination unit is configured to issue an alarm when determining that the temperature of the member in the processing container is not maintained at saturation.

6. A component temperature determination method, comprising: performing the following steps in a plasma processing apparatus having a processing container and an electrode: performing a pre-process of igniting plasma to increase the temperature of components within the processing container; After performing the pretreatment, applying radio frequency power to the electrode in a manner that does not cause plasma ignition; measuring a physical quantity related to the applied radio frequency power; as well as determining whether the temperature of the components in the processing container is saturated based on the measured physical quantity related to the radio frequency power, The physical quantity related to the RF power is at least any one of the following physical quantities: RF voltage, RF current, a phase difference between RF power and RF current, impedance, a change in RF voltage from an initial state in which the preprocessing has not been performed, a change in RF current from an initial state in which the preprocessing has not been performed, a change in the phase difference between RF power and RF current from an initial state in which the preprocessing has not been performed, and a change in impedance from an initial state in which the preprocessing has not been performed.

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