Wafer processing device and wafer processing method
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- HITACHI HIGH TECH CORP
- Filing Date
- 2025-01-23
- Publication Date
- 2026-07-30
Smart Images
Figure JP2025001972_30072026_PF_FP_ABST
Abstract
Description
Wafer processing apparatus and wafer processing method
[0001] The present invention relates to a wafer processing apparatus and a wafer processing method.
[0002] In semiconductor devices, further miniaturization and the development of three-dimensional device structures are progressing to meet the demands for lower power consumption and increased memory capacity. In the manufacturing of three-dimensional devices, because the structure is three-dimensional and complex, "isotropic etching," which allows etching in the lateral direction as well as the conventional "perpendicular etching" that etchs perpendicular to the wafer surface, is increasingly being used. Traditionally, isotropic etching has been performed using wet processing with chemical solutions, but with the progress of miniaturization, the problem of pattern collapse due to the surface tension of the chemical solution has become apparent. Therefore, in isotropic etching, it has become necessary to replace the conventional wet processing with chemical solutions with dry processing that does not use chemical solutions.
[0003] The need for gas etching is increasing, particularly in isotropic etching processes in three-dimensional semiconductor manufacturing. In gas etching, physical parameters such as pressure and wafer temperature significantly contribute to the chemical reaction, making accurate measurement of wafer temperature crucial for process control. However, methods that directly measure temperature using thermocouples are not suitable for mass production processes of semiconductor devices. Therefore, there is a need for non-contact temperature detection technology for semiconductor wafers.
[0004] An example of such conventional technology is the use of a radiation thermometer, which detects the temperature by sensing the amount of heat radiated from a semiconductor wafer. However, this technology is generally constrained by the melting points of various materials, and in the manufacturing process of typical semiconductor devices, the temperature of the semiconductor wafer is controlled to a value of around 500°C or lower. At such temperatures, stable temperature detection using a radiation thermometer becomes difficult. As an alternative to the technology using radiation thermometers, there is an absorption edge evaluation technology that stably detects the temperature using the temperature dependence of the frequency of the region edge (absorption edge) in the frequency (wavelength) range of electromagnetic waves absorbed by the semiconductor. In other words, this technology detects the temperature of the semiconductor wafer by measuring the spectrum of light transmitted or scattered and reflected through the semiconductor wafer and evaluating the absorption edge of that spectrum.
[0005] In manufacturing equipment for semiconductor devices, such as dry etching equipment, an absorption edge evaluation apparatus equipped with an infrared light source for wafer temperature measurement, as described in Patent Document 1, is known for detecting the temperature of a semiconductor wafer with high accuracy using the above-mentioned absorption edge evaluation technology. Furthermore, Patent Document 2 discloses a technology for indirectly measuring temperature by attaching a thermocouple to a lift pin.
[0006] Japanese Patent Publication No. 2018-73962, Japanese Patent Publication No. 2023-13120
[0007] In the conventional technology described in Patent Document 1, it was necessary to design the heater pattern and refrigerant circuit within the wafer stage to bypass the fiber installation hole installed as the optical path for temperature measurement. This resulted in uneven heating on the wafer stage, which could impair in-plane setting performance / uniformity and potentially compromise product quality. Furthermore, the amount of infrared light (also called infrared, IR, or IR light) transmitted through the wafer differs depending on the type of film due to impurity (dope) content or resistance value. Therefore, in order to perform accurate temperature measurement (temperature conversion), it was necessary to set the appropriate lighting time each time depending on the object being measured. In addition, in the temperature measurement of a gas medium using a temperature sensor on the lift pin portion described in Patent Document 2, it is common practice to reduce the back surface pressure of the gas when heating with IR light, which reduces heat transfer through the gas, making it difficult to perform high-precision temperature measurement.
[0008] Therefore, the present invention aims to provide a wafer processing apparatus that processes wafers by heating with electromagnetic waves, which can efficiently and accurately measure the temperature of wafers with various film types, thereby achieving processing with good product quality.
[0009] To solve the above problems, one representative wafer processing apparatus of the present invention comprises a processing chamber disposed inside a vacuum container, a wafer stage disposed inside the processing chamber on which a wafer to be processed is placed on its upper surface, a lamp disposed above the wafer stage and emitting electromagnetic waves into the processing chamber including the wafer stage, an electromagnetic wave permeator movably disposed inside the wafer stage and transmitting the electromagnetic waves, and a detector that receives the electromagnetic waves transmitted through the wafer and the electromagnetic wave permeator and detects the temperature of the wafer from the received spectrum.
[0010] According to the present invention, in a wafer processing apparatus that processes wafers by heating with electromagnetic waves, it is possible to efficiently and accurately measure the temperature of wafers with various film types, thereby achieving processing with good product quality. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.
[0011] Figure 1 is a schematic cross-sectional view showing the configuration of the wafer processing apparatus according to this embodiment. Figure 2 is a schematic diagram showing the configuration of a temperature detection device for detecting the wafer temperature in this embodiment. Figure 3 is a graph showing how the received light spectrum after passing through the wafer changes with the wafer temperature. Figure 4 is a graph showing an example of the received light spectrum after passing through the wafer when the wafer is at a predetermined temperature. Figure 5 is a graph showing an example of the process for measuring the wafer temperature in this embodiment. Figure 6 is a schematic diagram showing a mechanism for adjusting the detected light intensity in this embodiment. Figure 7 is a graph showing the change in the received light spectrum after passing through the wafer when adjusting the detected light intensity. Figure 8 is a time chart for adjusting the detected light intensity in this embodiment.
[0012] Embodiments of the present invention will be described below with reference to the drawings. The configurations described below are illustrative and do not limit the scope of the present invention in any way. In the following examples, identical components or parts are denoted by the same reference numerals, and repeated descriptions are omitted unless necessary.
[0013] (Configuration of the wafer processing apparatus) Figure 1 is a schematic cross-sectional view showing the configuration of the wafer processing apparatus according to this embodiment. The wafer processing apparatus 100 according to this embodiment (sometimes called a plasma processing apparatus or etching apparatus) includes a vacuum vessel made of aluminum or the like and a lamp that heats a wafer on a stage in a processing chamber located below it by irradiating it with infrared rays (IR). The apparatus comprises a discharge chamber that forms the upper part of the vacuum vessel and in which plasma is formed, a passage that connects the discharge chamber and the processing chamber below, and slits located inside the passage that have a plurality of gaps or holes through which highly reactive particles such as radicals generated by the formation of plasma pass.
[0014] In the plasma processing apparatus of this embodiment, the processing chamber 101 is a chamber located inside the base chamber 102 which constitutes the lower part of the vacuum vessel, and a wafer stage 104 (also simply called a stage) for placing a wafer 103 on its upper surface is located in the lower part of the inner chamber. A plasma source is installed above the processing chamber 101, and an ICP discharge method is used for the plasma source.
[0015] A cylindrical quartz chamber 105 constituting an ICP plasma source is installed above a processing chamber 101, and an ICP coil 106 is installed outside the quartz chamber 105. A high-frequency power source 107 for plasma generation is connected to the ICP coil via a matching unit 108.
[0016] The frequency of the high-frequency power is assumed to be in a frequency band of several tens of MHz, such as 13.56 MHz. On the upper part of the quartz chamber 105, a top plate 110 is installed, which constitutes the upper part of the vacuum chamber and the lid of the discharge chamber 109. A gas dispersion plate 111 and a shower plate 112 are installed below the top plate 110, and the processing gas is introduced into the processing chamber 101 through the inside of the discharge chamber 109 via the gas dispersion plate 111 and the shower plate 112.
[0017] The supply flow rate of the processing gas is adjusted by a mass flow controller installed for each gas species. In the example of FIG. 1, the mass flow controller is a mass flow controller unit 113 arranged inside one box-shaped housing, and is connected to a gas distributor 114 arranged on the downstream side of the mass flow controller unit 113. Thereby, the flow rate and composition of the gas supplied near the center of the discharge chamber 109 and the gas supplied near the outer periphery can be independently controlled and supplied, so that the spatial distribution of radicals in the discharge chamber 109 can be controlled in detail.
[0018] In FIG. 1, NH ３ , H ２ , CH ２ F ２ , CH ３ F, CH ３ OH, O ２ , NF ３ , Ar, N ２ , CHF ３ , CF ４ , H ２ O are shown in the figure as processing gases, but gases other than the above gases may also be used.
[0019] At the bottom of the processing chamber 101, a vacuum exhaust pipe 115 connects to an exhaust means 116 to reduce the pressure inside the processing chamber 101. The exhaust means 116 may consist of, for example, a turbomolecular pump, a mechanical booster pump, or a dry pump. In addition, a pressure regulating means 117 is installed upstream of the exhaust means 116 to adjust the pressure in the processing chamber 101 and the discharge chamber 109.
[0020] An IR lamp unit for heating wafers is installed above the processing chamber 101 and below the ICP coil 106. The IR lamp unit mainly consists of an IR lamp 118, a reflector 119 that reflects electromagnetic waves (sometimes called light) from the IR lamp, and an IR light transmission window 120, which is located below the IR lamp 118 and is made of a transparent material such as quartz that forms the top surface of the processing chamber 101. The reflector 119 is installed above the IR lamp 118 and reflects the electromagnetic waves emitted from the IR lamp 118 downwards.
[0021] A circular (circular) lamp is used for the IR lamp 118. In this embodiment, the electromagnetic waves emitted from the IR lamp 118 mainly consist of light in the visible light to infrared light region (referred to as IR light in this disclosure), but the bandwidth of the electromagnetic waves is not limited to this, and if not specifically limited, it may simply be called a lamp. The IR lamp 118 comprises three IR lamps 118-1, 118-2, and 118-3 arranged concentrically. In this embodiment, three are used, but two, four, etc., may also be used.
[0022] An IR lamp 118 is connected to an IR lamp power supply 121, and a high-frequency cut filter 122 is installed in between to prevent noise from the high-frequency power used for plasma generation from flowing into the IR lamp power supply. Furthermore, the IR lamp power supply 121 has a function that allows the power supplied to IR lamps 118-1, 118-2, and 118-3 to be controlled independently of each other, so that the radial distribution of the heating amount of the wafer can be adjusted. Note that some of the wiring associated with this function is omitted from the illustration in Figure 1.
[0023] Above the wafer stage 104, a channel 124 is formed that connects the processing chamber 101 and the discharge chamber 109, allowing particles in the plasma 123 formed in the discharge chamber 109 to be introduced into the processing chamber 101. A plate member 125 with multiple through holes or slits formed at predetermined positions is installed in this channel 124. The plate member 125 shields the introduction of charged particles such as ions and electrons generated in the plasma 123 into the processing chamber 101, allowing only neutral gases and neutral radicals to be introduced and supplied onto the wafer 103.
[0024] The wafer stage 104 has a refrigerant channel 126 formed inside for cooling the stage, and the refrigerant is circulated and supplied by a chiller 127. In addition, plate-shaped electrode plates 128 are embedded in the stage to fix the wafer 103 by electrostatic adsorption, and a DC power supply 129 is connected to each of them.
[0025] Furthermore, in order to efficiently cool and regulate the temperature of the wafer 103, He gas can be supplied between the back surface of the wafer 103 and the wafer stage 104. In addition, to prevent damage to the back surface of the wafer even when heating and cooling are performed while the wafer 103 is adsorbed, the wafer 103 mounting surface of the wafer stage 104 is coated with a resin such as polyimide.
[0026] Furthermore, a thermocouple 130 for measuring the temperature of the wafer stage 104 is installed inside the wafer stage 104, and this thermocouple 130 is connected to a thermocouple thermometer 131. In Figure 1, only one thermocouple 130 and thermocouple thermometer 131 are shown, but multiple may be installed.
[0027] (Temperature Detection Device) Figure 2 is a schematic diagram showing the configuration of a temperature detection device for detecting the temperature of a wafer in this embodiment. The temperature detection device 140 includes a pin 132, a drive shaft 133, a drive mechanism 134, a photoreceiver 135, an optical fiber 136, a spectrometer 137, and a photodetector 138. As shown in Figure 2, one or more pins 132 are provided inside the wafer stage 104 so as to penetrate the stage. At least one of the pins is a transparent pin 132-1 made of a transparent material such as sapphire, and the others are non-transparent pins 132-2 made of a non-transparent material such as ceramic. Note that all pins may be made of a transparent material.
[0028] An O-ring is installed between the pin 132, which is made of a transparent or opaque material, and the wafer stage 104, creating a tight seal to prevent air from below the stage from flowing into the processing chamber 101.
[0029] The pin 132 is connected to a drive shaft 133 located at the bottom of the stage, and the drive shaft 133 is connected to a drive mechanism 134 located at the bottom of the vacuum chamber. The drive mechanism 134 is composed of, for example, a stepping motor. However, the drive mechanism 134 is not limited to a stepping motor, and a simpler drive means may be used. The height of the pin is adjusted by driving the drive shaft in the vertical direction using the drive mechanism 134.
[0030] The transparent pins 132-1 allow electromagnetic waves (light) that have passed through the wafer 103 to pass through as electromagnetic wave conductors. The transmitted light is received by the photodetector 135. The received light is then transmitted from one end of the optical fiber 136 to the other end, where it is spectrally separated into predetermined wavelengths. The spectrally separated light is then sent to the photodetector 138. The photodetector 138 measures the light intensity at each wavelength, thereby obtaining data of the received spectrum (also simply called the spectrum) which represents the detected light intensity at each wavelength.
[0031] Furthermore, the pins may also have the function of supporting the wafer 103 by placing it on their upper ends. In this case, by driving the drive shaft in the vertical direction by the drive mechanism 134, the height of the pins 132 is adjusted vertically above the stage surface as pusher pins that support the wafer, and can be used to support and transfer the wafer during wafer loading and unloading. In this case, it is desirable that the number of pins be sufficient to support the wafer, for example, three or more.
[0032] The temperature detection device is integrated into the etching apparatus, but it may be integrated into various semiconductor processing equipment or semiconductor manufacturing equipment, not just etching apparatus. Furthermore, it can also be used as a standalone device.
[0033] (Controller) The wafer processing apparatus 100 includes a controller 139 that controls the entire wafer processing apparatus 100. The controller 139 controls the operation and output magnitude of each component, such as the high-frequency power supply 107, the matching unit 108, the DC power supply 129, the pressure regulating means 117 including the pressure regulating valve, the exhaust means 116, the mass flow controller unit 113, the gas distributor 114, the IR lamp power supply 121, or a gate valve (not shown).
[0034] The controller 139 receives the output of the thermocouple thermometer 131 and the photodetector 138, and generates command signals to adjust the operation of the power supply, valves, pumps, etc. to suit the processing based on the measurement data represented by the output. The controller 139 may also adjust the temperature of the wafer 103 by feeding back the temperature of the wafer 103 obtained based on the signal from the photodetector 138 and controlling the IR lamp power supply 121, thereby adjusting the intensity of the electromagnetic waves emitted from the infrared lamp. Furthermore, the controller 139 may change and adjust processing conditions such as the type and composition of the gas introduced into the processing chamber 101 or discharge chamber 109 and the pressure inside the vacuum vessel, according to the temperature of the wafer 103 detected based on the signal from the photodetector 138.
[0035] The temperature of the wafer stage 104 is preferably controlled by combining the IR lamp 118 and the chiller 127. At this time, the controller 139 may complementarily combine and control the temperature of the wafer stage 104 correlated with the temperature of the wafer 103, the temperature of the wafer 103 obtained based on the signal from the photodetector 138, and the temperature of the wafer stage 104 detected by the thermocouple thermometer 131.
[0036] (Principle of temperature measurement) Next, the principle and method of temperature measurement will be described with reference to FIGS. 3 and 4. FIG. 3 is a graph showing how the received light spectrum after passing through the wafer changes with the wafer temperature. The horizontal axis represents the wavelength, and the vertical axis represents the light intensity. As shown in FIG. 3, with respect to the line X indicating the intensity of the IR light before being irradiated on the wafer, the lines Y (Y0, Y1, Y2) indicating the light intensity after passing through the inside of the wafer have profiles with decreasing values and characteristic changes around specific wavelengths. That is, as indicated by α in FIG. 3, a range of values including a specific wavelength at which the intensity of the IR light rapidly increases and decreases before and after that occurs.
[0037] The bandgap of the semiconductor becomes smaller as the temperature increases, and excitation of lower-energy photons becomes possible, resulting in a shift of the absorption edge to the longer wavelength side. When the temperature of the wafer changes, the bandgap also changes accordingly, and the wavelength of the IR light absorbed and transmitted changes, so the wavelength of α also changes. For example, with reference to Y0 in FIG. 2, when the temperature of the wafer decreases, it shifts to the shorter wavelength side like Y1, and when the temperature of the wafer increases, it shifts to the longer wavelength side like Y2.
[0038] In addition to the transmitted light, it is also possible to use the light diffusely reflected on the front or back surface of the wafer as the IR light to be detected. However, in this case, compared with that in FIG. 3, since the intensity of the measured light is relatively weak, measures to increase the S / N ratio are required.
[0039] Figure 4 is a graph showing an example of a received light spectrum after light has passed through a wafer when the wafer is at a predetermined temperature. The horizontal axis represents wavelength, and the vertical axis represents light intensity. The raw spectrum obtained by the photodetector 138 of the light that has passed through wafer 103, passed through pin 132-1 and been received by photodetector 135, transmitted to spectrometer 137, and then spectrally separated is shown in Figure 4(a). The normalized spectrum obtained by performing normalization, including smoothing, on the raw spectrum is shown in Figure 4(b). In this embodiment, the wavelength determined by a specific intensity as shown by β for the normalized spectrum in Figure 4(b) is defined as the absorption edge wavelength (also simply called the absorption edge). Prior to the manufacture of the semiconductor device, correlation data between the wafer temperature and the shift amount γ of the absorption edge from a reference temperature, for example, a calibration formula, is obtained for the shift amount γ of the absorption edge from a predetermined light intensity infrared light source. Then, the wafer temperature calculation process (absorption edge evaluation) of wafer 103 is performed by converting the shift amount on the wafer to be measured using the infrared light source of the predetermined light intensity to the wafer temperature.
[0040] When processing the wafer 103, for example, Ar gas is introduced into the processing chamber 101 to heat the wafer 103. However, since the light absorption wavelength of gas molecules is on the longer wavelength side compared to the absorption edge wavelength of the semiconductor, its influence on temperature detection based on the absorption edge wavelength as shown in this embodiment is small. Therefore, it is possible to use multiple types of gas introduced into the processing chamber 101 and used when heating the wafer 103.
[0041] (Temperature Measurement Process) Next, the temperature measurement process will be described. Figure 5 is a graph showing an example of the process for measuring the temperature of a wafer in this embodiment. The wafer 103 is brought into the processing chamber 101, and the DC power supply 129 electrostatically attracts and fixes the wafer 103 to the stage, while cooling He gas is supplied to the back surface of the wafer (Figure 5(c)). The mass flow controller unit 113 and the gas distributor 114 adjust the flow rate of the processing gas supplied into the processing chamber and the gas composition distribution within the processing chamber 101, and the high-frequency power supply 107 starts the plasma discharge (Figure 5(a)). The processing gas is ionized and dissociated in the plasma 123, and the neutral gas and radicals pass through the plate member 125 and are supplied to the wafer 103. After that, the high-frequency power supply 107 is turned OFF to stop the plasma discharge (Figure 5(a)). The supply of He gas to the back surface of the wafer is stopped (Figure 5(c)), and the pressure regulating means 117 (pressure regulating bubble) is opened to release the pressure on the back surface of the wafer. Next, the output of the IR lamp power supply 121 is turned ON to light up the IR lamp 118 (Figure 5(b)). The IR light emitted from the IR lamp 118 passes through the IR light transmission window 120 and heats the wafer 103. After that, the output of the IR lamp power supply 121 is turned OFF (Figure 5(b)) to stop heating the wafer 103. Next, while supplying Ar gas into the processing chamber, He gas is supplied to the back surface of the wafer to start cooling the wafer (Figure 5(c)). Once cooling is complete, the process moves to the next cycle and cycle etching is performed again.
[0042] During the heating period by the IR lamp 118 (Fig. 5(b)), as shown by A in Fig. 5(d), the light from the IR lamp 118 is spectroscopically measured, and the wafer temperature is estimated from the absorption edge wavelength. During the subsequent cooling period, without the light or electromagnetic waves from the IR lamp 118, as shown by the dotted line (imaginary line) at B in Fig. 5(d), the wafer temperature cannot be estimated by the wafer temperature detection method from the absorption edge evaluation. On the other hand, as shown by C in Fig. 5(d), when the output of the IR lamp 118 is reduced and the IR lamp 118 is lit at low power during the cooling period, the wafer temperature can be detected from the absorption edge evaluation of the spectrum transmitted through the wafer, similar to the heating period. At this time, the decrease in the wafer temperature is suppressed compared to the case of B with the same cooling period. Also, the wafer temperature during cooling may be estimated by complementarily combining with the temperature of the wafer stage 104 detected by the thermocouple thermometer 131. If it is not necessary to measure the wafer temperature during cooling, B where the IR lamp 118 is turned off may be adopted.
[0043] (Adjustment of detection light intensity) The amount of transmitted light of the electromagnetic wave transmitted through the wafer varies depending on the impurity content of the wafer or the difference in the resistance value (difference in film type) caused thereby. Therefore, if the setting of the temperature detection device is fixed, depending on the film type of the wafer, the detection light intensity of the received light spectrum transmitted through the wafer may exceed the measurable range of the detector. Hereinafter, means for dealing with such a problem will be described using Figs. 6 to 8. Fig. 6 is a schematic diagram showing a mechanism for adjusting the detection light intensity in the present embodiment. Fig. 7 is a graph showing the change in the received light spectrum after passing through the wafer when adjusting the detection light intensity. Fig. 8 is a time chart when adjusting the detection light intensity in the present embodiment.
[0044] First, when wafer processing begins, the wafer 103 is placed on the wafer stage 104. At this time, the pin 132-1 moves to the pin position P shown in Figure 6(a) (Figure 8, step 1). Next, as heating by the IR lamp 118, which is not involved in the product process of processing and manufacturing the wafer, IR irradiation at a high power, such as 70% of the maximum output, is performed for 25 seconds (Pre-IR irradiation, Figure 8, step 2). The output of the IR lamp is not particularly limited, but for example, a lamp with a maximum output of several tens of kilowatts may be used. As a result, the transmitted light that has passed through the wafer 103 is received by the spectrometer 137 and photodetector 138 via the pin 132-1 made of a transparent material to obtain the light spectrum (Figure 8, step 3).
[0045] Next, the controller 139 determines whether the detected light intensity (Intensity) of the received spectrum obtained in step 3 deviates from the measurable range of the photodetector 138 in a predetermined wavelength interval (e.g., 20 nm) within the wavelength range (e.g., 1000 to 1320 nm) necessary for normalization and temperature conversion in absorption edge evaluation (e.g., whether there are any values exceeding the upper limit of the detector's dynamic range of 64000 count) (Intensity O.F. (Over Flow) determination, Figure 8, step 4). As shown in the spectrum at pin position P in Figure 7, if the detected light intensity exceeds the upper limit of the measurable range in the predetermined wavelength interval and is determined to be YES, the process proceeds to Figure 8, step 5. On the other hand, if it is determined to be NO, the process proceeds to Figure 8, step 6. If a charge storage member (CCD, etc.) is included in the spectrometer 137, the above determination may be made based on the measurable range (dynamic range) of the spectrometer 137.
[0046] Beforehand, a pin position Q is determined using a wafer with a film type that has high transmittance, such that the detected light intensity of the spectrum does not deviate from the measurable range (does not exceed the measurable upper limit). If this is determined to be correct, the controller 139 moves the pin 132-1, made of a transparent material, to pin position Q via the drive shaft 133 using a drive mechanism 134 connected to the pin 132-1, as shown in Figure 6(b), to increase the distance between the pin 132-1 and the wafer 103 (Figure 8, step 5). This reduces the amount of electromagnetic waves incident on and transmitted through the pin 132-1, and the detected light intensity of the spectrum can be kept within the dynamic range, as shown in the spectrum at pin position Q in Figure 7. The distance between the pin 132-1 and the wafer 103 may be adjusted at two points, such as pin positions P and Q in Figure 6, but it may also be adjusted at more than one pin position, or it may be adjusted linearly (continuously). Note that, when performing absorption edge evaluation, a larger spectral value obtained allows for more accurate temperature estimation, so it is preferable not to increase the distance between the pin position and the wafer as long as it does not exceed the measurement upper limit. By doing so, absorption edge evaluation can be performed with high accuracy and optimal light intensity without having to adjust the light collection time for each type of wafer film, and the wafer temperature can be obtained.
[0047] From this point onward, except for the vertical drive during wafer 103 transport, pin 132-1 is fixed at pin position Q in Figure 6(b), and the normal product process is continuously executed for a certain number of identical wafers, for example, one lot (Figure 8, step 6). After the product process is completed, the controller determines that processing is complete and controls the drive mechanism 134 again to return the pin to the initial pin position shown at P in Figure 6(a). These steps can be performed automatically by executing software stored in the controller.
[0048] Furthermore, the detection light intensity can be adjusted, for example, by adjusting the light collection time (e.g., several thousand ms) using the spectrometer 137 (or photodetector 138), or by other methods, and these methods can also be combined as appropriate.
[0049] As described above, according to this embodiment, since the electromagnetic wave permeator that transmits the transmitted light from the wafer to the spectrometer and detector is movably arranged inside the wafer stage, the detected light intensity can be adjusted. Furthermore, even if the detected light intensity of the transmitted light deviates from the measurable range depending on the type of film on the wafer, the position of the electromagnetic wave permeator can be easily adjusted in advance so that it falls within the measurable range. This allows for efficient and accurate wafer temperature measurement, enabling high-quality processing in the product process. Moreover, if the electromagnetic wave permeator is a standard feature on the wafer stage and is a pin (pusher pin) that supports and transfers the wafer, there is no need to provide a separate optical path for wafer temperature measurement on the wafer stage, thus avoiding the occurrence of thermal unevenness and problems with in-plane setting performance / uniformity, and further improvement in product quality can be expected.
[0050] Although the present invention has been specifically described above based on the above embodiments, the present invention is not limited to the above embodiments and can be modified in various ways without departing from the spirit of the invention.
[0051] The following describes embodiments that may constitute the present invention, but are not limited thereto. (Embodiment 1) A wafer processing apparatus comprising: a processing chamber disposed inside a vacuum vessel; a wafer stage disposed inside the processing chamber on which a wafer to be processed is placed on its upper surface; a lamp disposed above the wafer stage and emitting electromagnetic waves into the processing chamber including the wafer stage; an electromagnetic wave permeator movably disposed inside the wafer stage and transmitting the electromagnetic waves; and a detector that receives the electromagnetic waves transmitted through the wafer and the electromagnetic wave permeator and detects the temperature of the wafer from the received spectrum. (Embodiment 2) A wafer processing apparatus according to Embodiment 1, further comprising a controller that adjusts the intensity of electromagnetic waves emitted from the lamp based on the output from the detector. (Embodiment 3) A wafer processing apparatus according to Embodiment 2, wherein the controller determines whether the detected light intensity of the received spectrum deviates from the measurable range of the detector in a predetermined wavelength interval, and if it determines that it does, moves the electromagnetic wave permeator so that it falls within the measurable range. (Aspect 4) A wafer processing apparatus according to any one of aspects 1 to 3, wherein the electromagnetic wave permeator is a pin housed in a through hole provided in the wafer stage and moves up and down to support and transfer the wafer. (Aspect 5) A wafer processing apparatus according to any one of aspects 1 to 4, wherein the electromagnetic wave includes infrared (IR). (Aspect 6) A wafer processing apparatus according to any one of aspects 1 to 5, wherein the detector detects the temperature of the wafer based on the amount of shift of the absorption edge wavelength determined from the received spectrum. (Aspect 7) A wafer processing method comprising: placing a wafer to be processed on the upper surface of a wafer stage arranged in a processing chamber inside a vacuum vessel; radiating electromagnetic waves into the processing chamber including the wafer stage from a lamp arranged above the wafer stage; and receiving electromagnetic waves transmitted through an electromagnetic wave permeator arranged to move inside the wafer and the wafer stage in a detector, and detecting the temperature of the wafer from the received spectrum.(Aspect 8) A wafer processing method according to Aspect 7, wherein the controller adjusts the intensity of electromagnetic waves emitted from the lamp based on the output from the detector. (Aspect 9) A wafer processing method according to Aspect 8, wherein the controller determines whether the detected light intensity of the received light spectrum deviates from the measurable range of the detector in a predetermined wavelength interval, and if it determines that it does, moves the electromagnetic wave permeator so that it falls within the measurable range. (Aspect 10) A wafer processing method according to Aspect 9, wherein before performing a product process on the wafer, the lamp emits electromagnetic waves for a predetermined period of time, the controller makes the determination, and if it determines that it does, moves the electromagnetic wave permeator. (Aspect 11) A wafer processing method according to any one of Aspects 7 to 10, wherein the detector detects the temperature of the wafer based on the amount of shift of the absorption edge wavelength determined from the received light spectrum. (Aspect 12) A wafer processing method according to any one of aspects 7 to 11, wherein during the cooling period of the wafer, the lamp emits electromagnetic waves at a lower output than during the heating period, and the detector detects the temperature of the wafer.
[0052] 100...Wafer processing apparatus, 101...Processing chamber, 102...Base chamber, 103...Wafer, 104...Wafer stage, 105...Quartz chamber, 106...ICP coil, 107...High-frequency power supply, 108...Matching unit, 109...Discharge chamber, 110...Top plate, 111...Gas dispersion plate, 112...Shower plate, 113...Mass flow controller unit, 114...Gas distributor, 115...Vacuum exhaust piping, 116...Exhaust means, 117...Pressure regulating means, 118 (118-1, 118-2, 118-3)...IR lamp, 119...Refrigerator, 120...IR light transmission window, 121...Power supply for IR lamp, 122...High-frequency cut filter, 123...Plasma, 124...Flow path, 125...Plate member, 126...Refrigerant flow path, 127...Chiller, 128...Electrode plate, 129...DC power supply, 130...Thermocouple, 131...Thermocouple thermometer, 132 (132-1, 132-2)...Pin, 133...Drive shaft, 134...Drive mechanism, 135...Photodetector, 136...Optical fiber, 137...Spectrometer, 138...Photodetector, 139...Controller, 140...Temperature detection device
Claims
1. A wafer processing apparatus comprising: a processing chamber disposed inside a vacuum vessel; a wafer stage disposed inside the processing chamber on which a wafer to be processed is placed on its upper surface; a lamp disposed above the wafer stage and emitting electromagnetic waves into the processing chamber including the wafer stage; an electromagnetic wave permeator movably disposed inside the wafer stage and transmitting the electromagnetic waves; and a detector that receives the electromagnetic waves transmitted through the wafer and the electromagnetic wave permeator and detects the temperature of the wafer from the received spectrum.
2. A wafer processing apparatus according to claim 1, comprising a controller that adjusts the intensity of electromagnetic waves emitted from the lamp based on the output from the detector.
3. A wafer processing apparatus according to claim 2, wherein the controller determines whether the detected light intensity of the received light spectrum deviates from the measurable range of the detector in a predetermined wavelength interval, and if it determines that it does, moves the electromagnetic wave permeator so that it falls within the measurable range.
4. A wafer processing apparatus according to claim 1, wherein the electromagnetic wave permeator is a pin housed in a through hole provided in the wafer stage and moves up and down to support and transfer the wafer.
5. A wafer processing apparatus according to claim 1 or 2, wherein the electromagnetic wave includes infrared (IR) light.
6. A wafer processing apparatus according to claim 1 or 2, wherein the detector detects the temperature of the wafer based on the amount of shift of the absorption edge wavelength determined from the received spectrum.
7. A wafer processing method comprising: placing a wafer to be processed on the upper surface of a wafer stage located in a processing chamber inside a vacuum vessel; radiating electromagnetic waves into the processing chamber, including the wafer stage, from a lamp located above the wafer stage; and receiving electromagnetic waves that have passed through an electromagnetic wave permeable material movably arranged inside the wafer and the wafer stage in a detector, and detecting the temperature of the wafer from the received spectrum.
8. A wafer processing method according to claim 7, wherein the controller adjusts the intensity of electromagnetic waves emitted from the lamp based on the output from the detector.
9. A wafer processing method according to claim 8, wherein the controller determines whether the detected light intensity of the received light spectrum deviates from the measurable range of the detector in a predetermined wavelength interval, and if it determines that it does, moves the electromagnetic wave permeator so that it falls within the measurable range.
10. A wafer processing method according to claim 9, wherein, before performing a product process on the wafer, the lamp emits electromagnetic waves for a predetermined period of time, the controller makes the determination, and if it determines to be correct, the electromagnetic wave permeator moves.
11. A wafer processing method according to claim 7 or 8, wherein the detector detects the temperature of the wafer based on the amount of shift of the absorption edge wavelength determined from the received spectrum.
12. A wafer processing method according to claim 7, wherein during the cooling period of the wafer, the lamp emits electromagnetic waves at a lower output than during the heating period, and the detector detects the temperature of the wafer.