Processing device and processing method

Abstract

This processing device comprises: a processing container; a gas supply source configured to supply a noble gas and a processing gas into the processing container; a first excitation light source configured to irradiate the inside of the processing container with a first excitation light which puts the noble gas in a first excitation state; and a second excitation light source configured to irradiate the inside of the processing container with a second excitation light which puts the noble gas that is in the first excitation state in a second excitation state.

Description

Processing device and processing method

[0001] The present disclosure relates to processing devices and methods.

[0002] Patent Document 1 discloses a configuration in which a location for generating a first plasma is set upstream of a vacuum processing chamber in which a sample is placed, separate from the vacuum processing chamber, and metastable atoms generated there are injected into the vacuum processing chamber, generating a second plasma in the vacuum processing chamber.

[0003] Japanese Patent Application Laid-Open No. 2008-263226

[0004] The present disclosure provides a processing apparatus and a processing method capable of uniformly generating metastable excited atoms.

[0005] A processing apparatus according to one aspect of the present disclosure includes a processing vessel, a gas supply source configured to supply a noble gas and a processing gas into the processing vessel, a first excitation light source configured to irradiate the processing vessel with first excitation light that causes the noble gas to be in a first excited state, and a second excitation light source configured to irradiate the processing vessel with second excitation light that causes the noble gas in the first excited state to be in a second excited state.

[0006] According to the present disclosure, metastable excited atoms can be generated uniformly.

[0007] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a substrate processing apparatus according to a first embodiment of the present disclosure. FIG. 2 is a diagram showing an example of the transition of argon gas from the ground state to metastable excited atoms. FIG. 3 is a diagram showing an example of a combination of excitation light beams that cause a noble gas to become metastable excited atoms. FIG. 4 is a diagram showing an example of a combination of excitation light beams that cause a noble gas to become metastable excited atoms. FIG. 5 is a diagram showing an example of a combination of excitation light beams that cause a noble gas to become metastable excited atoms. FIG. 6 is a diagram showing an example of the configuration of a second excitation light source according to the first embodiment. FIG. 7 is a diagram showing an example of the configuration of a second excitation light source according to the first embodiment. FIG. 8 is a diagram showing an example of the relationship between the distance from a lithium fluoride window, the generation density of atoms in a first excited state, and the intensity of the second excitation light. FIG. 9 is a diagram showing an example of the relationship between the distance from a lithium fluoride window, the heater output, and the intensity of the second excitation light. FIG. 10 is a flowchart showing an example of substrate processing according to the first embodiment. FIG. 11 is a schematic cross-sectional view showing an example of the configuration of a substrate processing apparatus according to a second embodiment.

[0008] Hereinafter, embodiments of the disclosed processing apparatus and processing method will be described in detail with reference to the drawings. Note that the disclosed technology is not limited to the following embodiments.

[0009] Conventionally, radicals are generated using plasma, and processes are performed using the generated radicals. However, when using plasma, ions and electrons are also generated, which can cause damage due to ion bombardment and electrostatic charge. In response to this, a method is considered in which metastable excited atoms of a noble gas are generated using photoexcitation, and the resulting energy is used to dissociate the process gas and generate radicals. However, metastable excited atoms cannot be optically excited directly from the ground state, and multiple light sources are required to excite them in stages. Therefore, when using photoexcitation, it is expected that by controlling multiple light sources, metastable excited atoms can be generated uniformly.

[0010] 1 is a schematic cross-sectional view showing an example of the configuration of a substrate processing apparatus 1 according to a first embodiment of the present disclosure. As shown in FIG. 1, the substrate processing apparatus 1 includes an apparatus main body 10 and a controller 11 that controls the apparatus main body 10. The apparatus main body 10 includes a processing vessel 101, a mounting table 102, a gas supply mechanism 103, a first excitation light source 104, a second excitation light source 105, an emission sensor 106, and an exhaust mechanism 107.

[0011] The processing vessel 101 is formed in a substantially cylindrical shape, and a mounting table 102 is disposed in the substantially center of the bottom surface of the processing vessel 101. The shape of the processing vessel 101 is not limited to a substantially cylindrical shape and may be any shape, such as a rectangular parallelepiped. An irradiation window 111 that transmits the first excitation light input from the first excitation light source 104 and a detection window 113 in which the light emission sensor 106 is provided are formed in the sidewall 101a of the processing vessel 101. The irradiation window 111 is formed of, for example, lithium fluoride. An opening (not shown) through which the substrate W passes is formed in a portion (not shown) of the sidewall 101a, and the opening is opened and closed by a gate valve (not shown). An irradiation window 112 that transmits the second excitation light input from the second excitation light source 105 is formed in the top surface 101b of the processing vessel 101. The irradiation window 112 is formed of, for example, quartz.

[0012] The substrate W to be processed is placed on the mounting table 102. The mounting table 102 is generally disk-shaped and made of ceramics such as AlN. Inside the mounting table 102, lifting pins (not shown) for lifting and lowering the substrate W are provided so as to be able to protrude and retract into the upper surface of the mounting table 102. Note that the mounting table 102 has a mechanism for holding the substrate W, such as an electrostatic chuck or a mechanical chuck (not shown), but the mechanism for holding the substrate W is not limited to these.

[0013] Furthermore, a resistance heater 141 is embedded inside the mounting table 102, and the heater 141 heats the substrate W placed on the mounting table 102 in accordance with power supplied from a heater power supply 142. The heater 141 is divided into multiple regions on the substrate support surface of the mounting table 102, and power can be controlled for each region. Thermocouples (not shown) are also inserted in the mounting table 102, and power to the heater 141 is controlled for each region based on signals from the thermocouples, thereby controlling the temperature gradient of the substrate W. The temperature gradient (gradation) of the substrate W is controlled, for example, so that the side closer to the irradiation window 111 is higher temperature than the side farther from the irradiation window 111 between both ends of the diameter of the substrate W. In other words, the temperature of the mounting table 102 is controlled so that a gradation of the heater 141 output is formed corresponding to the temperature gradient.

[0014] The gas supply mechanism 103 includes a shower ring 121 that is ring-shaped and arranged along the inner wall of the processing vessel 101. The shower ring 121 includes a ring-shaped flow path provided therein and multiple outlets that are connected to the flow path and open to the inside of the flow path. A gas supply unit 123 is connected to the shower ring 121 via a pipe 122. The gas supply unit 123 includes multiple gas sources and multiple flow rate controllers. In one embodiment, the gas supply unit 123 is configured to supply a process gas containing at least one noble gas from the corresponding gas source to the shower ring 121 via the corresponding flow rate controller. The gas supplied to the shower ring 121 is then supplied into the processing vessel 101 through the multiple outlets. The gas supply mechanism 103 is an example of a gas supply source.

[0015] The gas supply unit 123 supplies a silicon-containing gas, a halogen-containing gas, a nitrogen-containing gas, a noble gas (rare gas), or the like, each of which is controlled to a predetermined flow rate, into the processing chamber 101 via the shower ring 121. In this embodiment, the silicon-containing gas is, for example, silane (SiH4) gas. In this embodiment, the halogen-containing gas is, for example, NF3 gas. In this embodiment, the nitrogen-containing gas is, for example, ammonia (NH3) gas. In this embodiment, the noble gas is, for example, argon (Ar) gas. Instead of argon gas, other noble gases such as neon (Ne) gas, krypton (Kr) gas, and xenon (Xe) gas may be used.

[0016] The first excitation light source 104 is controlled to irradiate the processing vessel 101 with, for example, vacuum ultraviolet light having a wavelength of 106.6660 nm as the first excitation light through the irradiation window 111. That is, the first excitation light is irradiated from the side of the processing vessel 101. At this time, the first excitation light is a sheet-like light having a width equal to or greater than the diameter of the substrate W to be processed. The sheet-like light may be generated using a lens and a mirror, or may be generated by laser scanning. The first excitation light source 104 may be, for example, an excimer lamp, a dye laser, a D2 lamp, or the like. Note that the first excitation light may be, for example, continuous light. The first excitation light converts a noble gas supplied into the processing vessel 101 from a ground state to a first excited state. For example, the first excitation light having a wavelength of 106.6660 nm converts argon gas supplied into the processing vessel 101 from a ground state (0 eV) to a first excited state (11.62 eV). The space between the first excitation light source 104 and the irradiation window 111 is maintained in a vacuum state. When argon gas is used as the noble gas, the first excitation light source 104 may use, for example, vacuum ultraviolet light with a wavelength of 104.8220 nm as the first excitation light. When vacuum ultraviolet light with a wavelength of 104.8220 nm is used, the first excited state is 11.83 eV. Since the first excitation light is absorbed by the noble gas, the intensity (light amount) decreases with increasing distance from the irradiation window 111.

[0017] The second excitation light source 105 is controlled to irradiate, for example, infrared light having a wavelength of 810.5921 nm as the second excitation light into the processing vessel 101 through the irradiation window 112. That is, the second excitation light is irradiated from above the processing vessel 101. At this time, the second excitation light is a beam-shaped light that irradiates the entire substrate W to be processed. The beam-shaped light that irradiates the entire substrate W to be processed may be generated using a lens and a mirror, or may be generated by laser scanning. Note that the second excitation light may be, for example, continuous light. The second excitation light converts a noble gas in a first excited state in the processing vessel 101 into a second excited state. For example, the second excitation light having a wavelength of 810.5921 nm converts argon gas in a first excited state (11.62 eV) in the processing vessel 101 into a second excited state (13.15 eV). When argon gas is used as the noble gas and vacuum ultraviolet light with a wavelength of 104.8220 nm is used as the first excitation light, infrared light with a wavelength of 826.6794 nm may be used as the second excitation light. When infrared light with a wavelength of 826.6794 nm is used, the second excited state becomes 13.33 eV.

[0018] The second excitation light source 105 may be connected to the irradiation window 112 via an optical fiber. In this case, the second excitation light source 105 can be disposed at a location other than the top of the processing vessel 101. This means that the number of structures above the processing vessel 101 can be reduced. Region 150 shown in FIG. 1 is a region irradiated with both the first excitation light and the second excitation light, and metastable excited atoms of the noble gas are generated in this region 150. That is, metastable excited atoms of the noble gas are generated only at the intersection of the first excitation light and the second excitation light. In FIG. 1 , the first excitation light and the second excitation light are represented by shading with a gradation. Region 150 is represented by shading without a gradation, assuming that metastable excited atoms are generated substantially uniformly. Other wavelength combinations of the first excitation light and the second excitation light and cases where other gases are used as the noble gas will be described later.

[0019] The light emission sensor 106 detects light emitted when the noble gas changes from the second excited state to metastable excited atoms. The light emission sensor 106 detects light emission in the processing vessel 101 through the detection window 113 and is controlled to output the detected light emission data to the controller 11. The controller 11 measures the light emission intensity distribution in the processing vessel 101 based on the input light emission data. Note that a plurality of light emission sensors 106 and detection windows 113 may be provided. Furthermore, the light emission intensity distribution in the processing vessel 101 can be measured even when only one light emission sensor 106 and one detection window 113 are used, using techniques such as optical emission tomography and integral photography. For example, if the processing vessel 101 has a good shape symmetry, the light emission intensity distribution of the entire processing space 10s in the processing vessel 101 can be measured by shifting the field of view of the light emission sensor 106 around one detection window 113.

[0020] Here, the transition of noble gases to metastable excited atoms will be described with reference to Figs. 2 to 5. Fig. 2 is a diagram showing an example of the transition of argon gas from the ground state to metastable excited atoms. As shown in Fig. 2, in this embodiment, when argon gas in the ground state (0 eV) is irradiated with first excitation light having a wavelength of 106.6660 nm, the argon atoms transition from the ground state (0 eV) to the first excited state (radiative: 11.62 eV) (step S1). Note that the electron orbit is 3s ２ 3p ６ From 3s ２ 3p ５ It becomes 4s.

[0021] When the argon atom in the first excited state is irradiated with the second excitation light having a wavelength of 810.5921 nm, the argon atom transitions from the first excited state to the second excited state (13.15 eV) (step S2). ２ 3p ５ 4s to 3s ２ 3p ５ It becomes 4p.

[0022] The argon atoms in the second excited state spontaneously emit light with a wavelength of 772.5886 nm or 867.0324 nm, de-exciting, and transition to metastable excited atoms of 11.55 eV or 11.72 eV (step S3). Note that from the second excited state of 13.15 eV, transition occurs to both metastable excited atoms of 11.55 eV and 11.72 eV. In addition, the electron orbit is 3s ２ 3p ５ 4p to 3s ２ 3p ５ 4s. As described above, metastable excited atoms of 11.55 eV and 11.72 eV cannot be optically excited directly from the ground state. In the substrate processing apparatus 1, the generation of metastable excited atoms can be detected by detecting spontaneously emitted light of wavelengths 772.5886 nm and 867.0324 nm with the light emission sensor 106.

[0023] In addition, in the transition of argon atoms, emissions of wavelengths 810.6 nm and 935.7 nm may be detected. Therefore, it is preferable that the light emission sensor 106 has a wavelength resolution capable of distinguishing between these wavelengths and wavelengths 772.5886 nm and 867.0324 nm. Furthermore, if the radicals in the process gas do not emit light near wavelengths 810.6 nm and 935.7 nm, the wavelengths 810.6 nm and 935.7 nm may also be used as data indirectly indicating the generation of metastable excited atoms. In this case, a light emission sensor 106 with a wavelength resolution sufficient to detect wavelengths 772.5886 nm and 867.0324 nm without distinguishing between wavelengths 810.6 nm and 935.7 nm may be used. Note that the light emission sensor 106 used should be capable of detecting spontaneous emission depending on the type of noble gas.

[0024] 3 to 5 are diagrams showing examples of combinations of excitation light that cause noble gases to become metastable excited atoms. Table 20 shown in FIG. 3 shows combinations of first excitation light, material of the irradiation window 111, second excitation light, spontaneous emission wavelength, and final state energy when neon gas is used as the noble gas. The final state energy indicates the energy level of the metastable excited atoms. As shown in Table 20, for neon gas, vacuum ultraviolet light with wavelengths of 73.58962 nm and 74.37195 nm is used as the first excitation light. The A coefficients of the first excitation light are 5.88E+8 (5.88×10 ８ ) [s －１ ], 4.40E+7 (4.40×10 ７ ) [s －１ ]. The A coefficient indicates the ease with which molecules or atoms in an excited state emit light. The energies of the first excited state are 16.84805369 eV and 16.67082693 eV, respectively. In the case of neon gas, it is difficult to use lithium fluoride as the material for the irradiation window 111 due to the short wavelength of the first excitation light. Therefore, a capillary plate (CP) having a large number of holes with diameters of approximately 1 μm to several hundred μm arranged two-dimensionally is used. The CP itself is made of a dielectric material such as lead glass. When a CP is used, the differential pressure is adjusted so that the process gas in the process vessel 101 does not leak to the first excitation light source 104 side.

[0025] As shown in Table 20, for neon gas, when the wavelength of the first excitation light is 73.58962 nm, six wavelengths from 660.07754 nm to 717.59154 nm can be used as the wavelength of the second excitation light. The six wavelengths are 660.07754 nm, 668.01205 nm, 671.88974 nm, 693.13787 nm, 702.5987 nm, and 717.59154 nm. Table 20 also lists the A coefficients, second excited state energies, and spontaneous emission wavelengths for each of the six wavelengths. The final state energies for metastable excited atoms resulting from transitions from each of the six wavelengths are 16.61907009 eV or 16.71538108 eV.

[0026] For neon gas, when the wavelength of the first excitation light is 74.37195 nm, seven wavelengths from 350.22171 nm to 724.71631 nm can be used as the wavelength of the second excitation light. The seven wavelengths are 350.22171 nm, 603.16666 nm, 609.78506 nm, 630.65329 nm, 638.4756 nm, 650.83255 nm, and 724.71631 nm. Table 20 also shows the A coefficients, second excited state energies, and spontaneous emission wavelengths for each of the seven wavelengths. The final state energies for metastable excited atoms resulting from transition from each of the seven wavelengths are 16.61907009 eV or 16.71538108 eV.

[0027] Table 21 shown in FIG. 4 shows combinations of the first excitation light, the material of the irradiation window 111, the second excitation light, the spontaneous emission wavelength, and the final state energy when argon gas is used as the noble gas. As shown in Table 21, for argon gas, vacuum ultraviolet light with wavelengths of 104.8220 nm and 106.6660 nm is used as the first excitation light. The A coefficients of the first excitation light are 5.32E+8 (5.32×10 ８ ) [s －１ ], 1.32E+8 (1.32×10 ８ ) [s －１ The emission window 111 may be made of lithium fluoride (LiF).

[0028] As shown in Table 21, when using argon gas with a first excitation light wavelength of 104.8220 nm, six wavelengths ranging from 826.6794 nm to 978.7186 nm can be used as the second excitation light wavelength. The six wavelengths are 826.6794 nm, 841.0521 nm, 852.3783 nm, 922.703 nm, 935.6787 nm, and 978.7186 nm. Table 21 also lists the A coefficients, second excited state energies, and spontaneous emission wavelengths for each of the six wavelengths. The final state energies resulting from transition from each of the six wavelengths to metastable excited atoms are 11.54835442 eV or 11.72316039 eV. Note that in the above explanation, digits are omitted, such as 11.55 eV or 11.72 eV, respectively.

[0029] Furthermore, in argon gas, when the wavelength of the first excitation light is 106.6660 nm, six wavelengths from 727.494 nm to 966.0435 nm can be used as the wavelength of the second excitation light. The six wavelengths are 727.494 nm, 738.6014 nm, 800.8359 nm, 810.5921 nm, 842.6963 nm, and 966.0435 nm. Table 21 also shows the A coefficients, second excited state energies, and spontaneous emission wavelengths for each of the six wavelengths. The final state energies for metastable excited atoms resulting from transition from each of the six wavelengths are 11.54835442 eV or 11.72316039 eV.

[0030] Table 22 shown in FIG. 5 shows combinations of the first excitation light, the material of the irradiation window 111, the second excitation light, the spontaneous emission wavelength, and the final state energy when krypton gas and xenon gas are used as the noble gas. As shown in Table 22, for krypton gas, vacuum ultraviolet light with wavelengths of 116.4867 nm and 123.5838 nm is used as the first excitation light. The A coefficients of the first excitation light are 3.09E+8 (3.09×10 ８ ) [s －１ ], 2.98E+8(2.98×10 ８ ) [s －１]. When the wavelength is 116.4867 nm, lithium fluoride (LiF) and magnesium fluoride (MgF2) can be used as the material for the irradiation window 111. When the wavelength is 123.5838 nm, lithium fluoride (LiF), magnesium fluoride (MgF2), and calcium fluoride (CaF2) can be used as the material for the irradiation window 111.

[0031] As shown in Table 22, for krypton gas, when the wavelength of the first excitation light is 116.4867 nm, four wavelengths from 440.120227 nm to 851.12106 nm can be used as the wavelength of the second excitation light. The four wavelengths are 440.120227 nm, 826.5514 nm, 828.33284 nm, and 851.12106 nm. Table 22 also shows the A coefficient, second excited state energy, and spontaneous emission wavelength for each of the four wavelengths. The final state energy of the metastable excited atom resulting from transition from each of the four wavelengths is 9.91523229 eV or 10.5624143 eV.

[0032] Furthermore, for krypton gas, when the wavelength of the first excitation light is 123.5838 nm, five wavelengths from 446.494273 nm to 975.44352 nm can be used as the wavelength of the second excitation light. The five wavelengths are 446.494273 nm, 819.23082 nm, 830.03907 nm, 877.91607 nm, and 975.44352 nm. Table 22 also shows the A coefficients, second excited state energies, and spontaneous emission wavelengths for each of the five wavelengths. The final state energies for metastable excited atoms resulting from transition from each of the five wavelengths are 9.91523229 eV or 10.5624143 eV.

[0033] As shown in Table 22, for xenon gas, vacuum ultraviolet rays with wavelengths of 129.5588 nm and 146.961 nm are used as the first excitation light. The A coefficients of the first excitation light are 2.53E+8 (2.53×10 ８ ) [s －１ ], 2.73E+8 (2.73×10 ８ ) [s －１]. When the wavelength is 129.5588 nm, lithium fluoride (LiF), magnesium fluoride (MgF2), calcium fluoride (CaF2), and strontium fluoride (SrF2) can be used as the material for the irradiation window 111. When the wavelength is 146.961 nm, lithium fluoride (LiF), magnesium fluoride (MgF2), calcium fluoride (CaF2), strontium fluoride (SrF2), and barium fluoride (BaF2) can be used as the material for the irradiation window 111.

[0034] As shown in Table 22, when xenon gas is used and the wavelength of the first excitation light is 129.5588 nm, six wavelengths from 826.8792 nm to 930.919 nm can be used as the wavelength of the second excitation light. The six wavelengths are 826.8792 nm, 834.91157 nm, 865.0916 nm, 869.4587 nm, 893.3282 nm, and 930.919 nm. Table 22 also shows the A coefficient, second excited state energy, and spontaneous emission wavelength for each of the six wavelengths. The final state energy of the metastable excited atom resulting from the transition from each of the six wavelengths is 8.3153161 eV or 9.4471951 eV.

[0035] Furthermore, for xenon gas, when the wavelength of the first excitation light is 146.961 nm, six wavelengths from 473.5476 nm to 1084.131 nm can be used as the wavelength of the second excitation light. The six wavelengths are 473.5476 nm, 491.788 nm, 895.47086 nm, 916.51667 nm, 992.5919 nm, and 1084.131 nm. Table 22 also shows the A coefficients, second excited state energies, and spontaneous emission wavelengths for each of the six wavelengths. The final state energies for metastable excited atoms resulting from transition from each of the six wavelengths are 8.3153161 eV or 9.4471951 eV.

[0036] Returning to the description of FIG. 1 , the exhaust mechanism 107 includes an exhaust pipe 131 provided on the lower surface 101 c of the processing vessel 101 and an exhaust device 132 connected to the exhaust pipe 131. The exhaust device 132 includes a vacuum pump, a pressure control valve, and the like. In one embodiment, the exhaust mechanism 107 is configured to adjust the pressure inside the processing vessel 101 by controlling the vacuum pump and the pressure control valve.

[0037] The control unit 11 has a memory, a processor, and an input / output interface. The memory stores programs to be executed by the processor and recipes including conditions for each process. The processor executes the programs read from the memory and controls each part of the apparatus main body 10 via the input / output interface based on the recipes stored in the memory.

[0038] For example, the control unit 11 controls each unit of the substrate processing apparatus 1 to perform a substrate processing method described below. In a detailed example, the control unit 11 executes a step of loading and preparing the substrate W into the processing vessel 101. The control unit 11 executes a step of supplying a noble gas and a processing gas into the processing vessel 101. The control unit 11 executes a step of irradiating the processing vessel 101 with first excitation light to change the noble gas to a first excited state. The control unit 11 executes a step of irradiating the processing vessel 101 with second excitation light to change the noble gas from the first excited state to a second excited state. The control unit 11 executes a step of dissociating the processing gas with the noble gas that has become metastable excited atoms from the second excited state, thereby processing the substrate W.

[0039] [Details of Second Excitation Light Source 105] Next, details of the second excitation light source 105 will be described with reference to FIGS. 6 and 7 . FIG. 6 is a diagram illustrating an example of the configuration of the second excitation light source in the first embodiment. In the example illustrated in FIG. 6 , a second excitation light source 105a is used as the second excitation light source 105. The second excitation light source 105a includes a plurality of pairs of a light source 160 and lenses 161 and 162. The light source 160 uses, for example, a lamp, an LED (Light Emitting Diode), a laser, or the like, and outputs, for example, infrared light as the second excitation light. The lens 161 is, for example, a magnifying lens, and the lens 162 is, for example, a collimating lens. The second excitation light output from the light source 160 is magnified by the lens 161, converted into a parallel beam 163 by the lens 162, and irradiated into the processing vessel 101 through the irradiation window 112. 6, the light beams 163 are depicted as if they are spaced apart, but in reality, there is no space between adjacent light beams 163. Furthermore, the second excitation light irradiated from the second excitation light source 105a is controlled so that the intensity is weaker on the side closer to the irradiation window 111 and stronger on the side farther from the irradiation window 111 within the processing vessel 101, as indicated by the gradation in FIG. 6. That is, the second excitation light source 105a is provided with a plurality of light sources 160, and the intensity of the second excitation light is controlled for each of the plurality of light sources 160. In the second excitation light source 105a, the outputs of the plurality of light sources 160 are controlled, respectively, so that a gradation is formed in the intensity of the second excitation light from the upstream side (the side closer to the irradiation window 111) to the downstream side (the side farther from the irradiation window 111) of the first excitation light. The combination of the light source 160 and the lenses 161 and 162 may be not only a parallel beam but also a sheet of light due to diffusion, or other beam shapes as long as a gradation in the intensity of the second excitation light can be formed.

[0040] FIG. 7 is a diagram illustrating an example of the configuration of a second excitation light source in the first embodiment. In the example illustrated in FIG. 7 , a second excitation light source 105b is used as the second excitation light source 105. The second excitation light source 105b includes a light source 170 and a light modulation filter 171. The light source 170 uses, for example, a lamp, an LED, a laser, or the like, and outputs, for example, infrared light as the second excitation light. The light modulation filter 171 is, for example, a liquid crystal filter, and modulates the amount of light output from the light source 170. The second excitation light output from the light source 170 is modulated by the light modulation filter 171 and irradiated into the processing vessel 101 through the irradiation window 112. Furthermore, the second excitation light irradiated from the second excitation light source 105b has a weak intensity on the side closer to the irradiation window 111 and a strong intensity on the side farther from the irradiation window 111 within the processing vessel 101, as indicated by the gradation in FIG. 7 . In the second excitation light source 105b, the transmittance of the dimming filter 171 is controlled, so that a gradation is formed in the intensity of the second excitation light from the upstream side (the side closer to the irradiation window 111) of the first excitation light to the downstream side (the side farther from the irradiation window 111).

[0041] [Relationship Between Distance from Irradiation Window 111 and Intensity of Second Excitation Light] Next, the relationship between the distance from the irradiation window 111 (LiF window), the generation density of atoms in the first excited state, and the intensity of the second excitation light will be described with reference to FIGS. 8 and 9. FIG. 8 is a diagram showing an example of the relationship between the distance from the lithium fluoride window, the generation density of atoms in the first excited state, and the intensity of the second excitation light. As shown in FIG. 8, the first excitation light irradiated from the irradiation window 111 is absorbed by the noble gas in the processing vessel 101, and the intensity (amount of light) decreases with increasing distance from the irradiation window 111. That is, as shown in graph 180, in the processing vessel 101, the generation density of atoms in the first excited state of the noble gas decreases with increasing distance from the irradiation window 111 (LiF window). In contrast, as shown in graph 181, the intensity of the second excitation light is controlled to increase with increasing distance from the irradiation window 111 (LiF window). That is, the intensity of the second excitation light is controlled to form a gradation such that the intensity becomes stronger as the distance from the irradiation window 111 (LiF window) increases. That is, in this embodiment, the spatial distribution of the second excitation light is adjusted, and the excitation efficiency from the first excited state to the second excited state is controlled. In other words, the gradation of the intensity of the second excitation light is controlled so that the light emission when the noble gas changes from the second excited state to metastable excited atoms is uniform within the horizontal plane of the processing vessel 101 (particularly within the plane of the region where the substrate W is present). This makes it possible to uniformly generate metastable excited atoms in the region 150 above the substrate W to be processed.

[0042] FIG. 9 shows an example of the relationship between the distance from the lithium fluoride window and the heater output and the intensity of the second excitation light. As shown in graph 182 of FIG. 9 , the intensity of the second excitation light is controlled to increase with increasing distance from the irradiation window 111 (LiF window). The substrate W is heated non-uniformly by the second excitation light, which is mainly infrared light, according to the intensity distribution of the second excitation light. Therefore, in order to achieve a uniform temperature across the substrate W, as shown in graph 183, the output of the heater 141 is controlled to decrease with increasing distance from the irradiation window 111 (LiF window). That is, the output of the heater 141 is controlled to form a gradation whose intensity is reversed from that of the second excitation light. That is, the temperature of the mounting table 102 is controlled to form a gradation of the heater 141 output whose intensity is reversed from that of the second excitation light. This allows correction of temperature changes in the substrate W caused by the second excitation light. The intensity distribution of the second excitation light may be adjusted to adjust process non-uniformity caused by uneven flow of the noble gas and the processing gas in the processing vessel 101 .

[0043] [Substrate Processing Method] Next, a substrate processing method according to the first embodiment will be described with reference to a flowchart of FIG.

[0044] The control unit 11 controls a gate valve (not shown) to open a loading / unloading port. When the loading / unloading port is open, the substrate W is loaded into the processing space 10s of the processing vessel 101 through the loading / unloading port and placed on the mounting table 102. That is, the control unit 11 controls the substrate processing apparatus 1 to load the substrate W into the processing vessel 101 (step S101). Note that the control unit 11 may also be a control device for the entire substrate processing system (not shown), including the substrate processing apparatus 1 and a transfer device in a transfer chamber (not shown) adjacent to the processing vessel 101. The control unit 11 controls the gate valve to close the loading / unloading port. Note that step S101 is an example of a process of loading and preparing the substrate W into the processing vessel 101.

[0045] The controller 11 controls the exhaust device 132 connected to the exhaust pipe 131 to reduce the pressure in the processing vessel 101 to a predetermined pressure. The controller 11 controls the gas supply unit 123 to supply a noble gas and a processing gas into the processing vessel 101 through the multiple outlets of the shower ring 121. The controller 11 controls the first excitation light source 104 to irradiate the processing vessel 101 with a first excitation light to convert the noble gas into a first excited state. The controller 11 also controls the second excitation light source 105 to irradiate the processing vessel 101 with a second excitation light to convert the noble gas from the first excited state into a second excited state. The noble gas spontaneously emits light from the second excited state, converting the noble gas into metastable excited atoms, dissociating the processing gas and processing the substrate W. The controller 11 measures the emission intensity distribution in the processing vessel 101 based on emission data detected by the emission sensor 106 during the transition from the second excited state to metastable excited atoms. The control unit 11 performs feedback control on the second excitation light source 105 based on the measured emission intensity distribution, for example, so that the emission becomes uniform in a horizontal plane. That is, the control unit 11 controls the first excitation light source 104 and the second excitation light source 105 to execute a substrate processing step of processing the substrate W using radicals generated from the processing gas by the noble gas that has become metastable excited atoms (step S102).

[0046] When the substrate processing process is completed, the control unit 11 stops the first excitation light and the second excitation light to stop the generation of metastable excited atoms. The control unit 11 also controls the gate valve to open the loading / unloading port. The control unit 11 controls the substrate processing apparatus 1 to lift the substrate W by causing substrate support pins (not shown) to protrude from the upper surface of the mounting table 102. When the loading / unloading port is open, the substrate W is unloaded from the processing vessel 101 by an arm of the transfer chamber (not shown) through the loading / unloading port. That is, the control unit 11 controls the substrate processing apparatus 1 to unload the substrate W from the processing vessel 101 (step S103). In this way, the control unit 11 controls the first excitation light source 104 and the second excitation light source 105 to uniformly generate metastable excited atoms. Furthermore, in this embodiment, radicals can be selectively generated in the processing gas without generating ions or electrons, thereby suppressing damage to the substrate W caused by ions or electrons. Furthermore, by controlling the first excitation light source 104 and the second excitation light source 105, it is possible to control the distribution of metastable excited atoms more precisely than when metastable excited atoms are generated using plasma.

[0047] Second Embodiment In the first embodiment, the shower ring 121 was used to supply the noble gas and process gas, but the substrate processing apparatus may be configured so that a gas flow path is provided inside the irradiation window 112 to supply the noble gas and process gas in a shower-like manner from above the substrate W. This embodiment will be described as the second embodiment. The substrate processing apparatus in the second embodiment is similar to the first embodiment except for the supply paths of the noble gas and process gas, and therefore a description of the overlapping configuration and operation will be omitted.

[0048] Fig. 11 is a schematic cross-sectional view showing an example of the configuration of a substrate processing apparatus according to the second embodiment. As shown in Fig. 11, the substrate processing apparatus 1a according to the second embodiment has an apparatus body 210 instead of the apparatus body 10 according to the first embodiment. The apparatus body 210 also has an irradiation window 212 instead of the irradiation window 112 according to the first embodiment.

[0049] The irradiation window 212 has a gas flow path 221 therein and a plurality of discharge holes 222 connected to each of the gas flow paths 221. A gas supply unit 123 is connected to one end of the gas flow path 221 via a pipe 220. The noble gas and process gas supplied to the gas flow path 221 are uniformly supplied to the process space 210s from the plurality of discharge holes 222 in a horizontal plane. In the process space 210s, metastable excited atoms are generated in a region 250 irradiated with both the first excitation light and the second excitation light from the first excitation light source 104 and the second excitation light source 105, similar to the region 150 of the first embodiment. In the region 250, the process gas is dissociated by the generated metastable excited atoms to generate radicals. The substrate W is processed by the generated radicals. As described above, in the substrate processing apparatus 1a of the second embodiment, metastable excited atoms can be uniformly generated by controlling the first excitation light source 104 and the second excitation light source 105.

[0050] According to each of the above-described embodiments, the processing apparatus (substrate processing apparatus 1, 1a) includes a processing vessel 101, a gas supply source (gas supply mechanism 103) configured to supply a noble gas and a processing gas into the processing vessel 101, a first excitation light source 104 configured to irradiate the processing vessel 101 with first excitation light that brings the noble gas into a first excited state, and a second excitation light source 105 configured to irradiate the processing vessel 101 with second excitation light that brings the noble gas in the first excited state into a second excited state. As a result, metastable excited atoms can be uniformly generated.

[0051] Moreover, according to each embodiment, the processing apparatus further includes an exhaust mechanism 107 configured to reduce the pressure inside the processing vessel 101. As a result, metastable excited atoms can be uniformly generated in a reduced pressure atmosphere.

[0052] According to each embodiment, the processing device further includes an emission sensor 106 configured to detect emission of light when the noble gas changes from the second excited state to metastable excited atoms, thereby enabling feedback control of the second excitation light source 105.

[0053] Furthermore, according to each embodiment, the first excitation light is irradiated from the side of the processing vessel 101, and the second excitation light is irradiated from above the processing vessel 101. As a result, damage to the substrate W caused by the first excitation light, which is mainly vacuum ultraviolet light, can be reduced.

[0054] Furthermore, according to each embodiment, the second excitation light source 105 is provided so that a gradation in intensity of the second excitation light is formed from the upstream side to the downstream side of the first excitation light in the processing vessel 101. As a result, metastable excited atoms can be generated uniformly.

[0055] Furthermore, according to each embodiment, the intensity of the second excitation light is set to be weaker upstream and stronger downstream of the first excitation light, thereby enabling the generation of metastable excited atoms uniformly.

[0056] Moreover, according to each embodiment, the processing apparatus further includes a mounting table 102 configured to incorporate a heater 141 inside the processing vessel 101. The temperature of the mounting table 102 is controlled so that a gradation in the output of the heater 141 is formed so that the intensity gradation of the second excitation light is reversed. As a result, it is possible to correct the temperature change of the substrate W caused by the second excitation light, which is mainly infrared light.

[0057] According to each embodiment, the processing apparatus further includes an optical emission sensor 106 configured to detect optical emission occurring when the noble gas is converted from the second excited state to metastable excited atoms. The intensity gradation of the second excitation light is controlled so that the optical emission occurring when the noble gas is converted from the second excited state to metastable excited atoms is uniform within the horizontal plane of the processing vessel 101. As a result, metastable excited atoms can be generated uniformly.

[0058] Furthermore, according to each embodiment, a plurality of second excitation light sources (light sources 160) are provided, and the intensity of the second excitation light is controlled for each of the plurality of second excitation light sources, thereby enabling more precise control of the intensity of the second excitation light.

[0059] Furthermore, according to each embodiment, the intensity gradation of the second excitation light is formed using the light control filter 171. As a result, various types of light sources can be used as the second excitation light source.

[0060] According to each embodiment, the light control filter is a liquid crystal filter, which allows various types of light sources to be used as the second excitation light source, and also allows for fine control of the intensity of the second excitation light.

[0061] Furthermore, according to each embodiment, the first excitation light is irradiated from the first excitation light source 104 through the lithium fluoride window (irradiation window 111) into the processing vessel 101. As a result, vacuum ultraviolet light can be used as the first excitation light.

[0062] Furthermore, according to each embodiment, the second excitation light is irradiated from the second excitation light source 105 through the optical fiber and the quartz window (irradiation window 112) into the processing vessel 101. As a result, the second excitation light source 105 can be disposed at a location other than the top of the processing vessel 101.

[0063] According to each embodiment, the noble gas is argon gas, and as a result, metastable excited atoms of argon can be generated.

[0064] According to each embodiment, the processing gas is a silicon-containing gas, and as a result, a silicon-containing film can be formed on the substrate W.

[0065] According to each embodiment, the processing gas is a halogen-containing gas, which allows cleaning the inside of the processing vessel 101. Furthermore, the substrate W can be etched.

[0066] Furthermore, according to each embodiment, the processing method includes the steps of supplying a noble gas and a processing gas into the processing vessel 101, irradiating the processing vessel 101 with first excitation light to change the noble gas to a first excited state, irradiating the processing vessel 101 with second excitation light to change the noble gas in the first excited state to a second excited state, and dissociating the processing gas with the noble gas that has become metastable excited atoms from the second excited state, thereby processing the substrate W. As a result, it is possible to uniformly generate metastable excited atoms, and to process the substrate W with radicals of the processing gas dissociated by the metastable excited atoms.

[0067] According to each embodiment, the processing method further includes a step of detecting luminescence when the noble gas changes from the second excited state to a metastable excited atom, so that the second excitation light can be controlled based on the luminescence when the noble gas changes from the second excited state to a metastable excited atom.

[0068] According to each embodiment, the step of bringing the atoms into the second excited state controls the intensity of the second excitation light based on the light emission detected in the light emission detection step, thereby enabling feedback control of the intensity of the second excitation light based on the light emission when the atoms become metastable excited atoms.

[0069] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and various omissions, substitutions, and modifications may be made to the above-described embodiments without departing from the spirit and scope of the appended claims.

[0070] In addition, in the above-described embodiments, the processing vessel 101 has been described as having a substantially cylindrical shape, but the shape is not limited to this. For example, the processing vessel 101 may have any shape, such as a rectangular parallelepiped shape. That is, regardless of the shape of the processing vessel 101, the distribution of the second excitation light can be controlled, and metastable excited atoms can be generated uniformly.

[0071] The present disclosure may also be configured as follows: (1) A processing apparatus comprising: a processing vessel; a gas supply source configured to supply a noble gas and a processing gas into the processing vessel; a first excitation light source configured to irradiate the processing vessel with first excitation light that causes the noble gas to be in a first excited state; and a second excitation light source configured to irradiate the processing vessel with second excitation light that causes the noble gas in the first excited state to be in a second excited state. (2) The processing apparatus according to (1), further comprising an exhaust mechanism configured to reduce the pressure in the processing vessel. (3) The processing apparatus according to (1) or (2), further comprising an emission sensor configured to detect emission when the noble gas changes from the second excited state to metastable excited atoms. (4) The processing apparatus according to any one of (1) to (3), wherein the first excitation light is irradiated from a side of the processing vessel, and the second excitation light is irradiated from above the processing vessel. (5) The processing apparatus according to (4), wherein the second excitation light source is provided in the processing vessel such that a gradation in intensity of the second excitation light is formed from the upstream side to the downstream side of the first excitation light. (6) The processing apparatus according to (5), wherein the intensity of the second excitation light is set so that, when the upstream side and the downstream side of the first excitation light are compared, the intensity is weaker on the upstream side and stronger on the downstream side. (7) The processing apparatus according to (5) or (6), further comprising a mounting table configured to incorporate a heater inside the processing vessel, wherein the mounting table has a temperature controlled to form a gradation in output of the heater such that the gradation in intensity of the second excitation light is reversed. (8) The processing apparatus according to any one of (5) to (7), further comprising an emission sensor configured to detect emission when the noble gas changes from the second excited state to metastable excited atoms, and the gradation of the intensity of the second excitation light is controlled so that the emission when the noble gas changes from the second excited state to the metastable excited atoms is uniform within a horizontal plane of the processing vessel.(9) The processing apparatus according to any one of (5) to (8), wherein a plurality of second excitation light sources are provided, and the intensity of the second excitation light is controlled for each of the plurality of second excitation light sources. (10) The processing apparatus according to any one of (5) to (8), wherein the gradation of the intensity of the second excitation light is formed using a light-adjusting filter. (11) The processing apparatus according to (10), wherein the light-adjusting filter is a liquid crystal filter. (12) The processing apparatus according to any one of (1) to (11), wherein the first excitation light is irradiated from the first excitation light source into the processing vessel through a lithium fluoride window. (13) The processing apparatus according to any one of (1) to (12), wherein the second excitation light is irradiated from the second excitation light source into the processing vessel through an optical fiber and a quartz window. (14) The processing apparatus according to any one of (1) to (13), wherein the noble gas is argon gas. (15) The processing apparatus according to any one of (1) to (14), wherein the processing gas is a silicon-containing gas. (16) The processing apparatus according to any one of (1) to (15), wherein the processing gas is a halogen-containing gas. (17) A processing method comprising: supplying a noble gas and a processing gas into the processing vessel; irradiating the processing vessel with first excitation light to change the noble gas to a first excited state; irradiating the processing vessel with second excitation light to change the noble gas from the first excited state to a second excited state; and dissociating the processing gas with the noble gas that has become metastable excited atoms from the second excited state, thereby processing a substrate. (18) The processing method according to (17), further comprising: detecting luminescence when the noble gas changes from the second excited state to the metastable excited atoms. (19) The processing method according to (18), wherein the step of bringing the substance into the second excited state includes controlling an intensity of the second excitation light based on the light emission detected in the light emission detection step.

[0072] REFERENCE SIGNS LIST 1, 1a Substrate processing apparatus 10, 210 Apparatus main body 11 Control unit 101 Processing vessel 102 Mounting table 103 Gas supply mechanism 104 First excitation light source 105 Second excitation light source 106 Light emission sensor 107 Exhaust mechanism 111, 112, 212 Irradiation window 113 Detection window 141 Heater 160, 170 Light source 161, 162 Lens 171 Light control filter W Substrate

Claims

1. A processing apparatus comprising: a processing vessel; a gas supply source configured to supply a noble gas and a processing gas into the processing vessel; a first excitation light source configured to irradiate the processing vessel with a first excitation light that brings the noble gas into a first excited state; and a second excitation light source configured to irradiate the processing vessel with a second excitation light that brings the noble gas in the first excited state into a second excited state.

2. The processing apparatus according to claim 1, further comprising an exhaust mechanism configured to reduce the pressure inside the processing vessel.

3. The processing apparatus of claim 1, further comprising an optical emission sensor configured to detect optical emission as said noble gas transitions from said second excited state to a metastable excited atom.

4. The processing apparatus according to claim 1, wherein the first excitation light is irradiated from a side of the processing vessel, and the second excitation light is irradiated from above the processing vessel.

5. The processing apparatus according to claim 4, wherein the second excitation light source is provided in the processing vessel such that a gradation is formed in the intensity of the second excitation light from the upstream side to the downstream side of the first excitation light.

6. The processing device according to claim 5, wherein the intensity of the second excitation light is set so that, when comparing the upstream side and the downstream side of the first excitation light, the intensity is weaker on the upstream side and stronger on the downstream side.

7. The processing apparatus according to claim 5, further comprising a mounting table configured to incorporate a heater inside the processing vessel, the mounting table having a temperature controlled so that a gradation in the output of the heater is formed so that the gradation in the intensity of the second excitation light is reversed.

8. The processing apparatus according to claim 5, further comprising an emission sensor configured to detect emission when the noble gas changes from the second excited state to the metastable excited atoms, and the gradation of the intensity of the second excitation light is controlled so that the emission when the noble gas changes from the second excited state to the metastable excited atoms is uniform within a horizontal plane of the processing vessel.

9. The processing device according to claim 5, wherein a plurality of the second excitation light sources are provided, and the intensity of the second excitation light is controlled for each of the plurality of second excitation light sources.

10. The processing device according to claim 5, wherein the gradation of the intensity of the second excitation light is formed using a dimming filter.

11. The processing device according to claim 10, wherein the light control filter is a liquid crystal filter.

12. The processing apparatus according to claim 1, wherein the first excitation light is irradiated from the first excitation light source through a lithium fluoride window into the processing vessel.

13. The processing apparatus according to claim 1, wherein the second excitation light is irradiated from the second excitation light source through an optical fiber and a quartz window into the processing vessel.

14. The processing apparatus of claim 1, wherein the noble gas is argon gas.

15. The processing apparatus of claim 1, wherein the process gas is a silicon-containing gas.

16. The processing apparatus of claim 1, wherein the process gas is a halogen-containing gas.

17. A processing method comprising the steps of: supplying a noble gas and a processing gas into the processing vessel; irradiating the processing vessel with a first excitation light to bring the noble gas into a first excited state; irradiating the processing vessel with a second excitation light to bring the noble gas from the first excited state into a second excited state; and dissociating the processing gas with the noble gas that has become metastable excited atoms from the second excited state, thereby processing a substrate.

18. The method of claim 17, further comprising the step of detecting emission of light as said noble gas transitions from said second excited state to said metastable excited atoms.

19. The processing method according to claim 18, wherein the step of placing the device in a second excited state includes controlling an intensity of the second excitation light based on the light emission detected in the step of detecting the light emission.

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