Substrate processing method and substrate processing apparatus

Abstract

To provide a substrate processing method and a substrate processing apparatus for modifying an interface between a silicon layer and an oxide layer.SOLUTION: The present invention provides a substrate processing method comprising: a step of preparing a substrate having a silicon layer and an oxide layer formed on the silicon layer; and a step of modifying an interface between the silicon layer and the oxide layer by supplying a process gas containing a hydrogen-containing gas to the substrate and irradiating the substrate with an ultraviolet light in a wavelength range of 135 nm to 190 nm.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing method and a substrate processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a method for modifying a high-dielectric thin film, which involves performing a modification process to modify a high-dielectric thin film formed on the surface of a workpiece using an organometallic compound material, and is characterized in that the modification process includes a modification step in which the high-dielectric thin film is modified by irradiating ultraviolet light onto the high-dielectric thin film in an inert gas atmosphere while maintaining the workpiece at a predetermined temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-194582 Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present disclosure provides a substrate processing method and a substrate processing apparatus for modifying an interface between a silicon layer and an oxide layer. [Means for solving the problem]

[0005] In order to solve the above problem, according to one aspect, there is provided a substrate processing method comprising the steps of: preparing a substrate having a silicon layer and an oxide layer formed on the silicon layer; and modifying the oxide layer by supplying a process gas containing a hydrogen-containing gas to the substrate and irradiating the substrate with ultraviolet light within a wavelength range of 135 nm to 190 nm. [Effects of the Invention]

[0006] According to one aspect, it is possible to provide a substrate processing method and a substrate processing apparatus for modifying an interface between a silicon layer and an oxide layer. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 illustrates an example of a processing system. [Figure 2] FIG. 1 is a diagram showing an example of a substrate processing apparatus that performs a modification process on a substrate. [Figure 3] 10 is a flowchart illustrating an example of a modification process. [Figure 4] 1 is an example of a schematic cross-sectional view of a substrate. [Figure 5] An example of a graph showing the photodissociation characteristics of hydrogen (H2). [Figure 6] 1 is an example of a graph showing the photodissociation characteristics of oxygen (O2). [Figure 7] 1 is an example of a graph showing the photodissociation characteristics of H2O. [Figure 8] 1 is an example of a graph showing the photodissociation characteristics of OH. [Figure 9] 1 is an example of a graph showing the relationship between treatment time and oxide layer film thickness. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] [Processing System] An example of a processing system for carrying out a substrate processing method according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of a processing system PS.

[0010] The processing system PS includes processing devices PM1-PM4, vacuum transfer chambers VTM, load lock chambers LL1-LL3, atmospheric transfer chamber LM, load ports LP1-LP3, and a general control unit CU. In the example shown in Fig. 1, the processing system PS is described as including multiple processing devices PM1-PM4, multiple load lock chambers LL1-LL3, and multiple load ports LP1-LP3, but this is not limiting. The processing system PS includes at least one processing device, at least one load lock chamber, and at least one load port. Furthermore, the processing system PS may include multiple vacuum transfer chambers VTM and / or atmospheric transfer chambers LM.

[0011] The processing devices PM1 to PM4 are connected to the vacuum transfer chamber VTM via gate valves G11 to G14, respectively. The processing devices PM1 to PM4 are configured so that the interiors thereof can be depressurized to a predetermined vacuum atmosphere. The processing devices PM1 to PM4 accommodate substrates W therein and perform desired processing thereon.

[0012] The vacuum transfer chamber VTM is configured so that its interior can be depressurized to a predetermined vacuum atmosphere. The vacuum transfer chamber VTM is provided with a first transfer device TR1 that can transfer substrates W in a depressurized state. The first transfer device TR1 transfers substrates W to processing devices PM1 to PM4 and load lock chambers LL1 to LL3. The first transfer device TR1 has, for example, two independently movable transfer arms FK11 and FK12.

[0013] The load lock chambers LL1 to LL3 are connected to the vacuum transfer chamber VTM via gate valves G21 to G23, respectively. The load lock chambers LL1 to LL3 are connected to the atmospheric transfer chamber LM via gate valves G31 to G33, respectively. The load lock chambers LL1 to LL3 are configured so that their interiors can be switched between an atmospheric atmosphere and a vacuum atmosphere.

[0014] The interior of the atmospheric transfer chamber LM is an atmospheric atmosphere. For example, a downflow of clean air is formed inside the atmospheric transfer chamber LM. An aligner AN that aligns the substrate W is provided inside the atmospheric transfer chamber LM. The aligner AN may be provided outside the atmospheric transfer chamber LM. A second transfer device TR2 is provided in the atmospheric transfer chamber LM. The second transfer device TR2 transfers the substrate W to the load lock chambers LL1 to LL3, the load ports LP1 to LP3, and the aligner AN.

[0015] The load ports LP1 to LP3 are provided on the long side wall surfaces of the atmospheric transfer chamber LM. Carriers C are attached to the load ports LP1 to LP3. The carriers C include carriers C that house substrates W and empty carriers C. The carriers C may be, for example, FOUPs (Front Opening Unified Pods).

[0016] The overall control unit CU may be, for example, a computer. The overall control unit CU includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and an auxiliary storage device. The CPU operates based on a program stored in the ROM or the auxiliary storage device, and controls each part of the processing system PS. For example, the overall control unit CU controls the operations of the processing devices PM1 to PM4, the first transfer device TR1, the second transfer device TR2, and the gate valves G11 to G14, G21 to G23, and G31 to G33. For example, the overall control unit CU controls the operation of switching the interior of the load lock chambers LL1 to LL3 between the air atmosphere and the vacuum atmosphere.

[0017] Next, the operation of the processing system PS will be described.

[0018] First, the second transfer device TR2 removes the substrate W from the carrier C, transports it to the aligner AN, and exits the aligner AN. Next, the aligner AN aligns the substrate W. Next, the second transfer device TR2 removes the substrate W from the aligner AN, transports it to the load lock chamber LL1, and exits the load lock chamber LL1. Next, the interior of the load lock chamber LL1 is switched from the air atmosphere to a vacuum atmosphere. Thereafter, the first transfer device TR1 removes the substrate W from the load lock chamber LL1 and transports it to the processing device PM1.

[0019] The processing apparatus PM1 performs a first process on the substrate W. Here, the first process is, for example, a film formation process for forming an oxide layer 220 (see FIG. 4(a) described later) on the substrate W having a silicon layer 210 (see FIG. 4(a) described later). The oxide layer 220 is either a silicon oxide layer containing silicon (Si) atoms and oxygen (O) atoms, or a metal oxide layer containing metal atoms (e.g., hafnium (Hf), zirconium (Zr), aluminum (Al), titanium (Ti), strontium (Sr), barium (Ba), lead (Pb), etc.) or a combination of metal atoms and oxygen (O) atoms. More specifically, the oxide layer 220 may be silicon oxide (SiO2), hafnium oxide (HfO2), zirconium oxide (ZrO2), aluminum oxide (Al2O3), titanium oxide (TiO2), strontium titanium oxide (SrTiO3), barium titanium oxide (BaTiO3), lead zirconium titanium oxide (PbZr 0.2 Ti 0.8 O3), etc. The processing apparatus PM1 is a film formation apparatus that performs film formation processing on a substrate W by, for example, an ALD (Atomic Layer Deposition) method, a CVD (Chemical Vapor Deposition) method, etc. The processing apparatus PM1 forms an oxide layer 220 (a silicon oxide layer, a metal oxide layer, etc.) on the substrate W by alternately or simultaneously supplying a source gas (a silicon-containing gas, an organometallic gas, etc.) and an oxidizing gas (an oxygen-containing gas) to the substrate W.

[0020] Next, the first transfer device TR1 takes the substrate W out of the processing device PM1 and transfers the taken-out substrate W to the processing device PM2.

[0021] The processing apparatus PM2 performs a second process on the substrate W. The second process is, for example, a modification process that modifies the interface between the silicon layer 210 and the oxide layer 220 (silicon oxide layer, metal oxide layer, etc.) formed on the substrate W. The processing apparatus PM2 is a modification apparatus that modifies the oxide layer 220 and the interface between the silicon layer 210 and the oxide layer 220 by irradiating the substrate W with ultraviolet light (UV light) in a predetermined wavelength range from a lamp in a process gas atmosphere. The range of modification may also include the bulk layer (the silicon layer 210 and a layer below the silicon layer 210). The processing apparatus PM2 (substrate processing apparatus 100 described later) that performs the modification process and the second process (modification process) will be described later with reference to FIGS. 2 to 4.

[0022] Next, the first transfer device TR1 takes the substrate W out of the processing device PM2 and transfers the taken-out substrate W to the processing device PM3.

[0023] The processing apparatus PM3 performs a third process on the substrate W. The third process is, for example, a heat treatment that heats the substrate W. The processing apparatus PM3 is a heat treatment apparatus that heats the substrate W by an RTA (Rapid Thermal Anneal) method by irradiating the substrate W with infrared light from an infrared lamp (e.g., a halogen lamp, a xenon lamp, etc.) in an inert gas (e.g., N2 gas) atmosphere.

[0024] Next, the first transfer device TR1 removes the substrate W from the processing device PM3, transfers the removed substrate W to the load lock chamber LL3, and exits the load lock chamber LL3. Next, the interior of the load lock chamber LL3 is switched from a vacuum atmosphere to an atmospheric atmosphere. Thereafter, the second transfer device TR2 removes the substrate W from the load lock chamber LL3 and stores the removed substrate W in the carrier C.

[0025] The processing device PM4 may be a processing device that performs the same process as any of the processing devices PM1 to PM3. The processing device PM4 may also be a processing device that performs a fourth process on the substrate W that is different from the processes PM1 to PM3. The fourth process may be performed before the first process, after the first process and before the second process, after the second process and before the third process, or after the third process.

[0026] In the above description, the substrate W is treated in the order of the oxide layer 220 formation treatment (first treatment), the oxide layer 220 modification treatment (second treatment), and the substrate W heating treatment (third treatment), but this is not limiting. The substrate W may be treated in the order of the oxide layer 220 formation treatment (first treatment), the substrate W heating treatment (third treatment), and the oxide layer 220 modification treatment (second treatment).

[0027] [Substrate processing equipment] Next, a processing apparatus PM2 (hereinafter also referred to as a substrate processing apparatus 100) that performs a second process (modification process) on a substrate W will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the substrate processing apparatus 100 (processing apparatus PM2) that performs a modification process on a substrate W.

[0028] The substrate processing apparatus 100 includes a processing chamber 10 , a mounting table 20 , a gas supply unit 30 , an ultraviolet ray irradiation unit 40 , an exhaust unit 50 , and a control unit 60 .

[0029] An opening 11 for transferring the substrate W is provided in the sidewall of the processing vessel 10. The opening 11 is opened and closed by a gate valve 12 (gate valve G12).

[0030] A mounting table 20 on which a substrate W is placed is provided within the processing vessel 10. The mounting table 20 is connected to a rotation driver 22 via a rotation shaft 21 that penetrates the bottom wall of the processing vessel 10. The space between the rotation shaft 21 and the bottom wall of the processing vessel 10 is rotatably sealed by a magnetic fluid seal or the like. The control unit 60 controls the rotation driver 22 to rotate the mounting table 20.

[0031] A heater 23 is provided on the mounting table 20. A temperature sensor (not shown) is also provided on the mounting table 20. The control unit 60 controls a heater power supply (not shown) that supplies power to the heater 23 based on the temperature of the mounting table 20 detected by the temperature sensor, thereby heating the mounting table 20 and the substrate W placed on the mounting table 20 to a desired temperature.

[0032] A nozzle serving as a gas supply unit 30 is provided on the sidewall of the processing vessel 10. A gas supply source 31 supplies a process gas to the gas supply unit 30. A control unit 60 controls the gas supply source 31 to supply the process gas into the processing vessel 10 via the gas supply unit 30.

[0033] A through-hole is provided in the ceiling wall of the processing vessel 10. A transmission window 42 that transmits ultraviolet light is provided in the through-hole. The space between the transmission window 42 and the ceiling wall of the processing vessel 10 is sealed with a sealing member or the like. An ultraviolet irradiation unit 40 having an ultraviolet lamp 41 is provided outside the transmission window 42.

[0034] The ultraviolet lamp 41 irradiates the interior of the processing chamber 10 with ultraviolet light in a predetermined wavelength range through the transmission window 42. Here, the predetermined wavelength range is a wavelength range from 135 nm to 190 nm. The ultraviolet lamp 41 may be, for example, a xenon (Xe) lamp. Alternatively, the ultraviolet lamp 41 may be configured using a light source (e.g., a deuterium lamp or a white light source such as sunlight) having a wide wavelength range including the predetermined wavelength range (135 nm to 190 nm) and a filter that transmits wavelengths in the predetermined wavelength range (135 nm to 190 nm). Alternatively, the filter may be a filter that cuts off a high-energy band with a wavelength of 135 nm or less. The filter may be provided in the ultraviolet lamp 41 or the transmission window 42.

[0035] The exhaust unit 50 includes a pressure adjustment valve, a vacuum pump, etc. The exhaust unit 50 is connected to an exhaust port 13 provided on the bottom wall of the processing vessel 10. The control unit 60 controls the exhaust unit 50 to exhaust gas from inside the processing vessel 10 and adjust the inside of the processing vessel 10 to a desired pressure.

[0036] The control unit 60 is, for example, a computer, and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or the auxiliary storage device, and controls the operation of the substrate processing apparatus 100. The control unit 60 may be provided inside or outside the substrate processing apparatus 100. When the control unit 60 is provided outside the substrate processing apparatus 100, the control unit 60 can control the substrate processing apparatus 100 via communication means such as wired or wireless.

[0037] Next, an example of a modification process (second process) performed in the substrate processing apparatus 100 will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a flowchart illustrating an example of the modification process. Fig. 4 is an example of a schematic cross-sectional view of a substrate W.

[0038] In step S101, the substrate W is prepared. Here, the control unit 60 opens the gate valve 12 (G12) and controls the first transfer device TR1 to transfer the substrate W into the processing chamber 10 and place it on the mounting table 20. When the first transfer device TR1 returns to the vacuum transfer chamber VTM, the control unit 60 closes the gate valve 12 (G12). The control unit 60 controls the heater power supply (not shown) to cause the heater 23 to generate heat, thereby heating the substrate W placed on the mounting table 20 to a predetermined temperature. The control unit 60 also controls the rotation drive unit 22 to rotate the mounting table 20 on which the substrate W is placed. The control unit 60 also controls the exhaust unit 50 to adjust the pressure inside the processing chamber 10 to a predetermined value.

[0039] 4(a) is an example of a schematic cross-sectional view of the substrate W prepared in step S101. The substrate W has a silicon layer 210 and an oxide layer 220 formed on the silicon layer 210. Specifically, the oxide layer 220 is formed on the silicon layer 210 of the substrate W in the processing apparatus PM1.

[0040] In step S102, ultraviolet irradiation (UV processing) is performed in a process gas atmosphere containing a hydrogen-containing gas. Here, the control unit 60 controls the gas supply source 31 to supply the process gas from the gas supply unit 30 into the process chamber 10. Here, the process gas contains a hydrogen-containing gas. The hydrogen-containing gas may be any one or a combination of hydrogen (H) gas, deuterium (D) gas, a gas containing hydrogen and nitrogen, ammonia (NH), hydrazine (NH), etc. The process gas may also contain an oxygen-containing gas. The oxygen-containing gas may be any one or a combination of oxygen (O) gas, nitric oxide (NO), nitrogen dioxide (NO), dinitrogen trioxide (NO), nitric oxide (CO), nitrogen dioxide (CO), etc. The partial pressure of the oxygen-containing gas in the process gas is preferably 0.1% or less to prevent the growth of an oxide layer (silicon oxide layer 211 described later) due to interfacial oxidation. The control unit 60 also controls the ultraviolet irradiation unit 40 to turn on the ultraviolet lamp 41, and irradiates ultraviolet light onto the process gas in the processing chamber 10 and onto the oxide layer 220 of the substrate W placed on the mounting table 20. The ultraviolet light dissociates oxygen (O) atoms in the oxide layer 220 and the oxygen-containing gas added to the process gas, and the active species of the dissociated oxygen (oxygen radicals, etc.) and the hydrogen-containing gas contained in the process gas modify the interface between the silicon layer 210 and the oxide layer 220 and the oxide layer 220.

[0041] Here, the modification treatment by ultraviolet irradiation is preferably carried out under the following treatment conditions. UV wavelength range: 135nm~190nm Temperature range of the substrate W during the process: 200°C to 800°C, preferably 250°C to 500°C, more preferably 300°C to 470°C Pressure range in the processing vessel 10 during the process: 10 Torr or less, preferably 0.1 Torr to 1 Torr Process gas: Hydrogen-containing gas (oxygen-containing gas of 0.1% or less may be added)

[0042] When the modification process is completed, the control unit 60 controls the gas supply source 31 to stop the supply of the process gas, controls the ultraviolet irradiation unit 40 to turn off the ultraviolet lamp 41, and controls the rotation drive unit 22 to stop the rotation of the mounting table 20. Then, the control unit 60 opens the gate valve 12 (G12) and controls the first transfer device TR1 to transfer the modified substrate W placed on the mounting table 20 out of the processing chamber 10. When the first transfer device TR1 returns to the vacuum transfer chamber VTM, the gate valve 12 (G12) is closed.

[0043] Next, the modification process will be further described.

[0044] By irradiating the substrate W with ultraviolet light in a hydrogen atmosphere, defects (e.g., Si dangling bond sites) at the interface between the silicon layer 210 and the oxide layer 220 are terminated with hydrogen (H), thereby improving electronic device characteristics (e.g., interface states, etc.). Furthermore, by irradiating the oxide layer 220 of the substrate W with ultraviolet light in a state where an oxygen-containing gas is added to the process gas, the interface between the silicon layer 210 and the oxide layer 220 is modified, and the film quality of the oxide layer 220 is also modified (e.g., densified, etc.).

[0045] 4(b) is an example of a schematic cross-sectional view of the substrate W after the modification process. Here, the longer the ultraviolet irradiation process time, the greater the effect of modifying the film quality of the oxide layer 220. Meanwhile, the silicon layer 210 in contact with the oxide layer 220 is oxidized to form a silicon oxide layer 211. This poses a problem in that the thickness of the oxide layer (the sum of the thicknesses of the oxide layer 220 and the silicon oxide layer 211) increases.

[0046] The modification process shown in FIG. 3 provides a substrate processing method that modifies the interface between the silicon layer 210 and the oxide layer 220 and the film quality of the oxide layer 220 while suppressing an increase in the thickness of the oxide layer (oxide layer 220 and silicon oxide layer 211).

[0047] When exposed to ultraviolet light, including short-wavelength ultraviolet light, high-energy hydrogen radicals cause hydrogen (H) termination and hydrogen (H) dissociation simultaneously, and it is thought that the effect (density) of hydrogen termination is in a certain equilibrium state. It is speculated that the balance between hydrogen (H) termination and hydrogen (H) dissociation, especially at high temperatures above 600°C, depends on the density of adsorbed hydrogen (H) near the interface. Furthermore, the higher the amount of adsorbed hydrogen (area density), the easier it is for hydrogen (H) to terminate.

[0048] FIG. 5 is an example of a graph showing the photodissociation characteristics of hydrogen (H2). The horizontal axis indicates the wavelength of the irradiated light. The vertical axis indicates the simulation results of the photodissociation characteristics (collision cross section). In FIG. 5, the predetermined wavelength range (135 nm to 190 nm) used in the modification process shown in FIG. 3 is indicated by a dashed line 500. The wavelength band in which photodecomposition of hydrogen (H2) occurs is indicated by symbol 510.

[0049] By limiting the wavelength of the applied ultraviolet light to a range of 135 nm or more (energy: 9.2 eV or less) and setting the process temperature to 800°C or less, the generation of high-energy hydrogen radicals is suppressed, as shown in Figure 5. This reduces the dissociation of hydrogen (H) terminated at dangling bond sites by high-energy hydrogen radicals. Therefore, by terminating defects (e.g., Si dangling bond sites) at the interface between the silicon layer 210 and the oxide layer 220 with hydrogen (H), electronic device characteristics (e.g., interface states, etc.) are improved.

[0050] Before the ultraviolet irradiation treatment, it is preferable to adsorb a sufficient amount of hydrogen (H) or deuterium (D) in advance at the target interface of the substrate W. For example, it is preferable to perform a heat treatment (third treatment) at a high temperature of 1000°C or higher after the ultraviolet irradiation treatment (second treatment).

[0051] FIG. 6 is an example of a graph showing the photodissociation characteristics of oxygen (O2). The horizontal axis indicates the wavelength of the irradiated light. The vertical axis indicates the simulation results of the photodissociation characteristics (collision cross section). In FIG. 6, the predetermined wavelength range (135 nm to 190 nm) used in the modification process shown in FIG. 3 is indicated by a dashed line 500. The wavelength band in which photodecomposition of oxygen (O2) occurs is indicated by reference numeral 520. The wavelength band indicated by reference numeral 520 includes a wavelength band 521 of less than 135 nm and a wavelength band 522 of 135 nm or more.

[0052] Here, in a wavelength band 521 of less than 135 nm, when oxygen (O2) dissociates, it mainly generates strong radicals (O1d). Also, in a wavelength band 522 of 135 nm or more, when oxygen (O2) dissociates, it mainly generates weak radicals (O3p).

[0053] By limiting the wavelength of the applied ultraviolet light to a range of 135 nm or more (energy: 9.2 eV or less) and setting the process temperature to 800°C or less, the generation of high-energy excited O1d* radicals from trace oxygen components (O2) present during the process is suppressed, as shown in Figure 6. This suppresses the silicon layer 210 from being oxidized by the high-energy excited O1d* radicals to form a silicon oxide layer 211. In other words, an increase in the thickness of the oxide layer (the sum of the thicknesses of the oxide layer 220 and the silicon oxide layer 211) is suppressed.

[0054] Furthermore, by limiting the wavelength of the applied ultraviolet light to a range of 135 nm or more (energy: 9.2 eV or less) and setting the process temperature to 800°C or less, low-energy excited O3p* radicals are generated from the trace oxygen component (O2) present during the process, as shown in Figure 6. As a result, the film quality of the oxide layer 220 is modified by the low-energy excited O3p* radicals.

[0055] FIG. 7 is an example of a graph showing the photodissociation characteristics of HO. The horizontal axis indicates the wavelength of the irradiated light. The vertical axis indicates the simulation results of the photodissociation characteristics (collision cross section). In FIG. 7, the upper limit (190 nm) of the predetermined wavelength range (135 nm to 190 nm) used in the modification process shown in FIG. 3 is indicated by dashed line 501. The wavelength band in which photodecomposition of HO occurs is indicated by symbol 530.

[0056] FIG. 8 is an example of a graph showing the photodissociation characteristics of OH. The horizontal axis indicates the wavelength of the irradiated light. The vertical axis indicates the simulation results of the photodissociation characteristics (collision cross section). In FIG. 8, the upper limit (190 nm) of the predetermined wavelength range (135 nm to 190 nm) used in the modification process shown in FIG. 3 is indicated by dashed line 501. The wavelength band in which photodecomposition of OH occurs is indicated by symbol 540.

[0057] Here, the oxide layer 220 of the substrate W contains HO and OH. By limiting the wavelength of the applied ultraviolet light to the range of 135 nm or more and 190 nm or less, the HO and OH can be decomposed, as shown in FIGS. 7 and 8. This prevents the thickness of the oxide layer (the total thickness of the oxide layer 220 and the silicon oxide layer 211) from increasing, and also improves the film quality of the oxide layer 220. That is, the impurities in the oxide layer 220, such as HO and OH, decomposed by the ultraviolet light, are passivated and confined in the oxide layer 220 without becoming a strong factor for oxidizing the silicon layer 210.

[0058] Even if a small amount (e.g., 0.1% or less in partial pressure) of oxygen-containing gas is added to the process gas, the increase in the thickness of the oxide layer (the total thickness of the oxide layer 220 and the silicon oxide layer 211) can be kept within an acceptable range. Furthermore, by adding an oxygen-containing gas, O3p* radicals in a low-energy excited state are generated, which can improve the effect of modifying the film quality of the oxide layer 220.

[0059] Fig. 9 is an example of a graph showing the relationship between treatment time and oxide layer film thickness. The horizontal axis is treatment time, and the vertical axis is oxide layer film thickness. The results of the modification treatment shown in Fig. 3 are shown by filled circles and a solid line. The results of the modification treatment in the reference example are shown by open circles and a dashed line.

[0060] In the modification process of the reference example, hydrogen (H2) gas and oxygen gas (O2) were supplied, and ultraviolet light in the wavelength range of 170 nm to 190 nm was irradiated to perform the modification process. As shown by the dashed line in Figure 9, the thickness of the oxide layer increases as the processing time increases. In contrast, the modification process shown in Figure 3 can ensure a long processing time while suppressing the thickness of the oxide layer. That is, by extending the processing time, the modification effect can be improved, and the increase in the thickness of the oxide layer can be kept within an acceptable range.

[0061] The substrate processing method (oxide layer modification method) of this embodiment using the substrate processing apparatus has been described above, but the present disclosure is not limited to the above-described embodiment, and various modifications and improvements are possible within the scope of the gist of the present disclosure described in the claims. [Explanation of symbols]

[0062] 10 Processing container 20 Mounting table 21 Rotation axis 22 Rotation drive unit 23 Heater 30 Gas supply unit 31 Gas supply source 40 UV irradiation unit 41 UV lamp 42 Transparent window 50 Exhaust section 60 Control Unit 100 Substrate processing apparatus 210 Silicon Layer 211 Silicon oxide layer 220 oxide layer PS Processing System W substrate

Claims

1. providing a substrate having a silicon layer and an oxide layer formed on the silicon layer; supplying a process gas containing a hydrogen-containing gas to the substrate and irradiating the substrate with ultraviolet light having a wavelength in the range of 135 nm to 190 nm to modify the interface between the silicon layer and the oxide layer; Substrate processing method.

2. The oxide layer is a silicon oxide layer or a metal oxide layer. The substrate processing method according to claim 1 .

3. the metal of the metal oxide layer is any of hafnium (Hf), zirconium (Zr), aluminum (Al), titanium (Ti), strontium (Sr), barium (Ba), lead (Pb), and combinations thereof; The substrate processing method according to claim 2 .

4. The hydrogen-containing gas is H ２ , D ２ Either The substrate processing method according to claim 1 .

5. The process temperature in the modifying step is in the range of 200°C to 800°C. The substrate processing method according to claim 1 .

6. the process gas comprises an oxygen-containing gas; The substrate processing method according to claim 1 .

7. The partial pressure of the oxygen-containing gas in the process gas is 0.1% or less. The substrate processing method according to claim 6 .

8. The oxygen-containing gas is O ２ That is, The substrate processing method according to claim 7 .

9. 1. A substrate processing apparatus for modifying a substrate having a silicon layer and an oxide layer formed on the silicon layer, comprising: A processing vessel; a mounting table provided in the processing chamber and configured to mount the substrate thereon; a gas supply unit that supplies a process gas containing a hydrogen-containing gas into the processing vessel; an ultraviolet irradiation unit having an ultraviolet lamp that irradiates ultraviolet light within a wavelength range of 135 nm to 190 nm into the processing vessel; Substrate processing equipment.

10. The ultraviolet lamp is a xenon lamp. The substrate processing apparatus according to claim 9 .

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