Substrate processing method and substrate processing apparatus

Abstract

A substrate processing method and a substrate processing apparatus are provided which modify an interface between a silicon layer and an oxide layer. A substrate processing method includes the following steps: preparing a substrate having a silicon layer and an oxide layer formed on the silicon layer; and 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 ultraviolet rays in a wavelength range of 135 nm to 190 nm to the substrate.

Description

Technical Field

[0001] This 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 film, which involves modifying a high dielectric film formed on the surface of a body using an organometallic compound material. The method is characterized in that the modification process includes a modification step in which the high dielectric film is modified by irradiating it with ultraviolet light in an atmosphere of inactive gas while maintaining the body at a specified temperature. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2007-194582 Summary of the Invention The problem the invention aims to solve

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

[0005] To address the aforementioned problems, a substrate processing method is provided, 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 the substrate with a process gas containing hydrogen gas and irradiating the substrate with ultraviolet light in the wavelength range of 135 nm to 190 nm. The effects of the invention

[0006] According to one aspect, a substrate processing method and a substrate processing apparatus for modifying the interface between a silicon layer and an oxide layer can be provided. Attached Figure Description

[0007] Figure 1 This is a diagram illustrating an example of a processing system. Figure 2 This figure shows an example of a substrate processing apparatus for performing modification treatment on a substrate. Figure 3 This is a flowchart illustrating an example of modification treatment. Figure 4A This is an example of a schematic cross-section of a substrate. Figure 4B This is an example of a schematic cross-section of a substrate. Figure 5This is an example of a graph showing the photodissociation properties of hydrogen (H2). Figure 6 This is an example of a graph showing the photodissociation properties of oxygen (O2). Figure 7 This is an example of a graph showing the photodissociation characteristics of H2O. Figure 8 This is an example of a graph showing the photodissociation characteristics of OH. Figure 9 This is an example of a graph showing the relationship between processing time and the thickness of the oxide layer. Detailed Implementation

[0008] The embodiments for carrying out this disclosure will now be described with reference to the accompanying drawings. In the drawings, the same structural parts are labeled with the same reference numerals, and sometimes repeated descriptions are omitted.

[0009] [Processing System] use Figure 1 An example of a processing system used to implement the substrate processing method according to this embodiment will be described. Figure 1 This is a diagram illustrating an example of a processing system PS.

[0010] The processing system PS includes processing units PM1~PM4, vacuum transfer chamber VTM, loading interlock chambers LL1~LL3, atmospheric transfer chamber LM, loading ports LP1~LP3, and an overall control unit CU. Furthermore, in Figure 1 In the example shown, the processing system PS is described as having multiple processing units PM1~PM4, multiple loading interlock chambers LL1~LL3, and multiple loading ports LP1~LP3, but is not limited thereto. The processing system PS may have at least one processing unit, at least one loading interlock chamber, and at least one loading port. Additionally, the processing system PS may also have multiple vacuum transfer chambers VTM and / or atmospheric transfer chambers LM.

[0011] Processing units PM1 to PM4 are connected to the vacuum transfer chamber VTM via gate valves G11 to G14, respectively. Processing units PM1 to PM4 are configured to reduce the internal pressure to a predetermined vacuum atmosphere. Processing units PM1 to PM4 house the substrate W and perform the desired processing inside.

[0012] The vacuum transfer chamber VTM is configured to reduce its internal pressure to a predetermined vacuum atmosphere. A first transfer device TR1 is provided in the vacuum transfer chamber VTM, capable of transferring substrate W under reduced pressure. The first transfer device TR1 transfers substrate W to processing devices PM1-PM4 and loading interlock chambers LL1-LL3. The first transfer device TR1, for example, has two independently movable transfer arms FK11 and FK12.

[0013] Loading interlock chambers LL1-LL3 are connected to the vacuum transfer chamber VTM via gate valves G21-G23. Loading interlock chambers LL1-LL3 are connected to the atmospheric transfer chamber LM via gate valves G31-G33. Loading interlock chambers LL1-LL3 are configured to switch between atmospheric and vacuum atmospheres.

[0014] The interior of the atmospheric transport chamber LM is filled with an atmospheric atmosphere. A downward flow of clean air, for example, is formed inside the atmospheric transport chamber LM. An alignment device AN for aligning the substrate W is installed inside the atmospheric transport chamber LM. The alignment device AN can also be installed outside the atmospheric transport chamber LM. A second transport device TR2 is installed in the atmospheric transport chamber LM. The second transport device TR2 transports the substrate W to the loading interlock chambers LL1~LL3, loading ports LP1~LP3, and the alignment device AN.

[0015] Loading ports LP1-LP3 are located on the long side wall of the atmospheric transport chamber LM. Carriers C are mounted on loading ports LP1-LP3. Carriers C include carriers C containing the substrate W and empty carriers C. Carriers C can be, for example, FOUP (Front Opening Unified Pod).

[0016] The overall control unit (CU) can be, for example, a computer. The CU includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and auxiliary storage devices. The CPU operates based on a program stored in the ROM or auxiliary storage devices, controlling various parts of the processing system PS. For example, the CU controls the operation of processing devices PM1-PM4, the first conveying device TR1, the second conveying device TR2, and gate valves G11-G14, G21-G23, and G31-G33. For example, the CU controls the switching of the interior of the loading interlock chambers LL1-LL3 between atmospheric and vacuum atmospheres.

[0017] Next, the actions of the processing system PS will be explained.

[0018] First, the second conveying device TR2 removes the substrate W from the carrier C, transports the removed substrate W to the aligner AN, and then exits from the aligner AN. Next, the aligner AN aligns the substrate W. Then, the second conveying device TR2 removes the substrate W from the aligner AN, transports the removed substrate W to the loading interlock chamber LL1, and then exits from the loading interlock chamber LL1. Next, the interior of the loading interlock chamber LL1 is switched from atmospheric atmosphere to vacuum atmosphere. Afterwards, the first conveying device TR1 removes the substrate W from the loading interlock chamber LL1 and transports the removed substrate W to the processing device PM1.

[0019] The processing apparatus PM1 performs a first processing on the substrate W. Here, the first processing is, for example, performed on a substrate having a silicon layer 210 (see below). Figure 4A An oxide layer 220 is formed on the substrate W (see below). Figure 4A The oxide layer 220 is formed by the deposition of a film. The oxide layer 220 is any one of the following: 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 is silicon oxide (SiO2), hafnium oxide (HfO2), zirconium oxide (ZrO2), aluminum oxide (Al2O3), titanium oxide (TiO2), strontium titanium oxide (SrTiO3), barium titanium oxide (BaTiO3), or lead zirconium titanium oxide (PbZr). 0.2 Ti 0.8 O3), etc. The processing apparatus PM1 is a film forming apparatus that performs film forming processing on the substrate W by methods such as ALD (Atomic Layer Deposition) and CVD (Chemical Vapor Deposition). The processing apparatus PM1 forms an oxide layer 220 (silicon oxide layer, metal oxide layer, etc.) on the substrate W by alternately or simultaneously supplying raw material gas (containing silicon gas, organometallic gas, etc.) and oxidizing gas (containing oxygen gas) to the substrate W.

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

[0021] The processing apparatus PM2 performs a second processing on the substrate W. This second processing 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) of a predetermined wavelength range from a lamp under a process gas atmosphere. Furthermore, the modification may also include the bulk layer (the silicon layer 210 and the layers below it). Moreover, regarding the processing apparatus PM2 (the substrate processing apparatus 100 described later) performing the modification processing and the second processing (modification processing), the following... Figures 2 to 4A 4B will be described later.

[0022] Next, the first conveying device TR1 takes the substrate W from the processing device PM2 and moves the taken-out substrate W to the processing device PM3.

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

[0024] Next, the first conveying device TR1 removes the substrate W from the processing device PM3, transports the removed substrate W to the loading interlock chamber LL3, and exits from the loading interlock chamber LL3. Then, the interior of the loading interlock chamber LL3 is switched from a vacuum atmosphere to an atmospheric atmosphere. Afterwards, the second conveying device TR2 removes the substrate W from the loading interlock chamber LL3 and houses the removed substrate W in the carrier C.

[0025] Furthermore, processing device PM4 can also be a processing device that performs the same processing as any one of processing devices PM1 to PM3. Additionally, processing device PM4 can also be a processing device that performs a fourth processing on substrate W, different from processing devices PM1 to PM3. The fourth processing can be performed at any of the following times: before the first processing, after the first processing and before the second processing, after the second processing and before the third processing, and after the third processing.

[0026] Furthermore, the substrate W has been described as being processed in the order of oxide layer 220 formation process (first process), oxide layer 220 modification process (second process), and substrate W heat treatment (third process), but this is not a limitation. The substrate W may also be processed in the order of oxide layer 220 formation process (first process), substrate W heat treatment (third process), and oxide layer 220 modification process (second process).

[0027] [Substrate Processing Apparatus] Next, use Figure 2 The processing apparatus PM2 (hereinafter also referred to as substrate processing apparatus 100) describes the second processing (modification processing) performed on substrate W. Figure 2 This is a diagram showing an example of a substrate processing apparatus 100 (processing apparatus PM2) that performs modification treatment on substrate W.

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

[0029] An opening 11 for conveying the substrate W is provided on the side wall of the processing container 10. The opening 11 is opened and closed by a gate valve 12 (gate valve G12).

[0030] A mounting stage 20 for placing a substrate W is provided inside the processing container 10. The mounting stage 20 is connected to a rotation drive unit 22 via a rotation shaft 21 that penetrates the bottom wall of the processing container 10. Furthermore, the rotation shaft 21 and the bottom wall of the processing container 10 are sealed in a rotatable manner by a magnetohydrodynamic seal or the like. The control unit 60 rotates the mounting stage 20 by controlling the rotation drive unit 22.

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

[0032] A nozzle serving as a gas supply unit 30 is provided on the side wall of the processing container 10. A gas supply source 31 supplies process gas to the gas supply unit 30. The control unit 60 supplies process gas into the processing container 10 via the gas supply unit 30 by controlling the gas supply source 31.

[0033] A through hole is provided in the top wall of the processing container 10. A transmission window 42 for transmitting ultraviolet light is provided in the through hole. Furthermore, the transmission window 42 is sealed to the top wall of the processing container 10 by a sealing member or the like. An ultraviolet irradiation section 40 with an ultraviolet lamp 41 is provided on the outside of the transmission window 42.

[0034] Ultraviolet lamp 41 irradiates the processing container 10 with ultraviolet light of a specified wavelength range through transmission window 42. Here, the specified wavelength range is from 135 nm to 190 nm. For example, a xenon (Xe) lamp can be used for ultraviolet lamp 41. Alternatively, ultraviolet lamp 41 can be configured with a light source having a wide wavelength range including the specified wavelength range (135 nm to 190 nm) (e.g., a white light source such as a deuterium lamp or sunlight), and a filter that transmits wavelengths within the specified wavelength range (135 nm to 190 nm). Alternatively, the filter can be a filter that blocks high-energy frequency bands below 135 nm. Furthermore, the filter can be provided either in ultraviolet lamp 41 or in transmission window 42.

[0035] The exhaust section 50 includes a pressure regulating valve, a vacuum pump, etc. The exhaust section 50 is connected to an exhaust port 13 located on the bottom wall of the processing container 10. The control section 60 controls the exhaust section 50 to discharge gas from the interior of the processing container 10 and adjust the interior of the processing container 10 to the 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), and auxiliary storage devices. The CPU operates based on a program stored in the ROM or auxiliary storage devices, controlling the operation of the board processing apparatus 100. The control unit 60 can be located inside or outside the board processing apparatus 100. When the control unit 60 is located outside the board processing apparatus 100, it can control the board processing apparatus 100 via wired or wireless communication methods.

[0037] Next, use Figure 3 as well as Figures 4A-4B An example of a modification process (second process) performed by the substrate processing apparatus 100 will be described. Figure 3 This is a flowchart illustrating an example of modification treatment. Figures 4A-4B This is an example of a cross-sectional schematic diagram of substrate W.

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

[0039] Figure 4A This is an example of a cross-sectional schematic diagram 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 by the processing apparatus PM1.

[0040] In step S102, ultraviolet irradiation treatment (UV treatment) is performed under a process gas atmosphere containing hydrogen gas. Here, the control unit 60 controls the gas supply source 31 to supply process gas from the gas supply unit 30 into the processing container 10. Here, the process gas contains hydrogen gas. The hydrogen gas can be any one or a combination of hydrogen (H2) gas, deuterium (D2) gas, gas containing hydrogen and nitrogen, ammonia (NH3), hydrazine (N2H4), etc. In addition, oxygen gas can also be added to the process gas. The oxygen gas can be any one or a combination of oxygen (O2) gas, nitric oxide (NO), nitrogen dioxide (NO2), dinitrogen trioxide (N2O3), nitric oxide (CO), nitrogen dioxide (CO2), etc. In addition, from the viewpoint of suppressing the film formation of oxide layer (silicon oxide layer 211 described later) caused by interface oxidation, the partial pressure of oxygen gas in the process gas is preferably 0.1% or less. Additionally, the control unit 60 controls the ultraviolet irradiation unit 40 to illuminate the ultraviolet lamp 41, irradiating the process gas inside the processing container 10 and the oxide layer 220 of the substrate W placed on the mounting stage 20 with ultraviolet light. The ultraviolet light causes the oxygen (O) atoms in the oxide layer 220 and the oxygen-containing gas added to the process gas to dissociate. The active species of the dissociated oxygen (oxygen free 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, as well as the oxide layer 220 itself.

[0041] Here, the following treatment conditions are preferred for modification treatment by ultraviolet irradiation. Ultraviolet wavelength range: 135nm~190nm The temperature range of substrate W in the process is 200℃~800℃, preferably 250℃~500℃, and more preferably 300℃~470℃. The pressure range within the processing vessel 10 in the process is below 10 Torr, preferably 0.1 Torr to 1 Torr. Process gas: Hydrogen-containing gas (or less than 0.1% oxygen-containing gas).

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

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

[0044] By irradiating the substrate W with ultraviolet light in a hydrogen atmosphere, defects at the interface between the silicon layer 210 and the oxide layer 220 (e.g., dangling bond sites of Si) are sealed by hydrogen (H), thereby improving the characteristics of the electronic components (e.g., interface energy levels). Alternatively, by irradiating the oxide layer 220 of the substrate W with ultraviolet light in a process gas containing oxygen, the interface between the silicon layer 210 and the oxide layer 220 is modified, and the film composition of the oxide layer 220 is modified (e.g., densified).

[0045] Figure 4B This is an example of a cross-sectional schematic diagram of the modified substrate W. Here, the longer the ultraviolet irradiation treatment time, the better the modification effect on the oxide layer 220. On the other hand, the silicon layer 210 in contact with the oxide layer 220 is oxidized to form a silicon oxide layer 211. As a result, the thickness of the oxide layer (the sum of the thicknesses of the oxide layer 220 and the silicon oxide layer 211) increases.

[0046] exist Figure 3 The modification process shown 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 the increase in the thickness of the oxide layer (oxide layer 220 and silicon oxide layer 211).

[0047] Under ultraviolet irradiation containing short-wavelength ultraviolet light, it is believed that hydrogen (H) termination and hydrogen (H) dissociation occur simultaneously through high-energy hydrogen radicals, with the hydrogen termination effect (density) in a certain equilibrium state. It is speculated that, especially at temperatures above 600°C, the equilibrium between hydrogen (H) termination and hydrogen (H) dissociation depends on the density of adsorbed hydrogen (H) near the interface. Furthermore, the higher the amount of adsorbed hydrogen (area density), the easier the hydrogen (H) termination.

[0048] Figure 5 This is an example of a graph showing the photodissociation characteristics of hydrogen (H2). The horizontal axis represents the wavelength of the incident light. The vertical axis represents the simulation results based on the photodissociation characteristics (collision cross-section). Furthermore, in Figure 5 In the middle, the dashed line 500 indicates that it is used for Figure 3 The specified wavelength range for the modification treatment shown is 135 nm to 190 nm. Additionally, reference numeral 510 indicates the wavelength band in which the photodecomposition of hydrogen (H2) occurs.

[0049] By limiting the wavelength of the provided ultraviolet light to above 135 nm (energy: below 9.2 eV) and setting the process temperature below 800°C, thus... Figure 5 As shown, the generation of high-energy hydrogen radicals is suppressed. This reduces the dissociation of hydrogen (H) at dangling bond sites due to high-energy hydrogen radicals. Consequently, defects at the interface between silicon layer 210 and oxide layer 220 (e.g., dangling bond sites of Si) are terminated by hydrogen (H), thereby improving electronic component properties (e.g., interface energy levels, etc.).

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

[0051] Figure 6 This is an example of a graph showing the photodissociation characteristics of oxygen (O2). The horizontal axis represents the wavelength of the incident light. The vertical axis represents the simulation results based on the photodissociation characteristics (collision cross-section). Furthermore, in Figure 6 In the middle, the dashed line 500 indicates that it is used for Figure 3 The specified wavelength range for the modification treatment is shown (135 nm to 190 nm). Additionally, reference numeral 520 indicates the wavelength band in which the photodecomposition of oxygen (O2) occurs. The wavelength band indicated by reference numeral 520 includes band 521 (below 135 nm) and band 522 (above 135 nm).

[0052] Here, in the band 521 below 135 nm, when oxygen (O2) dissociates, strong free radicals (O1d) are mainly generated. Furthermore, in the band 522 above 135 nm, when oxygen (O2) dissociates, weak free radicals (O3p) are mainly generated.

[0053] By limiting the wavelength of the provided ultraviolet light to above 135 nm (energy: below 9.2 eV) and setting the process temperature below 800°C, thus... Figure 6 As shown, the generation of high-energy excited states of O1d from the trace oxygen components (O2) originally present in the process is suppressed. Free radicals. This suppresses the O1d state of silicon layer 210 when excited by high energy. Free radical oxidation forms silicon oxide layer 211. In other words, it suppresses the increase in the thickness of the oxide layer (the sum of the thicknesses of oxide layer 220 and silicon oxide layer 211).

[0054] Furthermore, by limiting the wavelength of the provided ultraviolet light to a range of 135 nm or higher (energy: 9.2 eV or lower) and setting the process temperature to 800°C or lower, thus... Figure 6 As shown, trace amounts of oxygen (O2) present in the original process are converted into low-energy excited state O3p. Free radicals. Therefore, the low-energy excited state of O3p... Free radicals modify the film composition of oxide layer 220.

[0055] Figure 7 This is an example of a graph showing the photodissociation characteristics of H2O. The horizontal axis represents the wavelength of the incident light. The vertical axis represents the simulation results based on the photodissociation characteristics (collision cross-section). Furthermore, in Figure 7 In the middle, the dashed line 501 indicates that it is used for Figure 3 The upper limit (190 nm) of the specified wavelength range (135 nm to 190 nm) for the modification treatment shown is indicated by reference numeral 530, which denotes the wavelength band in which the photodecomposition of H2O occurs.

[0056] Figure 8 This is an example of a graph showing the photodissociation characteristics of OH. The horizontal axis represents the wavelength of the incident light. The vertical axis represents the simulation results based on the photodissociation characteristics (collision cross-section). Furthermore, in Figure 8 In the middle, the dashed line 501 indicates that it is used for Figure 3 The upper limit (190 nm) of the specified wavelength range (135 nm to 190 nm) for the modification treatment shown is indicated by reference numeral 540, which denotes the wavelength band in which the photodecomposition of OH occurs.

[0057] Here, the oxide layer 220 of the substrate W contains H2O and OH. The wavelength of the provided ultraviolet light is limited to a range of 135 nm or more and 190 nm or less, such as... Figure 7 and Figure 8 As shown, it is capable of decomposing H2O and OH. Therefore, it is possible to suppress the increase in the thickness of the oxide layer (the total thickness of oxide layer 220 and silicon oxide layer 211) and modify the film composition of oxide layer 220. That is, it has the effect of passivating and sealing the H2O and OH components, which are impurities in the oxide layer 220 film after being decomposed by ultraviolet light, within the oxide layer 220 film, preventing them from becoming strong factors for oxidizing silicon layer 210.

[0058] Furthermore, even with the addition of trace amounts (e.g., less than 0.1% partial pressure) of oxygen-containing gas to the process gas, the increase in the thickness of the oxide layer (the sum of the thicknesses of oxide layer 220 and silicon oxide layer 211) can be suppressed within acceptable limits. Additionally, by adding oxygen-containing gas, O3p in a low-energy excited state can be generated. Free radicals enhance the modification effect of oxide layer 220 film.

[0059] Figure 9 This is an example of a graph showing the relationship between processing time and oxide layer thickness. The horizontal axis represents processing time. The vertical axis represents oxide layer thickness. Figure 3 The results of the modification treatment shown are indicated by solid circles and solid lines. The results of the modification treatment in the reference example are indicated by hollow circles and dashed lines.

[0060] In the modification treatment of the reference example, hydrogen (H2) gas and oxygen gas (O2) were supplied, and the treatment was carried out by irradiation with ultraviolet light in the wavelength range of 170 nm to 190 nm. Figure 9 As shown by the dashed line, the longer the processing time, the greater the thickness of the oxide layer. Conversely, according to... Figure 3 The modification treatment shown can ensure a longer processing time while suppressing the thickness of the oxide layer. That is, it can extend the processing time to improve the modification effect and suppress the increase in the thickness of the oxide layer within an acceptable range.

[0061] The substrate processing method (oxide layer modification method) of this embodiment based on the substrate processing apparatus has been described above, but this disclosure is not limited to the above embodiment, etc., and various modifications and improvements can be made within the scope of the spirit of this disclosure as described in the claims.

[0062] Furthermore, this application claims priority based on Japanese Patent Application No. 2024-034217, filed on March 6, 2024, the entire contents of which are incorporated herein by reference. Explanation of reference numerals in the attached figures

[0063] 10: Processing container; 20: Placement stage; 21: Rotation shaft; 22: Rotation drive unit; 23: Heater; 30: Gas supply unit; 31: Gas supply source; 40: Ultraviolet irradiation unit; 41: Ultraviolet lamp; 42: Transmission window; 50: Exhaust unit; 60: Control unit; 100: Substrate processing apparatus; 210: Silicon layer; 211: Silicon oxide layer; 220: Oxide layer; PS: Processing system; W: Substrate.

Claims

1. A substrate processing method, comprising the following steps: Prepare a substrate having a silicon layer and an oxide layer formed on the silicon layer; and The interface between the silicon layer and the oxide layer is modified by supplying the substrate with a process gas containing hydrogen and irradiating the substrate with ultraviolet light in the wavelength range of 135 nm to 190 nm.

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

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

4. The substrate processing method according to claim 1, wherein, The hydrogen-containing gas is either H2 or D2.

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

6. The substrate processing method according to claim 1, wherein, The process gas contains oxygen.

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

8. The substrate processing method according to claim 7, wherein, The oxygen-containing gas is O2.

9. A substrate processing apparatus for modifying a substrate having a silicon layer and an oxide layer formed on the silicon layer, the substrate processing apparatus comprising: Handling containers; A mounting stage, disposed within the processing container, is used to mount the substrate; A gas supply unit supplies process gas containing hydrogen to the processing vessel; and The ultraviolet irradiation unit has an ultraviolet lamp that irradiates the processing container with ultraviolet light in the wavelength range of 135 nm to 190 nm.

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

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