Substrate processing method and substrate processing device

Abstract

Provided are a substrate processing method and a substrate processing device for modifying an interface between a silicon layer and an oxide layer.　This substrate processing method comprises: a step of preparing a substrate having a silicon layer and an oxide layer formed on the silicon layer; and a step of modifying the 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 ultraviolet rays in a wavelength range of 135–190 nm.

Description

Substrate processing method and substrate processing apparatus

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

[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 which 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.

[0003] JP 2007-194582 A

[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.

[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.

[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.

[0007] FIG. 1 is a diagram showing an example of a processing system; FIG. 2 is a diagram showing an example of a substrate processing apparatus that performs a modification process on a substrate; ２ ) photodissociation characteristics of oxygen (O ２ ) photodissociation characteristics of H ２ 1A and 1B are graphs showing an example of photodissociation characteristics of O. 1C are graphs showing an example of photodissociation characteristics of OH. 1D are graphs showing an example of a relationship between processing time and oxide layer film thickness.

[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, a vacuum transfer chamber VTM, load lock chambers LL1-LL3, an 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 multiple 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 interior thereof can be depressurized to a predetermined vacuum atmosphere. The processing devices PM1 to PM4 accommodate substrates W therein and perform desired processing.

[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 capable of transferring substrates W under a reduced pressure. The first transfer device TR1 transfers substrates W to the processing devices PM1 to PM4 and the 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 atmospheric transfer chamber LM has an atmospheric atmosphere inside. A downflow of clean air, for example, 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, front-opening unified pods (FOUPs).

[0016] The overall control unit CU may be, for example, a computer. The overall control unit CU includes a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), and an auxiliary storage device. The CPU operates based on a program stored in the ROM or the auxiliary storage device and controls each component of the processing system PS. For example, the overall control unit CU controls the operation 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 a vacuum atmosphere.

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

[0018] First, the second transport device TR2 takes out 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 transport device TR2 takes out 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 atmospheric atmosphere to a vacuum atmosphere. Thereafter, the first transport device TR1 takes out 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. 4A , which will be described later) on the substrate W having a silicon layer 210 (see FIG. 4A , which will be 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 is a silicon oxide (SiO ２ ), hafnium oxide (HfO ２ ), zirconium oxide (ZrO ２ ), aluminum oxide (Al ２ O ３ ), titanium oxide (TiO ２ ), strontium titanium oxide (SrTiO ３ ), barium titanium oxide (BaTiO ３ ), lead zirconium titanium oxide (PbZr ０．２ Ti ０．８ O ３) The processing apparatus PM1 is a film formation apparatus that performs a film formation process on a substrate W by, for example, an ALD (Atomic Layer Deposition) method, a CVD (Chemical Vapor Deposition) method, or the like. The processing apparatus PM1 forms an oxide layer 220 (a silicon oxide layer, a metal oxide layer, or the like) on the substrate W by alternately or simultaneously supplying a source gas (a silicon-containing gas, an organometallic gas, or the like) and an oxidizing gas (an oxygen-containing gas) to the substrate W.

[0020] Next, the first transport device TR1 takes the substrate W out of the processing device PM1 and transports 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 (such as a silicon oxide layer or a metal oxide layer) 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 (the substrate processing apparatus 100 described below) that performs the modification process and the second process (modification process) will be described later with reference to FIGS. 2 to 4A-4B.

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

[0023] The processing device PM3 performs a third process on the substrate W. The third process is, for example, a heat treatment for heating the substrate W. The processing device PM3 is configured to perform a third process on the substrate W by using an inert gas (for example, N ２ The heat treatment apparatus heats the substrate W by RTA (Rapid Thermal Anneal) in a gas (heat treatment gas) atmosphere by irradiating the substrate W with infrared light from an infrared lamp (for example, a halogen lamp or a xenon lamp).

[0024] Next, the first transport device TR1 removes the substrate W from the processing device PM3, transports the removed substrate W to the load lock chamber LL3, and exits from 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 transport 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 apparatus PM4 may be a processing apparatus that performs the same process as any of the processing apparatuses PM1 to PM3. The processing apparatus PM4 may also be a processing apparatus 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] Although the substrate W is described as being processed 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), the present invention is not limited to this. The substrate W may be processed 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 Apparatus] Next, a processing apparatus PM2 (hereinafter also referred to as the substrate processing apparatus 100) that performs the second processing (modification processing) on ​​the 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 the modification processing on the 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 transporting 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 in the processing vessel 10. The mounting table 20 is connected to a rotation drive unit 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 drive unit 22 to rotate the mounting table 20.

[0031] The mounting table 20 is provided with a heater 23. The mounting table 20 is also provided with a temperature sensor (not shown). 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 gap 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 ultraviolet light within a predetermined wavelength range into the processing chamber 10 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 within the predetermined wavelength range (135 nm to 190 nm). Alternatively, the filter may be a filter that cuts off a high-energy band with wavelengths 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 in 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 the modification process (second process) performed in the substrate processing apparatus 100 will be described with reference to Fig. 3 and Figs. 4A to 4B. Fig. 3 is a flowchart illustrating an example of the modification process. Figs. 4A to 4B are exemplary cross-sectional schematic views of a substrate W.

[0038] In step S101, a 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 vessel 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 vessel 10 to a predetermined value.

[0039] 4A 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 processing (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 is hydrogen (H ２ ) gas, deuterium (D ２ ) gas, gas containing hydrogen and nitrogen, ammonia (NH ３ ), hydrazine (N ２ H ４ ) or a combination thereof can be used. An oxygen-containing gas may be added to the process gas. The oxygen-containing gas is oxygen (O ２ ) gas, nitric oxide (NO), nitrogen dioxide (NO ２ ), nitrogen trioxide (N ２ O ３ ), nitric oxide (CO), nitrogen dioxide (CO ２), or a combination thereof. The partial pressure of the oxygen-containing gas in the process gas is preferably 0.1% or less in order to suppress growth of an oxide layer (a silicon oxide layer 211 described later) due to interfacial oxidation. The control unit 60 controls the ultraviolet irradiation unit 40 to turn on the ultraviolet lamp 41, thereby irradiating the process gas in the processing chamber 10 and the oxide layer 220 of the substrate W placed on the mounting table 20 with ultraviolet light. The ultraviolet light dissociates oxygen (O) atoms in the oxide layer 220 and the oxygen-containing gas added to the process gas, and the interface between the silicon layer 210 and the oxide layer 220 and the oxide layer 220 are modified by the active species of the dissociated oxygen (oxygen radicals, etc.) and the hydrogen-containing gas contained in the process gas.

[0041] Here, the modification process by ultraviolet irradiation preferably has the following processing conditions: Wavelength range of ultraviolet rays: 135 nm to 190 nm 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 inside 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 vessel 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] 4B 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 causes a problem of 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).

[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 (the oxide layer 220 and the 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 the effect (density) of hydrogen termination is thought to be in a state of equilibrium. It is speculated that the balance between hydrogen (H) termination and hydrogen (H) dissociation, particularly 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 shows the hydrogen (H ２ 5 is an example of a graph showing the photodissociation characteristics of hydrogen (H ). 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. ２The wavelength range in which photodecomposition of ) occurs is shown by reference numeral 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 FIG. 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] It is preferable to preliminarily adsorb a sufficient amount of hydrogen (H) or deuterium (D) at the target interface of the substrate W before the ultraviolet irradiation treatment. 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 shows the oxygen (O ２ 6 is an example of a graph showing the photodissociation characteristics of oxygen (O ). 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. ２ The wavelength range in which photodecomposition of β-glucan occurs is indicated by reference numeral 520. The wavelength range indicated by reference numeral 520 includes a wavelength range 521 of less than 135 nm and a wavelength range 522 of 135 nm or more.

[0052] Here, in the wavelength band 521 below 135 nm, oxygen (O ２ When oxygen (O ２ When OH dissociates, it mainly produces a weak radical (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 trace oxygen component (O ２) to suppress the generation of high-energy excited O1d* radicals. This suppresses the silicon layer 210 from being oxidized by the high-energy excited O1d* radicals to form the 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] In addition, 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, it is possible to remove trace oxygen components (O ２ ) to generate O3p* radicals in a low-energy excited state, thereby modifying the film quality of the oxide layer 220 with the O3p* radicals in a low-energy excited state.

[0055] FIG. 7 shows the H ２ 7 is an example of a graph showing the photodissociation characteristics of O. 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 a dashed line 501. ２ The wavelength range in which photodecomposition of O occurs is indicated by reference numeral 530 .

[0056] FIG. 8 is an example of a graph showing the photodissociation characteristics of OH. The horizontal axis represents the wavelength of the irradiated light. The vertical axis represents 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 a dashed line 501. The wavelength band in which photodecomposition of OH occurs is indicated by reference numeral 540.

[0057] Here, the oxide layer 220 of the substrate W contains H ２ By limiting the wavelength of the applied ultraviolet light to the range of 135 nm or more and 190 nm or less, as shown in FIGS. ２This can decompose O and OH. This can prevent the thickness of the oxide layer (the total thickness of the oxide layer 220 and the silicon oxide layer 211) from increasing, and can also improve the film quality of the oxide layer 220. That is, H, which is an impurity in the oxide layer 220 decomposed by ultraviolet light, can be removed. ２ This has the effect of passivating and confining O and OH components in the oxide layer 220 without making them 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] 9 is an example of a graph showing the relationship between treatment time and oxide layer film thickness. The horizontal axis represents treatment time, and the vertical axis represents 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 reforming process of the reference example, hydrogen (H ２ ) gas and oxygen gas (O ２ ) and irradiated with ultraviolet light in the wavelength range of 170 nm to 190 nm to perform a modification treatment. As shown by the dashed line in Figure 9, the thickness of the oxide layer increases as the treatment time increases. In contrast, the modification treatment shown in Figure 3 makes it possible to ensure a long treatment time while suppressing the thickness of the oxide layer. That is, by extending the treatment 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) according to the present embodiment using the substrate processing apparatus has been described above. However, 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 set forth in the claims.

[0062] 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.

[0063] REFERENCE SIGNS LIST 10 Processing vessel 20 Mounting table 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 steps of: preparing a substrate having a silicon layer and an oxide layer formed on the silicon layer; and 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, thereby modifying the interface between the silicon layer and the oxide layer.

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 of 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 hydrogen-containing gas is H ２ , D ２ The substrate processing method according to claim 1 , wherein the substrate processing method is any one of the following:

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

6. The substrate processing method according to claim 1, wherein the process gas includes an oxygen-containing gas.

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

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

9. 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 within the processing vessel on which the substrate is placed; a gas supply unit for supplying a process gas containing a hydrogen-containing gas into the processing vessel; and an ultraviolet irradiation unit having an ultraviolet lamp for irradiating the processing vessel with ultraviolet light within a 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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