Semiconductor device manufacturing method and substrate processing apparatus

Abstract

According to one embodiment, a method of manufacturing a semiconductor device and a substrate processing apparatus are provided. A method for manufacturing a semiconductor device includes radical oxidation of a first film using plasma generated by a processing gas containing a hydrogen isotope gas.

Description

[0001] Reference to relevant applications

[0002] This application enjoys priority based on Japanese Patent Application No. 2024-105391, filed on June 28, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This embodiment relates to a method for manufacturing a semiconductor device and a substrate processing apparatus. Background Technology

[0004] In the manufacturing process of semiconductor devices, a specified film is sometimes deposited on or above a substrate, and the deposited specified film is then subjected to free radical oxidation. In the manufacturing process of semiconductor devices, it is desirable to perform free radical oxidation efficiently. Summary of the Invention

[0005] The present invention relates to a method for manufacturing a semiconductor device, comprising: performing free radical oxidation on a first film using plasma generated by a process gas containing hydrogen isotope gas.

[0006] The present invention also relates to a substrate processing apparatus comprising: a stage disposed in a processing chamber for holding a substrate and including a first electrode; a gas supply system for supplying a processing gas containing a hydrogen isotope gas to the stage in the processing chamber; a second electrode disposed outside the processing chamber at a position separate from the stage; and an exhaust system for adjusting the pressure inside the processing chamber; wherein plasma can be generated in the processing chamber by applying a high-frequency voltage between the first electrode and the second electrode. Attached Figure Description

[0007] Figure 1 This is a flowchart illustrating a method for manufacturing a semiconductor device according to an embodiment.

[0008] Figures 2A-2E This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to an embodiment.

[0009] Figure 3 This is a diagram illustrating the configuration of a substrate processing apparatus used in a semiconductor device manufacturing method according to an embodiment.

[0010] Figure 4 This is a graph showing the change in oxide film thickness over processing time (when the flow rate is 30%).

[0011] Figure 5 This is a graph showing the change in oxide film thickness over processing time (when the flow rate is 20%).

[0012] Figure 6This is a graph showing the change in oxide film thickness over processing time (when the flow rate is 5%).

[0013] Figure 7 It represents the hydroxyl radical OH based on the flux ratio of hydrogen or its isotopes. * A graph showing the change in luminous intensity.

[0014] Figure 8 This is a flowchart illustrating a method for manufacturing a semiconductor device according to a first variation of the embodiment.

[0015] Figure 9 This is a diagram illustrating the configuration of a substrate processing apparatus used in a semiconductor device manufacturing method according to the first variation of the embodiment.

[0016] Figure 10 This is a flowchart illustrating a method for manufacturing a semiconductor device according to a second variation of the embodiment.

[0017] Figure 11A and Figure 11B This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to a second variation of the embodiment.

[0018] Figure 12A and Figure 12B This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to a second variation of the embodiment.

[0019] Figure 13 This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to a second variation of the embodiment.

[0020] Figure 14 This is a flowchart illustrating a method for manufacturing a semiconductor device according to the third variation of the embodiment.

[0021] Figure 15 This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to the third variation of the embodiment.

[0022] Figure 16 This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to the third variation of the embodiment.

[0023] Figure 17A and Figure 17B This is a cross-sectional view showing the warping of the substrate in the third variation of the embodiment.

[0024] Figure 18 This is a flowchart illustrating a method for manufacturing a semiconductor device according to the fourth variation of the embodiment.

[0025] Figure 19 This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to the fourth variation of the embodiment.

[0026] Figure 20 This is a cross-sectional view illustrating a method for manufacturing a semiconductor device according to the fourth variation of the embodiment. Detailed Implementation

[0027] According to this embodiment, a method for manufacturing a semiconductor device can be provided. The method for manufacturing a semiconductor device includes: performing free radical oxidation on a first film using plasma generated by a process gas containing a hydrogen isotope gas.

[0028] The method for manufacturing a semiconductor device according to the embodiments will now be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments.

[0029] (Implementation Method)

[0030] In the semiconductor device manufacturing method according to the embodiments, a predetermined film is deposited on or above a substrate, and the deposited predetermined film is subjected to free radical oxidation, but a method for efficiently performing free radical oxidation is implemented.

[0031] The manufacturing method of semiconductor device 100 can be as follows: Figure 1 and Figures 2A-2E Proceed as shown. Figure 1 This is a flowchart illustrating a method for manufacturing the semiconductor device 100. Hereinafter, the direction perpendicular to the main surface 10a of the substrate 10 will be defined as the Z direction, and the two directions orthogonal to each other in the plane perpendicular to the Z direction will be defined as the X direction and the Y direction. Figures 2A-2E These are YZ cross-sectional views showing the manufacturing method of the semiconductor device 100.

[0032] Prepare Figure 2A The substrate 10 (S1) is shown. The substrate 10 has a generally disk-shaped form and a generally circular shape when viewed from above in the XY direction. The substrate 10 may be formed of a material with semiconductors (e.g., silicon) as the main component. The substrate 10 has a main surface 10a on the +Z side.

[0033] When preparing the substrate 10, a [structure] is formed on or above (on the +Z side) the main surface 10a of the substrate 10. Figure 2B The high longitudinal and transverse structure TR is shown. Figure 2B The example shown illustrates a case where a high longitudinal and transverse structure TR is formed on the main surface 10a of a substrate 10.

[0034] A film 11 is deposited on or above the main surface 10a of a substrate 10 using methods such as CVD (Chemical Vapor Deposition) or sputtering. The film 11 can be formed of an insulating material. A resist pattern PR with openings corresponding to holes 11a1 is formed on the main surface 11a of the film 11. The resist pattern PR is used as a mask to etch the film using methods such as RIE (Reactive Ion Etching) under anisotropic processing conditions. As a result, holes 11a1 with a high aspect ratio when viewed in cross-section including the Z-axis are formed in the film 11. A high aspect ratio means that the aspect ratio (= hole depth / hole bottom width) is greater than 1. In other words, a high aspect ratio structure TR with holes 11a1 with a high aspect ratio is obtained in the film 11.

[0035] When forming a high longitudinal and transverse structure TR, it can be deposited on the side and bottom surfaces of hole 11a1. Figure 2C The treated membrane 12 (S2) is shown.

[0036] The membrane to be treated 12 is deposited on the membrane 11 by CVD, sputtering or other methods. The main surface 11a of the cover membrane 11 in the deposited membrane to be treated is removed by RIE or other methods, leaving only the side and bottom surfaces of the cover holes 11a1.

[0037] During the deposition of the treated film 12, the substrate 10 is placed in... Figure 3 In the substrate processing apparatus 1 shown, an oxidation process (S3) is performed on the film to be processed 12. Figure 3 This is a diagram showing the configuration of the substrate processing apparatus 1 used in the manufacturing method of the semiconductor device 100.

[0038] The oxidation process (S3) in the substrate processing apparatus 1 can also be performed by using plasma generated from a processing gas containing hydrogen isotope gas and oxygen to perform free radical oxidation on the film 12 to be processed. The free radical oxidation process using plasma is an isotropic process, which is called PIO (Plasma Isotropic Oxidization) process.

[0039] The substrate processing apparatus 1 includes a vacuum container 2, a stage 3, a gas supply system 4, electrodes 5, a power supply unit 6, an exhaust system 7, and a controller 8.

[0040] The controller 8 can comprehensively control all parts of the board processing device 1.

[0041] A processing chamber CH is formed inside the vacuum container 2. The processing chamber CH is a chamber used to generate plasma PL inside it. The vacuum container 2 has an upper wall 2a, a side wall 2b, and a bottom wall 2c. The upper wall 2a is disposed on the +Z side, and the bottom wall 2c is disposed on the -Z side. The upper wall 2a may also have slits 2a1 and 2a2 at positions on the outer side in the XY direction. The bottom wall 2c may also have holes 2i at any position.

[0042] The stage 3 is disposed within the processing chamber CH. The stage 3 may also be disposed near the bottom wall 2c within the processing chamber CH. The stage 3 has a main body 3a, electrodes 3b, and a heater 3c. The main body 3a extends in a plate-like or disc-like shape in the XY direction. The main body 3a may be formed of an insulating material. A mounting surface 3d is formed on the +Z side of the main body 3a. A substrate 10 may be mounted on the mounting surface 3d. The electrodes 3b and the heater 3c may also be embedded within the main body 3a. The electrodes 3b extend in a plate-like or disc-like shape in the XY direction. The electrodes 3b may be formed of a conductive material. The electrodes 3b may be connected to a ground potential via wiring. The heater 3c can heat the substrate 10 via the main body 3a under the control of the controller 8. Although not shown, the stage 3 may also have a mechanism for adsorbing the substrate 10.

[0043] The gas supply system 4 supplies a processing gas containing hydrogen isotope gas and oxygen to the stage 3 in the processing chamber CH. The hydrogen isotope gas can be deuterium (D2) or tritium (T2). The following description focuses on the case where the hydrogen isotope gas is deuterium, but the following description is also applicable to the case where the hydrogen isotope gas is tritium.

[0044] The gas supply system 4 includes gas cylinders 4a-4c, regulating valves 4d-4f, gas piping 4g-4n, and a cover 4t. Gas cylinders 4a, 4b, and 4c store deuterium (D2), light hydrogen (H2), and oxygen (O2), respectively. For example, gas cylinder 4c stores... 16 O2 gas. The cover 4t has a gas inlet 4u. Gas storage cylinders 4a to 4c are respectively connected to gas piping 4g to 4i. The cover 4t separately covers the upper wall 2a in the Z direction, forming a buffer chamber 4v. The buffer chamber 4v is connected to the gas inlet 4u on the +Z side and to gaps 2a1 and 2a2 on the -Z side. Adjusting valves 4d to 4f are respectively located between gas piping 4g and 4n, and their opening degree can be controlled by the controller 8.

[0045] Electrode 5 is positioned outside the processing chamber CH, separate from the stage 3. Electrode 5 can also be positioned on the +Z side of the side wall 2b. Electrode 5 includes a coil 5a. The coil 5a can also be wound around the +Z side of the side wall 2b.

[0046] The power supply unit 6 can supply high-frequency power to the electrode 5. The power supply unit 6 includes a high-frequency power supply 6a, a matching device 6b, and a sensor 6c. The high-frequency power supply 6a can supply high-frequency power to the electrode 5 under the control of the controller 8. The sensor 6c monitors the information of the supplied high-frequency traveling wave and reflected wave, and supplies the monitoring results to the matching device 6b. The matching device 6b performs impedance matching by reducing the power of the reflected wave based on the monitoring results of the sensor 6c.

[0047] The exhaust system 7 can reduce the pressure in the processing chamber CH and adjust the pressure within CH. The exhaust system 7 includes a vacuum pump 7a, an adjusting valve 7b, and vacuum piping 7c and 7d. The vacuum pump 7a operates under the control of the controller 8. The adjusting valve 7b is located between the vacuum piping 7c and 7d and its opening and closing can be controlled by the controller 8.

[0048] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between the electrode 3b and the electrode 5, and generates plasma PL (S4) in the processing chamber CH by a processing gas containing hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas).

[0049] For example, when the substrate 10 is placed on the placement surface 3d of the stage 3, the controller 8 heats the substrate 10. The controller 8 can also control the heater 3c to heat the substrate 10 to a temperature of 300°C or higher and 800°C or lower.

[0050] Furthermore, if the temperature of substrate 10 is below 300°C, there is a possibility that the film formation rate of free radical oxidation will decrease to below the permissible level. If the temperature of substrate 10 exceeds 800°C, thermal oxidation of the film 12 being treated will also occur in addition to free radical oxidation, making it possible that the control of the film formation rate will become difficult.

[0051] In parallel with the heating of the substrate 10, the controller 8 operates the vacuum pump 7a while controlling the opening of the regulating valve 7b so that the pressure of the processing chamber CH is above 50 Pa and below 300 Pa, thereby reducing the pressure in the processing chamber CH through the vacuum pipes 7c and 7d.

[0052] Furthermore, if the pressure of CH in the processing chamber is below 50 Pa, there is a possibility that the oxidation rate will decrease to below the permissible level. If the pressure of CH in the processing chamber exceeds 300 Pa, there is a possibility that plasma may not be generated within the CH in the processing chamber.

[0053] Controller 8 begins supplying a processing gas containing hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas) into the processing chamber CH. Controller 8 opens regulating valves 4d and 4f while regulating valve 4e is closed. This introduces hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas) from gas cylinders 4a and 4c into gas pipe 4n via gas pipes 4g, 4i, 4j, and 4m, where they mix to form a processing gas containing hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas). The processing gas is then introduced from gas pipe 4n into buffer chamber 4v via gas inlet 4u. The processing gas in buffer chamber 4v is supplied from slits 2a1 and 2a2 to the stage 3 in the processing chamber CH.

[0054] At this time, controller 8 continues to control the opening of regulating valve 7b such that the pressure of the processing chamber CH is 50 Pa or more and 300 Pa or less. In addition, controller 8 controls the opening of regulating valves 4d and 4f such that the flow rate of hydrogen isotope gas (e.g., D2 gas) is 5% or more and 95% or less of the flow rate of the processing gas.

[0055] Furthermore, if the flow rate of hydrogen isotope gas is less than 5%, there is a possibility that the step coverage of the oxide film formed by free radical oxidation will be lower than the permissible level. If the flow rate of hydrogen isotope gas exceeds 95%, there is a possibility that the step coverage of the oxide film formed by free radical oxidation will be lower than the permissible level.

[0056] If the pressure in the processing chamber CH stabilizes, the controller 8 begins supplying high-frequency power from the power supply unit 6 to the electrode 5. This applies a high-frequency voltage between electrode 3b and electrode 5, creating an induced magnetic field within the processing chamber CH. Hydrogen isotopes (e.g., D2 gas) and oxygen (O2 gas) contained in the processing gas are excited by the plasma, forming, for example, a donut-shaped plasma PL. This plasma PL can also be a low-potential plasma. The D2 gas and O2 gas dissociate through the plasma PL, generating hydroxyl radicals OH. * Reactants include free radicals, deuterium ions, and oxygen ions. Due to the low potential of plasma PL, free radicals and the like in the processing gas can be supplied approximately uniformly to the vicinity of the exposed surface 12a of the film 12 to be processed on the substrate 10 without accelerating deuterium ions and oxygen ions.

[0057] Therefore, the treated membrane 12 is subjected to free radical oxidation (S5). Free radical oxidation can also be performed as follows: Figure 2D As shown, the oxidation is performed near the exposed surface 12a in the treated film 12, replacing the portion near the exposed surface 12a with an oxide film 13. Alternatively, free radical oxidation can also be performed as follows: Figure 2EThe entire film 12 to be treated is replaced with an oxide film 13 as shown. Figure 2D and Figure 2E The dashed arrow indicates that the oxidative free radicals and ions in the treatment gas are supplied approximately uniformly to the vicinity of the exposed surface 12a of the membrane 12 being treated.

[0058] Then, to Figure 2D or Figure 2E The substrate 10 shown is further subjected to a prescribed process to manufacture a semiconductor device 100.

[0059] As described above, in this embodiment, the method for manufacturing the semiconductor device 100 employs plasma generated by a processing gas containing hydrogen isotope gas and oxygen to perform free radical oxidation on the film 12 to be processed. Therefore, compared to performing free radical oxidation on the film 12 to be processed using plasma generated by a processing gas containing hydrogen and oxygen, free radical oxidation can be performed more efficiently.

[0060] For example, when the substrate processing apparatus 1 uses plasma generated by a processing gas containing hydrogen and oxygen at a flow rate ratio of 30%:70% to perform free radical oxidation on the film 12 to be processed, the thickness of the oxide film 13 varies depending on the processing time. Figure 4 The change is as shown by the dashed line. Figure 4 This is a graph showing the change in oxide film thickness over processing time (when the flow rate ratio is 30%). At processing time t1, oxide film 13 is formed at film thickness h1, and at processing time t2 (>t1), oxide film 13 is formed at film thickness h2 (>h1).

[0061] On the other hand, when the substrate processing apparatus 1 uses plasma generated by a processing gas containing D2 gas and oxygen at a flow rate ratio of 30%:70% to perform free radical oxidation on the film 12 to be processed, the thickness of the oxide film 13 varies depending on the processing time. Figure 4 The change is as shown by the solid line. At processing time t1, oxide film 13 is formed with film thickness d1, and at processing time t2, oxide film 13 is formed with film thickness d2 (>d1).

[0062] Regarding the film formation rate at each processing time, the film formation rate was higher when using plasma generated from a processing gas containing hydrogen isotopes and oxygen, compared to when using plasma generated from a processing gas containing hydrogen and oxygen. As can be seen from processing time t1, film thickness d1 is greater than film thickness h1. As can be seen from processing time t2, film thickness d2 is greater than film thickness h2.

[0063] Regarding the film formation rate, it is improved when using a plasma generated by a process gas containing hydrogen isotopes and oxygen, compared to when using a plasma generated by a process gas containing hydrogen and oxygen. As can be seen from the processing time t1 to t2, the slope of the solid line (d2-d1) / (t2-t1) is greater than the slope of the dashed line (h2-h1) / (t2-t1).

[0064] Alternatively, when the substrate processing apparatus 1 uses plasma generated from a processing gas containing hydrogen and oxygen at a flow rate ratio of 20%:80% to perform free radical oxidation on the film 12 to be processed, the thickness of the oxide film 13 is determined according to the processing time, such as... Figure 5 The change is as shown by the dashed line. Figure 5 This is a graph showing the change in oxide film thickness over processing time (when the flow rate ratio is 20%). At processing time t11, oxide film 13 is formed at a thickness of h11, and at processing time t12 (>t11), oxide film 13 is formed at a thickness of h12 (>h11).

[0065] On the other hand, when the substrate processing apparatus 1 uses plasma generated by a processing gas containing D2 gas and oxygen at a flow rate ratio of 20%:80% to perform free radical oxidation on the film 12 to be processed, the thickness of the oxide film 13 varies depending on the processing time. Figure 5 The change is as shown by the solid line. At processing time t11, oxide film 13 is formed with film thickness d11, and at processing time t12, oxide film 13 is formed with film thickness d12 (>d11).

[0066] Regarding the film formation rate at each processing time, the film formation rate was increased when using plasma generated by a processing gas containing hydrogen isotopes and oxygen, compared to when using plasma generated by a processing gas containing hydrogen and oxygen. As can be seen from processing time t11, film thickness d11 is greater than film thickness h11. As can be seen from processing time t12, film thickness d12 is greater than film thickness h12.

[0067] Regarding the film formation rate, it is improved when using a plasma generated by a process gas containing hydrogen isotopes and oxygen, compared to when using a plasma generated by a process gas containing hydrogen and oxygen. As can be seen from the processing time t11–t12, the slope of the solid line (d12–d11) / (t12–t11) is greater than the slope of the dashed line (h12–h11) / (t12–t11).

[0068] Alternatively, when the substrate processing apparatus 1 uses plasma generated from a processing gas containing hydrogen and oxygen at a flow rate ratio of 5%:95% to perform free radical oxidation on the film 12 to be processed, the thickness of the oxide film 13 is determined according to the processing time, such as... Figure 6 The change is as shown by the dashed line. Figure 6This is a graph showing the change in oxide film thickness over processing time (when the flow rate ratio is 5%). At processing time t21, oxide film 13 is formed at film thickness h21, and at processing time t22 (>t21), oxide film 13 is formed at film thickness h22 (>h21).

[0069] On the other hand, when the substrate processing apparatus 1 uses plasma generated by a processing gas containing D2 gas and oxygen at a flow rate ratio of 5%:95% to perform free radical oxidation on the film 12 to be processed, the thickness of the oxide film 13 varies depending on the processing time. Figure 6 The change is as shown by the solid line. At processing time t21, oxide film 13 is formed according to film thickness d21, and at processing time t22, oxide film 13 is formed according to film thickness d22 (>d21).

[0070] The amount of film formed at each processing time is the same when using plasma generated by a processing gas containing hydrogen and oxygen and when using plasma generated by a processing gas containing hydrogen isotope gas and oxygen. As can be seen from processing time t21, film thickness d21 and film thickness h21 are of the same degree. As can be seen from processing time t22, film thickness d22 and film thickness h22 are of the same degree.

[0071] The film formation rate is equivalent when using plasma generated by a process gas containing hydrogen and oxygen and when using plasma generated by a process gas containing hydrogen isotope gas and oxygen. As can be seen from the processing time t11 to t12, the slope of the solid line (d12-d11) / (t12-t11) is equivalent to the slope of the dashed line (h12-h11) / (t12-t11).

[0072] Alternatively, when the substrate processing apparatus 1 uses plasma generated by a processing gas containing hydrogen at a flow rate of 0% to 100% to perform free radical oxidation on the film 12 being processed, hydroxyl radicals OH... * Luminous intensity such as Figure 7 As shown by the dashed line. Figure 7 It represents the hydroxyl radical OH based on the flux ratio of hydrogen or its isotopes. * A graph showing the change in luminescence intensity. Hydroxyl radical (OH) * The luminescence intensity is related to the step coverage of the oxide film 13. This is achieved by utilizing hydroxyl radicals (OH) passing through the treated film 11. * The oxidized areas can be detected by luminescence within a specified spectral band (e.g., a spectral band with wavelengths of 306–315 nm). This leads to the inference of hydroxyl radicals (OH). * The stronger the luminescence intensity, the better the step coverage of oxide film 13. Figure 7The changes shown by the dashed line indicate a mountain-shaped change that roughly exceeds the threshold, ranging from 5% to 95%. It can be inferred that by setting the hydrogen flow rate ratio to between 5% and 95%, the luminescence intensity at which the step coverage of oxide film 13 reaches an acceptable level is approximately achieved. The threshold can be determined experimentally in advance as the value corresponding to the step coverage of oxide film 13 and the acceptable level.

[0073] On the other hand, when the substrate processing apparatus 1 uses plasma generated by a processing gas containing D2 gas at a flow rate ratio of 0% to 100% to perform free radical oxidation on the film 12 being processed, the luminescence intensity of the hydroxyl radical OH* is as follows: Figure 7 As shown by the solid line. Figure 7 The change of the solid line is visible, showing a mountain-shaped change that is roughly above the threshold between 5% and 95%, suggesting that by setting the hydrogen flow ratio to be between 5% and 95%, the step coverage of oxide film 13 is roughly at the permissible level of luminescence intensity.

[0074] Regarding the hydroxyl radicals (OH) in a flow ratio of 5% to 95% * The luminescence intensity is improved when using a plasma generated with a process gas containing hydrogen and oxygen, compared to plasma generated with a process gas containing hydrogen and oxygen. As seen at a flow rate ratio of 5%, the solid line value Id1 is greater than the dashed line value Ih1. At a flow rate ratio of 95%, the solid line value Id2 is greater than the dashed line value Ih2. Within the range of flow rates above 5% and below 95%, the solid line curve is located on the high luminescence intensity side compared to the dashed line curve. Therefore, it can be inferred that the step coverage of the oxide film 13 based on free radical oxidation is improved when using plasma generated with a process gas containing hydrogen and oxygen, compared to plasma generated with a process gas containing hydrogen and oxygen.

[0075] Furthermore, the processing gas used in S4 can also be a mixture of hydrogen, hydrogen isotope gas, and oxygen. For example, in Figure 1In step S4, controller 8 begins supplying a processing gas containing hydrogen (H2 gas), a hydrogen isotope gas (e.g., D2 gas), and oxygen (O2 gas) into the processing chamber CH. Controller 8 opens regulating valves 4d, 4e, and 4f. This allows hydrogen (H2 gas), hydrogen isotope gas (e.g., D2 gas), and oxygen (O2 gas) to be introduced from gas cylinders 4a, 4b, and 4c via gas pipes 4g, 4h, 4i, 4j, 4k, and 4m into gas pipe 4n, where they mix to form a processing gas containing hydrogen (H2 gas), hydrogen isotope gas (e.g., D2 gas), and oxygen (O2 gas). The processing gas is then introduced from gas pipe 4n through gas inlet 4u into buffer chamber 4v. The processing gas in buffer chamber 4v is then supplied through gaps 2a1 and 2a2 to the stage 3 in the processing chamber CH. At this time, the controller 8 controls the opening of the regulating valves 4d, 4e, and 4f respectively, such that the flow rate ratio of hydrogen isotope gas (e.g., D2 gas) to the flow rate of the processing gas is 5% or more and 95% or less. In this case, by ensuring that the flow rate ratio of hydrogen isotope gas to the flow rate of the processing gas is 5% or more and 95% or less, the step coverage of the oxide film 13 based on free radical oxidation can be improved.

[0076] Furthermore, the processing gas used in S4 may further contain rare gases such as helium and argon. The processing gas may also be a mixture of hydrogen isotope gas, oxygen, and rare gases, or a mixture of hydrogen, hydrogen isotope gas, oxygen, and rare gases. Even in this case, by making the flow rate ratio of hydrogen isotope gas to processing gas flow rate between 5% and 95%, the step coverage of the oxide film 13 based on free radical oxidation can be improved.

[0077] Alternatively, as a first variation of the implementation, such as Figure 8 As shown, the oxidation treatment (S103) can also be carried out as follows: Figure 9 In the substrate processing apparatus 201 shown, plasma generated by a processing gas containing hydrogen isotope gas and oxygen isotope gas is used to perform free radical oxidation on the film 12 to be processed. Figure 8 This is a flowchart illustrating a method for manufacturing a semiconductor device 100 according to a first variation of the embodiment. Figure 9 This is a diagram showing the configuration of the substrate processing apparatus 201 used in the manufacturing method of the semiconductor device 100 according to the first variation of the embodiment.

[0078] The substrate processing apparatus 201 has a gas supply system 204 instead of the gas supply system 4 (see reference). Figure 3The gas supply system 204 can supply a processing gas containing hydrogen isotope gas and oxygen isotope gas to the stage 3 in the processing chamber CH. The hydrogen isotope gas can be deuterium (D2) or tritium (T2). The oxygen isotope gas can be oxygen-17 (…). 17 O2 gas, or oxygen 18 ( 18 O2) gas. Hereinafter, deuterium will be used as the hydrogen isotope gas and deuterium as the oxygen isotope gas. 17 The following explanation focuses on the case of O2 gas, but it can also be applied to other combinations of hydrogen isotope gas and oxygen isotope gas.

[0079] The gas supply system 204 further includes a gas storage cylinder 4p, a regulating valve 4q, and gas piping 4r and 4s. The gas storage cylinder 4p stores... 17 O2 gas. Gas cylinder 4p is connected to gas piping 4r. Adjusting valve 4q is located between gas piping 4r and 4s, and its opening and closing degree can be controlled by controller 8.

[0080] In the substrate processing apparatus 201, the controller 8 applies a high-frequency voltage between the electrode 3b and the electrode 5, and transmits a gas containing hydrogen isotope gas (e.g., D2 gas) and oxygen isotope gas (e.g., D2 gas). 17 The processing gas (O2 gas) generates plasma PL (S104) in the processing chamber CH.

[0081] For example, when the substrate 10 is placed on the placement surface 3d of the stage 3, the controller 8 heats the substrate 10. The controller 8 can also control the heater 3c to heat the substrate 10 to a temperature of 300°C or higher and 800°C or lower.

[0082] At the same time, the controller 8 operates the vacuum pump 7a and controls the opening of the regulating valve 7b so that the pressure in the processing chamber CH is above 50 Pa and below 300 Pa, thereby reducing the pressure in the processing chamber CH through the vacuum pipes 7c and 7d.

[0083] Controller 8 begins supplying a gas containing hydrogen isotopes (e.g., D2 gas) and oxygen isotopes (e.g., D2 gas) into the processing chamber CH. 17 The controller 8 opens regulating valves 4d and 4q from the closed state of regulating valves 4e and 4f. This allows hydrogen isotope gas (e.g., D2 gas) and oxygen isotope gas (e.g., O2 gas) to be introduced from gas cylinders 4a and 4p into gas pipe 4n via gas pipes 4g, 4r, 4j, and 4s. 17 O2 gas) is mixed in gas piping 4n to become a gas containing hydrogen isotopes (e.g., D2 gas) and oxygen isotopes (e.g., O2 gas), respectively. 17The processing gas (O2 gas) is introduced from the gas pipe 4n through the gas inlet 4u into the buffer chamber 4v. The processing gas in the buffer chamber 4v is supplied from the gaps 2a1 and 2a2 to the stage 3 in the processing chamber CH.

[0084] At this time, controller 8 continues to control the opening of regulating valve 7b such that the pressure of the processing chamber CH is 50 Pa or more and 300 Pa or less. In addition, controller 8 controls the opening of regulating valves 4d and 4q respectively such that the flow rate of hydrogen isotope gas (e.g., D2 gas) is 5% or more and 95% or less of the flow rate of the processing gas.

[0085] When the pressure in the processing chamber CH stabilizes, the controller 8 begins to supply high-frequency power from the power supply unit 6 to the electrode 5. This applies a high-frequency voltage between electrode 3b and electrode 5, creating an induced magnetic field within the processing chamber CH. The processing gas contains hydrogen isotope gas (e.g., D2 gas) and oxygen isotope gas (e.g., D2 gas). 17 O2 gas is excited by the plasma to form, for example, a donut-shaped plasma PL. This plasma PL can also be a low-potential plasma. D2 gas, 17 O2 gas dissociates upon passing through plasma (PL) to generate hydroxyl radicals (OH). * Reactants include free radicals, deuterium ions, and oxygen ions. Due to the low potential of plasma PL, free radicals and the like in the processing gas can be supplied approximately uniformly to the vicinity of the exposed surface 12a of the film 12 to be processed on the substrate 10 without accelerating deuterium ions and oxygen ions.

[0086] Therefore, the treated membrane 12 is subjected to free radical oxidation (S105). Free radical oxidation can also be performed as follows: Figure 2D As shown, the process is performed near the exposed surface 12a of the treated film 12, replacing the portion near the exposed surface 12a with an oxide film 13. Alternatively, free radical oxidation can also be performed as follows: Figure 2E The entire film 12 to be treated is replaced with an oxide film 13 as shown. Figure 2D and Figure 2E The dashed arrow indicates that the oxidative free radicals and ions in the treatment gas are supplied approximately uniformly to the vicinity of the exposed surface 12a of the membrane 12 being treated.

[0087] Thus, in the manufacturing method of the semiconductor device 100, plasma generated by a processing gas containing hydrogen isotope gas and oxygen isotope gas can be used to perform free radical oxidation on the film 12 to be processed. Therefore, free radical oxidation can be performed more efficiently than when using plasma generated by a processing gas containing hydrogen and oxygen to perform free radical oxidation on the film 12 to be processed.

[0088] For example, regarding the film formation rate, it can be increased when using a plasma generated by a process gas containing hydrogen isotope gas and oxygen isotope gas compared to using a plasma generated by a process gas containing hydrogen isotope gas and oxygen.

[0089] Alternatively, regarding the step coverage of oxide film 13, it can be improved when using plasma generated by a process gas containing hydrogen isotope gas and oxygen isotope gas compared to plasma generated by a process gas containing hydrogen isotope gas and oxygen isotope gas.

[0090] Furthermore, in the manufacturing method of the semiconductor device 100, the processing gas used in S4 can be a mixture of hydrogen, hydrogen isotope gas, and oxygen isotope gas, or a mixture of hydrogen, hydrogen isotope gas, oxygen, and oxygen isotope gas. For example, in Figure 10 In step S4, controller 8 begins supplying the processing chamber CH with a mixture of hydrogen (H2 gas), hydrogen isotope gas (e.g., D2 gas), oxygen (O2 gas), and oxygen isotope gas (e.g., D2 gas). 17 The controller 8 opens regulating valves 4d, 4e, 4f, and 4q. This allows hydrogen (H2 gas), hydrogen isotope gas (e.g., D2 gas), oxygen (O2 gas), and oxygen isotope gas (e.g., O2 gas) to be dispensed from storage cylinders 4a, 4b, 4c, and 4p. 17 O2 gas is introduced into gas pipe 4n via gas pipes 4g, 4h, 4i, 4r, 4j, 4k, 4m, and 4s, where it mixes to form a mixture containing hydrogen (H2 gas), hydrogen isotope gas (e.g., D2 gas), oxygen (O2 gas), and oxygen isotope gas (e.g., D2 gas). 17 The processing gas (O2 gas) is introduced from gas pipe 4n through gas inlet 4u into buffer chamber 4v. The processing gas in buffer chamber 4v can be supplied to stage 3 in processing chamber CH through gaps 2a1 and 2a2. Controller 8 controls the opening of regulating valves 4d, 4e, 4f, and 4q respectively, such that the flow rate ratio of hydrogen isotope gas (e.g., D2 gas) to the flow rate of processing gas is 5% or more and 95% or less. In this case, by making the flow rate ratio of hydrogen isotope gas to the flow rate of processing gas 5% or more and 95% or less, the step coverage of oxide film 13 based on free radical oxidation can also be improved.

[0091] Furthermore, the processing gas used in S4 may further contain rare gases such as helium and argon. The processing gas may also be a mixture of hydrogen isotope gas, oxygen isotope gas, and rare gases; a mixture of hydrogen, hydrogen isotope gas, oxygen isotope gas, and rare gases; or a mixture of hydrogen, hydrogen isotope gas, oxygen, oxygen isotope gas, and rare gases. In this case, by making the flow rate ratio of hydrogen isotope gas to processing gas flow rate 5% or more and 95% or less, the step coverage of the oxide film 13 based on free radical oxidation can also be improved.

[0092] Alternatively, as a second variation of the embodiment, the idea of ​​the embodiment can also be applied to the formation of the barrier insulating film in the manufacturing method of a semiconductor device 300, such as a three-dimensional memory. For example, the manufacturing method of the semiconductor device 300 can also be as follows: Figures 10-13 Proceed as shown. Figure 10 This is a flowchart illustrating a method for manufacturing a semiconductor device 300 according to a second variation of the embodiment. Figure 11A , Figure 11B , Figure 12A , Figure 12B , Figure 13 This is a YZ cross-sectional view showing the manufacturing method of the semiconductor device 300.

[0093] When preparing the substrate 10 (S1), a [structure] is formed on or above (+Z side) the main surface 10a of the substrate 10. Figure 11A The laminate SST(S206) is shown. In Figure 11A The example shown illustrates a case where a laminate SST is formed on the main surface 10a of a substrate 10.

[0094] An insulating layer 111 and a sacrificial layer 151 are alternately and repeatedly stacked on the main surface 10a of the substrate 10. Figure 11A The example shown is a case where the number of repetitions is 6, but the number of repetitions is not limited to 6 and can be more. The insulating layer 111 can be formed of a material with a semiconductor oxide (e.g., silicon oxide) as the main component. The sacrificial layer 151 can be formed of a material that ensures an etch selectivity ratio with the insulating layer 111. The sacrificial layer 151 can be formed of a material with a semiconductor nitride (e.g., silicon nitride) as the main component. An insulating layer 113 is stacked on the Z-side sacrificial layer 151. The insulating layer 113 can be formed of a material with a semiconductor oxide (e.g., silicon oxide) as the main component. Thus, by alternately and repeatedly stacking the insulating layer 111 and the sacrificial layer 151, and further stacking the insulating layer 113, a laminate SST can be obtained.

[0095] When the stacked body SST is obtained, a storage hole 120 is formed in the stacked body SST (S207).

[0096] On the main surface 113a of the insulating layer 113 on the +Z side of the stacked structure SST, a resist pattern RP1 with an opening RP1a corresponding to the storage via 120 is formed. Using the resist pattern RP1 as a mask, etching is performed under anisotropic processing conditions using methods such as RIE (Residual Etching) until the substrate 10 is reached. Thus, as... Figure 11B As shown, a storage hole 120 is formed on the laminate SST, extending along the Z direction to the substrate 10.

[0097] Furthermore, by alternating and repeating multiple times Figure 11A The process shown and Figure 11B The process shown can also form the storage hole 120. Therefore, storage holes 120 with a high aspect ratio can be easily formed.

[0098] When forming the storage hole 120, such as Figure 12A As shown, a semiconductor nitride film 312 is deposited on the side and bottom surfaces of the storage hole 120 by a CVD method or the like (S202). The semiconductor nitride film 312 can be formed from a material with silicon nitride as the main component.

[0099] During the deposition of the semiconductor nitride film 312, the substrate 10 is placed in the substrate processing apparatus 1 (see reference 1). Figure 3 In the process, the semiconductor nitride film 312 is subjected to oxidation treatment (S203).

[0100] The oxidation process (S203) can also be performed in the substrate processing apparatus 1 by PIO processing, which uses plasma generated by a processing gas containing hydrogen isotope gas and oxygen to perform free radical oxidation on the semiconductor nitride film 312.

[0101] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between electrodes 3b and 5, generating plasma PL (S4) in the processing chamber CH using a processing gas containing hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas). By applying the high-frequency voltage between electrodes 3b and 5, an induced magnetic field is formed in the processing chamber CH. The hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas) contained in the processing gas are excited by the plasma, forming, for example, a donut-shaped plasma PL. This plasma PL can also be a low-potential plasma. The D2 gas and O2 gas dissociate through the plasma PL, generating hydroxyl radicals OH. * Reactants such as free radicals, deuterium ions, and oxygen ions are present. Due to the low potential of the plasma PL, free radicals and the like in the treatment gas can be supplied approximately uniformly to the vicinity of the exposed surface 312a of the semiconductor nitride film 312 through the storage hole 120 without accelerating deuterium ions and oxygen ions.

[0102] Therefore, free radical oxidation is performed on the semiconductor nitride film 312 (S205). Free radical oxidation can also be performed near the exposed surface 312a of the semiconductor nitride film 312, replacing the portion near the exposed surface 312a with an oxide film 313. Alternatively, free radical oxidation can also be performed as follows: Figure 12B The entire semiconductor nitride film 312 is replaced with an oxide film 313 as shown. Figure 12B The dashed arrow indicates that oxidative radicals and ions in the processing gas can be supplied approximately uniformly to the vicinity of the exposed surface 312a of the semiconductor nitride film 312. This allows a block insulation film containing the oxide film 313 to be formed on the side and bottom surfaces of the storage hole 120.

[0103] In the storage hole 120, a charge accumulation film and a tunnel insulating film are further deposited sequentially. The charge accumulation film can be formed of an insulating material such as silicon nitride. The tunnel insulating film can be formed of an insulating material such as silicon oxide. The bottom portion of the storage hole 120 in the barrier insulating film, charge accumulation film, and tunnel insulating film can be selectively removed.

[0104] Semiconductor films are deposited on the side and bottom surfaces of the storage hole 120. The semiconductor films can be formed from a material whose main component is a substantially impurity-free semiconductor (e.g., polycrystalline silicon). The crystallinity of the semiconductor film can be improved by heat-treating it at a specified temperature. Furthermore, a core component is embedded in the storage hole 120. The core component can be formed from an insulating material such as silicon oxide. This forms a columnar structure that penetrates the stacked structure SST in the Z direction.

[0105] The sacrificial layer 151 of the laminate SST is removed. An insulating film is formed on the exposed surface of the voids formed by the removal. The insulating film can be formed using an insulating material such as aluminum oxide. A conductive layer 112 can be further embedded in the voids. The conductive layer 112 can be formed from a material whose main component is a conductive material (such as a metal such as tungsten). Thus, by alternately and repeatedly stacking the conductive layer 112 and the insulating layer 111, and further stacking the insulating layer 113, the laminate SST can be formed.

[0106] Therefore, as Figure 13As shown, a memory cell array structure MCA is formed by a three-dimensional arrangement of multiple memory cells MC. In the memory cell array structure MCA, multiple memory cells MC and their Z-direction selection gates SGS and SGD at multiple locations where multiple conductive layers 112 in the stacked body SSTA intersect with the semiconductor films SF of multiple pillars PL are formed. Furthermore, the conductive region (not shown) disposed on the -Z side of the stacked body SSTA functions as the source region in the memory cell array structure MCA. The conductive layer 112 on the -Z side of the multiple conductive layers 112 functions as the source-side selection gate line. The conductive layer 112 on the +Z side of the multiple conductive layers 112 functions as the drain-side selection gate line. The remaining conductive layers 112 in the multiple conductive layers 112 each function as word lines.

[0107] In other words, a semiconductor device 300 that functions as a three-dimensional memory can be manufactured.

[0108] Thus, in the manufacturing method of the semiconductor device 300, the semiconductor nitride film 312 is subjected to free radical oxidation using plasma generated by a process gas containing hydrogen isotope gas and oxygen. Therefore, free radical oxidation can be performed more efficiently than when the semiconductor nitride film 312 is subjected to free radical oxidation using plasma generated by a process gas containing hydrogen and oxygen.

[0109] Furthermore, in the manufacturing method of the semiconductor device 300, by employing free radical oxidation in the formation of the barrier insulating film, the step coverage of the oxide film 313 can be easily improved, thereby enhancing the insulating properties of the formed barrier insulating film. This suppresses the reverse tunneling phenomenon, where charge tunnels from the conductive layer 112 (which serves as the word line) through the barrier insulating film and accumulates in the charge accumulation film. Therefore, in the semiconductor device 300, the operational reliability of the memory cell MC can be improved.

[0110] Alternatively, as a third variation of the embodiment, the idea of ​​the embodiment can also be applied to the oxidation of the exposed surface of the semiconductor film in the manufacturing method of a semiconductor device 400, such as a three-dimensional memory. For example, the manufacturing method of the semiconductor device 400 can also be as follows: Figures 14-16 Proceed as shown. Figure 14 This is a flowchart illustrating a method for manufacturing a semiconductor device 400 according to the third variation of the embodiment. Figure 15 , Figure 16 This is a YZ cross-sectional view showing the manufacturing method of the semiconductor device 400. Figure 17A , Figure 17B This is a YZ cross-sectional view showing the warping of substrate 10.

[0111] After performing S1 to S207 in the same manner as in the second variation of the embodiment, as follows: Figure 15As shown, an insulating film 414 is deposited on the side and bottom surfaces of the storage hole 120 by a CVD method or the like (S308). The insulating film 414 can also be deposited by a multilayer film comprising a barrier insulating film 414a, a charge storage film 414b, and a tunnel insulating film 414c.

[0112] A barrier insulating film 414a, a charge storage film 414b, and a tunnel insulating film 414c are sequentially deposited on the side and bottom surfaces of the storage hole 120. The barrier insulating film 414a can be formed of an insulating material such as silicon oxide. The charge storage film 414b can be formed of an insulating material such as silicon nitride. The tunnel insulating film 414c can be formed of an insulating material such as silicon oxide. The bottom surface portion of the storage hole in the barrier insulating film 414a, the charge storage film 414b, and the tunnel insulating film 414c can be selectively removed.

[0113] Semiconductor films 412 are deposited on the side and bottom surfaces of the storage hole (S302). The semiconductor film 412 may be formed of a material whose main component is a substantially impurity-free semiconductor (e.g., polycrystalline silicon).

[0114] By subjecting the semiconductor film 412 to heat treatment (S309) at a specified temperature, the crystallinity of the semiconductor film 412 can be improved.

[0115] At this time, due to the differences in the direction and amount of thermal deformation of each film formed on the +Z side of the substrate 10, such as Figure 17A As shown, the substrate 10 as a whole tends to warp in a convex shape on the -Z side. The substrate 10 that is warped in a convex shape on the -Z side is difficult to process because it is difficult to vacuum-adhere it onto the stage ST of the apparatus in subsequent processes.

[0116] In contrast, the substrate 10 is placed into the substrate processing apparatus 1 (see reference 1). Figure 3 In the process, the semiconductor film 412 is subjected to oxidation treatment (S303).

[0117] The oxidation process (S303) can also be performed in the substrate processing apparatus 1 by PIO processing, which uses plasma generated by a processing gas containing hydrogen isotope gas and oxygen to perform free radical oxidation on the semiconductor film 412.

[0118] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between electrodes 3b and 5, generating plasma PL (S4) in the processing chamber CH using a processing gas containing hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas). By applying the high-frequency voltage between electrodes 3b and 5, an induced magnetic field is formed in the processing chamber CH. The hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas) contained in the processing gas are excited by the plasma, forming, for example, a donut-shaped plasma PL. This plasma PL can also be a low-potential plasma. The D2 gas and O2 gas dissociate through the plasma PL, generating hydroxyl radicals OH. * Reactants such as free radicals, deuterium ions, and oxygen ions are present. Due to the low potential of plasma PL, free radicals and the like in the treatment gas can be supplied approximately uniformly to the vicinity of the exposed surface 412a of the semiconductor film 412 through the storage hole 120 without accelerating deuterium ions and oxygen ions.

[0119] Thus, semiconductor film 412 is oxidized by free radicals (S305). Free radical oxidation can also be performed as follows: Figure 16 As shown, the exposed surface 412a in the semiconductor film 412 (refer to...) Figure 15 The process is carried out near the exposed surface 412a of the semiconductor film 412, replacing the portion near the exposed surface 412a with the oxide film 413. Figure 16 The dashed arrow indicates that the oxidative free radicals and ions in the processing gas are supplied approximately uniformly to the vicinity of the exposed surface 412a of the semiconductor film 412.

[0120] At this time, in addition to the differences in the direction and amount of thermal deformation of each film formed on the +Z side of the substrate 10, the direction and amount of thermal deformation of the additional oxide film 413 are also considered. Figure 17B As shown, the substrate 10 can be warped in a convex shape to the +Z side as a whole. The substrate 10, which is warped in a convex shape to the +Z side, is easy to handle because it can be easily vacuum-adsorbed onto the stage ST of the device in subsequent processes.

[0121] Then, a core component is embedded in the storage hole 120. The core component can be formed of an insulating material such as silicon oxide. This forms a columnar body that penetrates the laminate SST in the Z direction.

[0122] The sacrificial layer 151 of the laminate SST is removed. An insulating film is formed on the exposed surface of the voids formed by the removal. The insulating film can be formed of an insulating material such as aluminum oxide. A conductive layer 112 is further embedded in the voids. The conductive layer 112 can be formed of a material whose main component is a conductive material (such as a metal such as tungsten). Thus, a laminate SSTa is formed by alternately and repeatedly stacking the conductive layer 112 and the insulating layer 111.

[0123] This results in a memory cell array structure MCA (refer to) formed by a three-dimensional arrangement of multiple memory cells MC. Figure 13 In a memory cell array structure (MCA), multiple memory cells (MCs) are formed at multiple locations where multiple conductive layers 112 in a stacked structure (SSTa) intersect with semiconductor films SF of multiple pillars (PL). Furthermore, a conductive region (not shown) disposed on the +Z side of the stacked structure (SSTa) functions as a source region in the memory cell array structure (MCA). The conductive layer 112 on the +Z side of the multiple conductive layers 112 functions as a source-side select gate line. The conductive layer 112 on the -Z side of the multiple conductive layers 112 functions as a drain-side select gate line. The remaining conductive layers 112 in the multiple conductive layers 112 each function as word lines.

[0124] In other words, a semiconductor device 400 is manufactured that functions as a three-dimensional memory.

[0125] Thus, in the manufacturing method of the semiconductor device 400, free radical oxidation is performed on the exposed surface 412a of the semiconductor film 412 using plasma generated by a process gas containing hydrogen isotope gas and oxygen. Therefore, free radical oxidation can be performed more efficiently than when free radical oxidation is performed on the exposed surface 412a of the semiconductor film 412 using plasma generated by a process gas containing hydrogen and oxygen.

[0126] Furthermore, in the manufacturing method of the semiconductor device 400, by efficiently performing free radical oxidation on the exposed surface 412a of the semiconductor film 412, the warping direction of the substrate 10 can be easily changed from the -Z side convex direction to the +Z side convex direction.

[0127] Alternatively, as a fourth variation of the embodiment, the idea of ​​the embodiment can also be applied to the formation of the tunnel insulating film in the manufacturing method of a semiconductor device 500, such as a three-dimensional memory. For example, the manufacturing method of the semiconductor device 500 can also be as follows: Figures 18-20 Proceed as shown. Figure 18 This is a flowchart illustrating a method for manufacturing a semiconductor device 500 according to the fourth variation of the embodiment. Figure 19 , Figure 20 This is a YZ cross-sectional view showing the manufacturing method of the semiconductor device 300.

[0128] After performing S1 to S207 in the same manner as in the second variation of the embodiment, as follows: Figure 19 As shown, an insulating film is deposited on the side and bottom surfaces of the storage hole 120 by a method such as CVD (S408).

[0129] On the side and bottom surfaces of the storage hole 120, a barrier insulating film 514 and a charge storage film 515 are sequentially deposited as insulating films. The barrier insulating film 514 can be formed of an insulating material such as silicon oxide. The charge storage film 515 can be formed of an insulating material such as silicon nitride.

[0130] In addition, such as Figure 19 As shown, a semiconductor nitride film 512 (S402) is deposited on the side and bottom surfaces of the storage hole 120 by a CVD method or the like. The semiconductor nitride film 512 can be formed from a material with silicon nitride as the main component.

[0131] During the deposition of the semiconductor nitride film 512, the substrate 10 is placed in the substrate processing apparatus 1 (refer to...). Figure 3 In the process, the semiconductor nitride film 512 is subjected to oxidation treatment (S403).

[0132] The oxidation process (S403) can also be performed in the substrate processing apparatus 1 by PIO processing, which uses plasma generated by a processing gas containing hydrogen isotope gas and oxygen to perform free radical oxidation on the semiconductor nitride film 512.

[0133] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between electrodes 3b and 5, generating plasma PL (S4) in the processing chamber CH using a processing gas containing hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas). By applying the high-frequency voltage between electrodes 3b and 5, an induced magnetic field is formed in the processing chamber CH. The hydrogen isotope gas (e.g., D2 gas) and oxygen (O2 gas) contained in the processing gas are excited by the plasma, forming, for example, a donut-shaped plasma PL. This plasma PL can also be a low-potential plasma. The D2 gas and O2 gas dissociate through the plasma PL, generating hydroxyl radicals OH. * Reactants such as free radicals, deuterium ions, and oxygen ions are present. Due to the low potential of the plasma PL, free radicals and the like in the treatment gas can be supplied approximately uniformly to the vicinity of the exposed surface 512a of the semiconductor nitride film 512 through the storage hole 120 without accelerating deuterium ions and oxygen ions.

[0134] Thus, the semiconductor nitride film 512 is oxidized by free radicals (S405). Free radical oxidation can also be performed as follows: Figure 20 The entire semiconductor nitride film 512 is replaced with an oxide film 513 as shown. Figure 20 The dashed arrow indicates that the oxidized free radicals and ions in the processing gas are supplied approximately uniformly to the vicinity of the exposed surface 512a of the semiconductor nitride film 512. As a result, a tunnel insulating film containing an oxide film 513 is formed on the side and bottom surfaces of the storage hole 120.

[0135] In the storage hole 120, a portion of the bottom surface of the storage hole 120 in the blocking insulating film 514, charge storage film 515, and tunnel insulating film 513 is selectively removed.

[0136] Semiconductor films are deposited on the side and bottom surfaces of the storage via 120. The semiconductor films can be formed from a material whose main component is a substantially impurity-free semiconductor (e.g., polycrystalline silicon). Heat treatment of the semiconductor films at a specified temperature can improve their crystallinity. Then, a core component is embedded in the storage via 120. The core component can be formed from an insulating material such as silicon oxide. This forms a columnar structure that penetrates the stacked structure SST in the Z direction.

[0137] The sacrificial layer 151 of the laminate SST is removed. An insulating film is formed on the exposed surface of the voids formed by the removal. The insulating film can be formed of an insulating material such as aluminum oxide. A conductive layer 112 is further embedded in the voids. The conductive layer 112 can be formed of a material whose main component is a conductive material (such as a metal such as tungsten). Thus, the laminate SST is formed by alternately and repeatedly stacking the conductive layer 112 and the insulating layer 111, and further stacking the insulating layer 113.

[0138] Thus, a memory cell array structure MCA (refer to) can be formed by three-dimensionally arranging multiple memory cells MC. Figure 13 In a memory cell array structure (MCA), multiple memory cells (MC) and their Z-direction selection gates (SGS and SGD) are formed at multiple locations where multiple conductive layers 112 in the stacked structure SSTA intersect with the semiconductor films SF of multiple pillars PL. Furthermore, the conductive region (not shown) disposed on the -Z side of the stacked structure SSTA functions as the source region in the memory cell array structure (MCA). The conductive layer 112 on the -Z side of the multiple conductive layers 112 functions as the source-side selection gate line. The conductive layer 112 on the +Z side of the multiple conductive layers 112 functions as the drain-side selection gate line. The remaining conductive layers 112 function as word lines.

[0139] In other words, a semiconductor device 500 that can function as a three-dimensional memory can be manufactured.

[0140] Thus, in the manufacturing method of the semiconductor device 500, the semiconductor nitride film 512 is subjected to free radical oxidation using plasma generated by a process gas containing hydrogen isotope gas and oxygen. Therefore, free radical oxidation can be performed more efficiently than when the semiconductor nitride film 512 is subjected to free radical oxidation using plasma generated by a process gas containing hydrogen and oxygen.

[0141] Furthermore, in the manufacturing method of the semiconductor device 500, by employing free radical oxidation in a processing gas containing hydrogen isotope gas during the formation of the tunnel insulating film, the step coverage of the oxide film 513 can be easily improved, and a structure formed by sealing the interface between the charge accumulation film and the tunnel insulating film with hydrogen isotopes (e.g., deuterium) can be created. This suppresses bonding defects caused by electrical stress at the interface between the charge accumulation film and the tunnel insulating film during data writing and erasing in the memory cell MC, thereby suppressing malfunctions caused by bonding defects. Therefore, the operational reliability of the memory cell MC can be improved in the semiconductor device 500.

[0142] Several embodiments of the present invention have been described, but these embodiments are given by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the invention described in the claims and its equivalents.

Claims

1. A method of manufacturing a semiconductor device, comprising: The radical oxidation is performed on the first film using plasma generated by a treatment gas containing a hydrogen isotope gas.

2. The method for manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas and oxygen.

3. The method for manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing hydrogen, the hydrogen isotope gas, and oxygen.

4. The method for manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas and an oxygen isotope gas.

5. The method for manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas, oxygen, and a rare gas.

6. The method for manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas, oxygen, and a rare gas.

7. The method for manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas, oxygen, and a rare gas.

8. The method for manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas, oxygen, and a rare gas.

9. The method of manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas at a temperature of 300°C or higher and 800°C or lower.

10. The method of manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas at a pressure of 50 Pa or higher and 300 Pa or lower.

11. The method of manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas at a flow rate ratio of 5% or higher and 95% or lower.

12. The method of manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas.

13. The method of manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: The radical oxidation is performed on the first film using plasma generated by the treatment gas containing the hydrogen isotope gas. Further comprising: a laminate in which a first insulating film and a second insulating film are alternately stacked a plurality of times, a hole extending in a stacking direction in the laminate is formed, and a semiconductor nitride film is deposited on an inner side surface and a bottom surface of the hole as the first film; 14. The method of manufacturing a semiconductor device according to claim 1, wherein The radical oxidation includes: Plasma of the treatment gas is generated, and a radical oxidation is performed on an exposed surface of the semiconductor nitride film. Further comprising: a laminate in which a first insulating film and a second insulating film are alternately stacked a plurality of times, a hole extending in a stacking direction in the laminate is formed, a third insulating film is deposited on an inner side surface and a bottom surface of the hole, and a semiconductor film is deposited on an inner side surface and a bottom surface of the third insulating film in the hole as the first film; The radical oxidation includes: A plasma of the processing gas is generated to perform radical oxidation on the exposed surface of the semiconductor film.

15. The method of manufacturing a semiconductor device according to claim 1, wherein Further provided are: a laminate in which a first insulating film and a second insulating film are alternately stacked multiple times, a hole extending in the stacking direction in the laminate, a third insulating film deposited on the inner side surface and the bottom surface of the hole, and a semiconductor nitride film deposited as the first film on the inner side surface and the bottom surface of the third insulating film in the hole; the radical oxidation includes: a plasma of the processing gas is generated to perform radical oxidation on the exposed surface of the semiconductor nitride film.

16. The method of manufacturing a semiconductor device according to claim 1, wherein the radical oxidation includes: a plasma of the processing gas containing the hydrogen isotope gas is uniformly supplied to the surface of the first film to perform radical oxidation on the first film.

17. A substrate processing apparatus comprising: a stage configured in a processing chamber to hold a substrate and including a first electrode, a gas supply system configured to supply a processing gas containing a hydrogen isotope gas to the stage in the processing chamber, a second electrode configured at a position separate from the stage outside the processing chamber, and an exhaust system configured to adjust a pressure in the processing chamber; wherein, a plasma is generated in the processing chamber by applying a high-frequency voltage between the first electrode and the second electrode.

18. The substrate processing apparatus of claim 17, wherein, the gas supply system is configured to supply the processing gas containing the hydrogen isotope gas and an oxygen isotope gas to the stage in the processing chamber.

19. The substrate processing apparatus of claim 17, wherein, the gas supply system is configured to supply the processing gas containing the hydrogen isotope gas, oxygen gas, and a rare gas to the stage in the processing chamber.

20. The substrate processing apparatus of claim 17, wherein, the gas supply system is configured to supply the processing gas containing the hydrogen isotope gas, an oxygen isotope gas, and a rare gas to the stage in the processing chamber.

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