Method of manufacturing semiconductor device and substrate processing apparatus

Abstract

In view of the foregoing, exemplary embodiments provide a method of manufacturing a semiconductor device and a substrate processing apparatus capable of efficiently performing radical oxidation.SOLUTION: According to one embodiment, a method for manufacturing a semiconductor device is provided. The method of manufacturing a semiconductor device includes performing radical oxidation on a first film using plasma generated by a processing gas containing a gas of an isotope of hydrogen.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present embodiment relates to a method for manufacturing a semiconductor device and a substrate processing apparatus. [Background technology]

[0002] In the manufacturing process of a semiconductor device, a predetermined film is deposited on or above a substrate, and the deposited predetermined film is sometimes subjected to radical oxidation. In the manufacturing process of a semiconductor device, it is desirable that the radical oxidation be carried out efficiently. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-143476 [Patent Document 2] Japanese Patent Application Publication No. 2022-144969 [Patent Document 3] Japanese Patent Application Publication No. 2018-157035 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one embodiment is to provide a semiconductor device manufacturing method and a substrate processing apparatus that can efficiently perform radical oxidation. [Means for solving the problem]

[0005] According to one embodiment, there is provided a method for manufacturing a semiconductor device, the method including radically oxidizing a first film using plasma generated from a process gas including a gas of a hydrogen isotope. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a flowchart showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 2]1A to 1C are cross-sectional views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 3] 1 is a diagram showing the configuration of a substrate processing apparatus used in a semiconductor device manufacturing method according to an embodiment; [Figure 4] FIG. 10 is a graph showing the change in oxide film thickness depending on the processing time (when the flow rate ratio is 30%). [Figure 5] FIG. 10 is a graph showing the change in oxide film thickness depending on the processing time (when the flow rate ratio is 20%). [Figure 6] FIG. 10 is a graph showing the change in oxide film thickness depending on the processing time (when the flow rate ratio is 5%). [Figure 7] FIG. 1 is a graph showing the change in hydroxyl radical OH* emission intensity depending on the flow rate ratio of hydrogen or its isotopes. [Figure 8] 10 is a flowchart showing a method for manufacturing a semiconductor device according to a first modified example of the embodiment. [Figure 9] FIG. 10 is a diagram showing the configuration of a substrate processing apparatus used in a semiconductor device manufacturing method according to a first modified example of the embodiment. [Figure 10] 10 is a flowchart showing a method for manufacturing a semiconductor device according to a second modified example of the embodiment. [Figure 11] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a second modified example of the embodiment. [Figure 12] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a second modified example of the embodiment. [Figure 13] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a second modified example of the embodiment. [Figure 14] 10 is a flowchart showing a method for manufacturing a semiconductor device according to a third modified example of the embodiment. [Figure 15] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a third modified example of the embodiment. [Figure 16] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a third modified example of the embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing warpage of a substrate in a third modified example of the embodiment. [Figure 18] 10 is a flowchart showing a method for manufacturing a semiconductor device according to a fourth modified example of the embodiment. [Figure 19] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a fourth modified example of the embodiment. [Figure 20] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a fourth modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, a method for manufacturing a semiconductor device according to an embodiment will be described in detail with reference to the accompanying drawings, although the present invention is not limited to the embodiment.

[0008] (Embodiment) In the method for manufacturing a semiconductor device according to the embodiment, a predetermined film is deposited on or above a substrate, and the deposited predetermined film is radically oxidized, but the method is devised to perform the radical oxidation efficiently.

[0009] The method for manufacturing the semiconductor device 100 may be performed as shown in Figures 1 and 2. Figure 1 is a flowchart showing the method for manufacturing the semiconductor device 100. In the following, the direction perpendicular to the main surface 10a of the substrate 10 is defined as the Z direction, and two directions perpendicular to each other in a plane perpendicular to the Z direction are defined as the X direction and the Y direction. Figures 2(a) to 2(e) are YZ cross-sectional views showing the method for manufacturing the semiconductor device 100.

[0010] The substrate 10 shown in FIG. 2(a) is prepared (S1). The substrate 10 has a substantially disk shape, and is substantially circular in the XY plane view. The substrate 10 may be formed of a material containing a semiconductor (e.g., silicon) as a main component. The substrate 10 has a main surface 10a on the +Z side.

[0011] When the substrate 10 is prepared, the high aspect structure TR shown in Fig. 2(b) is formed on or above (on the +Z side of) the main surface 10a of the substrate 10. Fig. 2(b) illustrates the case where the high aspect structure TR is formed on the main surface 10a of the substrate 10.

[0012] A film 11 is deposited on or above the main surface 10a of the substrate 10 by a CVD (Chemical Vapor Deposition) method, a sputtering method, or the like. The film 11 may be made of an insulating material. A resist pattern PR having an opening corresponding to the hole 11a1 is formed on the main surface 11a of the film 11. Etching is performed under anisotropic processing conditions using the resist pattern PR as a mask by a RIE (Reactive Ion Etching) method or the like. As a result, a hole 11a1 having a high aspect ratio in a cross-sectional view including the Z axis is formed in the film 11. A high aspect ratio refers to an aspect ratio (= hole depth / hole bottom width) greater than 1. In other words, a high aspect structure TR is obtained in which a high aspect ratio hole 11a1 is formed in the film 11.

[0013] After the high aspect structure TR is formed, a film to be processed 12 shown in FIG. 2(c) is deposited on the side and bottom surfaces of the hole 11a1 (S2).

[0014] The target film 12 is deposited on the film 11 by a CVD method, a sputtering method, or the like. Of the deposited target film 12, the portion covering the main surface 11a of the film 11 is removed by an RIE method or the like, leaving the portion covering the side and bottom surfaces of the hole 11a1.

[0015] After the target film 12 is deposited, the substrate 10 is carried into a substrate processing apparatus 1 as shown in Fig. 3, where an oxidation treatment (S3) is performed on the target film 12. Fig. 3 is a diagram showing the configuration of the substrate processing apparatus 1 used in the manufacturing method of the semiconductor device 100.

[0016] The oxidation process (S3) may be performed by radically oxidizing the target film 12 using plasma generated from a processing gas containing a hydrogen isotope gas and oxygen gas in the substrate processing apparatus 1. The radical oxidation process using plasma is an isotropic process and is referred to as PIO (Plasma Isotropic Oxidization) process.

[0017] The substrate processing apparatus 1 includes a vacuum chamber 2 , a stage 3 , a gas supply system 4 , an electrode 5 , a power supply unit 6 , an exhaust system 7 , and a controller 8 .

[0018] The controller 8 is capable of controlling each part of the substrate processing apparatus 1 in an integrated manner.

[0019] The vacuum vessel 2 defines a processing chamber CH inside. The processing chamber CH is a chamber for generating a plasma PL inside. The vacuum vessel 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 have slits 2a1, 2a2 at positions on the outer sides in the XY directions. The bottom wall 2c may have a hole 2i at an arbitrary position.

[0020] The stage 3 is disposed in the processing chamber CH. The stage 3 may be disposed near the bottom wall 2c of the processing chamber CH. The stage 3 has a main body 3a, an electrode 3b, and a heater 3c. The main body 3a extends in a plate-like or disk-like shape in the X and Y directions. The main body 3a may be formed of an insulating material. The +Z side surface of the main body 3a forms a mounting surface 3d. A substrate 10 may be placed on the mounting surface 3d. The electrode 3b and the heater 3c may each be embedded in the main body 3a. The electrode 3b extends in a plate-like or disk-like shape in the X and Y directions. The electrode 3b may be formed of a conductive material. The electrode 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 have a mechanism for adsorbing the substrate 10.

[0021] The gas supply system 4 can supply a process gas containing a hydrogen isotope gas and oxygen gas toward the stage 3 in the process chamber CH. The hydrogen isotope gas may be deuterium gas (D2) or tritium gas (T2). The following description will focus on the case where the hydrogen isotope gas is deuterium gas, but the following description can also be applied to the case where the hydrogen isotope gas is tritium gas.

[0022] The gas supply system 4 includes gas cylinders 4a to 4c, regulating valves 4d to 4f, gas pipes 4g to 4n, and a cover 4t. The gas cylinders 4a, 4b, and 4c store deuterium gas (D2), hydrogen gas (H2), and oxygen gas (O2), respectively. The gas cylinder 4c stores, for example, 16 It stores O2 gas. The lid 4t has a gas inlet 4u. The gas cylinders 4a to 4c are connected to gas pipes 4g to 4i, respectively. The lid 4t covers the upper wall 2a at a distance 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 the slits 2a1 and 2a2 on the -Z side. The adjustment valves 4d to 4f are arranged between the gas pipes 4g to 4n, respectively, and their opening / closing and opening degrees can be controlled by a controller 8.

[0023] The electrode 5 is disposed outside the processing chamber CH at a position spaced apart from the stage 3. The electrode 5 may be disposed on the +Z side of the side wall 2b. The electrode 5 includes a coil 5a. The coil 5a may be wound around the +Z side of the side wall 2b.

[0024] The power supply unit 6 is capable of supplying high-frequency power to the electrode 5. The power supply unit 6 has a high-frequency power supply 6a, a matching box 6b, and a sensor 6c. The high-frequency power supply 6a is capable of supplying high-frequency power to the electrode 5 under the control of a controller 8. The sensor 6c monitors information on the forward and reflected high-frequency waves being supplied, and supplies the monitoring results to the matching box 6b. The matching box 6b performs impedance matching so as to reduce the power of the reflected waves according to the monitoring results of the sensor 6c.

[0025] The exhaust system 7 can reduce the pressure inside the processing chamber CH and adjust the pressure inside the processing chamber CH. The exhaust system 7 has a vacuum pump 7a, an adjustment valve 7b, and vacuum pipes 7c and 7d. The vacuum pump 7a can be operated under the control of a controller 8. The adjustment valve 7b is disposed between the vacuum pipes 7c and 7d, and the opening and closing and the opening degree of the adjustment valve 7b can be controlled by the controller 8.

[0026] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between the electrode 3b and the electrode 5, and generates a plasma PL in the processing chamber CH using a processing gas containing a hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) (S4).

[0027] For example, when the substrate 10 is placed on the placement surface 3d of the stage 3, the controller 8 increases the temperature of the substrate 10. The controller 8 may control the heater 3c to heat the substrate 10 to a temperature of 300°C or higher and 800°C or lower.

[0028] If the temperature of the substrate 10 falls below 300° C., the film formation rate by radical oxidation may fall below an allowable level. If the temperature of the substrate 10 exceeds 800° C., thermal oxidation of the target film 12 may occur in addition to radical oxidation, making it difficult to control the film formation rate.

[0029] In parallel with the temperature increase of the substrate 10, the controller 8 operates the vacuum pump 7a and controls the opening of the adjustment valve 7b so that the pressure in the processing chamber CH is between 50 Pa and 300 Pa, thereby reducing the pressure inside the processing chamber CH via the vacuum pipes 7c and 7d.

[0030] If the pressure in the processing chamber CH falls below 50 Pa, the oxidation rate may fall below an allowable level. If the pressure in the processing chamber CH exceeds 300 Pa, plasma may not be generated in the processing chamber CH.

[0031] The controller 8 starts supplying a process gas containing a hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) to the process chamber CH. The controller 8 opens the control valves 4d and 4f while keeping the control valve 4e closed. This allows the hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) from the gas cylinders 4a and 4c to be introduced into the gas pipe 4n via the gas pipes 4g, 4i, 4j, and 4m, where they are mixed to form a process gas containing the hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas). The process gas is introduced from the gas pipe 4n into the buffer chamber 4v via the gas inlet 4u. The process gas in the buffer chamber 4v is supplied through the slits 2a1 and 2a2 toward the stage 3 in the process chamber CH.

[0032] At this time, the controller 8 continues to control the aperture of the adjustment valve 7b so that the pressure in the processing chamber CH is not less than 50 Pa and not more than 300 Pa. The controller 8 also controls the apertures of the adjustment valves 4d and 4f so that the flow rate ratio of the hydrogen isotope gas (e.g., D2 gas) to the processing gas is not less than 5% and not more than 95%.

[0033] If the flow rate ratio of the hydrogen isotope gas is less than 5%, the step coverage of the oxide film formed by radical oxidation may fall below the allowable level.If the flow rate ratio of the hydrogen isotope gas is more than 95%, the step coverage of the oxide film formed by radical oxidation may fall below the allowable level.

[0034] When the pressure in the processing chamber CH stabilizes, the controller 8 starts supplying high-frequency power from the power supply unit 6 to the electrode 5. This applies a high-frequency voltage between the electrode 3b and the electrode 5, forming an induction magnetic field in the processing chamber CH. The hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) contained in the processing gas are each plasma-excited, forming, for example, a doughnut-shaped plasma PL. This plasma PL may be a plasma with a low electric potential. The D2 gas and O2 gas are each dissociated by the plasma PL to form hydroxyl radicals OH *Reactive species such as oxidizing radicals, deuterium ions, and oxygen ions are generated. Because the electric potential of the plasma PL is low, the deuterium ions and oxygen ions are not accelerated, and the oxidizing radicals and the like in the processing gas are supplied almost uniformly to the vicinity of the exposed surface 12a of the processing target film 12.

[0035] As a result, the target film 12 is radical-oxidized (S5). As shown in FIG. 2(d), the radical oxidation may be performed near the exposed surface 12a of the target film 12, and the portion of the target film 12 near the exposed surface 12a may be replaced with an oxide film 13. Alternatively, as shown in FIG. 2(e), the radical oxidation may be performed on the entire target film 12, and the entire target film 12 may be replaced with an oxide film 13. The dotted arrows in FIGS. 2(d) and 2(e) indicate that oxidizing radicals and ions in the processing gas are supplied approximately uniformly near the exposed surface 12a of the target film 12.

[0036] Then, the substrate 10 shown in FIG. 2(d) or 2(e) is subjected to further predetermined steps to manufacture the semiconductor device 100.

[0037] As described above, in the embodiment, the method for manufacturing the semiconductor device 100 radically oxidizes the target film 12 using plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas. This allows the radical oxidation to be performed more efficiently than when the target film 12 is radically oxidized using plasma generated from a process gas containing hydrogen gas and oxygen gas.

[0038] For example, when the substrate processing apparatus 1 radically oxidizes the target film 12 using plasma generated from a processing gas containing hydrogen gas and oxygen gas at a flow rate ratio of 30%:70%, the thickness of the oxide film 13 changes with processing time as shown by the dotted line in Figure 4. Figure 4 is a diagram showing the change in oxide film thickness with processing time (when the flow rate ratio is 30%). At processing time t1, the oxide film 13 is formed to a thickness h1, and at processing time t2 (>t1), the oxide film 13 is formed to a thickness h2 (>h1).

[0039] On the other hand, when the substrate processing apparatus 1 radically oxidizes the target film 12 using plasma generated from a processing gas containing D2 gas and oxygen gas at a flow rate ratio of 30%:70%, the thickness of the oxide film 13 changes with processing time as shown by the solid line in Fig. 4. At processing time t1, the oxide film 13 is formed to a thickness d1, and at processing time t2, the oxide film 13 is formed to a thickness d2 (>d1).

[0040] The film deposition amount at each processing time is greater when plasma generated from a processing gas containing hydrogen isotope gas and oxygen gas is used than when plasma generated from a processing gas containing hydrogen gas and oxygen gas is used. At processing time t1, film thickness d1 is greater than film thickness h1. At processing time t2, film thickness d2 is greater than film thickness h2.

[0041] The deposition rate is higher when plasma generated from a process gas containing hydrogen isotope gas and oxygen gas is used than when plasma generated from a process gas containing hydrogen gas and oxygen gas is used. Looking at the period from process time t1 to t2, the slope of the solid line (d2-d1) / (t2-t1) is larger than the slope of the dotted line (h2-h1) / (t2-t1).

[0042] Alternatively, when the substrate processing apparatus 1 radically oxidizes the target film 12 using plasma generated from a processing gas containing hydrogen gas and oxygen gas at a flow rate ratio of 20%:80%, the thickness of the oxide film 13 changes with processing time as shown by the dotted line in Figure 5. Figure 5 is a diagram showing the change in oxide film thickness with processing time (when the flow rate ratio is 20%). At processing time t11, the oxide film 13 is formed to a thickness h11, and at processing time t12 (>t11), the oxide film 13 is formed to a thickness h12 (>h11).

[0043] On the other hand, when the substrate processing apparatus 1 radically oxidizes the target film 12 using plasma generated from a processing gas containing D2 gas and oxygen gas at a flow rate ratio of 20%:80%, the thickness of the oxide film 13 changes with processing time as shown by the solid line in Fig. 5. At processing time t11, the oxide film 13 is formed to a thickness d11, and at processing time t12, the oxide film 13 is formed to a thickness d12 (>d11).

[0044] The film deposition amount at each processing time is larger when using plasma generated from a processing gas containing hydrogen gas and oxygen gas than when using plasma generated from a processing gas containing hydrogen gas and oxygen gas. At processing time t11, film thickness d11 is larger than film thickness h11. At processing time t12, film thickness d12 is larger than film thickness h12.

[0045] The deposition rate is higher when plasma generated from a process gas containing hydrogen isotope gas and oxygen gas is used than when plasma generated from a process gas containing hydrogen gas and oxygen gas is used. Looking at the period from process time t11 to t12, the slope of the solid line (d12-d11) / (t12-t11) is larger than the slope of the dotted line (h12-h11) / (t12-t11).

[0046] Alternatively, when the substrate processing apparatus 1 radically oxidizes the target film 12 using plasma generated from a processing gas containing hydrogen gas and oxygen gas at a flow rate ratio of 5%:95%, the thickness of the oxide film 13 changes with processing time as shown by the dotted line in Figure 6. Figure 6 is a diagram showing the change in oxide film thickness with processing time (when the flow rate ratio is 5%). At processing time t21, the oxide film 13 is formed to a thickness h21, and at processing time t22 (>t21), the oxide film 13 is formed to a thickness h22 (>h21).

[0047] On the other hand, when the substrate processing apparatus 1 radically oxidizes the target film 12 using plasma generated from a processing gas containing D2 gas and oxygen gas at a flow rate ratio of 5%:95%, the thickness of the oxide film 13 changes with processing time as shown by the solid line in Fig. 6. At processing time t21, the oxide film 13 is formed to a thickness d21, and at processing time t22, the oxide film 13 is formed to a thickness d22 (>d21).

[0048] The film formation amount at each processing time is similar when using plasma generated from a processing gas containing hydrogen gas and oxygen gas and when using plasma generated from a processing gas containing a hydrogen isotope gas and oxygen gas. At processing time t21, film thickness d21 is similar to film thickness h21. At processing time t22, film thickness d22 is similar to film thickness h22.

[0049] The deposition rate is similar when using plasma generated from a process gas containing hydrogen gas and oxygen gas, and when using plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas. Looking at the period from process time t11 to t12, the slope of the solid line (d12-d11) / (t12-t11) is similar to the slope of the dotted line (h12-h11) / (t12-t11).

[0050] Alternatively, when the substrate processing apparatus 1 radically oxidizes the film 12 to be processed using plasma generated from a processing gas containing hydrogen gas at a flow rate ratio of 0% to 100%, hydroxyl radicals OH * The emission intensity is shown by the dotted line in Figure 7. Figure 7 shows the emission intensity of the hydroxyl radical OH as a function of the flow rate ratio of hydrogen or its isotopes. * This is a graph showing the change in luminescence intensity. * The emission intensity is correlated with the step coverage of the oxide film 13. Hydroxy radicals OH * The hydroxyl radical OH *It is estimated that the stronger the emission intensity, the better the step coverage of the oxide film 13. Looking at the change in the dotted line in Figure 7, it shows a mountain-like change that generally exceeds the threshold value when the flow rate ratio of hydrogen gas is 5% or more and 95% or less, and it is estimated that by setting the flow rate ratio of hydrogen gas to 5% or more and 95% or less, the emission intensity will generally be at an acceptable level for the step coverage of the oxide film 13. The threshold value can be experimentally determined in advance as a value corresponding to the acceptable level of step coverage of the oxide film 13.

[0051] On the other hand, when the substrate processing apparatus 1 radically oxidizes the target film 12 using plasma generated from a processing gas containing D2 gas at a flow rate ratio of 0% to 100%, hydroxyl radicals OH * The emission intensity is as shown by the solid line in Fig. 7. Looking at the change in the solid line in Fig. 7, it shows a mountain-like change that generally exceeds the threshold value when the flow rate ratio of hydrogen gas is between 5% and 95%, and it is estimated that by setting the flow rate ratio of hydrogen gas between 5% and 95%, the emission intensity is such that the step coverage of oxide film 13 is generally at an acceptable level.

[0052] Hydroxy radical OH at flow rate ratios of 5% to 95% * The emission intensity is higher when plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas is used than when plasma generated from a process gas containing hydrogen gas and oxygen gas is used. At a flow rate ratio of 5%, the solid line value Id1 is higher than the dotted line value Ih1. At a flow rate ratio of 95%, the solid line value Id2 is higher than the dotted line value Ih2. In the flow rate ratio range of 5% to 95%, the solid line curve is closer to the high emission intensity side than the dotted line curve. This suggests that the step coverage of the oxide film 13 due to radical oxidation can be improved when plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas is used than when plasma generated from a process gas containing hydrogen gas and oxygen gas is used.

[0053] The process gas used in S4 may be a mixture of hydrogen gas, a hydrogen isotope gas, and oxygen gas. For example, in S4 shown in FIG. 1, the controller 8 starts supplying a process gas containing hydrogen gas (H2 gas), a hydrogen isotope gas (e.g., D2 gas), and oxygen gas (O2 gas) to the process chamber CH. The controller 8 opens the control valves 4d, 4e, and 4f. This causes hydrogen gas (H2 gas), a hydrogen isotope gas (e.g., D2 gas), and oxygen gas (O2 gas) from gas cylinders 4a, 4b, and 4c to be introduced into the gas pipe 4n via gas pipes 4g, 4h, 4i, 4j, 4k, and 4m. The gases are mixed in the gas pipe 4n to produce a process gas containing hydrogen gas (H2 gas), a hydrogen isotope gas (e.g., D2 gas), and oxygen gas (O2 gas). The process gas is introduced from the gas pipe 4n into the buffer chamber 4v via the gas inlet 4u. The processing gas in the buffer chamber 4v is supplied from the slits 2a1 and 2a2 toward the stage 3 in the processing chamber CH. At this time, the controller 8 controls the apertures of the adjustment valves 4d, 4e, and 4f so that the flow rate ratio of the hydrogen isotope gas (e.g., D2 gas) to the processing gas is 5% or more and 95% or less. In this case, too, by setting the flow rate ratio of the hydrogen isotope gas to the processing gas to 5% or more and 95% or less, the step coverage of the oxide film 13 formed by radical oxidation can be improved.

[0054] The process gas used in S4 may further contain a rare gas such as helium gas or argon gas. The process gas may be a mixed gas of a hydrogen isotope gas, oxygen gas, and a rare gas, or a mixed gas of hydrogen gas, a hydrogen isotope gas, oxygen gas, and a rare gas. Even in this case, the step coverage of the oxide film 13 formed by radical oxidation can be improved by setting the flow rate ratio of the hydrogen isotope gas to the process gas to be 5% or more and 95% or less.

[0055] Alternatively, as a first modification of the embodiment, as shown in Fig. 8, the oxidation process (S103) may be performed by radically oxidizing the target film 12 using plasma generated from a process gas containing a hydrogen isotope gas and an oxygen isotope gas in a substrate processing apparatus 201 shown in Fig. 9. Fig. 8 is a flowchart showing a method for manufacturing the semiconductor device 100 according to the first modification of the embodiment. Fig. 9 is a diagram showing the configuration of the substrate processing apparatus 201 used in the method for manufacturing the semiconductor device 100 according to the first modification of the embodiment.

[0056] The substrate processing apparatus 201 has a gas supply system 204 instead of the gas supply system 4 (see FIG. 3). The gas supply system 204 can supply a processing gas containing a hydrogen isotope gas and an oxygen isotope gas toward the stage 3 in the processing chamber CH. The hydrogen isotope gas may be deuterium gas (D2) or tritium gas (T2). The oxygen isotope gas may be oxygen-17 ( 17 O2) gas or oxygen-18 ( 18 In the following, the hydrogen isotope gas is deuterium gas and the oxygen isotope gas is 17 The following description will be centered on the case of O2 gas, but the following description can also be applied to other combinations of specific examples of hydrogen isotope gases and specific examples of oxygen isotope gases.

[0057] The gas supply system 204 further includes a gas cylinder 4p, an adjusting valve 4q, and gas pipes 4r and 4s. 17 The gas cylinder 4p stores O2 gas. The gas cylinder 4p is connected to the gas pipe 4r. The adjusting valve 4q is disposed between the gas pipes 4r and 4s, and the opening and closing and the opening degree thereof can be controlled by the controller 8.

[0058] In the substrate processing apparatus 201, the controller 8 applies a high frequency voltage between the electrode 3b and the electrode 5, and a gas of a hydrogen isotope (e.g., D2 gas) and a gas of an oxygen isotope (e.g., 17 A plasma PL is generated in the processing chamber CH using a processing gas containing O 2 gas (S104).

[0059] For example, when the substrate 10 is placed on the placement surface 3d of the stage 3, the controller 8 increases the temperature of the substrate 10. The controller 8 may control the heater 3c to heat the substrate 10 to a temperature of 300°C or higher and 800°C or lower.

[0060] In parallel with this, the controller 8 operates the vacuum pump 7a and controls the opening of the adjustment valve 7b so that the pressure in the processing chamber CH is between 50 Pa and 300 Pa, thereby reducing the pressure inside the processing chamber CH via the vacuum pipes 7c and 7d.

[0061] The controller 8 controls the flow of a hydrogen isotope gas (e.g., D2 gas) and an oxygen isotope gas (e.g., 17 The controller 8 starts supplying the processing gas containing the hydrogen isotope gas (e.g., D2 gas) and the oxygen isotope gas (e.g., O2 gas) to the processing chamber CH. The controller 8 opens the adjustment valves 4d and 4q while keeping the adjustment valves 4e and 4f closed. This allows the gas cylinders 4a and 4p to supply the hydrogen isotope gas (e.g., D2 gas) and the oxygen isotope gas (e.g., 17 O2 gas) is introduced into the gas pipe 4n via the gas pipes 4g, 4r, 4j, and 4s, and mixed in the gas pipe 4n to produce a hydrogen isotope gas (e.g., D2 gas) and an oxygen isotope gas (e.g., 17 The processing gas contains oxygen (O2 gas). The processing gas is introduced from a gas pipe 4n through a gas inlet 4u into a buffer chamber 4v. The processing gas in the buffer chamber 4v is supplied from slits 2a1 and 2a2 toward the stage 3 in the processing chamber CH.

[0062] At this time, the controller 8 continues to control the aperture of the adjustment valve 7b so that the pressure in the processing chamber CH is not less than 50 Pa and not more than 300 Pa. The controller 8 also controls the apertures of the adjustment valves 4d and 4q so that the flow rate ratio of the hydrogen isotope gas (e.g., D2 gas) to the processing gas is not less than 5% and not more than 95%.

[0063] When the pressure in the processing chamber CH stabilizes, the controller 8 starts supplying high-frequency power from the power supply unit 6 to the electrode 5. This applies a high-frequency voltage between the electrode 3b and the electrode 5, forming an induction magnetic field in the processing chamber CH. The processing gas contains a hydrogen isotope gas (e.g., D2 gas) and an oxygen isotope gas (e.g., 17 The D2 gas and the O2 gas are each plasma-excited to form, for example, a doughnut-shaped plasma PL. This plasma PL may be a plasma with a low electric potential. 17 O2 gas is dissociated by plasma PL and forms hydroxyl radicals OH * Reactive species such as oxidizing radicals, deuterium ions, and oxygen ions are generated. Because the electric potential of the plasma PL is low, the deuterium ions and oxygen ions are not accelerated, and the oxidizing radicals and the like in the processing gas are supplied almost uniformly to the vicinity of the exposed surface 12a of the processing target film 12.

[0064] As a result, the target film 12 is radical-oxidized (S105). As shown in FIG. 2(d), the radical oxidation may be performed near the exposed surface 12a of the target film 12, and the portion of the target film 12 near the exposed surface 12a may be replaced with an oxide film 13. Alternatively, as shown in FIG. 2(e), the radical oxidation may be performed on the entire target film 12, and the entire target film 12 may be replaced with an oxide film 13. The dotted arrows in FIGS. 2(d) and 2(e) indicate that oxidizing radicals and ions in the processing gas are supplied approximately uniformly near the exposed surface 12a of the target film 12.

[0065] Thus, in the method for manufacturing the semiconductor device 100, the target film 12 is radically oxidized using plasma generated from a process gas containing a hydrogen isotope gas and an oxygen isotope gas, thereby enabling more efficient radical oxidation than when the target film 12 is radically oxidized using plasma generated from a process gas containing hydrogen gas and oxygen gas.

[0066] For example, the film formation rate may be higher when using plasma generated from a processing gas containing a gas of a hydrogen isotope and a gas of an oxygen isotope than when using plasma generated from a processing gas containing a gas of a hydrogen isotope and an oxygen gas.

[0067] Alternatively, the step coverage of the oxide film 13 may be greater when using plasma generated from a process gas containing a gas of a hydrogen isotope and a gas of an oxygen isotope than when using plasma generated from a process gas containing a gas of a hydrogen isotope and an oxygen gas.

[0068] In the manufacturing method of the semiconductor device 100, the process gas used in S4 may be a mixed gas of hydrogen gas, a gas of a hydrogen isotope, and a gas of an oxygen isotope, or a mixed gas of hydrogen gas, a gas of a hydrogen isotope, oxygen gas, and a gas of an oxygen isotope. For example, in S4 of FIG. 10, the controller 8 controls a mixture of hydrogen gas (H2 gas), a gas of a hydrogen isotope (e.g., D2 gas), oxygen gas (O2 gas), and a gas of an oxygen isotope (e.g., 17 The controller 8 starts supplying the processing gas containing hydrogen gas (H gas), a hydrogen isotope gas (e.g., D gas), oxygen gas (O gas), and an oxygen isotope gas (e.g., D gas) to the processing chamber CH. The controller 8 opens the adjustment valves 4d, 4e, 4f, and 4q. As a result, hydrogen gas (H gas), a hydrogen isotope gas (e.g., D gas), oxygen gas (O gas), and an oxygen isotope gas (e.g., D gas) are supplied from the gas cylinders 4a, 4b, 4c, and 4p. 17 O2 gas) are introduced into gas pipe 4n via gas pipes 4g, 4h, 4i, 4r, 4j, 4k, 4m, and 4s, and mixed in gas pipe 4n to produce hydrogen gas (H2 gas), a gas of a hydrogen isotope (e.g., D2 gas), oxygen gas (O2 gas), and a gas of an oxygen isotope (e.g., 17The process gas contains hydrogen and oxygen (O2 gas). The process gas is introduced from gas pipe 4n through gas inlet 4u into buffer chamber 4v. The process gas in buffer chamber 4v is supplied to stage 3 in process chamber CH through slits 2a1 and 2a2. Controller 8 controls the apertures of adjustment valves 4d, 4e, 4f, and 4q so that the ratio of the flow rate of the hydrogen isotope gas (e.g., D2 gas) to the flow rate of the process gas is 5% or more and 95% or less. In this case, too, by setting the flow rate ratio of the hydrogen isotope gas to the flow rate of the process gas to 5% or more and 95% or less, the step coverage of oxide film 13 formed by radical oxidation can be improved.

[0069] The process gas used in S4 may further contain a rare gas such as helium gas or argon gas. The process gas may be a mixed gas of a hydrogen isotope gas, an oxygen isotope gas, and a rare gas, or a mixed gas of hydrogen gas, a hydrogen isotope gas, an oxygen isotope gas, and a rare gas, or a mixed gas of hydrogen gas, a hydrogen isotope gas, an oxygen gas, an oxygen isotope gas, and a rare gas. Even in this case, the step coverage of the oxide film 13 formed by radical oxidation can be improved by setting the flow rate ratio of the hydrogen isotope gas to the process gas to be 5% or more and 95% or less.

[0070] Alternatively, as a second modified example of the embodiment, the concept of the embodiment may be applied to the formation of a block insulating film in a manufacturing method of a semiconductor device 300 such as a three-dimensional memory. For example, the manufacturing method of the semiconductor device 300 may be performed as shown in FIGS. 10 to 13. FIG. 10 is a flowchart showing a manufacturing method of the semiconductor device 300 according to the second modified example of the embodiment. FIGS. 11(a), 11(b), 12(a), 12(b), and 13 are YZ cross-sectional views showing the manufacturing method of the semiconductor device 300.

[0071] When the substrate 10 is prepared (S1), a stacked body SST shown in Fig. 11(a) is formed on or above (on the +Z side of) the main surface 10a of the substrate 10 (S206). Fig. 11(a) illustrates the case where the stacked body SST is formed on the main surface 10a of the substrate 10.

[0072] Insulating layers 111 and sacrificial layers 151 are alternately and repeatedly stacked on the main surface 10a of the substrate 10. While FIG. 11(a) illustrates an example in which the number of repetitions is six, the number of repetitions is not limited to six and may be greater. The insulating layer 111 may be formed of a material primarily containing a semiconductor oxide (e.g., silicon oxide). The sacrificial layer 151 is formed of a material that can ensure an etching selectivity with respect to the insulating layer 111. The sacrificial layer 151 may be formed of a material primarily containing a semiconductor nitride (e.g., silicon nitride). An insulating layer 113 is stacked on the sacrificial layer 151 closest to the Z side. The insulating layer 113 may be formed of a material primarily containing a semiconductor oxide (e.g., silicon oxide). This results in a stacked structure SST in which the insulating layers 111 and the sacrificial layers 151 are alternately and repeatedly stacked multiple times and the insulating layer 113 is further stacked.

[0073] Once the stacked body SST is obtained, a memory hole 120 is formed in the stacked body SST (S207).

[0074] A resist pattern RP1 having an opening RP1a corresponding to the memory hole 120 is formed on the main surface 113a of the insulating layer 113 on the most +Z side of the stacked body SST. Etching is performed by an RIE method or the like using the resist pattern RP1 as a mask under anisotropic processing conditions until the substrate 10 is reached. As a result, as shown in FIG. 11(b), a memory hole 120 extending in the stacked body SST in the Z direction and reaching the substrate 10 is formed in the stacked body SST.

[0075] 11(a) and the step shown in Fig. 11(b) may be alternately repeated multiple times to form the memory hole 120. This makes it possible to easily form the memory hole 120 with a high aspect ratio.

[0076] 12(a), a semiconductor nitride film 312 is deposited on the side and bottom surfaces of the memory hole 120 by a CVD method or the like (S202). The semiconductor nitride film 312 can be formed of a material containing silicon nitride as a main component.

[0077] After the semiconductor nitride film 312 is deposited, the substrate 10 is carried into the substrate processing apparatus 1 (see FIG. 3), and the semiconductor nitride film 312 is subjected to an oxidation treatment (S203).

[0078] The oxidation process (S203) may be performed in the substrate processing apparatus 1 by PIO process, which radically oxidizes the semiconductor nitride film 312 using plasma generated from a processing gas containing a hydrogen isotope gas and oxygen gas.

[0079] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between the electrode 3b and the electrode 5 to generate a plasma PL in the processing chamber CH using a processing gas containing a hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) (S4). By applying a high-frequency voltage between the electrode 3b and the electrode 5, an induction magnetic field is formed in the processing chamber CH. The hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) contained in the processing gas are each plasma-excited to form, for example, a doughnut-shaped plasma PL. This plasma PL may be a plasma with a low electric potential. The D2 gas and O2 gas are each dissociated by the plasma PL to form hydroxyl radicals OH. * Reactive species such as oxidizing radicals, deuterium ions, and oxygen ions are generated. Because the electric potential of the plasma PL is low, the deuterium ions and oxygen ions are not accelerated, and the oxidizing radicals and the like in the processing gas are supplied almost uniformly to the vicinity of the exposed surface 312a of the semiconductor nitride film 312 through the memory holes 120.

[0080] As a result, the semiconductor nitride film 312 is radically oxidized (S205). The radical oxidation may be performed near the exposed surface 312a of the semiconductor nitride film 312, and the portion of the semiconductor nitride film 312 near the exposed surface 312a may be replaced with an oxide film 313. Alternatively, as shown in FIG. 12(b), the radical oxidation may be performed on the entire semiconductor nitride film 312, and the entire semiconductor nitride film 312 may be replaced with an oxide film 313. The dotted arrows in FIG. 12(b) indicate that oxidizing radicals and ions in the process gas are supplied approximately uniformly near the exposed surface 312a of the semiconductor nitride film 312. As a result, a block insulating film including the oxide film 313 is formed on the side surface and bottom surface of the memory hole 120.

[0081] A charge storage film and a tunnel insulating film are further deposited in this order in the memory hole 120. The charge storage film may be made of an insulating material such as silicon nitride. The tunnel insulating film may be made of an insulating material such as silicon oxide. Portions of the block insulating film, the charge storage film, and the tunnel insulating film at the bottom of the memory hole 120 are selectively removed.

[0082] A semiconductor film is deposited on the side and bottom surfaces of the memory hole 120. The semiconductor film may be formed of a material whose main component is a semiconductor (e.g., polysilicon) that is substantially free of impurities. The semiconductor film is subjected to a heat treatment at a predetermined temperature to improve the crystallinity of the semiconductor film. Then, a core member is buried in the memory hole 120. The core member may be formed of an insulator such as silicon oxide. This forms a columnar body that penetrates the stack SST in the Z direction.

[0083] The sacrificial layer 151 of the stacked body SST is removed. An insulating film is formed on the exposed surface of the void formed by the removal. The insulating film may be made of an insulating material such as aluminum oxide. A conductive layer 112 is further buried in the void. The conductive layer 112 may be made of a material containing a conductor (for example, a metal such as tungsten) as its main component. This forms a stacked body SSTa in which the conductive layers 112 and the insulating layers 111 are alternately stacked, and an insulating layer 113 is further stacked on top of them.

[0084] As a result, a memory cell array structure MCA is formed in which a plurality of memory cells MC are arranged three-dimensionally, as shown in FIG. 13. In the memory cell array structure MCA, a plurality of memory cells MC and select gates SGS, SGD at both ends in the Z direction are formed at a plurality of positions where a plurality of conductive layers 112 in the stacked body SSTa intersect with the semiconductor films SF of a plurality of pillars PL. A conductive region (not shown) arranged on the −Z side of the stacked body SSTa functions as a source region in the memory cell array structure MCA. The conductive layer 112 on the −Z side of the plurality of conductive layers 112 functions as a source-side select gate line. The conductive layer 112 on the +Z side of the plurality of conductive layers 112 functions as a drain-side select gate line. The remaining conductive layers 112 of the plurality of conductive layers 112 function as word lines.

[0085] That is, a semiconductor device 300 that functions as a three-dimensional memory is manufactured.

[0086] Thus, in the method for manufacturing the semiconductor device 300, the semiconductor nitride film 312 is radically oxidized using plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas. This allows the radical oxidation to be performed more efficiently than when the semiconductor nitride film 312 is radically oxidized using plasma generated from a process gas containing hydrogen gas and oxygen gas.

[0087] Furthermore, in the method for manufacturing the semiconductor device 300, radical oxidation is used to form the block insulating film, which makes it possible to easily improve the step coverage of the oxide film 313, thereby improving the insulating performance of the formed block insulating film. This makes it possible to suppress the occurrence of a back tunneling phenomenon in which charges tunnel from the conductive layer 112 serving as a word line through the block insulating film and accumulate in the charge storage film. Therefore, the operational reliability of the memory cells MC in the semiconductor device 300 can be improved.

[0088] Alternatively, as a third modified example of the embodiment, the concept of the embodiment may be applied to oxidation of an exposed surface of a semiconductor film in a manufacturing method of a semiconductor device 400 such as a three-dimensional memory. For example, the manufacturing method of the semiconductor device 400 may be performed as shown in FIGS. 14 to 16. FIG. 14 is a flowchart showing the manufacturing method of the semiconductor device 400 according to the third modified example of the embodiment. FIGS. 15 and 16 are YZ cross-sectional views showing the manufacturing method of the semiconductor device 400. FIGS. 17(a) and 17(b) are YZ cross-sectional views showing warpage of the substrate 10.

[0089] After steps S1 to S207 are performed in the same manner as in the second modified example of the embodiment, an insulating film 414 is deposited on the side and bottom surfaces of the memory hole 120 by a CVD method or the like (S308), as shown in Fig. 15. The insulating film 414 may be deposited as a multilayer film including a block insulating film 414a, a charge storage film 414b, and a tunnel insulating film 414c.

[0090] A block insulating film 414a, a charge storage film 414b, and a tunnel insulating film 414c are deposited in this order on the side and bottom surfaces of the memory hole 120. The block insulating film 414a may be made of an insulator such as silicon oxide. The charge storage film 414b may be made of an insulator such as silicon nitride. The tunnel insulating film 414c may be made of an insulator such as silicon oxide. Portions of the block insulating film 414a, the charge storage film 414b, and the tunnel insulating film 414c on the bottom surface of the memory hole are selectively removed.

[0091] A semiconductor film 412 is deposited on the side and bottom surfaces of the memory hole (S302). The semiconductor film 412 may be formed of a material whose main component is a semiconductor (for example, polysilicon) that does not substantially contain impurities.

[0092] The semiconductor film 412 is subjected to a heat treatment at a predetermined temperature (S309), and the crystallinity of the semiconductor film 412 is improved.

[0093] 17(a), due to differences in the direction and amount of thermal deformation of each film formed on the +Z side of the substrate 10, the substrate 10 as a whole tends to warp convexly toward the -Z side. The substrate 10 warped convexly toward the -Z side is difficult to handle, for example, it is difficult to vacuum-adsorb onto the stage ST of the apparatus in subsequent processes.

[0094] On the other hand, the substrate 10 is carried into the substrate processing apparatus 1 (see FIG. 3), and the semiconductor film 412 is subjected to an oxidation treatment (S303).

[0095] The oxidation process (S303) may be performed in the substrate processing apparatus 1 by PIO process, which radically oxidizes the semiconductor film 412 using plasma generated from a process gas containing a hydrogen isotope gas and an oxygen gas.

[0096] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between the electrode 3b and the electrode 5 to generate a plasma PL in the processing chamber CH using a processing gas containing a hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) (S4). By applying a high-frequency voltage between the electrode 3b and the electrode 5, an induction magnetic field is formed in the processing chamber CH. The hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) contained in the processing gas are each plasma-excited to form, for example, a doughnut-shaped plasma PL. This plasma PL may be a plasma with a low electric potential. The D2 gas and O2 gas are each dissociated by the plasma PL to form hydroxyl radicals OH. * Reactive species such as oxidizing radicals, deuterium ions, and oxygen ions are generated. Because the electric potential of the plasma PL is low, the deuterium ions and oxygen ions are not accelerated, and the oxidizing radicals and the like in the processing gas are supplied almost uniformly to the vicinity of the exposed surface 412a of the semiconductor film 412 through the memory holes 120.

[0097] 16, the radical oxidation is carried out in the vicinity of the exposed surface 412a (see FIG. 15) of the semiconductor film 412, and the portion of the semiconductor film 412 in the vicinity of the exposed surface 412a may be replaced with an oxide film 413. The dotted arrows in FIG. 16 indicate that oxidizing radicals and ions in the processing gas are supplied approximately uniformly to the vicinity of the exposed surface 412a of the semiconductor film 412.

[0098] 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 oxide film 413 are added, which may cause the substrate 10 as a whole to warp convexly toward the +Z side, as shown in Fig. 17(b). The substrate 10 warped convexly toward the +Z side is easy to handle, for example, it is easy to vacuum-suck onto the stage ST of the apparatus in a later process.

[0099] Thereafter, a core member is buried in the memory hole 120. The core member may be made of an insulating material such as silicon oxide, thereby forming a columnar body that penetrates the stacked body SST in the Z direction.

[0100] The sacrificial layer 151 of the stacked body SST is removed. An insulating film is formed on the exposed surface of the void formed by the removal. The insulating film may be made of an insulating material such as aluminum oxide. A conductive layer 112 is further buried in the void. The conductive layer 112 may be made of a material containing a conductor (for example, a metal such as tungsten) as its main component. This forms a stacked body SSTa in which the conductive layers 112 and the insulating layers 111 are alternately stacked.

[0101] This forms a memory cell array structure MCA (see FIG. 13) in which a plurality of memory cells MC are arranged three-dimensionally. In the memory cell array structure MCA, a plurality of memory cells MC are formed at a plurality of positions where a plurality of conductive layers 112 in the stacked body SSTa intersect with the semiconductor films SF of a plurality of pillars PL. A conductive region (not shown) arranged on the +Z side of the stacked body SSTa functions as a source region in the memory cell array structure MCA. The conductive layer 112 of the plurality of conductive layers 112 closest to the +Z side functions as a source-side selection gate line. The conductive layer 112 of the plurality of conductive layers 112 closest to the -Z side functions as a drain-side selection gate line. The remaining conductive layers 112 of the plurality of conductive layers 112 function as word lines.

[0102] That is, a semiconductor device 400 that functions as a three-dimensional memory is manufactured.

[0103] Thus, in the method for manufacturing the semiconductor device 400, the exposed surface 412a of the semiconductor film 412 is radically oxidized using plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas. This allows the radical oxidation to be performed more efficiently than when the exposed surface 412a of the semiconductor film 412 is radically oxidized using plasma generated from a process gas containing hydrogen gas and oxygen gas.

[0104] Furthermore, in the manufacturing method of the semiconductor device 400, the exposed surface 412a of the semiconductor film 412 is efficiently radically oxidized, so that the warpage direction of the substrate 10 can be easily changed from a convex direction toward the -Z side to a convex direction toward the +Z side.

[0105] Alternatively, as a fourth modified example of the embodiment, the concept of the embodiment may be applied to the formation of a tunnel insulating film in a manufacturing method of a semiconductor device 500 such as a three-dimensional memory. For example, the manufacturing method of the semiconductor device 500 may be performed as shown in Figures 18 to 20. Figure 18 is a flowchart showing the manufacturing method of the semiconductor device 500 according to the fourth modified example of the embodiment. Figures 19 and 20 are YZ cross-sectional views showing the manufacturing method of the semiconductor device 300.

[0106] After steps S1 to S207 are performed in the same manner as in the second modified example of the embodiment, an insulating film is deposited on the side and bottom surfaces of the memory hole 120 by a CVD method or the like (S408), as shown in FIG.

[0107] A block insulating film 514 and a charge storage film 515 are sequentially deposited as insulating films on the side and bottom surfaces of the memory hole 120. The block insulating film 514 may be made of an insulator such as silicon oxide. The charge storage film 515 may be made of an insulator such as silicon nitride.

[0108] 19, a semiconductor nitride film 512 is deposited on the side and bottom surfaces of the memory hole 120 by a CVD method or the like (S402). The semiconductor nitride film 512 can be formed from a material containing silicon nitride as a main component.

[0109] After the semiconductor nitride film 512 is deposited, the substrate 10 is carried into the substrate processing apparatus 1 (see FIG. 3), and the semiconductor nitride film 512 is subjected to an oxidation treatment (S403).

[0110] The oxidation process (S403) may be performed in the substrate processing apparatus 1 by PIO process, which radically oxidizes the semiconductor nitride film 512 using plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas.

[0111] In the substrate processing apparatus 1, the controller 8 applies a high-frequency voltage between the electrode 3b and the electrode 5 to generate a plasma PL in the processing chamber CH using a processing gas containing a hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) (S4). By applying a high-frequency voltage between the electrode 3b and the electrode 5, an induction magnetic field is formed in the processing chamber CH. The hydrogen isotope gas (e.g., D2 gas) and oxygen gas (O2 gas) contained in the processing gas are each plasma-excited to form, for example, a doughnut-shaped plasma PL. This plasma PL may be a plasma with a low electric potential. The D2 gas and O2 gas are each dissociated by the plasma PL to form hydroxyl radicals OH. *Reactive species such as oxidizing radicals, deuterium ions, and oxygen ions are generated. Because the electric potential of the plasma PL is low, the deuterium ions and oxygen ions are not accelerated, and the oxidizing radicals and the like in the processing gas are supplied almost uniformly to the vicinity of the exposed surface 512a of the semiconductor nitride film 512 through the memory holes 120.

[0112] As a result, the semiconductor nitride film 512 is radical-oxidized (S405). As shown in FIG. 20, the radical oxidation is performed on the entire semiconductor nitride film 512, and the entire semiconductor nitride film 512 may be replaced with an oxide film 513. The dotted arrows in FIG. 20 indicate that oxidizing 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 including the oxide film 513 is formed on the side surface and bottom surface of the memory hole 120.

[0113] In the memory hole 120, the block insulating film 514, the charge storage film 515, and the portions of the tunnel insulating film 513 at the bottom of the memory hole 120 are selectively removed.

[0114] A semiconductor film is deposited on the side and bottom surfaces of the memory hole 120. The semiconductor film may be formed of a material whose main component is a semiconductor (e.g., polysilicon) that is substantially free of impurities. The semiconductor film is subjected to a heat treatment at a predetermined temperature to improve the crystallinity of the semiconductor film. Then, a core member is buried in the memory hole 120. The core member may be formed of an insulator such as silicon oxide. This forms a columnar body that penetrates the stack SST in the Z direction.

[0115] The sacrificial layer 151 of the stacked body SST is removed. An insulating film is formed on the exposed surface of the void formed by the removal. The insulating film may be made of an insulating material such as aluminum oxide. A conductive layer 112 is further buried in the void. The conductive layer 112 may be made of a material containing a conductor (for example, a metal such as tungsten) as its main component. This forms a stacked body SSTa in which the conductive layers 112 and the insulating layers 111 are alternately stacked, and an insulating layer 113 is further stacked on top of them.

[0116] This forms a memory cell array structure MCA (see FIG. 13) in which a plurality of memory cells MC are arranged three-dimensionally. In the memory cell array structure MCA, a plurality of memory cells MC and select gates SGS, SGD at both ends in the Z direction are formed at a plurality of positions where a plurality of conductive layers 112 in the stacked body SSTa intersect with the semiconductor films SF of a plurality of pillars PL. A conductive region (not shown) arranged on the -Z side of the stacked body SSTa functions as a source region in the memory cell array structure MCA. The conductive layer 112 on the -Z side of the plurality of conductive layers 112 functions as a source-side select gate line. The conductive layer 112 on the +Z side of the plurality of conductive layers 112 functions as a drain-side select gate line. The remaining conductive layers 112 of the plurality of conductive layers 112 function as word lines.

[0117] That is, a semiconductor device 500 that functions as a three-dimensional memory is manufactured.

[0118] Thus, in the method for manufacturing the semiconductor device 500, the semiconductor nitride film 512 is radically oxidized using plasma generated from a process gas containing a hydrogen isotope gas and oxygen gas. This allows the radical oxidation to be performed more efficiently than when the semiconductor nitride film 512 is radically oxidized using plasma generated from a process gas containing hydrogen gas and oxygen gas.

[0119] Furthermore, in the manufacturing method of the semiconductor device 500, by using radical oxidation with a process gas containing a gas of a hydrogen isotope to form the tunnel insulating film, the step coverage of the oxide film 513 can be easily improved, and a structure can be formed in which the interface between the charge storage film and the tunnel insulating film is terminated with a hydrogen isotope (e.g., deuterium). This makes it possible to suppress the occurrence of bond defects due to electrical stress at the interface between the charge storage film and the tunnel insulating film during data write and erase operations in the memory cells MC, and to suppress malfunctions due to bond defects. Therefore, the operational reliability of the memory cells MC in the semiconductor device 500 can be improved.

[0120] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0121] 1,201 substrate processing equipment, 100,300,400,500 semiconductor equipment.

Claims

1. radically oxidizing the first film using a plasma generated from a process gas containing a hydrogen isotope gas. A method for manufacturing a semiconductor device.

2. The radical oxidation is radically oxidizing the first film using plasma generated from the process gas containing the hydrogen isotope gas and oxygen gas. The method for manufacturing a semiconductor device according to claim 1 .

3. The radical oxidation is radically oxidizing the first film using plasma generated by the process gas containing the hydrogen isotope gas and the oxygen isotope gas. The method for manufacturing a semiconductor device according to claim 1 .

4. The radical oxidation is radically oxidizing the first film using plasma generated by the process gas containing the hydrogen isotope gas, oxygen gas, and a rare gas. The method for manufacturing a semiconductor device according to claim 1 .

5. The radical oxidation is radically oxidizing the first film using plasma generated by the process gas containing the hydrogen isotope gas, the oxygen isotope gas, and a rare gas. The method for manufacturing a semiconductor device according to claim 1 .

6. The radical oxidation is radically oxidizing the first film at a temperature of 300° C. to 800° C. using plasma generated from the processing gas containing the hydrogen isotope gas. The method for manufacturing a semiconductor device according to claim 1 .

7. The radical oxidation is radically oxidizing the first film at a pressure of 50 Pa or more and 300 Pa or less using plasma generated from the processing gas containing the hydrogen isotope gas. The method for manufacturing a semiconductor device according to claim 1 .

8. The radical oxidation is radically oxidizing the first film using plasma generated by the processing gas containing the hydrogen isotope gas at a flow rate ratio of 5% to 95%. The method for manufacturing a semiconductor device according to claim 1 .

9. forming a laminate in which first insulating films and second insulating films are alternately stacked a plurality of times; forming a hole extending in a stacking direction of the laminate; depositing a semiconductor nitride film as the first film on the inner side surface and bottom surface of the hole; further comprising The radical oxidation is generating a plasma of the processing gas and radically oxidizing the exposed surface of the semiconductor nitride film. The method for manufacturing a semiconductor device according to claim 1 .

10. forming a laminate in which first insulating films and second insulating films are alternately stacked a plurality of times; forming a hole extending in a stacking direction of the laminate; depositing a third insulating film on the inner side surface and the bottom surface of the hole; depositing a semiconductor film as the first film on an inner side surface and a bottom surface of the third insulating film in the hole; Furthermore, The radical oxidation is generating a plasma of the processing gas and radically oxidizing the exposed surface of the semiconductor film. The method for manufacturing a semiconductor device according to claim 1 .

11. forming a laminate in which first insulating films and second insulating films are alternately stacked a plurality of times; forming a hole extending in a stacking direction of the laminate; depositing a third insulating film on the inner side surface and the bottom surface of the hole; depositing a semiconductor nitride film as the first film on an inner side surface and a bottom surface of the third insulating film in the hole; Furthermore, The radical oxidation is generating a plasma of the processing gas and radically oxidizing the exposed surface of the semiconductor nitride film. The method for manufacturing a semiconductor device according to claim 1 .

12. a stage disposed in the processing chamber, on which the substrate is placed, and including a first electrode; a gas supply system capable of supplying a process gas containing a hydrogen isotope gas toward the stage in the process chamber; a second electrode disposed outside the processing chamber at a position spaced apart from the stage; an exhaust system capable of adjusting the pressure inside the processing chamber; Equipped with A high frequency voltage can be applied between the first electrode and the second electrode to generate plasma in the processing chamber. Substrate processing equipment.

13. The gas supply system is capable of supplying the process gas containing the hydrogen isotope gas and the oxygen isotope gas toward the stage in the process chamber. The substrate processing apparatus according to claim 12 .

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