Substrate processing method and substrate processing apparatus

Abstract

To provide a technology that can form a film in which deuterium concentration is high and oxidation of a surface is suppressed.SOLUTION: A substrate processing method according to one aspect of the present disclosure comprises the steps of: preparing a substrate that has an object film on a surface; forming a barrier film that covers the object film; supplying a deuterium gas and an oxygen gas to the object film that is covered by the barrier film and injecting deuterium into the object film; and removing the barrier film after the deuterium is injected into the object film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART A semiconductor memory device is known that contains deuterium at the interface between a semiconductor substrate and a gate insulating film of a transistor at a ratio greater than the ratio of deuterium to hydrogen that exists in nature (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-77621 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can form a film with a high concentration of deuterium and suppressed surface oxidation. [Means for solving the problem]

[0005] A substrate processing method according to one aspect of the present disclosure includes the steps of: preparing a substrate having a target film on a surface thereof; forming a barrier film to cover the target film; supplying deuterium gas and oxygen gas to the target film covered with the barrier film to inject deuterium into the target film; and removing the barrier film after deuterium has been injected into the target film. [Effects of the Invention]

[0006] According to the present disclosure, a film having a high concentration of deuterium and suppressed surface oxidation can be formed. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a flowchart illustrating a substrate processing method according to an embodiment. [Figure 2] 1 is a schematic cross-sectional view illustrating a substrate processing method according to an embodiment; [Figure 3] 1 is a schematic view showing a substrate processing apparatus according to an embodiment; [Figure 4] Figure showing the comparison results of deuterium concentration and oxide film thickness in Experiment 1 [Figure 5] Comparison of deuterium concentrations in Experiment 2 DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] [Substrate Processing Method] A substrate processing method according to an embodiment will be described with reference to Figures 1 and 2. As shown in Figure 1, the substrate processing method according to the embodiment includes a preparation step S10, a barrier film formation step S20, a deuterium introduction step S30, and a barrier film removal step S40.

[0010] In the preparation step S10, as shown in FIG. 2(a), a substrate 101 having a target film 102 on its surface is prepared. The substrate 101 is, for example, a silicon wafer. The target film 102 is, for example, a film containing silicon and nitrogen. The target film 102 is, for example, a silicon nitride film or a silicon oxynitride film.

[0011] The barrier film forming step S20 is performed after the preparation step S10. In the barrier film forming step S20, as shown in FIG. 2(b), a barrier film 103 is formed on the target film 102. The barrier film 103 covers the target film 102 and prevents oxygen from penetrating into the target film 102. The barrier film 103 is a film that allows more deuterium to pass through than oxygen to pass through. The barrier film 103 is formed of, for example, silicon oxide, aluminum oxide, or polysilicon. The method for forming the barrier film 103 is not particularly limited. For example, the barrier film 103 can be formed by atomic layer deposition (ALD) or chemical vapor deposition (CVD).

[0012] The deuterium introduction step S30 is performed after the barrier film formation step S20. In the deuterium introduction step S30, as shown in FIG. 2( c), deuterium gas and oxygen gas are supplied to the target film 102 covered with the barrier film 103, and deuterium 104 is implanted into the target film 102. The target film 102 is covered with the barrier film 103, through which the amount of deuterium 104 passing through is greater than the amount of oxygen passing through. Therefore, the deuterium 104 passes through the barrier film 103 and is implanted into the target film 102, whereas oxygen is blocked by the barrier film 103 and is difficult to implant into the target film 102. In this way, in the deuterium introduction step S30, deuterium 104 can be implanted into the target film 102 while suppressing the implantation of oxygen into the target film 102.

[0013] The barrier film removal step S40 is performed after the deuterium introduction step S30. In the barrier film removal step S40, as shown in FIG. 2(d), deuterium 104 is implanted into the target film 102, and then the barrier film 103 is removed. The method for removing the barrier film 103 is not particularly limited. If the barrier film 103 is made of silicon oxide, the barrier film 103 can be removed by, for example, chemical oxide removal (COR), which involves chemical etching without generating plasma. In COR, hydrogen fluoride (HF) gas and ammonia (NH) gas are supplied, and the hydrogen fluoride gas and ammonia gas react with the silicon oxide to generate ammonium silicofluoride [(NH)SiF], which is then sublimated by heating. This allows the barrier film 103, made of silicon oxide, to be selectively etched and removed while leaving the target film 102. When the barrier film 103 is made of polysilicon, for example, by supplying chlorine trifluoride (ClF3) gas or fluorine (F2) gas, the barrier film 103 made of polysilicon can be selectively etched and removed while leaving the target film 102.

[0014] As a result of the above, the target film 102 into which the deuterium 104 is implanted is formed.

[0015] According to the substrate processing method of the embodiment, in the deuterium introducing step S30, deuterium gas and oxygen gas are supplied to the target film 102 covered with the barrier film 103, and deuterium 104 is implanted into the target film 102. This allows deuterium 104 to be implanted into the target film 102 while the barrier film 103 suppresses implantation of oxygen into the target film 102. Therefore, it is possible to form a target film 102 having a high concentration of deuterium 104 and in which surface oxidation is suppressed.

[0016] It is preferable that the barrier film formation step S20, the deuterium introduction step S30, and the barrier film removal step S40 are performed in the same processing chamber. This reduces downtime. Furthermore, since there is no need to transport substrates between different processing chambers, the risk of particle generation can be reduced. However, the barrier film formation step S20, the deuterium introduction step S30, and the barrier film removal step S40 may be performed in different processing chambers. Furthermore, at least two of the barrier film formation step S20, the deuterium introduction step S30, and the barrier film removal step S40 may be performed in the same processing chamber.

[0017] [Substrate Processing Apparatus] A substrate processing apparatus according to an embodiment will be described with reference to Fig. 3. As shown in Fig. 3, the substrate processing apparatus 1 includes a processing container 10, a boat 20, a gas supply unit 30, an exhaust unit 40, a heating unit 50, and a control unit 60.

[0018] The processing vessel 10 is formed in a cylindrical shape with a processing space 10a inside. The processing vessel 10 performs heat treatment with a substrate W accommodated in the processing space 10a. The processing vessel 10 has a cylindrical tube body 11 with a substantially hemispherical ceiling and an open bottom end, a manifold 12 connected to the bottom end of the tube body 11, and a lid 15 connected to the bottom end of the manifold 12.

[0019] The cylindrical body 11 is made of a heat-resistant material such as quartz. The cylindrical body 11 extends vertically (heightwise) and constitutes most of the processing space 10a of the processing vessel 10. In Fig. 3, the processing vessel 10 is shown as having a single cylindrical body 11, but is not limited thereto. For example, the processing vessel 10 may have a multi-layer structure in which multiple cylinders (outer cylinder, inner cylinder) are concentrically stacked.

[0020] The manifold 12 and the lid 15 are made of, for example, stainless steel. The manifold 12 has a flange 13 at its upper end, which supports the lower end of the cylindrical main body 11. The lower end of the cylindrical main body 11 and the flange 13 are airtightly connected via a seal member 14 such as an O-ring. Similarly, the lower end of the manifold 12 and the lid 15 are in airtight contact via a seal member 16 such as an O-ring.

[0021] A rotating shaft 18 penetrates the center of the lid 15 via a magnetic fluid seal 17. The rotating shaft 18 has a boat 20 at its upper portion and is connected to a rotation drive unit 19. The rotating shaft 18 rotates relative to the processing vessel 10 by the rotation of the rotation drive unit 19. This causes the boat 20 to rotate.

[0022] The lower part of the rotating shaft 18 is rotatably supported by an arm 22 of an elevating mechanism 21 such as a boat elevator. A rotating plate 23 is provided at the upper end of the rotating shaft 18, and the boat 20 is placed on the rotating plate 23 via a quartz heat-retaining stand 24. Therefore, the lid 15 and the boat 20 move up and down together by raising and lowering the elevating mechanism 21, so that the boat 20 can be inserted into and removed from the cylindrical main body 11.

[0023] The boat 20 is a substrate holder that extends vertically (heightwise) within the processing vessel 10 and holds a plurality of substrates W at predetermined intervals along the vertical direction. The boat 20 is removed from the processing vessel 10 by the lowering of the lifting mechanism 21, and then each substrate W is placed on the boat 20. After each substrate W is placed on the boat 20, the boat 20 is inserted into the processing vessel 10 by the raising of the lifting mechanism 21.

[0024] The gas supply unit 30 is configured to be able to introduce various process gases used in the substrate processing method described above into the processing space 10 a. The gas supply unit 30 includes a deuterium supply unit 31, an oxygen supply unit 32, an inert gas supply unit 33, a silicon-containing gas supply unit 34, a hydrogen fluoride supply unit 35, and an ammonia supply unit 36.

[0025] The deuterium supply unit 31 includes a deuterium supply pipe 311 inside the processing vessel 10 and a deuterium supply path 312 outside the processing vessel 10. The deuterium supply path 312 is provided with a deuterium source 313, a mass flow controller 314, and a deuterium valve 315, in this order from upstream to downstream in the gas flow direction. Thus, the supply timing of deuterium gas from the deuterium source 313 is controlled by the deuterium valve 315, and the flow rate is adjusted to a predetermined value by the mass flow controller 314. The deuterium gas flows from the deuterium supply path 312 into the deuterium supply pipe 311 and is discharged from the deuterium supply pipe 311 into the processing vessel 10.

[0026] The oxygen supply unit 32 includes an oxygen supply pipe 321 inside the processing vessel 10 and an oxygen supply path 322 outside the processing vessel 10. The oxygen supply path 322 is provided with an oxygen source 323, a mass flow controller 324, and an oxygen valve 325, in this order from upstream to downstream in the gas flow direction. Thus, the supply timing of oxygen gas from the oxygen source 323 is controlled by the oxygen valve 325, and the flow rate is adjusted to a predetermined value by the mass flow controller 324. The oxygen gas flows from the oxygen supply path 322 into the oxygen supply pipe 321 and is discharged from the oxygen supply pipe 321 into the processing vessel 10.

[0027] The inert gas supply unit 33 includes an inert gas supply pipe 331 inside the processing vessel 10 and an inert gas supply path 332 outside the processing vessel 10. The inert gas supply path 332 is provided with an inert gas source 333, a mass flow controller 334, and an inert gas valve 335, in this order from upstream to downstream in the gas flow direction. Thus, the supply timing of the inert gas from the inert gas source 333 is controlled by the inert gas valve 335, and the flow rate is adjusted to a predetermined value by the mass flow controller 334. The inert gas flows from the inert gas supply path 332 into the inert gas supply pipe 331 and is discharged from the inert gas supply pipe 331 into the processing vessel 10.

[0028] The silicon-containing gas supply unit 34 includes a silicon-containing gas supply pipe 341 inside the processing vessel 10 and a silicon-containing gas supply path 342 outside the processing vessel 10. The silicon-containing gas supply path 342 is provided with a silicon-containing gas source 343, a mass flow controller 344, and a silicon-containing gas valve 345, in this order from upstream to downstream in the gas flow direction. Thus, the supply timing of the silicon-containing gas from the silicon-containing gas source 343 is controlled by the silicon-containing gas valve 345, and the flow rate is adjusted to a predetermined value by the mass flow controller 344. The silicon-containing gas flows from the silicon-containing gas supply path 342 into the silicon-containing gas supply pipe 341 and is then discharged from the silicon-containing gas supply pipe 341 into the processing vessel 10.

[0029] The hydrogen fluoride supply unit 35 includes a hydrogen fluoride supply pipe 351 inside the processing vessel 10 and a hydrogen fluoride supply path 352 outside the processing vessel 10. The hydrogen fluoride supply path 352 is provided with, in this order from upstream to downstream in the gas flow direction, a hydrogen fluoride source 353, a mass flow controller 354, and a hydrogen fluoride valve 355. Thus, the supply timing of the hydrogen fluoride gas from the hydrogen fluoride source 353 is controlled by the hydrogen fluoride valve 355, and the flow rate is adjusted to a predetermined value by the mass flow controller 354. The hydrogen fluoride gas flows from the hydrogen fluoride supply path 352 into the hydrogen fluoride supply pipe 351 and is discharged from the hydrogen fluoride supply pipe 351 into the processing vessel 10.

[0030] The ammonia supply unit 36 includes an ammonia supply pipe 361 inside the processing vessel 10 and an ammonia supply path 362 outside the processing vessel 10. The ammonia supply path 362 is provided with an ammonia source 363, a mass flow controller 364, and an ammonia valve 365, in this order from upstream to downstream in the gas flow direction. Thus, the supply timing of ammonia gas from the ammonia source 363 is controlled by the ammonia valve 365, and the flow rate is adjusted to a predetermined value by the mass flow controller 364. The ammonia gas flows from the ammonia supply path 362 into the ammonia supply pipe 361 and is discharged from the ammonia supply pipe 361 into the processing vessel 10.

[0031] Each gas supply pipe (deuterium supply pipe 311, oxygen supply pipe 321, inert gas supply pipe 331, silicon-containing gas supply pipe 341, hydrogen fluoride supply pipe 351, and ammonia supply pipe 361) is made of, for example, quartz and is fixed to the cylindrical main body 11 or the manifold 12. Each gas supply pipe extends linearly in the vertical direction near the cylindrical main body 11, and then bends in an L-shape within the manifold 12 and extends horizontally, thereby penetrating the manifold 12. The gas supply pipes are arranged side by side along the circumferential direction of the cylindrical main body 11 and are formed at the same height as each other.

[0032] A plurality of deuterium outlets 316 are provided in the deuterium supply pipe 311 at a portion located in the cylindrical body 11. A plurality of oxygen outlets 326 are provided in the oxygen supply pipe 321 at a portion located in the cylindrical body 11. A plurality of inert gas outlets 336 are provided in the inert gas supply pipe 331 at a portion located in the cylindrical body 11. A plurality of silicon-containing gas outlets 346 are provided in the silicon-containing gas supply pipe 341 at a portion located in the cylindrical body 11. A plurality of hydrogen fluoride outlets 356 are provided in the hydrogen fluoride supply pipe 351 at a portion located in the cylindrical body 11. A plurality of ammonia outlets 366 are provided in the ammonia supply pipe 361 at a portion located in the cylindrical body 11.

[0033] The outlets (deuterium outlet 316, oxygen outlet 326, inert gas outlet 336, silicon-containing gas outlet 346, hydrogen fluoride outlet 356, and ammonia outlet 366) are formed at predetermined intervals along the extension direction of the respective gas supply pipes. Each outlet discharges gas in the horizontal direction. The interval between each outlet is set to be the same as the interval between the substrates W held in the boat 20, for example. The height position of each outlet is set to be the midpoint between vertically adjacent substrates W. This allows each outlet to efficiently supply gas to the opposing surfaces between adjacent substrates W.

[0034] The gas supply unit 30 may mix multiple types of gases and discharge the mixed gas from a single supply pipe. The gas supply pipes (deuterium supply pipe 311, oxygen supply pipe 321, inert gas supply pipe 331, silicon-containing gas supply pipe 341, hydrogen fluoride supply pipe 351, and ammonia supply pipe 361) may have different shapes and arrangements. For example, in a configuration in which the supply flow rate of deuterium is high, the deuterium supply pipe 311 may be thicker than the oxygen supply pipe 321. The supply flow rate of the inert gas relative to the supply flow rates of deuterium gas and oxygen gas may be significantly lower, and the substrate processing apparatus 1 may not supply an inert gas. Furthermore, the substrate processing apparatus 1 may be configured to supply other gases in addition to deuterium gas, oxygen gas, inert gas, silicon-containing gas, hydrogen fluoride gas, and ammonia gas.

[0035] The exhaust unit 40 is provided at an exhaust port 41 formed on the side wall of the upper part of the manifold 12. The exhaust unit 40 has an exhaust path 42 connected to the exhaust port 41. A pressure adjustment valve 43 and a vacuum pump 44 are provided in the exhaust path 42, in this order from the upstream side to the downstream side in the gas flow direction. The exhaust unit 40 operates the pressure adjustment valve 43 and the vacuum pump 44 under the control of the control unit 60, and adjusts the pressure inside the processing vessel 10 using the pressure adjustment valve 43 while the vacuum pump 44 sucks the gas inside the processing vessel 10.

[0036] The heating unit 50 has a cylindrical heater 51 that surrounds the cylindrical body 11 on the radially outer side of the cylindrical body 11. The heater 51 heats the entire periphery of the processing vessel 10, thereby heating each substrate W accommodated in the processing vessel 10.

[0037] The control unit 60 may be a computer having one or more processors 61, a memory 62, an input / output interface (not shown), and electronic circuits. The processor 61 is one or a combination of a CPU, an ASIC, an FPGA, a circuit made up of multiple discrete semiconductors, etc. The memory 62 includes a volatile memory and a non-volatile memory (e.g., a compact disc, a DVD, a hard disk, a flash memory, etc.) and stores a program for operating the substrate processing apparatus 1 and a recipe such as process conditions for substrate processing. The processor 61 executes the program and recipe stored in the memory 62 to control each component of the substrate processing apparatus 1 and perform the aforementioned substrate processing method.

[0038] [Operation of the Substrate Processing Apparatus] A description will be given of the operation when the substrate processing method according to the embodiment is carried out in the substrate processing apparatus 1. In the following, the case where the barrier film 103 is made of silicon oxide will be described as an example.

[0039] First, the control unit 60 controls the lifting mechanism 21 to load the boat 20 holding multiple substrates W into the processing vessel 10, and then airtightly closes and seals the opening at the bottom of the processing vessel 10 with the lid 15. Each substrate W is a substrate 101 having a target film 102 on its surface.

[0040] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform the barrier film formation process S20. Specifically, first, the control unit 60 controls the exhaust unit 40 to reduce the pressure inside the processing chamber 10 to a predetermined level, and controls the heating unit 50 to adjust and maintain the substrate temperature at a predetermined level. Next, the control unit 60 controls the gas supply unit 30 to alternately and repeatedly supply a silicon-containing gas and an oxygen gas into the processing chamber 10. As a result, a barrier film 103 made of silicon oxide is formed on the target film 102. Note that a purge gas may be supplied between the supply of the silicon-containing gas and the supply of the oxygen gas.

[0041] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform the deuterium introduction step S30. Specifically, the control unit 60 first controls the exhaust unit 40 to reduce the pressure inside the processing chamber 10 to a predetermined value, and then controls the heating unit 50 to adjust and maintain the substrate temperature at a predetermined value. The predetermined pressure is, for example, 1 Torr (133 Pa) or less. The predetermined temperature is, for example, 300°C or higher and lower than 900°C. Next, the control unit 60 controls the gas supply unit 30 to supply deuterium gas and oxygen gas into the processing chamber 10. Supplying deuterium gas and oxygen gas into the processing chamber 10 activates the deuterium gas more effectively than supplying only deuterium gas into the processing chamber 10. This allows deuterium to be smoothly introduced into the target film 102, increasing the concentration of deuterium in the target film 102. At this time, the target film 102 is covered with a barrier film 103 through which a larger amount of deuterium 104 passes than a larger amount of oxygen passes. Therefore, deuterium 104 passes through the barrier film 103 and is implanted into the target film 102, whereas oxygen is blocked by the barrier film 103 and is difficult to implant into the target film 102. In this way, in the deuterium introduction step S30, deuterium 104 can be implanted into the target film 102 while suppressing implantation of oxygen into the target film 102.

[0042] In the deuterium introduction step S30, the control unit 60 can adjust the concentration of deuterium introduced into the target film 102 by controlling the ratio of the flow rate of deuterium gas to the flow rate of oxygen gas (hereinafter referred to as the "D2 / O2 ratio"). For example, the D2 / O2 ratio is preferably 2 to 20. If the D2 / O2 ratio is lower than 2, the oxygen concentration in the processing chamber 10 increases, which tends to increase the oxide film thickness of the target film 102. If the D2 / O2 ratio is higher than 20, the oxygen concentration in the processing chamber 10 decreases, which tends to decrease the amount of deuterium taken up by the target film 102.

[0043] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform the barrier film removal process S40. Specifically, the control unit 60 first controls the exhaust unit 40 to reduce the pressure inside the processing chamber 10 to a predetermined level, and then controls the heating unit 50 to adjust and maintain the substrate temperature at a predetermined level. Next, the control unit 60 controls the gas supply unit 30 to supply hydrogen fluoride (HF) gas and ammonia (NH) gas into the processing chamber 10. As a result, the hydrogen fluoride gas and the ammonia gas react with the silicon oxide constituting the barrier film 103 to generate ammonium silicofluoride [(NH)SiF]. Next, the control unit 60 controls the heating unit 50 to heat the substrate to a predetermined temperature, causing the ammonium silicofluoride to sublimate. As a result, the silicon oxide is selectively etched, and the barrier film 103 on the target film 102 is removed.

[0044] Next, the control unit 60 increases the pressure inside the processing vessel 10 to atmospheric pressure and decreases the temperature inside the processing vessel 10 to the unloading temperature, and then controls the lifting mechanism 21 to unload the boat 20 from the processing vessel 10.

[0045] As described above, the substrate processing method according to the embodiment in the substrate processing apparatus 1 can form the target film 102 having a high concentration of deuterium and having its surface inhibited from oxidation.

[0046] [Experimental results] First, an experiment (hereinafter referred to as "Experiment 1") was conducted to evaluate the influence of differences in heat treatment conditions on the amount of deuterium introduced into the silicon nitride film, which is the target film 102, and the thickness of the oxide film formed on the surface of the silicon nitride film. In Experiment 1, first, a heat treatment was performed on a silicon nitride film under the following two different conditions A and B in the above-mentioned substrate processing apparatus 1. Next, the concentration of deuterium contained in each silicon nitride film that had been heat treated under conditions A and B, and the thickness of the oxide film formed on the surface of the silicon nitride film were measured.

[0047] (Condition A) Gas type: Deuterium gas Pressure: 90 Torr (12 kPa) Temperature: 700℃ Time: 1 hour (Condition B) Gas type: Deuterium gas + Oxygen gas Pressure: 0.35 Torr (46.7 Pa) Temperature: 700°C (same as condition A) Time: 1 hour (same as Condition A)

[0048] Figure 4 shows the comparison results of deuterium concentration and oxide film thickness in Experiment 1. In Figure 4, the vertical axis on the left shows the average deuterium concentration [atoms / cc] contained in the silicon nitride film from the surface to a depth of 10 nm, and the vertical axis on the right shows the thickness [Å] of the oxide film formed on the surface of the silicon nitride film. In Figure 4, the bars show the deuterium concentration, and the circles show the oxide film thickness.

[0049] As shown in Figure 4, condition B has a higher deuterium concentration and a thicker oxide film than condition A. This result indicates that heat treatment under conditions in which deuterium gas and oxygen gas are supplied can form a silicon nitride film with a higher deuterium concentration than heat treatment under conditions in which deuterium gas is supplied without oxygen gas, but the oxide film formed on the surface of the silicon nitride film is thicker. The thicker oxide film under condition B is thought to be due to the oxidation of the surface of the silicon nitride film by oxygen radicals generated from the oxygen gas.

[0050] Next, an experiment (hereinafter referred to as "Experiment 2") was conducted to evaluate the effect of differences in the material of the barrier film 103 on the amount of deuterium introduced into the silicon nitride film, which is the target film 102. In Experiment 2, first, test samples were prepared in which a silicon nitride film and a barrier film 103 formed from various materials (silicon oxide, aluminum oxide, and polysilicon) were stacked in this order on a bare silicon wafer. For comparison, a test sample was also prepared in which a silicon nitride film was formed on a bare silicon wafer but no barrier film 103 was formed. Next, the prepared test samples were subjected to a heat treatment under the same condition C below in the aforementioned substrate processing apparatus 1. Next, the concentration of deuterium contained in the silicon nitride film was measured for each of the heat-treated test samples.

[0051] (Condition C) Gas type: Deuterium gas Pressure: 90 Torr (12 kPa) Temperature: 700℃ Duration: 3 hours

[0052] Figure 5 shows the comparison results of deuterium concentration in Experiment 2. In Figure 5, the vertical axis represents the concentration of deuterium [atoms / cc] contained in the silicon nitride film from the surface to a thickness of 10 nm. The bar graph in Figure 5 shows, from left to right, the results for the cases where there is no barrier film 103, where there is a barrier film 103 made of silicon oxide, where there is a barrier film 103 made of aluminum oxide, and where there is a barrier film 103 made of polysilicon.

[0053] 5, there is a slight difference in the concentration of deuterium contained in the silicon nitride film between the case where the barrier film 103 is present and the case where the barrier film 103 is not present, but this is considered to be within the range of variation. From this result, it is considered that deuterium passes through the barrier film 103 made of silicon oxide, aluminum oxide, or polysilicon and has almost no effect on the amount of deuterium introduced into the silicon nitride film.

[0054] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0055] 101 Substrate 102 Target membrane 103 Barrier Film 104 Deuterium

Claims

1. providing a substrate having a target film on its surface; forming a barrier film covering the target film; supplying deuterium gas and oxygen gas to the target film covered with the barrier film to inject deuterium into the target film; removing the barrier film after the target film is implanted with deuterium; A substrate processing method comprising:

2. the step of forming the barrier film, the step of implanting deuterium, and the step of removing the barrier film are performed in the same processing chamber; The substrate processing method according to claim 1 .

3. The step of implanting deuterium includes: placing the substrate in a processing chamber evacuated to 1 Torr or less; maintaining the substrate at a temperature of 300°C or greater but less than 900°C; supplying deuterium gas and oxygen gas into the processing chamber; Including, The substrate processing method according to claim 1 .

4. a ratio of the flow rate of the deuterium gas to the flow rate of the oxygen gas supplied into the processing chamber is 2 to 20 times; The substrate processing method according to claim 3 .

5. The barrier film is a film that allows a greater amount of deuterium to pass through than an amount of oxygen to pass through. The substrate processing method according to claim 1 .

6. the barrier film is formed of silicon oxide, aluminum oxide, or polysilicon; The substrate processing method according to claim 1 .

7. the barrier film is formed of silicon oxide, the step of removing the barrier film includes supplying hydrogen fluoride gas and ammonia gas to the substrate; The substrate processing method according to claim 1 .

8. The target film is a film containing silicon and nitrogen. The substrate processing method according to claim 1 .

9. The target film is a silicon nitride film or a silicon oxynitride film. The substrate processing method according to claim 8 .

10. A substrate processing apparatus including a processing vessel, a gas supply unit, and a control unit, The control unit placing a substrate having a target film on its surface in the processing chamber; forming a barrier film covering the target film in the processing chamber; supplying deuterium gas and oxygen gas into the processing chamber and injecting deuterium into the target film covered with the barrier film; removing the barrier film in the processing chamber after deuterium is implanted into the target film; configured to control the gas supply to perform Substrate processing equipment.

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