Substrate processing method and substrate processing apparatus

Abstract

To provide a technology capable of increasing the deuterium concentration in an insulating film.SOLUTION: A substrate processing method according to an embodiment of the present disclosure includes the steps of preparing a substrate having an insulating film on a surface thereof, heating the substrate from a first temperature to a second temperature higher than the first temperature, and maintaining the substrate at the second temperature, and the step of heating to the second temperature includes supplying at least one of deuterium gas and hydrogen gas to the substrate, and the step of maintaining at the second temperature includes supplying deuterium gas to the substrate.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] There is known a technique for incorporating deuterium at a ratio greater than the ratio of deuterium to hydrogen present in nature at the interface between a semiconductor substrate and a gate insulating film formed on the semiconductor substrate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-77621 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can increase the deuterium concentration in an insulating film. [Means for solving the problem]

[0005] A substrate processing method according to one embodiment of the present disclosure includes the steps of preparing a substrate having an insulating film on a surface thereof, heating the substrate from a first temperature to a second temperature higher than the first temperature, and maintaining the substrate at the second temperature, wherein the heating to the second temperature step includes supplying at least one of deuterium gas and hydrogen gas to the substrate, and the maintaining at the second temperature step includes supplying deuterium gas to the substrate. Effect of the Invention

[0006] According to the present disclosure, the deuterium concentration in the insulating film can be increased. [Brief description of the drawings]

[0007] [Figure 1]3 is a flowchart illustrating a substrate processing method according to the embodiment. [Diagram 2] 4 is a timing chart showing a first example of a substrate processing method according to the embodiment. [Diagram 3] 6 is a timing chart showing a second example of the substrate processing method according to the embodiment. [Figure 4] 10 is a timing chart showing a third example of a substrate processing method according to the embodiment. [Diagram 5] 10 is a timing chart showing a fourth example of a substrate processing method according to the embodiment. [Figure 6] 1 is a schematic cross-sectional view showing a substrate processing apparatus according to an embodiment. [Figure 7] FIG. 1 shows the results of measuring the deuterium concentration in a silicon nitride film (1). [Figure 8] FIG. 2 shows the results of measuring the deuterium concentration in a silicon nitride film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0009] [Substrate Processing Method] A substrate processing method according to an embodiment will be described with reference to Figs. 1 to 5. Fig. 1 is a flow chart showing the substrate processing method according to the embodiment. Fig. 2 is a timing chart showing a first example of the substrate processing method according to the embodiment. Fig. 3 is a timing chart showing a second example of the substrate processing method according to the embodiment. Fig. 4 is a timing chart showing a third example of the substrate processing method according to the embodiment. Fig. 5 is a timing chart showing a fourth example of the substrate processing method according to the embodiment. Figs. 2 to 5 show the temperature of the substrate, the pressure in the processing vessel, the supply and stop of deuterium (D2) gas, and the supply and stop of hydrogen (H2) gas in each step of the substrate processing method according to the embodiment.

[0010] As shown in FIG. 1, the substrate processing method according to the embodiment includes a preparation step S1, a pressure reduction step S2, a temperature increase step S3, a temperature maintaining step S4, a temperature decrease step S5, and a pressure increase step S6.

[0011] The preparation step S1 includes preparing a substrate having a silicon nitride film on its surface. The preparation step S1 includes accommodating the substrate in a processing vessel that can be depressurized by an exhaust device. The substrate is, for example, a semiconductor wafer. The silicon nitride film may contain hydrogen atoms (H) in the film. The silicon nitride film may contain NH bonds in the film.

[0012] The depressurization step S2 is performed after the preparation step S1. As shown in Fig. 2 to Fig. 5, the depressurization step S2 includes reducing the pressure in the processing vessel from a first pressure P1 to a second pressure P2. The first pressure P1 is, for example, atmospheric pressure. The second pressure P2 is, for example, a base pressure. The base pressure is, for example, the highest degree of vacuum that can be reached with the maximum exhaust capacity of an exhaust device.

[0013] The depressurization step S2 may include maintaining the substrate at a first temperature T1 as shown in FIG. 2 to FIG. 5. The first temperature T1 is, for example, 750° C. or less. In this case, it is easy to suppress the desorption of hydrogen atoms contained in the silicon nitride film. The first temperature T1 may be 650° C. or less. In this case, it is particularly easy to suppress the desorption of hydrogen atoms contained in the silicon nitride film. By suppressing the desorption of hydrogen atoms contained in the silicon nitride film, deuterium atoms are easily introduced in the temperature maintaining step S4. This is because it is considered that in the temperature maintaining step S4, hydrogen atoms contained in the silicon nitride film are replaced with deuterium atoms, thereby introducing deuterium atoms into the silicon nitride film.

[0014] The depressurization step S2 may include starting a supply of deuterium gas in the middle of the process and continuing to supply deuterium gas until the end of the process, as shown in Figures 2 and 4. The depressurization step S2 may include starting a supply of hydrogen gas in the middle of the process and continuing to supply hydrogen gas until the end of the process, as shown in Figures 3 and 5. The depressurization step S2 may include starting a supply of a mixed gas of deuterium gas and hydrogen gas in the middle of the process and continuing to supply the mixed gas until the end of the process. By supplying at least one of deuterium gas and hydrogen gas in the depressurization step S2, the pressure in the processing vessel is increased from the second pressure P2 to a third pressure P3.

[0015] The temperature increasing step S3 is performed after the pressure reducing step S2. The temperature increasing step S3 includes increasing the temperature of the substrate from a first temperature T1 to a second temperature T2, as shown in Figures 2 to 5. The second temperature T2 is a temperature higher than the first temperature T1.

[0016] The temperature increasing step S3 includes supplying deuterium gas to the substrate as shown in FIG. 2 and FIG. 4. In this case, deuterium atoms are introduced into the silicon nitride film. The temperature increasing step S3 may include supplying hydrogen gas to the substrate as shown in FIG. 3 and FIG. 5. In this case, desorption of hydrogen atoms contained in the silicon nitride film is suppressed. By suppressing desorption of hydrogen atoms contained in the silicon nitride film, deuterium atoms are easily introduced in the temperature maintaining step S4. This is because, in the temperature maintaining step S4, it is considered that hydrogen atoms contained in the silicon nitride film are replaced with deuterium atoms, so that deuterium atoms are introduced into the silicon nitride film. Since hydrogen gas is cheaper than deuterium gas, deuterium atoms can be introduced into the silicon nitride film at low cost. The temperature increasing step S3 may include supplying a mixed gas of deuterium gas and hydrogen gas to the substrate. In this case, deuterium atoms are introduced into the silicon nitride film and desorption of hydrogen atoms contained in the silicon nitride film is suppressed. In contrast, when neither deuterium gas nor hydrogen gas is supplied to the substrate in the temperature increasing step S3, hydrogen atoms contained in the silicon nitride film tend to be desorbed as the substrate temperature increases, making it difficult to introduce deuterium atoms into the silicon nitride film at a high concentration.

[0017] As shown in Figures 2 and 4, deuterium gas may be continuously supplied to the substrate before the start of the temperature increase step S3, in other words, from the depressurization step S2. In this case, it is easy to introduce deuterium atoms into the silicon nitride film at a high concentration. The supply of deuterium gas to the substrate may start from the start of the temperature increase step S3, or may start halfway through the temperature increase step S3. As shown in Figures 2 and 4, deuterium gas may be continuously supplied to the substrate throughout the entire period of the temperature increase step S3. In this case, it is easy to introduce deuterium atoms into the silicon nitride film at a high concentration.

[0018] As shown in Figures 3 and 5, hydrogen gas may be continuously supplied to the substrate before the start of the temperature increase step S3, in other words, from the depressurization step S2. In this case, it is easy to suppress the desorption of hydrogen atoms contained in the silicon nitride film. The supply of hydrogen gas to the substrate may start from the start of the temperature increase step S3, or may start halfway through the temperature increase step S3. As shown in Figures 3 and 5, hydrogen gas may be continuously supplied to the substrate throughout the entire period of the temperature increase step S3. In this case, it is particularly easy to suppress the desorption of hydrogen atoms contained in the silicon nitride film.

[0019] The temperature maintaining step S4 is performed after the temperature increasing step S3. The temperature maintaining step S4 includes maintaining the substrate at a second temperature T2, as shown in FIGS. 2 to 5. The temperature maintaining step S4 includes supplying deuterium gas to the substrate. In this case, hydrogen atoms contained in the silicon nitride film are replaced with deuterium atoms, thereby introducing deuterium atoms into the silicon nitride film. The deuterium gas may be continuously supplied to the substrate throughout the entire period of the temperature maintaining step S4, as shown in FIGS. 2 to 5. In this case, it is easy to introduce a high concentration of deuterium atoms into the silicon nitride film.

[0020] The second temperature T2 is, for example, 500° C. or higher. In this case, hydrogen atoms contained in the silicon nitride film are easily replaced by deuterium atoms. The second temperature T2 may be 800° C. or higher. In this case, hydrogen atoms contained in the silicon nitride film are particularly easily replaced by deuterium atoms. The second temperature T2 is, for example, 1000° C. or lower. In this case, desorption of deuterium atoms contained in the silicon nitride film is easily suppressed. The second temperature T2 may be 900° C. or lower. In this case, desorption of deuterium atoms contained in the silicon nitride film is particularly easily suppressed.

[0021] The temperature lowering step S5 is performed after the temperature maintaining step S4. The temperature lowering step S5 includes lowering the temperature of the substrate from the second temperature T2 to the first temperature T1, as shown in FIG. 2 to FIG. 5. The temperature lowering step S5 may include reducing the pressure in the processing vessel by an exhaust device without supplying deuterium gas and hydrogen gas to the substrate, as shown in FIG. 2 and FIG. 3. The temperature lowering step S5 may include supplying deuterium gas to the substrate, as shown in FIG. 4 and FIG. 5. In this case, it is easy to suppress the desorption of deuterium atoms contained in the silicon nitride film in the temperature lowering step S5. The deuterium gas may be continuously supplied to the substrate throughout the entire period of the temperature lowering step S5, as shown in FIG. 4 and FIG. 5. In this case, it is particularly easy to suppress the desorption of deuterium atoms contained in the silicon nitride film.

[0022] The pressure increasing step S6 is performed after the temperature decreasing step S5. As shown in Figures 2 to 5, the pressure increasing step S6 includes increasing the pressure in the processing vessel from the second pressure P2 to the first pressure P1. As shown in Figures 2 to 5, the pressure increasing step S6 includes increasing the pressure in the processing vessel from the second pressure P2 to the first pressure P1 by, for example, supplying an inert gas into the processing vessel without supplying deuterium gas and hydrogen gas to the substrate. After the pressure in the processing vessel is increased from the second pressure P2 to the first pressure P1, the substrate is unloaded from the processing vessel.

[0023] As described above, according to the substrate processing method of the embodiment, the temperature increasing step S3 and the temperature maintaining step S4 are performed in this order. The temperature increasing step S3 includes supplying at least one of deuterium gas and hydrogen gas to the substrate. The temperature maintaining step S4 includes supplying deuterium gas to the substrate. In this case, the deuterium concentration in the silicon nitride film can be increased. This is believed to be because the desorption of hydrogen atoms contained in the silicon nitride film is suppressed in the temperature increasing step S3, and the efficiency of replacing hydrogen atoms contained in the silicon nitride film with deuterium atoms is improved in the temperature maintaining step S4.

[0024] [Substrate Processing Apparatus] A substrate processing apparatus 1 according to an embodiment will be described with reference to Fig. 6. As shown in Fig. 6, 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.

[0025] The processing vessel 10 is formed in a cylindrical shape with a processing space 10a inside. The processing vessel 10 performs heat processing with a substrate W accommodated in the processing space 10a. The processing vessel 10 has a cylindrical tube body 11 having a substantially hemispherical ceiling portion and an open lower end, a manifold 12 connected to the lower end of the tube body 11, and a lid body 15 connected to the lower end of the manifold 12.

[0026] The cylindrical body 11 is made of a heat-resistant material such as quartz. The cylindrical body 11 extends long in the vertical direction (height direction) and constitutes most of the processing space 10a of the processing vessel 10. In Fig. 6, the processing vessel 10 has one cylindrical body 11, but is not limited thereto, and for example, the processing vessel 10 may have a multi-layer structure in which multiple cylinders (outer cylinder, inner cylinder) are stacked concentrically.

[0027] Manifold 12 and lid 15 are formed of, for example, stainless steel. Manifold 12 has a flange portion 13 at its upper end, and flange portion 13 supports the lower end of cylindrical body 11. The lower end of cylindrical body 11 and flange portion 13 are airtightly connected via a seal member 14 such as an O-ring. Similarly, the lower end of manifold 12 and lid 15 are in airtight contact with each other via a seal member 16 such as an O-ring.

[0028] A rotating shaft 18 passes through 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 rotary drive unit 19. The rotating shaft 18 rotates relative to the processing vessel 10 by the rotation of the rotary drive unit 19. This causes the boat 20 to rotate.

[0029] The lower part of the rotating shaft 18 is rotatably supported by an arm 22 of a lifting 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 retention stand 24. Therefore, the lid 15 and the boat 20 move up and down together by raising and lowering the lifting mechanism 21, so that the boat 20 can be inserted into and removed from the cylindrical main body 11.

[0030] The boat 20 is a substrate holder that extends in the vertical direction (height direction) within the processing vessel 10 and holds a plurality of substrates W at predetermined intervals along the vertical direction. Each substrate W is placed on the boat 20 after it has been removed from the processing vessel 10 by the lowering of the lifting mechanism 21. After each substrate W is placed on the boat 20, the lifting mechanism 21 raises the boat 20 to insert it into the processing vessel 10.

[0031] The gas supply unit 30 is configured to be able to introduce various process gases used in the above-mentioned substrate processing method into the processing space 10a. The gas supply unit 30 includes a deuterium supply unit 31, a hydrogen supply unit 32, and an inert gas supply unit 33.

[0032] 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. A deuterium source 313, a mass flow controller 314, and a deuterium valve 315 are installed in the deuterium supply path 312, in this order from upstream to downstream in the gas flow direction. Thus, the supply timing of the 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.

[0033] The hydrogen supply unit 32 includes a hydrogen supply pipe 321 inside the processing vessel 10, and a hydrogen supply path 322 outside the processing vessel 10. A hydrogen source 323, a mass flow controller 324, and a hydrogen valve 325 are provided in the hydrogen supply path 322, in this order from upstream to downstream in the gas flow direction. Thus, the supply timing of hydrogen gas from the hydrogen source 323 is controlled by the hydrogen valve 325, and the flow rate is adjusted to a predetermined value by the mass flow controller 324. The hydrogen gas flows from the hydrogen supply path 322 into the hydrogen supply pipe 321, and is discharged from the hydrogen supply pipe 321 into the processing vessel 10.

[0034] The inert gas supply unit 33 includes an inert gas supply pipe 331 in 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. The inert gas is, for example, argon gas. The inert gas may be nitrogen gas.

[0035] Each gas supply pipe (deuterium supply pipe 311, hydrogen supply pipe 321, inert gas supply pipe 331) is made of, for example, quartz. Each gas supply pipe is fixed to the cylindrical body 11 or the manifold 12. Each gas supply pipe extends linearly in the vertical direction near the cylindrical body 11, and is bent in an L-shape within the manifold 12 to extend horizontally, thereby penetrating the manifold 12. Each gas supply pipe is provided next to each other in the circumferential direction of the cylindrical body 11, and is formed at the same height as each other.

[0036] 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 hydrogen outlets 326 are provided in the hydrogen 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.

[0037] The outlets (deuterium outlet 316, hydrogen outlet 326, inert gas outlet 336) 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 the midpoint between the substrates W adjacent in the vertical direction. This allows each outlet to efficiently supply gas to the opposing surfaces between the adjacent substrates W.

[0038] The gas supply unit 30 may mix a plurality of types of gases and discharge the mixed gas from one supply pipe. The gas supply pipes (deuterium supply pipe 311, hydrogen supply pipe 321, inert gas supply pipe 331) may have different shapes and arrangements. The gas supply unit 30 may be configured to be able to supply other gases in addition to deuterium gas, hydrogen gas, and inert gas.

[0039] The exhaust unit 40 is provided at an exhaust port 41 formed on a side wall of an upper portion 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 upstream to downstream 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 in the processing vessel 10 by the pressure adjustment valve 43 while the vacuum pump 44 sucks the gas in the processing vessel 10.

[0040] 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.

[0041] The control unit 60 may be a computer having one or more processors 61, a memory 62, an input / output interface (not shown), and an electronic circuit. The processor 61 is a combination of one or more of a CPU, an ASIC, an FPGA, a circuit made of a plurality of discrete semiconductors, and the like. 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 above-mentioned substrate processing method.

[0042] [Operation of the Substrate Processing Apparatus] An operation of the substrate processing apparatus 1 when carrying out the substrate processing method according to the embodiment will be described. In the following, an example will be described in which the control unit 60 executes the process shown in Fig. 2. The control unit 60 can execute the processes shown in Figs. 3 to 5 in the same manner as the process shown in Fig. 2.

[0043] First, the control unit 60 controls the lifting mechanism 21 to load the boat 20 holding the multiple substrates W into the processing vessel 10, and air-tightly closes and seals the opening at the bottom of the processing vessel 10 with the lid 15. Each substrate W has a silicon nitride film on its surface.

[0044] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform a depressurization step S2. Specifically, the control unit 60 controls the exhaust unit 40 to reduce the pressure in the processing vessel 10 from a first pressure P1 to a second pressure P2. The control unit 60 controls the heating unit 50 to maintain the substrate W at a first temperature T1. The control unit 60 controls the gas supply unit 30 to start supplying deuterium gas into the processing vessel 10. As a result, the pressure in the processing vessel 10 is increased from the second pressure P2 to a third pressure P3.

[0045] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform a temperature increase step S3. Specifically, the control unit 60 controls the heating unit 50 to increase the temperature of the substrate W from the first temperature T1 to a second temperature T2. The control unit 60 controls the gas supply unit 30 to continue supplying deuterium gas into the processing vessel 10, while controlling the exhaust unit 40 to maintain the pressure inside the processing vessel 10 at a third pressure P3.

[0046] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform a temperature maintaining step S4. Specifically, the control unit 60 controls the heating unit 50 to maintain the temperature of the substrate W at the second temperature T2. The control unit 60 controls the gas supply unit 30 to continue supplying deuterium gas into the processing vessel 10, while controlling the exhaust unit 40 to maintain the pressure in the processing vessel 10 at a third pressure P3. After a predetermined time has elapsed, the control unit 60 controls the gas supply unit 30 to stop supplying deuterium gas into the processing vessel 10.

[0047] Next, the control unit 60 controls the exhaust unit 40 and the heating unit 50 to perform a temperature decreasing process S5. Specifically, the control unit 60 controls the heating unit 50 to decrease the temperature of the substrate W from the second temperature T2 to the first temperature T1. The control unit 60 controls the exhaust unit 40 to decrease the pressure in the processing vessel 10 from the third pressure P3 to the second pressure P2.

[0048] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform a pressure increase step S6. Specifically, the control unit 60 controls the gas supply unit 30 to supply an inert gas into the processing vessel 10, and controls the exhaust unit 40 to stop exhausting the processing vessel 10. As a result, the pressure in the processing vessel 10 is increased from the second pressure P2 to the first pressure P1. The control unit 60 controls the heating unit 50 to maintain the temperature of the substrate W at the first temperature T1.

[0049] Next, the control unit 60 lowers the temperature of the substrates W to the unloading temperature, and then controls the lifting mechanism 21 to unload the boat 20 from the processing vessel 10. In this manner, the processing of the substrates W held in the boat 20 is completed.

[0050] [Example] An example will be described in which it was confirmed that the deuterium concentration in a silicon nitride film can be increased by the substrate processing method according to the embodiment.

[0051] In the embodiment, a substrate having a silicon nitride film on its surface was prepared, and the prepared substrate was accommodated in the processing vessel 10 of the above-described substrate processing apparatus 1, and deuterium atoms were introduced into the silicon nitride film under the following conditions A to F. Next, the deuterium concentration in the silicon nitride film was measured by secondary ion mass spectrometry (SIMS).

[0052] (Condition A) In condition A, the depressurization step S2, the temperature increase step S3, the temperature maintenance step S4, the temperature decrease step S5, and the pressure increase step S6 were performed on the prepared substrate in this order. In the depressurization step S2, the temperature of the substrate was maintained at 600° C., deuterium gas and hydrogen gas were not supplied into the processing vessel 10, and the pressure in the processing vessel 10 was reduced from atmospheric pressure to the base pressure. In the temperature increase step S3, the temperature of the substrate was increased from 600° C. to 800° C., deuterium gas and hydrogen gas were not supplied into the processing vessel 10, and the pressure in the processing vessel 10 was reduced from the base pressure to 12 kPa (90 Torr). In the temperature maintenance step S4, the temperature of the substrate was maintained at 800° C., deuterium gas was continuously supplied into the processing vessel 10 throughout the entire process, and the pressure in the processing vessel 10 was maintained at 12 kPa. In the temperature decreasing step S5, the temperature of the substrate was decreased from 800° C. to 600° C., and the pressure in the processing vessel 10 was reduced from 12 kPa to the base pressure without supplying deuterium gas and hydrogen gas into the processing vessel 10. In the pressure increasing step S6, the temperature of the substrate was maintained at 600° C., and an inert gas was supplied into the processing vessel 10, and the pressure in the processing vessel 10 was increased from the base pressure to atmospheric pressure.

[0053] (Condition B) In condition B, hydrogen gas was continuously supplied into the processing vessel 10 throughout the entire period of the temperature increasing step S3. The other conditions were the same as those in condition A.

[0054] (Condition C) In condition C, deuterium gas was continuously supplied into the processing vessel 10 throughout the entire period of the temperature increasing step S3. The other conditions were the same as those in condition A.

[0055] (Condition D) In condition D, deuterium gas was continuously supplied into the processing vessel 10 throughout the entire period of the temperature decreasing step S5. The other conditions were the same as those in condition A.

[0056] (Condition E) In condition E, hydrogen gas was continuously supplied into the processing vessel 10 throughout the entire period of the temperature increasing step S3, and deuterium gas was continuously supplied into the processing vessel 10 throughout the entire period of the temperature decreasing step S5. The other conditions were the same as those of condition A.

[0057] (Condition F) In condition F, deuterium gas was continuously supplied into the processing vessel 10 throughout the entire period of the temperature increasing step S3, and deuterium gas was continuously supplied into the processing vessel 10 throughout the entire period of the temperature decreasing step S5. The other conditions were the same as those of condition A.

[0058] 7 and 8 are diagrams showing the results of measuring the deuterium concentration in silicon nitride films. Fig. 7 shows the deuterium concentration in silicon nitride films into which deuterium atoms have been introduced under conditions A, B, and C. Fig. 8 shows the deuterium concentration in silicon nitride films into which deuterium atoms have been introduced under conditions D, E, and F.

[0059] 7, the left, center, and right graphs respectively show the deuterium concentrations in silicon nitride films into which deuterium atoms have been introduced under condition A, condition B, and condition C. In Fig. 7, the deuterium concentrations in the silicon nitride films into which deuterium atoms have been introduced under condition A, condition B, and condition C are shown as ratios to the deuterium concentration in the silicon nitride film into which deuterium atoms have been introduced under condition A.

[0060] In Fig. 8, the left, center, and right graphs respectively show the deuterium concentrations in silicon nitride films into which deuterium atoms have been introduced under conditions D, E, and F. In Fig. 8, the deuterium concentrations in the silicon nitride films into which deuterium atoms have been introduced under conditions D, E, and F are shown as ratios to the deuterium concentration in a silicon nitride film into which deuterium atoms have been introduced under condition D.

[0061] 7, it can be seen that the deuterium concentration in the silicon nitride film under conditions B and C is about 20% higher than that under condition A. This result shows that the deuterium concentration in the silicon nitride film can be increased by supplying hydrogen gas or deuterium gas into the processing vessel 10 in the temperature rise step S3.

[0062] 8, it can be seen that the deuterium concentration in the silicon nitride film under condition E is about 20% higher than that under condition D, and the deuterium concentration in the silicon nitride film under condition F is about 40% higher than that under condition D. This result shows that the deuterium concentration in the silicon nitride film can be increased by supplying hydrogen gas or deuterium gas into the processing vessel 10 in the temperature increasing step S3. In particular, when deuterium gas is continuously supplied into the processing vessel 10 throughout the entire period of the temperature decreasing step S5, it was shown that the deuterium concentration in the silicon nitride film can be increased by supplying deuterium gas into the processing vessel 10 in the temperature increasing step S3 compared to supplying hydrogen gas.

[0063] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0064] In the above embodiment, the insulating film is a silicon nitride film, but the present disclosure is not limited thereto. The insulating film may be a film constituting at least a part of a charge storage layer used in a memory cell. The insulating film may be a silicon oxide film or a silicon oxynitride film. The insulating film may contain hydrogen atoms therein. When the insulating film is a silicon oxide film, the insulating film may contain OH bonds. When the insulating film is a silicon oxynitride film, the insulating film may contain NH bonds and OH bonds.

[0065] In the above embodiment, the substrate processing apparatus is a batch type apparatus that processes a plurality of substrates at once, but the present disclosure is not limited to this. For example, the substrate processing apparatus may be a single-wafer type apparatus that processes substrates one by one. [Explanation of symbols]

[0066] S1 Preparation process S3 Heating process S4 Temperature maintenance process

Claims

1. preparing a substrate having an insulating film on a surface thereof; raising the temperature of the substrate from a first temperature to a second temperature higher than the first temperature; maintaining the substrate at the second temperature; having The step of increasing the temperature to the second temperature includes supplying at least one of deuterium gas and hydrogen gas to the substrate; maintaining the substrate at the second temperature includes supplying deuterium gas to the substrate; A method for processing a substrate.

2. The at least one gas is continuously supplied throughout the entire period of the step of increasing the temperature to the second temperature. The method for processing a substrate according to claim 1 .

3. The at least one gas is continuously supplied before the step of increasing the temperature to the second temperature is started. The substrate processing method according to claim 2 .

4. The deuterium gas is continuously supplied throughout the entire period of the step of maintaining the second temperature. The method for processing a substrate according to claim 1 .

5. The method further comprises the step of decreasing the temperature of the substrate from the second temperature to the first temperature, The step of lowering the temperature to the first temperature includes supplying deuterium gas to the substrate. The method of claim 1 .

6. The deuterium gas is continuously supplied throughout the entire period of the step of decreasing the temperature to the first temperature. The substrate processing method according to claim 5 .

7. the at least one gas is deuterium gas; The substrate processing method according to claim 1 .

8. The at least one gas is hydrogen gas. The substrate processing method according to claim 1 .

9. The at least one gas is a mixture of deuterium gas and hydrogen gas. The substrate processing method according to claim 1 .

10. The insulating film is a silicon nitride film. The substrate processing method according to claim 1 .

11. a processing vessel for accommodating a substrate having an insulating film on its surface; a gas supply unit for supplying a gas into the processing chamber; a heating unit that heats the substrate accommodated in the processing vessel; A control unit; Equipped with The control unit is heating the substrate in the processing chamber from a first temperature to a second temperature higher than the first temperature; maintaining the substrate at the second temperature in the processing chamber; and controlling the heating unit to perform the steps of: the control unit is configured to control the gas supply unit to supply at least one of deuterium gas and hydrogen gas to the substrate in the step of increasing the temperature to the second temperature; The control unit is configured to control the gas supply unit to supply deuterium gas to the substrate in the step of maintaining the substrate at the second temperature. Substrate processing equipment.

Images