Substrate processing method and substrate processing apparatus

Abstract

The invention provides a substrate processing method and a substrate processing apparatus, and provides a technology capable of improving deuterium concentration in an insulating film. A substrate processing method according to one embodiment of the present disclosure includes: 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; and maintaining the substrate at the second temperature, in which the step of raising the temperature to the second temperature includes supplying deuterium gas and / or hydrogen gas to the substrate, and the step of maintaining the temperature to the second temperature includes supplying deuterium gas to the substrate.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method and a substrate processing device. Background Art

[0002] There is known a technique for causing an interface between a semiconductor substrate and a gate insulating film formed on the semiconductor substrate to contain deuterium at a ratio greater than the ratio of deuterium to hydrogen existing in nature (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-77621 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The present disclosure provides a technology capable of increasing the deuterium concentration in an insulating film.

[0008] Solutions for solving problems

[0009] A substrate processing method according to one embodiment of the present invention includes the following steps: preparing a substrate having an insulating film on its surface; 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 step of heating the substrate to the second temperature includes supplying at least one of deuterium gas and hydrogen gas to the substrate, and the step of maintaining the substrate at the second temperature includes supplying deuterium gas to the substrate.

[0010] Effects of the Invention

[0011] According to the present disclosure, the deuterium concentration in the insulating film can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 1 is a flowchart showing a substrate processing method according to an embodiment.

[0013] Figure 2 It is a timing chart showing a first example of the substrate processing method according to the embodiment.

[0014] Figure 3 It is a timing chart showing a second example of the substrate processing method according to the embodiment.

[0015] Figure 4 It is a timing chart showing a third example of the substrate processing method according to the embodiment.

[0016] Figure 5 It is a timing chart showing a fourth example of the substrate processing method according to the embodiment.

[0017] Figure 6 It is a schematic cross-sectional view showing a substrate processing apparatus according to an embodiment.

[0018] Figure 7 FIG. (1) shows the results of measuring the deuterium concentration in the silicon nitride film.

[0019] Figure 8 FIG. (2) shows the results of measuring the deuterium concentration in the silicon nitride film. DETAILED DESCRIPTION

[0020] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the attached drawings. In all the attached drawings, the same or corresponding components or parts are marked with the same or corresponding reference numerals, and repeated descriptions are omitted.

[0021] 〔Substrate processing method〕

[0022] Reference Figures 1 to 5 A substrate processing method according to an embodiment will be described. Figure 1 1 is a flowchart showing a substrate processing method according to an embodiment. Figure 2 It is a timing chart showing a first example of the substrate processing method according to the embodiment. Figure 3 It is a timing chart showing a second example of the substrate processing method according to the embodiment. Figure 4 It is a timing chart showing a third example of the substrate processing method according to the embodiment. Figure 5 1 is a timing chart showing a fourth example of the substrate processing method according to the embodiment. Figures 2 to 5 , the temperature of the substrate, the pressure in the processing container, the supply and stop of deuterium (D 2 ) gas, and the supply and stop of hydrogen (H 2 ) gas in each step of the substrate processing method involved in the embodiment are shown.

[0023] like Figure 1 As shown, the substrate processing method according to the embodiment includes a preparation step S1 , a decompression step S2 , a temperature increasing step S3 , a temperature maintaining step S4 , a temperature decreasing step S5 , and a pressure increasing step S6 .

[0024] The preparation step S1 includes preparing a substrate having a silicon nitride film on the surface. The preparation step S1 includes accommodating the substrate in a processing container 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.

[0025] The decompression step S2 is performed after the preparation step S1. Figures 2 to 5As shown, the pressure in the processing container is reduced 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 vacuum degree that can be achieved by the maximum exhaust capacity of the exhaust device.

[0026] The decompression step S2 can be performed as follows Figures 2 to 5 As shown, the substrate is maintained at a first temperature T1. The first temperature T1 is, for example, below 750°C. In this case, it is easy to suppress the separation of hydrogen atoms contained in the silicon nitride film. The first temperature T1 may also be below 650°C. In this case, it is particularly easy to suppress the separation of hydrogen atoms contained in the silicon nitride film. By suppressing the separation of hydrogen atoms contained in the silicon nitride film, it is easy to introduce deuterium atoms in the temperature maintenance step S4. This is because it can be considered that in the temperature maintenance step S4, the hydrogen atoms contained in the silicon nitride film are replaced by deuterium atoms, thereby introducing the deuterium atoms into the silicon nitride film.

[0027] The decompression step S2 can be performed as follows Figure 2 and Figure 4 As shown in FIG. 1 , the deuterium gas supply may be started from the middle of the process and continued until the end of the process. The decompression step S2 may also be performed as follows: Figure 3 and Figure 5 As shown in the figure, the supply of hydrogen gas is started from the middle of the process and the hydrogen gas is continuously supplied until the end of the process. The decompression step S2 may also include starting the supply of a mixed gas of deuterium gas and hydrogen gas from the middle of the process and the mixed gas is continuously supplied until the end of the process. By supplying at least one gas of deuterium gas and hydrogen gas in the decompression step S2, the pressure in the processing container is increased from the second pressure P2 to the third pressure P3.

[0028] The heating step S3 is performed after the decompression step S2. Figures 2 to 5 As shown, the substrate is heated from a first temperature T1 to a second temperature T2. The second temperature T2 is a temperature higher than the first temperature T1.

[0029] The heating process S3 is as follows Figure 2 and Figure 4 The heating step S3 may include supplying deuterium gas to the substrate as shown. In this case, deuterium atoms are introduced into the silicon nitride film. Figure 3 and Figure 5As shown, the process includes supplying hydrogen to the substrate. In this case, the separation of hydrogen atoms contained in the silicon nitride film is suppressed. By suppressing the separation of hydrogen atoms contained in the silicon nitride film, it is easy to introduce deuterium atoms in the temperature maintenance process S4. This is because it can be considered that in the temperature maintenance process S4, the hydrogen atoms contained in the silicon nitride film are replaced by deuterium atoms, thereby the deuterium atoms are introduced into the silicon nitride film. Hydrogen is cheaper than deuterium, so deuterium atoms can be introduced into the silicon nitride film at a low cost. The heating process S3 may also include supplying a mixed gas of deuterium and hydrogen to the substrate. In this case, deuterium atoms are introduced into the silicon nitride film and the separation of hydrogen atoms contained in the silicon nitride film is suppressed. In contrast, in the case where neither deuterium nor hydrogen is supplied to the substrate in the heating process S3, the hydrogen atoms contained in the silicon nitride film become easy to separate as the temperature of the substrate rises. Therefore, it is difficult to introduce deuterium atoms into the silicon nitride film at a high concentration.

[0030] Deuterium can also be Figure 2 and Figure 4 As shown in FIG. 1 , deuterium gas is continuously supplied to the substrate before the start of the heating step S3, in other words, from the decompression step S2. In this case, it is easy to introduce deuterium atoms into the silicon nitride film at a high concentration. Deuterium gas can be supplied to the substrate from the start time of the heating step S3 or from the middle of the heating step S3. Deuterium gas can also be supplied to the substrate as shown in FIG. Figure 2 and Figure 4 As shown in FIG. 1 , deuterium atoms are continuously supplied to the substrate during the entire period of the temperature raising step S3. In this case, deuterium atoms are easily introduced into the silicon nitride film at a high concentration.

[0031] Hydrogen can also be Figure 3 and Figure 5 As shown in FIG. 1 , hydrogen gas is continuously supplied to the substrate before the start of the heating step S3, in other words, from the decompression step S2. In this case, it is easy to suppress the separation of hydrogen atoms contained in the silicon nitride film. Hydrogen gas can be supplied to the substrate from the start time of the heating step S3 or from the middle of the heating step S3. Hydrogen gas can also be supplied to the substrate as shown in FIG. Figure 3 and Figure 5 As shown in FIG. 1 , hydrogen atoms are continuously supplied to the substrate during the entire period of the temperature raising step S3. In this case, it is particularly easy to suppress the release of hydrogen atoms contained in the silicon nitride film.

[0032] The temperature maintenance step S4 is performed after the temperature raising step S3. Figures 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 the deuterium atoms into the silicon nitride film. The deuterium gas may also be supplied as shown in FIG. Figures 2 to 5As shown in FIG. 1 , deuterium atoms are continuously supplied to the substrate during the entire period of the temperature maintaining step S4. In this case, deuterium atoms are easily introduced into the silicon nitride film at a high concentration.

[0033] The second temperature T2 is, for example, above 500°C. In this case, it is easy for hydrogen atoms contained in the silicon nitride film to be replaced by deuterium atoms. The second temperature T2 may also be above 800°C. In this case, it is particularly easy for hydrogen atoms contained in the silicon nitride film to be replaced by deuterium atoms. The second temperature T2 is, for example, below 1000°C. In this case, it is easy to suppress the separation of deuterium atoms contained in the silicon nitride film. The second temperature T2 may also be below 900°C. In this case, it is particularly easy to suppress the separation of deuterium atoms contained in the silicon nitride film.

[0034] The cooling process S5 is performed after the temperature maintaining process S4. Figures 2 to 5 As shown in FIG. 1 , the substrate is cooled from the second temperature T2 to the first temperature T1. The cooling step S5 may be as follows: Figure 2 and Figure 3 As shown, the process includes not supplying deuterium and hydrogen to the substrate and reducing the pressure in the processing container by means of an exhaust device. The temperature reduction step S5 may be as follows. Figure 4 and Figure 5 In this case, it is easy to suppress the release of deuterium atoms contained in the silicon nitride film in the temperature reduction step S5. The deuterium gas can also be supplied to the substrate as shown. Figure 4 and Figure 5 As shown in FIG. 1 , deuterium is continuously supplied to the substrate during the entire period of the temperature drop step S5. In this case, it is particularly easy to suppress the release of deuterium atoms contained in the silicon nitride film.

[0035] The pressure increasing step S6 is performed after the temperature decreasing step S5. Figures 2 to 5 As shown in FIG. 1 , the pressure in the processing container is increased from the second pressure P2 to the first pressure P1. The pressure increasing step S6 is as shown in FIG. Figures 2 to 5 As shown, deuterium gas and hydrogen gas are not supplied to the substrate, and the pressure in the processing container is increased from the second pressure P2 to the first pressure P1 by, for example, supplying an inert gas into the processing container. After the pressure in the processing container is increased from the second pressure P2 to the first pressure P1, the substrate is removed from the processing container.

[0036] As described above, according to the substrate processing method involved in the embodiment, the temperature raising step S3 and the temperature maintaining step S4 are sequentially performed. The temperature raising step S3 includes supplying at least one gas 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. It can be considered that this is because the separation of hydrogen atoms contained in the silicon nitride film is suppressed in the temperature raising step S3, and the replacement efficiency of hydrogen atoms contained in the silicon nitride film to deuterium atoms is improved in the temperature maintaining step S4.

[0037] 〔Substrate processing equipment〕

[0038] Reference Figure 6 The substrate processing apparatus 1 according to the embodiment will be described. Figure 6 As shown, the substrate processing apparatus 1 includes a processing container 10 , a wafer boat 20 , a gas supply unit 30 , an exhaust unit 40 , a heating unit 50 , and a control unit 60 .

[0039] The processing container 10 is formed in a cylindrical shape having a processing space 10a therein. The processing container 10 performs heat treatment in a state where the substrate W is accommodated in the processing space 10a. The processing container 10 includes a barrel body 11, a manifold 12 connected to the lower end of the barrel body 11, and a cover 15 connected to the lower end of the manifold 12. The barrel body 11 is a cylindrical shape having a substantially hemispherical top and an open lower end.

[0040] The barrel body 11 is formed of a heat-resistant material such as quartz. The barrel body 11 extends long in the vertical direction (height direction) and constitutes most of the processing space 10a of the processing container 10. Figure 6 2 shows a structure in which the processing container 10 has a single cylinder body 11, but the present invention is not limited thereto. For example, the processing container 10 may have a multi-layer structure in which a plurality of cylinders (outer cylinder, inner cylinder) are overlapped in a concentric circle.

[0041] The manifold 12 and the cover 15 are formed of, for example, stainless steel. The manifold 12 has a flange 13 at the upper end, and the flange 13 supports the lower end of the cylinder body 11. The lower end of the cylinder body 11 and the flange 13 are airtightly connected via a sealing member 14 such as an O-ring. Similarly, the lower end of the manifold 12 and the cover 15 are in airtight contact via a sealing member 16 such as an O-ring.

[0042] The rotating shaft 18 passes through the center of the cover 15 via a magnetic fluid seal 17. The rotating shaft 18 has a wafer boat 20 on the top and is connected to a rotation drive unit 19. The rotating shaft 18 rotates relative to the processing container 10 by the rotation of the rotation drive unit 19. Thus, the wafer boat 20 rotates.

[0043] The lower part of the rotating shaft 18 is rotatably supported by an arm 22 of a lifting mechanism 21 such as a wafer boat lift. A rotating plate 23 is provided at the upper end of the rotating shaft 18, and the wafer boat 20 is placed on the rotating plate 23 via a quartz heat-insulating table 24. Therefore, the cover 15 and the wafer boat 20 can be moved up and down integrally by raising and lowering the lifting mechanism 21, so that the wafer boat 20 can be accommodated in the barrel body 11 and detached from the barrel body 11.

[0044] The wafer boat 20 is a substrate holder that extends in the vertical direction (height direction) in the processing container 10 and holds a plurality of substrates W at predetermined intervals in the vertical direction. The wafer boat 20 places each substrate W in a state where it is separated from the processing container 10 by the descent of the elevating mechanism 21. After placing each substrate W, the wafer boat 20 is inserted into the processing container 10 by the ascent of the elevating mechanism 21.

[0045] The gas supply unit 30 is configured to be able to introduce various processing gases used in the above-mentioned substrate processing method into the processing space 10 a . The gas supply unit 30 includes a deuterium supply unit 31 , a hydrogen supply unit 32 , and an inert gas supply unit 33 .

[0046] The deuterium supply unit 31 includes a deuterium supply pipe 311 in the processing container 10 and a deuterium supply path 312 outside the processing container 10. In the deuterium supply path 312, a deuterium source 313, a mass flow controller 314, and a deuterium valve 315 are sequentially arranged from upstream to downstream in the flow direction of the gas. Thus, the deuterium gas from the deuterium source 313 is controlled in supply timing by the deuterium valve 315, and is adjusted to a predetermined flow rate by the mass flow controller 314. The deuterium gas flows from the deuterium supply path 312 into the deuterium supply pipe 311, and is ejected from the deuterium supply pipe 311 into the processing container 10.

[0047] The hydrogen supply unit 32 includes a hydrogen supply pipe 321 in the processing container 10 and a hydrogen supply path 322 outside the processing container 10. In the hydrogen supply path 322, a hydrogen source 323, a mass flow controller 324, and a hydrogen valve 325 are sequentially arranged from upstream to downstream in the flow direction of the gas. Thus, the supply timing of hydrogen gas from the hydrogen source 323 is controlled by the hydrogen valve 325, and the mass flow controller 324 is adjusted to a predetermined flow rate. Hydrogen gas flows from the hydrogen supply path 322 into the hydrogen supply pipe 321, and is ejected from the hydrogen supply pipe 321 into the processing container 10.

[0048] The inert gas supply unit 33 includes an inert gas supply pipe 331 in the processing container 10 and an inert gas supply path 332 outside the processing container 10. In the inert gas supply path 332, an inert gas source 333, a mass flow controller 334, and an inert gas valve 335 are sequentially arranged from upstream to downstream in the flow direction of the gas. Thus, the supply timing of the inert gas of the inert gas source 333 is controlled by the inert gas valve 335, and the mass flow controller 334 is adjusted to a predetermined flow rate. The inert gas flows from the inert gas supply path 332 to the inert gas supply pipe 331, and is ejected from the inert gas supply pipe 331 into the processing container 10. The inert gas is, for example, argon gas. The inert gas may also be nitrogen gas.

[0049] Each gas supply pipe (deuterium supply pipe 311, hydrogen supply pipe 321, inert gas supply pipe 331) is formed of quartz, for example. Each gas supply pipe is fixed to the barrel body 11 or the manifold 12. Each gas supply pipe extends linearly in the vicinity of the barrel body 11 along the vertical direction, and is bent in an L-shape in the manifold 12 and extends in the horizontal direction, thereby penetrating the manifold 12. Each gas supply pipe is arranged along the circumferential direction of the barrel body 11 and is formed at the same height as each other.

[0050] The deuterium supply pipe 311 is provided with a plurality of deuterium ejection ports 316 at the location of the cartridge body 11. The hydrogen supply pipe 321 is provided with a plurality of hydrogen ejection ports 326 at the location of the cartridge body 11. The inert gas supply pipe 331 is provided with a plurality of inert gas ejection ports 336 at the location of the cartridge body 11.

[0051] Each of the ejection ports (deuterium ejection port 316, hydrogen ejection port 326, inert gas ejection port 336) is formed at predetermined intervals along the extension direction of each gas supply pipe. Each ejection port discharges gas in a horizontal direction. The interval between each of the ejection ports is set to be the same as the interval between substrates W held on the wafer boat 20, for example. The position of each ejection port in the height direction is set at the middle position between adjacent substrates W in the vertical direction. Thus, each ejection port can efficiently supply gas to the facing surfaces between adjacent substrates W.

[0052] The gas supply unit 30 may also mix a plurality of types of gases and eject 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 also be of different shapes and configurations. The gas supply unit 30 may also be configured to supply other gases in addition to deuterium gas, hydrogen gas, and inert gas.

[0053] The exhaust unit 40 is provided at an exhaust port 41 formed on the side wall of the upper portion of the manifold 12. The exhaust unit 40 has an exhaust path 42 connected to the exhaust port 41. In the exhaust path 42, a pressure regulating valve 43 and a vacuum pump 44 are provided in order from upstream to downstream in the flow direction of the gas. The exhaust unit 40 operates the pressure regulating valve 43 and the vacuum pump 44 based on the control of the control unit 60, and the vacuum pump 44 sucks the gas in the processing container 10 while the pressure regulating valve 43 adjusts the pressure in the processing container 10.

[0054] The heating unit 50 includes a cylindrical heater 51 surrounding the barrel body 11 on the radially outer side of the barrel body 11. The heater 51 heats the entire circumference of the processing container 10 to heat each substrate W accommodated in the processing container 10.

[0055] The control unit 60 can be applied to 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 composed of a plurality of discrete semiconductors, etc. The memory 62 includes a volatile memory, a non-volatile memory (such as a CD, a DVD, a hard disk, a floppy disk, etc.), and the memory 62 stores a program for operating the substrate processing device 1, a process condition for substrate processing, and other processes. The processor 61 controls the various structures of the substrate processing device 1 to implement the above-mentioned substrate processing method by executing the program and process stored in the memory 62.

[0056] [Operation of substrate processing apparatus]

[0057] The operation of the substrate processing method according to the embodiment is described below. Figure 2 The control unit 60 can be executed with the execution Figure 2 The processing shown is performed in the same way Figures 3 to 5 Processing shown.

[0058] First, the control unit 60 controls the lifting mechanism 21 to load the wafer boat 20 holding a plurality of substrates W into the processing container 10, and seals the lower opening of the processing container 10 by airtightly plugging it with the cover 15. Each substrate W has a silicon nitride film on its surface.

[0059] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform the decompression step S2. Specifically, the control unit 60 controls the exhaust unit 40 to reduce the pressure in the processing container 10 from the first pressure P1 to the second pressure P2. The control unit 60 controls the heating unit 50 to maintain the substrate W at the first temperature T1. The control unit 60 controls the gas supply unit 30 to start supplying deuterium gas into the processing container 10. As a result, the pressure in the processing container 10 is increased from the second pressure P2 to the third pressure P3.

[0060] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform the temperature raising step S3. Specifically, the control unit 60 controls the heating unit 50 to raise the temperature of the substrate W from the first temperature T1 to the second temperature T2. The control unit 60 controls the gas supply unit 30 to continue to supply the deuterium gas into the processing container 10, and controls the exhaust unit 40 to maintain the pressure in the processing container 10 at the third pressure P3.

[0061] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform the temperature maintenance 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 the deuterium gas into the processing container 10, and controls the exhaust unit 40 to maintain the pressure in the processing container 10 at the third pressure P3. After a predetermined time has passed, the control unit 60 controls the gas supply unit 30 to stop supplying the deuterium gas into the processing container 10.

[0062] Next, the control unit 60 controls the exhaust unit 40 and the heating unit 50 to perform the temperature reduction step S5. Specifically, the control unit 60 controls the heating unit 50 to reduce 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 reduce the pressure in the processing container 10 from the third pressure P3 to the second pressure P2.

[0063] Next, the control unit 60 controls the gas supply unit 30, the exhaust unit 40, and the heating unit 50 to perform the pressure increasing step S6. Specifically, the control unit 60 controls the gas supply unit 30 to supply the inert gas into the processing container 10, and controls the exhaust unit 40 to stop exhausting the processing container 10. Thus, the pressure in the processing container 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.

[0064] Next, after cooling the substrates W to the unloading temperature, the control unit 60 controls the lifting mechanism 21 to unload the wafer boat 20 from the processing container 10. Through the above steps, the processing of the plurality of substrates W held in the wafer boat 20 is completed.

[0065] [Example]

[0066] An example in which it is confirmed that the deuterium concentration in the silicon nitride film can be increased by the substrate processing method according to the embodiment will be described.

[0067] In the embodiment, a substrate having a silicon nitride film on the surface is prepared, the prepared substrate is accommodated in the processing container 10 of the above-mentioned substrate processing apparatus 1, and deuterium atoms are introduced into the silicon nitride film by the following conditions A to F. Then, the deuterium concentration in the silicon nitride film is measured by secondary ion mass spectrometry (SIMS).

[0068] (Condition A)

[0069] In condition A, the prepared substrate is sequentially subjected to a decompression step S2, a heating step S3, a temperature maintaining step S4, a temperature decreasing step S5, and a pressure increasing step S6. In the decompression step S2, the temperature of the substrate is maintained at 600°C, deuterium gas and hydrogen gas are not supplied into the processing container 10, and the pressure in the processing container 10 is reduced from atmospheric pressure to the basic pressure. In the heating step S3, the temperature of the substrate is increased from 600°C to 800°C, deuterium gas and hydrogen gas are not supplied into the processing container 10, and the pressure in the processing container 10 is increased from the basic pressure to 12 kPa (90 Torr). In the temperature maintaining step S4, the temperature of the substrate is maintained at 800°C, deuterium gas is continuously supplied into the processing container 10 during the entire process, and the pressure in the processing container 10 is maintained at 12 kPa. In the temperature reduction step S5, the temperature of the substrate is reduced from 800° C. to 600° C., deuterium gas and hydrogen gas are not supplied into the processing container 10, and the pressure in the processing container 10 is reduced from 12 kPa to the basic pressure. In the pressure increase step S6, the temperature of the substrate is maintained at 600° C., an inert gas is supplied into the processing container 10, and the pressure in the processing container 10 is increased from the basic pressure to the atmospheric pressure.

[0070] (Condition B)

[0071] In condition B, hydrogen gas is continuously supplied into the processing container 10 during the entire period of the temperature increasing step S3. The other conditions are the same as those of condition A.

[0072] (Condition C)

[0073] In condition C, deuterium gas is continuously supplied into the processing container 10 during the entire period of the temperature increasing step S3. The other conditions are the same as those of condition A.

[0074] (condition D)

[0075] In condition D, deuterium gas is continuously supplied into the processing container 10 during the entire period of the temperature drop step S5. The other conditions are the same as condition A.

[0076] (Condition E)

[0077] In condition E, hydrogen gas is continuously supplied into the processing container 10 during the entire period of the temperature increase step S3 , and deuterium gas is continuously supplied into the processing container 10 during the entire period of the temperature decrease step S5 . The other conditions are the same as condition A.

[0078] (Condition F)

[0079] In condition F, deuterium gas is continuously supplied into the processing container 10 during the entire period of the temperature increase step S3 , and deuterium gas is continuously supplied into the processing container 10 during the entire period of the temperature decrease step S5 . The other conditions are the same as condition A.

[0080] Figure 7 and Figure 8 2 is a graph showing the results of measuring the deuterium concentration in the silicon nitride film. Figure 7 , the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to conditions A, B, and C. Figure 8 Graph 2 shows the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to conditions D, E, and F. FIG.

[0081] exist Figure 7 In FIG. 1 , the left, center, and right graphs respectively show the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to conditions A, B, and C. Figure 7 , the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to conditions A, B, and C is shown as a ratio to the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to condition A.

[0082] exist Figure 8 In FIG. 1 , the left, center, and right graphs respectively show the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to conditions D, E, and F. Figure 8 , the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to conditions D, E, and F is shown as a ratio to the deuterium concentration in the silicon nitride film after deuterium atoms are introduced according to condition D.

[0083] like Figure 7 As shown, 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 container 10 in the temperature raising step S3.

[0084] like Figure 8As shown in the figure, it can be seen that under condition E, the deuterium concentration in the silicon nitride film is about 20% higher than that under condition D, and under condition F, the deuterium concentration in the silicon nitride film 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 container 10 in the temperature raising step S3. This result shows that, in particular, when deuterium gas is continuously supplied into the processing container 10 during the entire period of the temperature lowering step S5, the deuterium concentration in the silicon nitride film can be increased more by supplying deuterium gas into the processing container 10 in the temperature raising step S3 than by supplying hydrogen gas.

[0085] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The embodiments described above may be omitted, replaced, or modified in various ways without departing from the appended claims and the gist thereof.

[0086] In the above-mentioned embodiment, the case where the insulating film is a silicon nitride film is described, but the present disclosure is not limited thereto. The insulating film may be a film constituting at least a portion of a charge accumulation layer used in a memory cell. The insulating film may also be a silicon oxide film or a silicon oxynitride film. The insulating film may contain hydrogen atoms in the film. In the case where the insulating film is a silicon oxide film, the insulating film may contain an OH bond. In the case where the insulating film is a silicon oxynitride film, the insulating film may contain an NH bond or an OH bond.

[0087] In the above-mentioned embodiment, the substrate processing apparatus is described as a batch type apparatus that processes a plurality of substrates simultaneously, but the present disclosure is not limited thereto. For example, the substrate processing apparatus may also be a single wafer type apparatus that processes substrates one by one.

[0088] Description of Reference Numerals

[0089] S1: preparation process; S3: heating process; S4: temperature maintenance process.

Claims

1. A substrate processing method, comprising the following steps: 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; as well as maintaining the substrate at the second temperature, The step of raising the temperature to the second temperature includes supplying at least one of deuterium gas and hydrogen gas to the substrate. The step of maintaining the second temperature includes supplying deuterium gas to the substrate.

2. The substrate processing method according to claim 1, wherein: The at least one gas is continuously supplied throughout the entire process of raising the temperature to the second temperature.

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

4. The substrate processing method according to claim 1, wherein: The deuterium gas is continuously supplied throughout the step of maintaining the second temperature.

5. The substrate processing method according to claim 1, wherein: The method further comprises the step of cooling the substrate from the second temperature to the first temperature. The step of cooling the substrate to the first temperature includes supplying deuterium gas to the substrate.

6. The substrate processing method according to claim 5, wherein: The deuterium gas is continuously supplied throughout the process of lowering the temperature to the first temperature.

7. The substrate processing method according to any one of claims 1 to 6, wherein: The at least one gas is deuterium gas.

8. The substrate processing method according to any one of claims 1 to 6, wherein: The at least one gas is hydrogen.

9. The substrate processing method according to any one of claims 1 to 6, wherein: The at least one gas is a mixed gas of deuterium and hydrogen.

10. The substrate processing method according to any one of claims 1 to 6, wherein: The insulating film is a silicon nitride film.

11. A substrate processing device comprising: a processing container that accommodates a substrate having an insulating film on its surface; a gas supply unit for supplying gas into the processing container; a heating unit configured to heat the substrate contained in the processing container; and Control Department, in, The control unit is configured to control the heating unit to perform the following steps: Raising the temperature of the substrate from a first temperature to a second temperature higher than the first temperature in the processing container; and maintaining the substrate at the second temperature in the processing container, 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 raising 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 second temperature.

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