Substrate processing method and substrate processing apparatus

Abstract

To provide a technique for further increasing the concentration of deuterium in a substrate.SOLUTION: A substrate processing method of processing a substrate in a processing chamber includes a step (a) of heating the substrate to a set processing temperature, a step (b) of supplying deuterium into the processing chamber, a step (c) of supplying oxygen into the processing chamber, and a step (d) of discharging the deuterium and the oxygen from the inside of the processing chamber to set the inside of the processing chamber to a set processing pressure. Thus, the substrate processing method can further enrich the substrate with deuterium by supplying deuterium and oxygen together.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a semiconductor memory device in which a deuterium heat treatment is performed to incorporate deuterium into a silicon film at a ratio greater than the ratio of deuterium to hydrogen present in nature. The semiconductor memory device incorporating deuterium has improved device characteristics (e.g., film leakage characteristics, hysteresis characteristics, etc.). [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 further increase the deuterium concentration in a substrate. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a substrate processing method for processing a substrate in a processing vessel, the method comprising: the substrate has an insulating film on its surface, Perform the following steps (a) to (d) together. By processing the substrate, deuterium is incorporated into the insulating film. SUMMARY OF THE INVENTION A method for processing a substrate is provided. (a) heating the substrate to a set processing temperature; (b) supplying deuterium into the processing vessel; (c) supplying oxygen into the processing vessel (d) exhausting the deuterium and the oxygen from the processing vessel to set the processing pressure inside the processing vessel to a set processing pressure; [Effects of the Invention]

[0006] According to one embodiment, the deuterium concentration in the substrate can be further increased. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory view schematically illustrating a substrate on which a substrate processing method according to an embodiment is performed; [Figure 2] 1 is a schematic vertical cross-sectional view showing a vertical heat treatment apparatus according to an embodiment of the present invention; [Figure 3] 10 is a timing chart showing an example of a substrate processing method performed by the vertical heat treatment apparatus. [Figure 4] 10 is a logarithmic graph showing the deuterium concentration of a wafer W when annealing is performed as an example. [Figure 5] 5(a) is a logarithmic graph showing the deuterium concentration of the wafer W versus the processing temperature when an annealing process is performed as an example, and FIG. 5(b) is a graph showing the change in oxide film thickness versus the processing temperature when a substrate processing method according to this embodiment is performed as an example. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] 1 is an explanatory diagram schematically illustrating a substrate to be subjected to a substrate processing method according to one embodiment. As shown in FIG. 1, the substrate processing method according to one embodiment performs an annealing process (heat treatment) on a wafer W, which is an example of a substrate. The wafer W to be processed is used, for example, in semiconductor memories and has a wafer body WB and an insulating film (base layer) WI formed on the surface of the wafer body WB. The wafer W has an amorphous silicon film or the like formed on the insulating film WI.

[0010] The wafer body WB can be a semiconductor substrate such as silicon. The wafer body WB may also be in a form in which multiple types of films are first stacked. The insulating film WI has the function of insulating the gate in a semiconductor memory, for example. Examples of this insulating film WI include a silicon nitride film (SiN film) and a silicon oxide film (SiO2 film). In a form in which the insulating film WI is stacked on the wafer body WB (in a state in which annealing is performed), the insulating film WI may be flat or may have irregularities.

[0011] In the substrate processing method, deuterium ( 2 The device characteristics of the wafer W are significantly improved by adding deuterium to the insulating film WI. Note that the target for deuterium incorporation is not limited to the insulating film WI, but may be various structures in which deuterium can improve the device characteristics of the substrate.

[0012] 2 is a schematic vertical cross-sectional view showing a vertical heat treatment apparatus 1 according to one embodiment. As shown in FIG. 2, in the substrate processing method, an annealing process is performed using a vertical heat treatment apparatus 1, which is a substrate processing apparatus. The vertical heat treatment apparatus 1 includes a processing vessel 10, a wafer boat 20, a gas supply unit 30, an exhaust unit 40, a heating unit 50, and a control unit 60.

[0013] The processing vessel 10 of the vertical heat treatment apparatus 1 is formed in a cylindrical shape with a processing space 10a therein, and performs an annealing process with a wafer 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.

[0014] The cylindrical body 11 is made of a heat-resistant material such as quartz. The cylindrical body 11 extends vertically (longitudinal direction: height direction) and constitutes most of the processing space 10a of the processing vessel 10. Although the processing vessel 10 in FIG. 2 is shown as having a single cylindrical body 11, the present invention is not limited thereto and may have a multi-layer structure in which, for example, multiple cylinders (an outer cylinder, an inner cylinder) are concentrically stacked.

[0015] Manifold 12 and lid 15 are made of, for example, stainless steel. Manifold 12 has a flange 13 at its upper end, which supports the lower end of cylindrical main body 11. The lower end of cylindrical main body 11 and flange 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 via a seal member 16 such as an O-ring.

[0016] A rotation shaft 18 penetrates the center of the lid 15 via a magnetic fluid seal 17. The rotation shaft 18 has a wafer boat 20 on the top and is connected to a rotation drive unit 19. The rotation of the rotation drive unit 19 causes the rotation of the rotation shaft 18 relative to the processing vessel 10. This causes the wafer boat 20 to rotate.

[0017] 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 wafer boat 20 is placed on the rotating plate 23 via a quartz heat retention table 24. Therefore, the lid 15 and the wafer boat 20 move up and down together by raising and lowering the lifting mechanism 21, so that the wafer boat 20 can be inserted into and removed from the cylindrical main body 11.

[0018] The wafer boat 20 of the vertical heat treatment apparatus 1 is a substrate holder that extends vertically (heightwise) within the processing vessel 10 and holds a plurality of wafers W at predetermined intervals along the vertical direction. The wafer boat 20 is removed from the processing vessel 10 by the lowering of the lifting mechanism 21, and then each wafer W is placed on the wafer boat 20. After each wafer W is placed on the wafer boat 20, the lifting mechanism 21 is raised to insert the wafer boat 20 into the processing vessel 10.

[0019] The gas supply unit 30 of the vertical heat treatment apparatus 1 according to this embodiment is configured to be able to introduce multiple types of gases into the treatment space 10a. Specifically, the gas supply unit 30 supplies deuterium gas to be incorporated into the insulating film WI during the annealing treatment, as well as oxygen gas and an inert gas (e.g., N2 gas). For this reason, the gas supply unit 30 includes a deuterium supply unit 31, an oxygen supply unit 32, and an inert gas supply unit 33.

[0020] 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 gas 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 the deuterium gas from the deuterium gas 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.

[0021] Similarly, 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 gas 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 gas 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.

[0022] 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.

[0023] Each gas supply pipe (deuterium supply pipe 311, oxygen supply pipe 321, inert gas supply pipe 331) 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.

[0024] A plurality of deuterium outlets 316 are provided in the deuterium supply pipe 311 at a position located in the cylindrical body 11. A plurality of oxygen outlets 326 are provided in the oxygen supply pipe 321 at a position located in the cylindrical body 11. A plurality of inert gas outlets 336 are provided in the inert gas supply pipe 331 at a position located in the cylindrical body 11. The outlets (deuterium outlets 316, oxygen outlets 326, inert gas outlets 336) are formed at predetermined intervals along the extension direction of the respective gas supply pipes and discharge gas in the horizontal direction. The intervals between the outlets are set to be the same as the intervals between the wafers W held in the wafer boat 20, for example. The height position of each outlet is set to be the midpoint between vertically adjacent wafers W. This allows each outlet to efficiently supply gas to the opposing surfaces between adjacent wafers W.

[0025] The gas supply unit 30 may mix multiple types of gases and discharge the mixed gas from one supply pipe. Alternatively, the gas supply pipes (deuterium supply pipe 311, oxygen supply pipe 321, and inert gas supply pipe 331) may have different shapes or arrangements. For example, in a configuration in which a large amount of deuterium is supplied, the deuterium supply pipe 311 may be wider than the oxygen supply pipe 321. Furthermore, the supply amount of inert gas relative to the supply amounts of deuterium gas and oxygen gas may be significantly smaller, and the vertical heat treatment apparatus 1 may be configured not to supply an inert gas. Furthermore, the vertical heat treatment apparatus 1 may be configured to supply another gas in addition to deuterium gas, oxygen gas, and inert gas.

[0026] The exhaust unit 40 is provided at a gas outlet 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 gas outlet 41, and a pressure adjustment valve 43 and a pump 44 are provided in this order from the upstream side to the downstream side in the gas flow direction on the exhaust path 42. The exhaust unit 40 operates the pressure adjustment valve 43 and the pump 44 under the control of the control unit 60, and adjusts the pressure inside the processing vessel 10 with the pressure adjustment valve 43 while the pump 44 sucks the gas inside the processing vessel 10.

[0027] 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 wafer W accommodated in the processing vessel 10.

[0028] The control unit 60 of the vertical heat treatment apparatus 1 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, and a circuit made up of multiple discrete semiconductors. The memory 62 includes volatile memory and nonvolatile memory (e.g., a compact disc, a DVD, a hard disk, a flash memory, etc.) and stores a program for operating the vertical heat treatment apparatus 1 and a recipe for the annealing process conditions, etc.

[0029] The processor 61 executes the program and recipe stored in the memory 62 to control each component of the vertical heat treatment apparatus 1 and perform the substrate processing method. In the substrate processing method according to this embodiment, the processor 61 controls the operation of each component so that at least the following steps (a) to (d) are performed together. (a) a heating step of heating the processing vessel 10 to a set processing temperature; (b) Deuterium supply step of supplying deuterium into the processing vessel 10 (c) Oxygen supply step for supplying oxygen into the processing vessel 10 (d) An exhaust process of exhausting deuterium and oxygen from the processing vessel 10 to set the pressure inside the processing vessel 10 to a set value.

[0030] Specifically, in the heating step (a), the processor 61 controls the operation of the heater 51 of the heating unit 50 to heat the processing vessel 10, thereby adjusting the temperature of the wafer W accommodated in the processing vessel 10. By simultaneously performing the deuterium supply step (b) and the oxygen supply step (c), the vertical heat processing apparatus 1 can process the wafer W at a lower temperature than a conventional method of performing an annealing process by supplying only deuterium gas (hereinafter referred to as a conventional substrate processing method). For example, the processing temperature of the wafer W in the conventional substrate processing method is set to approximately 800°C. In contrast, the processing temperature range in the heating step (a) according to this embodiment can be set to approximately 500°C to 700°C.

[0031] The substrate processing method then performs a deuterium supplying step (b) and an oxygen supplying step (c) to introduce deuterium gas and oxygen gas into the wafer W in the processing chamber 10. The deuterium gas flows within the processing space 10a and causes a radical reaction with the insulating film WI of the wafer W, which is heated in the heating step. Meanwhile, the oxygen gas mixes with the deuterium gas within the processing space 10a, activating the radical reaction of deuterium. As a result, deuterium is smoothly incorporated (added) into the insulating film WI of the wafer W, increasing the deuterium concentration in the insulating film WI of the wafer W.

[0032] In the deuterium supplying process and the oxygen supplying process, the processor 61 can adjust the concentration of deuterium incorporated into the insulating film WI of the wafer W by appropriately controlling the flow rates of deuterium gas and oxygen gas. For example, the ratio of the flow rate of deuterium gas to the flow rate of oxygen gas (hereinafter referred to as the D2 / O2 ratio) is preferably set in the range of 2 to 20 (see also the examples described later). When the D2 / O2 ratio is less than 2, the oxygen concentration in the processing chamber 10 increases, resulting in a thicker oxide film of the insulating film WI. On the other hand, when the D2 / O2 ratio is more than 20, the oxygen concentration in the processing chamber 10 is low, resulting in a reduced amount of deuterium incorporated into the insulating film WI.

[0033] In addition, in the exhaust step (d), the processor 61 operates the pump 44 of the exhaust unit 40 to suck gas from the processing vessel 10 and controls the opening of the pressure adjustment valve 43 to adjust the pressure inside the processing vessel 10. The pressure inside the processing vessel 10 is preferably set to, for example, 1 Torr (=133.32 Pa) or less, and in this embodiment, it is set to 0.35 Torr (=46.66 Pa). In conventional substrate processing methods, the pressure inside the processing vessel 10 is set to approximately 90 Torr (=11999 Pa).

[0034] That is, the vertical heat treatment apparatus 1 can realize a lower temperature annealing process and a higher concentration of deuterium incorporated into the wafer W by performing the above steps (a) to (d) together.

[0035] The vertical heat treatment apparatus 1 according to this embodiment is basically configured as described above, and the operation and effects of the substrate treatment method will be described below.

[0036] When the processor 61 of the vertical heat treatment apparatus 1 starts operation upon startup, such as when the power is turned on, it executes a program stored in the memory 62 to perform the substrate processing method. For example, as a pre-processing step of the substrate processing method, the processor 61 operates the lifting mechanism 21 to place the wafer boat 20, on which a plurality of wafers W are placed, into the processing vessel 10. The lid 15, raised by the lifting mechanism 21, comes into contact with the manifold 12, thereby hermetically sealing the processing vessel 10.

[0037] Thereafter, the processor 61 starts the above steps (a) to (d) of the substrate processing method at appropriate timing. Fig. 3 is a timing chart showing an example of the substrate processing method performed by the vertical heat processing apparatus 1. As shown in Fig. 3, in the pre-processing of the substrate processing method, the exhaust unit 40 reduces the pressure inside the processing container 10, and the heating unit 50 heats the processing container 10.

[0038] Specifically, the processor 61 starts the exhaust step (d) at time t1, evacuating the processing vessel 10 with the pump 44, and gradually opening the pressure adjustment valve 43 from 0%. Also at time t1, the processor 61 opens the deuterium valve 315 to start the deuterium supply step (b) in which deuterium gas is supplied from the deuterium gas source 313 into the processing vessel 10 via the deuterium supply path 312 and the deuterium supply pipe 311. In conjunction with the supply of deuterium gas, the processor 61 also opens the inert gas valve 335 to supply inert gas from the inert gas source 333 into the processing vessel 10 via the inert gas supply path 332 and the inert gas supply pipe 331.

[0039] Therefore, the vertical heat treatment apparatus 1 introduces deuterium gas and inert gas into the processing vessel 10 simultaneously with exhausting the gas from the processing vessel 10. At this time, the exhaust rate from the processing vessel 10 is greater than the flow rates of the deuterium gas and inert gas supplied to the processing vessel 10. In addition, the flow rate of the inert gas is sufficiently smaller than the flow rate of the deuterium gas. As a result, the pressure in the processing vessel 10 is gradually reduced, and the gas in the processing space 10a is replaced with deuterium gas. For example, at time t2, which is after time t1, the pressure in the processing vessel 10 becomes constant at a pressure corresponding to the aperture of the pressure adjustment valve 43.

[0040] Furthermore, at time t2 during the pre-processing, the processor 61 activates the heater 51 of the heating unit 50 to start the heating step (a) of heating the processing vessel 10. The heating by the heater 51 gradually increases the temperature inside the processing vessel 10, and the temperature reaches a processing temperature (e.g., 600°C) for performing the annealing process.

[0041] The processor 61 starts the main annealing process at time t3 when the temperature inside the processing vessel 10 reaches the processing temperature. Then, at time t3, the processor 61 opens the oxygen valve 325 to start the oxygen supply step (c) of supplying oxygen gas from the oxygen gas source 323 into the processing vessel 10 via the oxygen supply path 322 and the oxygen supply pipe 321. As a result, the pressure inside the processing vessel 10 becomes slightly elevated and constant (e.g., 0.35 Torr), and the main annealing process is performed while maintaining this processing pressure in the substrate processing method.

[0042] In this annealing process, the vertical heat treatment apparatus 1 maintains a constant process temperature in the process chamber 10. The process chamber 10 is evacuated while deuterium gas and oxygen gas are supplied into the process chamber 10, thereby maintaining a constant process pressure within the process chamber 10. In other words, the substrate processing method simultaneously performs steps (a) to (d) in this annealing process. As a result, the deuterium gas supplied into the process chamber 10 undergoes a radical reaction with the oxygen gas, resulting in a large amount of deuterium gas being incorporated into the insulating film WI. The duration of this annealing process is not particularly limited, but may be, for example, approximately 30 to 120 minutes. Furthermore, the processor 61 may operate the rotation drive unit 19 to rotate the wafer boat 20 during this annealing process. This allows the deuterium introduced into the wafers W to be more uniform in the surface direction. The wafer boat 20 may be rotated from the pre-processing stage.

[0043] In the substrate processing method, after the main annealing process is performed for a predetermined period of time, the main annealing process is terminated and the process proceeds to post-processing. For example, at the start of post-processing at time t4, the processor 61 stops heating by the heating unit 50 (heater 51) and closes the oxygen valve 325 to stop the supply of oxygen gas into the processing vessel 10. As a result, the temperature of the processing vessel 10 gradually decreases, and the pressure inside the processing vessel 10 also decreases slightly.

[0044] Then, at time t5 when the temperature of the processing vessel 10 has decreased, the processor 61 reduces the aperture of the pressure adjustment valve 43. At this time t5, the supply of deuterium gas and inert gas continues, so the pressure inside the processing vessel 10 increases. Thereafter, at time t6, the processor 61 closes the deuterium valve 315 and also closes the inert gas valve 335 to stop the supply of deuterium gas and inert gas. This completes the post-processing, and the processor 61 ends the substrate processing method.

[0045] The substrate processing method is not limited to the above operations and may take various modifications. For example, in the above embodiment, deuterium gas is supplied first in the pretreatment process and oxygen gas is supplied in the subsequent annealing process. However, oxygen gas may be supplied first in the pretreatment process and deuterium gas may be supplied in the subsequent annealing process. In short, in the pretreatment process, it is sufficient to replace the gas while reducing the pressure inside the processing vessel 10 to a predetermined pressure. In the annealing process using deuterium gas and oxygen gas, the same effect can be obtained regardless of which gas is supplied first. In the substrate processing method, deuterium gas and oxygen gas may be supplied simultaneously into the processing vessel 10.

[0046] [Example] Fig. 4 is a logarithmic graph showing the deuterium concentration of a wafer W when annealing was performed as an example. In Fig. 4, the horizontal axis represents the depth from the surface of the wafer W (insulating film WI), and the vertical axis represents the deuterium concentration. The thick line represents the deuterium concentration along the depth direction of the wafer W when the substrate processing method according to this embodiment is performed. The thin line represents the deuterium concentration along the depth direction of the wafer W when the conventional substrate processing method is performed.

[0047] As shown in FIG. 4, the insulating film WI of the wafer W has a thickness of about 18 nm from the surface. The deuterium concentration of this insulating film WI is 10 18The deuterium concentration is below [atoms / cc] and is comparable to the natural deuterium concentration. It can be seen that the deuterium concentration increases when annealing is performed, as deuterium is incorporated into the insulating film WI.

[0048] Furthermore, for the same depth from the surface of the wafer W, the deuterium concentration in the substrate processing method according to this embodiment is greater than that in the conventional substrate processing method. That is, the substrate processing method can be said to incorporate more deuterium into the insulating film WI by supplying deuterium gas and oxygen gas together during the annealing process. In the example, the processing pressure in the processing vessel 10 in the substrate processing method according to this embodiment is 0.35 Torr, while the processing pressure in the processing vessel in the conventional substrate processing method is 90 Torr. Other process conditions (such as the duration and temperature) are the same. Therefore, when the annealing process is performed at the same processing pressure, the deuterium concentration in the substrate processing method according to this embodiment is greater than that in the conventional substrate processing method.

[0049] 5(a) is a logarithmic graph showing the deuterium concentration of a wafer W versus the processing temperature when an annealing process was performed as an example. In FIG. 5(a), the horizontal axis represents the processing temperature, and the vertical axis represents the deuterium concentration of the insulating film WI. In this example, the dotted line indicates the change in deuterium concentration versus the processing temperature in the conventional substrate processing method. The bold line indicates the change in deuterium concentration versus the processing temperature when the D2 / O2 ratio is doubled, and the bold two-dot chain line indicates the change in deuterium concentration versus the processing temperature when the D2 / O2 ratio is 20 times higher.

[0050] As shown in Figure 5(a), in the case of the conventional substrate processing method, the processing temperature is 700°C or higher and the deuterium concentration is 10 20 [atoms / cc], and the treatment temperature is 800°C or higher and the deuterium concentration is 10 21 In contrast, when the D2 / O2 ratio is doubled, the treatment temperature is 500°C or higher and the deuterium concentration is 10 20[atoms / cc], and the deuterium concentration is 10 21 In addition, when the D2 / O2 ratio is 20 times, the deuterium concentration exceeds 10 20 [atoms / cc], and the treatment temperature is 700°C or higher and the deuterium concentration is 10 21 [atoms / cc]. Therefore, it can be said that at the same processing temperature, supplying deuterium gas and oxygen gas together increases the deuterium concentration. Conversely, it can be seen that the processing temperature can be set lower in the substrate processing method according to this embodiment in which deuterium gas and oxygen gas are supplied together.

[0051] Furthermore, the deuterium concentration when the D2 / O2 ratio is 2 is slightly higher than when the D2 / O2 ratio is 20. This indicates that supplying more oxygen gas tends to increase the deuterium concentration.

[0052] 5(b) is a graph showing the change in oxide film thickness with respect to the processing temperature when the substrate processing method according to the present embodiment is performed as an example. In FIG. 5(b), the horizontal axis represents the processing temperature, and the vertical axis represents the oxide film thickness.

[0053] As shown in FIG. 5(b), when the D2 / O2 ratio is 2x, the oxide film thickness increases, while when the D2 / O2 ratio is 20x, the oxide film thickness is suppressed. Therefore, in implementing the substrate processing method, if you want to suppress the oxide film thickness, you can simply reduce the flow rate of oxygen gas relative to the flow rate of deuterium gas. Therefore, in the substrate processing method, by supplying deuterium gas and oxygen gas at an appropriate D2 / O2 ratio depending on the wafer W to be processed, you can achieve a balance between the deuterium concentration and the oxide film thickness. For example, if the formation of an oxide film is not a problem, you can set the D2 / O2 ratio to about 2x to 5x and the processing temperature low (e.g., in the range of about 500°C to 600°C). On the other hand, if you want to suppress the formation of an oxide film, you can set the D2 / O2 ratio to about 15x to 20x and the processing temperature high (e.g., in the range of about 600°C to 700°C).

[0054] The technical ideas and effects of the present disclosure explained in the above embodiments will be described below.

[0055] A first aspect of the present disclosure is a substrate processing method for processing a substrate (wafer W) in a processing chamber 10, in which the following steps (a) to (d) are performed together. (a) Heating the substrate to a set processing temperature (b) supplying deuterium into the processing vessel 10 (c) Supplying oxygen into the processing vessel 10 (d) A step of exhausting deuterium and oxygen from the processing vessel 10 to set the processing pressure inside the processing vessel 10 to a set processing pressure.

[0056] As described above, the substrate processing method supplies deuterium and oxygen into the processing vessel 10 while the processing vessel 10 is being heated, thereby allowing a larger amount of deuterium to be incorporated into the substrate (wafer W) than if only deuterium were supplied into the processing vessel 10, thereby further increasing the deuterium concentration in the substrate. This further improves the device characteristics of the substrate. For example, if the substrate is a semiconductor memory, a film containing a high concentration of deuterium will significantly improve the reliability of the device.

[0057] Furthermore, at the start of processing the substrate (wafer W), one of steps (b) and (c) is started first, and the other of steps (b) and (c) is started after the processing pressure inside the processing vessel 10 has reached the processing pressure. This allows the substrate processing method to perform the main annealing process using deuterium and oxygen in a state where the processing pressure in the processing vessel 10 is stabilized, making it possible to uniform the distribution of deuterium taken into the substrate.

[0058] The timing for starting the other of the steps (b) and (c) is the timing when the substrate (wafer W) is heated to the processing temperature in the step (a). This allows the substrate processing method to perform the annealing process using deuterium and oxygen at an elevated processing temperature, thereby reducing waste of deuterium and oxygen.

[0059] In step (a), the processing temperature is set in the range of 500° C. to 700° C. This enables the substrate processing method to perform annealing at a lower processing temperature than conventional annealing processes, thereby promoting energy savings during processing and suppressing damage to the substrate (wafer W).

[0060] In step (d), the processing pressure is set to 1 Torr or less, which allows the substrate processing method to process the substrate (wafer W) in a low-pressure environment inside the processing chamber 10, thereby minimizing the supply amounts of deuterium and oxygen.

[0061] The ratio of the flow rate of deuterium introduced in step (b) to the flow rate of oxygen supplied in step (c) is in the range of 2 to 20. This allows the substrate processing method to stably incorporate deuterium into the substrate (wafer W).

[0062] Furthermore, the substrate (wafer W) has an insulating film WI on its surface, and deuterium is incorporated into the insulating film WI by processing the substrate. As a result, the substrate has an insulating film WI that contains a large amount of deuterium, and the leakage characteristics, hysteresis characteristics, etc. of the insulating film WI are significantly improved.

[0063] A second aspect of the present disclosure is a substrate processing apparatus (vertical heat treatment apparatus 1) for processing a substrate (wafer W), which includes a processing vessel 10 that accommodates a substrate therein, a heating unit 50 that heats the substrate, a deuterium supply unit 31 that supplies deuterium into the processing vessel 10, an oxygen supply unit 32 that supplies oxygen into the processing vessel 10, an exhaust unit 40 that exhausts deuterium and oxygen from inside the processing vessel 10, and a control unit 60 that controls the heating unit 50, the deuterium supply unit 31, the oxygen supply unit 32, and the exhaust unit 40, and the control unit 60 performs the following steps (a) to (d) together. (a) A step of heating the processing vessel 10 to a set processing temperature. (b) supplying deuterium into the processing vessel 10 (c) Supplying oxygen into the processing vessel 10 (d) A step of exhausting deuterium and oxygen from the processing vessel 10 to set the processing pressure inside the processing vessel 10 to a set processing pressure.

[0064] This allows the substrate processing apparatus (vertical heat processing apparatus 1) to further increase the deuterium concentration in the substrate (wafer W).

[0065] The processing vessel 10 can accommodate a plurality of substrates (wafers W) arranged in a predetermined direction, the deuterium supply unit 31 has a deuterium supply pipe 311 extending in the processing vessel 10 along the arrangement direction of the plurality of substrates, the deuterium supply pipe 311 having a plurality of deuterium outlets 316 for discharging deuterium along the extension direction, and the oxygen supply unit 32 has an oxygen supply pipe 321 adjacent to the deuterium supply pipe 311 in the processing vessel 10 and extending in the arrangement direction of the plurality of substrates, the oxygen supply pipe 321 having a plurality of oxygen outlets 326 for discharging oxygen along the extension direction. This allows the substrate processing apparatus (vertical heat processing apparatus 1) to process a plurality of substrates at once and effectively incorporate deuterium into the substrates.

[0066] The substrate processing method and substrate processing apparatus according to the presently disclosed embodiments are illustrative in all respects and not restrictive. Various modifications and improvements to the embodiments are possible without departing from the spirit and scope of the appended claims. The features described in the above embodiments may be configured differently and may be combined within a consistent range. While the substrate processing apparatus according to the present embodiment is exemplified as a vertical heat treatment apparatus 1 that performs a substrate processing method on a substrate arranged vertically, the substrate processing apparatus is not limited to this. For example, the substrate processing apparatus may be an apparatus that performs a substrate processing method on a plurality of substrates arranged horizontally, or an apparatus that performs a substrate processing method on a single substrate. [Explanation of symbols]

[0067] 1. Vertical heat treatment equipment 10 Processing container 30 Gas supply unit 31 Deuterium Supply Unit 32 Oxygen supply unit 40 Discharge section 50 Heating section 60 Control Unit W wafer WI insulating film

Claims

1. A substrate processing method for processing a substrate in a processing vessel, comprising: the substrate has an insulating film on its surface, A substrate processing method comprising the steps of (a) to (d) below, whereby deuterium is incorporated into the insulating film by processing the substrate: (a) heating the substrate to a set processing temperature; (b) supplying deuterium into the processing vessel; (c) supplying oxygen into the processing vessel (d) exhausting the deuterium and the oxygen from the processing vessel to set the processing pressure inside the processing vessel to a set processing pressure;

2. At the start of the substrate processing, one of the steps (b) and (c) is started first, and the other of the steps (b) and (c) is started after the pressure inside the processing container reaches the processing pressure. The substrate processing method according to claim 1 .

3. the timing at which the other of the step (b) and the step (c) is started is the timing at which the substrate is heated in the step (a) and reaches the processing temperature; The substrate processing method according to claim 2.

4. In the step (a), the treatment temperature is set in the range of 500°C to 700°C. The substrate processing method according to claim 1 .

5. In the step (d), the processing pressure is set to 1 Torr or less. The substrate processing method according to claim 1 .

6. a ratio of the flow rate of the deuterium introduced in the step (b) to the flow rate of the oxygen supplied in the step (c) is in the range of 2 to 20 times; The substrate processing method according to claim 1 .

7. A substrate processing apparatus for processing a substrate, a processing vessel for accommodating a substrate therein; a heating unit that heats the substrate; a deuterium supply unit for supplying deuterium into the processing vessel; an oxygen supply unit that supplies oxygen into the processing vessel; an exhaust unit that exhausts the deuterium and the oxygen from the processing chamber; a control unit that controls the heating unit, the deuterium supply unit, the oxygen supply unit, and the exhaust unit, the substrate has an insulating film on its surface, The control unit controls the substrate processing apparatus to simultaneously perform the following steps (a) to (d), thereby incorporating the deuterium into the insulating film: (a) heating the substrate to a set processing temperature; (b) supplying the deuterium into the processing vessel; (c) supplying the oxygen into the processing vessel (d) exhausting the deuterium and the oxygen from the processing vessel to set the processing pressure inside the processing vessel to a set processing pressure;

8. the processing vessel is capable of arranging a plurality of the substrates in a predetermined direction; the deuterium supply unit includes a deuterium supply pipe extending in a direction in which the plurality of substrates are arranged within the processing chamber, the deuterium supply pipe has a plurality of deuterium outlets that discharge the deuterium along an extension direction; the oxygen supply unit includes an oxygen supply pipe adjacent to the deuterium supply pipe in the processing chamber and extending along an arrangement direction of the plurality of substrates; The oxygen supply pipe has a plurality of oxygen outlets that discharge the oxygen along an extension direction. The substrate processing apparatus according to claim 7 .

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