Film formation method and film formation device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- TOKYO ELECTRON LTD
- Filing Date
- 2026-01-26
- Publication Date
- 2026-08-06
Smart Images
Figure JP2026002348_06082026_PF_FP_ABST
Abstract
Description
Film deposition method and film deposition apparatus
[0001] This disclosure relates to a film deposition method and a film deposition apparatus.
[0002] A technique is known that involves performing multiple cycles, each including the steps of supplying a silicon source gas containing an organic amino-functionalized oligosiloxane compound into a processing vessel, and supplying an oxidizing gas into the processing vessel adjusted to a pressure of 1 to 10 Torr (for example, Patent Document 1).
[0003] Japanese Patent Publication No. 2021-141229
[0004] This disclosure provides a technology for forming silicon oxide films.
[0005] A film-forming method according to one aspect of the present disclosure is a film-forming method for forming a silicon oxide film, comprising: (a) supplying a silicon raw material gas containing a silicon-containing compound represented by the following formula (1) to a substrate; and (b) supplying an oxidizing gas to the substrate, wherein steps (a) and (b) are performed alternately.
[0006] In formula (1), R1, R2, and R3 are hydrogen atoms or linear, branched, or cyclic alkyl groups, and R4, R5, and R6 are linear, branched, or cyclic alkyl groups.
[0007] According to this disclosure, a silicon oxide film can be formed.
[0008] This is a flowchart illustrating a film deposition method according to an embodiment. This is a schematic cross-sectional view showing an example of a substrate before the supply of silicon source gas and oxidizing gas. This is a schematic cross-sectional view showing an example of a substrate after the supply of silicon source gas. This is a schematic cross-sectional view showing an example of a substrate after the supply of oxidizing gas. This is a schematic cross-sectional view showing an example of a substrate W after a silicon oxide film has been deposited. This is a schematic diagram illustrating an example of the properties of a silicon-containing compound in the embodiment. This is a vertical cross-sectional view showing a hot-wall type film deposition apparatus according to an embodiment. This is a horizontal cross-sectional view showing a hot-wall type film deposition apparatus according to an embodiment. This is a vertical cross-sectional view showing a cold-wall type film deposition apparatus according to an embodiment. This is a graph showing an example of the relationship between the substrate temperature and the growth rate of the silicon oxide film in the embodiment. This is a graph showing another example of the relationship between the substrate temperature and the growth rate of the silicon oxide film in the embodiment. This is a graph showing an example of the step coverage of the silicon oxide film in the embodiment. This is a graph showing another example of the step coverage of the silicon oxide film in the embodiment.
[0009] Hereinafter, exemplary embodiments of the present disclosure, not limited to those described herein, will be described with reference to the attached drawings. In all attached drawings, identical or corresponding members or parts are denoted by the same or corresponding reference numerals, and redundant descriptions are omitted. In this specification, when a numerical range is indicated using "~", such as "lower limit A to upper limit B", it means that the range is greater than or equal to lower limit A and less than or equal to upper limit B.
[0010] [Film Formation Method] The film formation method according to the embodiment will be described with reference to Figures 1 to 3. Figure 1 is a flowchart of the film formation method according to the embodiment. Figure 2 is a schematic cross-sectional diagram illustrating the film formation method according to the embodiment. Figure 3 is a schematic diagram illustrating an example of the properties of silicon-containing compound SC.
[0011] The film deposition method according to this embodiment is a film deposition method for depositing a silicon oxide film 101 on a substrate W. The silicon oxide film 101 is a film containing silicon (Si) and oxygen (O). Examples of silicon oxide films 101 include SiO films, SiOC films, SiON films, and SiOCN films. The atomic ratio of Si to O in the SiO film is not limited to 1:2. The atomic ratio of Si to O may be, for example, 1:1. The same applies to SiOC films, SiON films, and SiOCN films.
[0012] The substrate W is placed, for example, in the processing container of the film deposition apparatus (for example, the processing container 10 provided in the hot-wall type film deposition apparatus 1H shown in Figures 4 and 5, or the processing container 1 provided in the cold-wall type film deposition apparatus 1C shown in Figure 6). An example of the substrate W is a semiconductor substrate such as a silicon wafer. Figure 2A is a schematic cross-sectional view showing an example of the substrate W before the silicon raw material gas and oxidizing gas are supplied. As shown in Figure 2A, the substrate W has a recess R formed on its upper surface U. The aspect ratio of the recess R (the ratio of the depth of the recess R to the opening width of the recess R) is preferably 10 or more and 50 or less. However, the aspect ratio of the recess R is not limited thereto. In the film deposition method according to the embodiment, a silicon oxide film 101 is deposited on the upper surface U and the inner surface R1 of the recess R of the substrate W. When describing the upper surface U and inner surface R1 of the substrate W without distinction, they are collectively referred to as the "surface of the substrate W" below. Furthermore, although we will use a substrate W having a recess R as an example, the substrate W does not necessarily have to have a recess R. In other words, the surface of the substrate W may be flat.
[0013] The substrate processing method according to the embodiment comprises steps S11 to S14 shown in Figure 1. Step S11 includes supplying a silicon raw material gas containing a silicon-containing compound SC to the substrate W. The silicon-containing compound SC is a compound represented by the following formula (1).
[0014]
[0015] In formula (1), R1, R2, and R3 are hydrogen atoms or linear, branched, or cyclic alkyl groups. R4, R5, and R6 are linear, branched, or cyclic alkyl groups. The number of carbon atoms in the linear or branched alkyl groups in R1 to R6 is, for example, one to four. Examples of linear or branched alkyl groups in R1 to R6 include methyl, ethyl, propyl, and butyl groups. The number of carbon atoms in the cyclic alkyl groups in R1 to R6 is, for example, three or four. Examples of cyclic alkyl groups in R1 to R6 include cyclopropyl and cyclobutyl groups. R1 to R6 may be the same or different from each other.
[0016] An example of a silicon-containing compound SC is 3,5-dimethylpyrazolyltrimethoxysilane, represented by the following formula (2). However, silicon-containing compounds SC are not limited to 3,5-dimethylpyrazolyltrimethoxysilane.
[0017]
[0018] Examples of properties possessed by silicon-containing compounds SC include high adsorption to substrate W and high heat resistance. Referring to Figure 3, an example of the mechanism by which the high adsorption and high heat resistance of silicon-containing compounds SC are exhibited will be explained using 3,5-dimethylpyrazolyltrimethoxysilane as an example. However, silicon-containing compounds SC may also possess properties other than high adsorption and high heat resistance.
[0019] As shown in FIG. 3, 3,5-dimethylpyrazolyltrimethoxysilane has a first moiety S1 containing a pyrazolyl group. The nitrogen atom in the pyrazolyl group of the first moiety S1 has a lone pair of electrons that is not involved in the bonding with other atoms of the pyrazolyl group. That is, the pyrazolyl group of the first moiety S1 has high nucleophilicity derived from the lone pair of electrons. On the other hand, on the surface of the substrate W, adsorption sites such as hydrogen atoms and hydroxyl groups that terminate the constituent atoms (e.g., Si) of the substrate W are located. As 3,5-dimethylpyrazolyltrimethoxysilane approaches the substrate W, the pyrazolyl group of the first moiety S1 binds to the adsorption site on the substrate W. Thereby, 3,5-dimethylpyrazolyltrimethoxysilane can be adsorbed on the substrate W. By having a pyrazolyl group, 3,5-dimethylpyrazolyltrimethoxysilane has high adsorptivity. That is, regarding high adsorptivity, it is important for the silicon-containing compound SC to have a pyrazolyl group that binds to Si.
[0020] Further, 3,5-dimethylpyrazolyltrimethoxysilane further has a second moiety S2 containing Si and three methoxy groups that bind to Si. Thereby, 3,5-dimethylpyrazolyltrimethoxysilane has the property of being difficult to thermally decompose. That is, 3,5-dimethylpyrazolyltrimethoxysilane (silicon-containing compound SC) has high heat resistance. That is, regarding high heat resistance, it is important for the silicon-containing compound SC to have an alkoxy group that binds to Si. Since the silicon-containing compound SC has a pyrazolyl group that binds to Si and an alkoxy group that binds to Si, it has high adsorptivity and high heat resistance.
[0021] FIG. 2B is a cross-sectional schematic view showing an example of the substrate W after the silicon source gas is supplied. In step S11, by supplying the silicon source gas to the substrate W, the silicon-containing compound SC binds to the adsorption site on the substrate W. Thereby, as shown in FIG. 2B, the silicon-containing compound SC is adsorbed on the surface of the substrate W.
[0022] Step S11 may include supplying a purge gas to the substrate W after supplying the silicon raw material gas to the substrate W. The purge gas, for example, discharges the excess silicon-containing compound SC that has not reacted with the adsorption sites on the substrate W to the outside of the processing vessel. The purge gas is, for example, nitrogen (N ２ ), or argon (Ar) gas.
[0023] An example of the processing conditions of step S11 is as follows. - Flow rate of silicon raw material gas: 0.1 sccm to 50 sccm - Temperature of substrate W: 200°C to 700°C - Processing pressure: 0.1 Torr to 10 Torr (13.3 Pa to 1.33 kPa) - Processing time: 10 seconds to 100 seconds
[0024] Step S12 is performed after step S11. Step S12 includes supplying an oxidation gas containing an oxidizing agent OA to the substrate W. As the oxidizing agent OA, for example, oxygen (O ２ ) molecules or ozone (O ３ ) molecules can be used. Further, step S12 may include generating oxygen plasma from O ２ molecules. In this case, active species such as oxygen radicals contained in the oxygen plasma act as the oxidizing agent OA. Note that the oxidizing agent OA only needs to contain oxygen atoms (O), and instead of O ２ molecules, H ２ O, NO, N ２ O, NO ２ , CO, CO ２ may contain at least one of them.
[0025] Step S12 preferably includes setting the temperature of the substrate W to 450°C or higher. Further, step S12 may include supplying an oxidation gas heated to 450°C or higher.
[0026] Figure 2C is a schematic cross-sectional view showing an example of the substrate W after the oxidizing gas has been supplied. Figure 2D is a schematic cross-sectional view showing an example of the substrate W after the silicon oxide film 101 has been formed. In step S12, when the oxidizing gas containing the oxidizing agent OA is supplied to the substrate W, the oxidizing agent OA reacts with the silicon-containing compound SC in an oxidation reaction, as shown in Figure 2C. As a result, the silicon oxide film 101 is formed, as shown in Figure 2D.
[0027] Step S12 may include supplying a purge gas to the substrate W after supplying an oxidizing gas to the substrate W. The purge gas discharges, for example, excess oxidizing agent OA that has not reacted with the silicon-containing compound SC to the outside of the processing container. The purge gas is, for example, N ２ It is gas or Ar gas.
[0028] An example of the processing conditions for step S12 is as follows: • Oxidizing gas flow rate: 100 sccm to 1000 sccm • Substrate W temperature: 200°C to 700°C • Processing pressure: 0.1 Torr to 100 Torr (13.3 Pa to 13.3 kPa) • Processing time: 10 seconds to 300 seconds
[0029] The film deposition method according to the embodiment involves alternately performing steps S11 and S12. Incidentally, a film deposition method using the Atomic Layer Deposition (ALD) method (ALD process) is known, in which two types of gases containing different raw materials are alternately supplied to a substrate to deposit a desired thin film. In the ALD process, a thin film is formed by utilizing the self-controlled surface reaction of each raw material so that atomic layers (molecular layers) of each raw material are stacked alternately. As a result, a high-quality thin film with high step coverage can be obtained. In a general ALD process, for example, the temperature of the substrate is set to a relatively low temperature (for example, a temperature of about 400°C or lower) to consider the thermal decomposition of the raw materials.
[0030] In the film formation method according to this embodiment, a silicon raw material gas containing a silicon-containing compound SC that can bond to adsorption sites on the substrate W and has high heat resistance is used. Therefore, even when the temperature of the substrate W exceeds 400°C, the silicon-containing compound SC can be reacted with the adsorption sites on the substrate W in a self-controlled manner. This makes it possible to form one or more molecular layers containing the silicon-containing compound SC. Furthermore, since the temperature of the substrate W is raised to a temperature above 400°C, O ３ O is less reactive than molecules and oxygen plasma. ２ Even when the molecule is used as the oxidizing agent OA, the silicon-containing compound SC and O ２ Molecules can be reacted. That is, as an oxidizing agent OA, for example, O ２ Even when using molecules, a surface reaction can occur with one or more molecular layers containing the silicon-containing compound SC to form a silicon oxide film 101. On the other hand, when the temperature of the substrate W is lowered to, for example, 400°C or below, O ３ By using highly reactive oxidizing agents OA such as molecules and oxygen radicals, a silicon oxide film 101 can be formed by the ALD process. Therefore, according to the film formation method of the embodiment, the types of oxidizing agents OA that can be used for forming the silicon oxide film 101 can be increased. Note that for forming the silicon oxide film 101 at temperatures above 400°C, O ３ It is also possible to use highly reactive oxidizing agents such as molecules and oxygen radicals (OA).
[0031] Furthermore, according to the film formation method of the embodiment, stable O is obtained even at high temperatures. ２ The molecule can be used as an oxidizing agent OA. Therefore, O can reach deep positions in the recesses R of the substrate W. ２ This ensures sufficient molecular concentration. As a result, even if the aspect ratio of the recess R is high, the silicon oxide film 101 can be deposited to a deep position in the recess R. Consequently, the step coverage of the silicon oxide film 101 deposited on the surface of the substrate W having a recess R with a high aspect ratio can be increased. However, the combination of the substrate W temperature and the oxidizing agent OA in the film deposition method of this disclosure is not limited to the above example.
[0032] Step S13 includes determining whether the number of repetitions of the processing cycle consisting of steps S11 and S12 has reached a set number. Step S13 is performed each time steps S11 and S12 of one cycle are completed.
[0033] As shown in Figure 1, if the number of repetitions of the processing cycle consisting of steps S11 and S12 reaches the set number ("YES" in step S13), steps S11 and S12 are not performed again. On the other hand, if the number of repetitions of the processing cycle consisting of steps S11 and S12 has not reached the set number ("NO" in step S13), steps S11 and S12 are performed again.
[0034] By repeatedly performing steps S11 and S12 alternately, the thickness of the silicon oxide film 101 can be increased. Furthermore, by using the ALD process, the controllability of the silicon oxide film 101 thickness can be improved. The number of times set in step S13 can be appropriately selected according to the growth rate of the silicon oxide film 101 per cycle of steps S11 and S12.
[0035] Step S14 includes annealing the silicon oxide film 101. Step S14 is performed after step S13. In step S14, the annealing temperature of the silicon oxide film 101 is preferably higher than the temperature of the substrate W when steps S11 and S12 are performed. The annealing temperature of the silicon oxide film 101 is, for example, above the highest temperature of the substrate W during the period when steps S11 and S12 are performed and below 1000°C. By annealing the silicon oxide film 101, the film quality of the silicon oxide film 101 can be further improved. However, in the film formation method according to the embodiment, step S14 may be omitted.
[0036] [Film Deposition Apparatus] An example of a film deposition apparatus suitable for carrying out the film deposition method according to the embodiment will be described. Examples of suitable film deposition apparatuses include a hot-wall type film deposition apparatus 1H and a cold-wall type film deposition apparatus 1C.
[0037] First, an example of the configuration of a hot-wall type film deposition apparatus 1H according to the embodiment will be described with reference to Figures 4 and 5. Figure 4 is a vertical cross-sectional view showing the hot-wall type film deposition apparatus 1H according to the embodiment. Figure 5 is a horizontal cross-sectional view showing the hot-wall type film deposition apparatus 1H according to the embodiment.
[0038] The hot-wall type film deposition apparatus 1H is a batch-type apparatus that processes multiple substrates W at once, for example. As shown in Figure 4, the hot-wall type film deposition apparatus 1H comprises a processing container 10, a gas supply unit 30, an exhaust unit 40, a heating unit 50, and a control unit 90.
[0039] The processing container 10 is configured to accommodate the substrate W. The processing container 10 is also configured to allow for reduced pressure inside. The processing container 10 accommodates the substrate W. The processing container 10 has an inner tube 11 and an outer tube 12. The inner tube 11 has a cylindrical shape with a ceiling that is open at the bottom. The outer tube 12 has a cylindrical shape with a ceiling that is open at the bottom and covers the outside of the inner tube 11. The inner tube 11 and the outer tube 12 are made of a heat-resistant material such as quartz. The inner tube 11 and the outer tube 12 have a double-tube structure arranged coaxially.
[0040] A housing portion 13 for accommodating a gas supply pipe is formed along the longitudinal direction (vertical direction) of the inner pipe 11. For example, a portion of the side wall of the inner pipe 11 is made to protrude outward to form a convex portion 14, and the inside of the convex portion 14 is formed as the housing portion 13.
[0041] A rectangular opening 15 is formed along the longitudinal direction on the side wall of the inner tube 11. The opening 15 faces the housing section 13.
[0042] The opening 15 is a gas exhaust port formed to allow the gas inside the inner pipe 11 to be exhausted. The length of the opening 15 is the same as the length of the boat 16, or it is longer than the length of the boat 16 and extends vertically in both directions.
[0043] The lower end of the processing container 10 is supported by a cylindrical manifold 17. The manifold 17 is made of, for example, stainless steel. A flange 18 is formed at the upper end of the manifold 17. The flange 18 supports the lower end of the outer pipe 12. A sealing member 19, such as an O-ring, is provided between the flange 18 and the lower end of the outer pipe 12. This maintains airtightness inside the outer pipe 12.
[0044] An annular support portion 20 is provided on the inner wall of the upper part of the manifold 17. The support portion 20 supports the lower end of the inner pipe 11. A lid 21 is airtightly attached to the opening at the lower end of the manifold 17 via a sealing member 22 such as an O-ring. This airtightly closes the opening at the lower end of the processing container 10, i.e., the opening of the manifold 17. The lid 21 is made of, for example, stainless steel.
[0045] A rotating shaft 24 is provided through the center of the lid 21 via a magnetic fluid seal 23. The lower part of the rotating shaft 24 is rotatably supported by an arm 25A of a lifting mechanism 25, which consists of a boat elevator.
[0046] A rotating plate 26 is provided at the upper end of the rotating shaft 24. A boat 16 that holds substrates W is placed on the rotating plate 26 via a quartz warming stand 27. The boat 16 rotates by rotating the rotating shaft 24. The boat 16 moves up and down together with the lid 21 by raising and lowering the lifting mechanism 25. This allows the boat 16 to be inserted into and removed from the processing container 10. The boat 16 can be housed inside the processing container 10. The boat 16 holds multiple substrates W (for example, 50 to 150) in a shelf-like manner. The boat 16 holds multiple substrates W with vertical spacing between them in a substantially horizontal manner.
[0047] The gas supply unit 30 supplies gas into the processing container 10. Specifically, the gas supply unit 30 is configured to introduce various processing gases into the inner pipe 11. The gas supply unit 30 includes a silicon raw material gas supply unit 31, an oxidizing gas supply unit 32, and a purge gas supply unit 33.
[0048] The silicon raw material gas supply unit 31 includes a gas supply pipe 31a inside the processing container 10 and a supply channel 31b outside the processing container 10. In the supply channel 31b, a silicon raw material gas source 31c, a mass flow controller 31d, and a valve 31e are provided in order from the upstream side to the downstream side in the direction of gas flow. As a result, the supply timing of the silicon raw material gas from the silicon raw material gas source 31c is controlled by the valve 31e, and the flow rate is adjusted to a predetermined level by the mass flow controller 31d. The silicon raw material gas flows from the supply channel 31b into the gas supply pipe 31a and is discharged from the gas supply pipe 31a into the processing container 10.
[0049] The oxidizing gas supply unit 32 includes a gas supply pipe 32a inside the processing container 10 and a supply channel 32b outside the processing container 10. In the supply channel 32b, an oxidizing gas source 32c, a mass flow controller 32d, and a valve 32e are provided in order from upstream to downstream in the direction of gas flow. As a result, the supply timing of the oxidizing gas from the oxidizing gas source 32c is controlled by the valve 32e, and the flow rate is adjusted to a predetermined level by the mass flow controller 32d. The oxidizing gas flows from the supply channel 32b into the gas supply pipe 32a and is discharged from the gas supply pipe 32a into the processing container 10. The oxidizing gas supply unit 32 may also have at least one of a mechanism for plasmaizing the oxidizing gas and a mechanism for independently heating the oxidizing gas separately from the heating unit 50. This allows plasmaized oxidizing gas and heated oxidizing gas to be supplied to the substrate W.
[0050] The purge gas supply unit 33 includes a gas supply pipe 33a inside the processing container 10 and a supply channel 33b outside the processing container 10. In the supply channel 33b, a purge gas source 33c, a mass flow controller 33d, and a valve 33e are provided in order from the upstream side to the downstream side in the direction of gas flow. As a result, the supply timing of the purge gas from the purge gas source 33c is controlled by the valve 33e, and the flow rate is adjusted to a predetermined level by the mass flow controller 33d. The purge gas flows from the supply channel 33b into the gas supply pipe 33a and is discharged from the gas supply pipe 33a into the processing container 10.
[0051] Each gas supply pipe 31a, 32a, and 33a is fixed to the manifold 17. Each gas supply pipe 31a, 32a, and 33a is made of, for example, quartz. Each gas supply pipe 31a, 32a, and 33a extends linearly in the vertical direction near the inner pipe 11 and then bends in an L-shape within the manifold 17 to extend horizontally, thereby penetrating the manifold 17. The gas supply pipes 31a, 32a, and 33a are arranged side by side along the circumferential direction of the inner pipe 11 and are formed at the same height.
[0052] As shown in Figure 5, multiple discharge ports 31f, 32f, and 33f are provided in the portions located within the inner tubes 11 of each of the gas supply pipes 31a, 32a, and 33a. Each discharge port 31f, 32f, and 33f is formed at predetermined intervals along the extending direction of each gas supply pipe 31a, 32a, and 33a. Each discharge port 31f, 32f, and 33f discharges gas horizontally from the radially outer side of the substrate W toward the substrate W. Each discharge port 31f, 32f, and 33f discharges gas parallel to the main surface of the substrate W. The spacing between the discharge ports is set to be the same as, for example, the spacing between the substrates W held by the boat 16. The height position of each discharge port is set to be, for example, an intermediate position between adjacent substrates W in the vertical direction. In this case, each discharge port can efficiently supply gas to the opposing surfaces between adjacent substrates W.
[0053] The gas supply unit 30 may mix multiple types of gases and discharge the mixed gas from a single gas supply pipe. Each gas supply pipe 31a, 32a, and 33a may have a different shape or arrangement from the others. The gas supply unit 30 may further include a gas supply pipe for supplying another gas, such as an inert gas.
[0054] The exhaust section 40 exhausts the gas discharged from the inner pipe 11 through the opening 15 and through the space P1 between the inner pipe 11 and the outer pipe 12, which is discharged from the gas outlet 41. The gas outlet 41 is located on the upper side wall of the manifold 17 and is formed above the support section 20. An exhaust passage 42 is connected to the gas outlet 41. A pressure regulating valve 43 and a vacuum pump 44 are sequentially installed in the exhaust passage 42 to allow exhaust from inside the processing container 10.
[0055] The heating unit 50 is configured to raise the temperature of the substrate W. The heating unit 50 is provided around the outer tube 12. The heating unit 50 is provided, for example, on the base plate 28. The heating unit 50 has a cylindrical shape so as to cover the outer tube 12. The heating unit 50 includes, for example, a heating element and heats each substrate W inside the processing container 10. The temperature of the substrate W is adjusted by the operation of the heating unit 50 in response to a control signal from the control unit 90. In addition, the inner tube 11 and outer tube 12 of the processing container 10 are heated in response to the heating of the substrate W by the heating unit 50. That is, when the film deposition method according to the embodiment is carried out using a hot-wall type film deposition apparatus 1H, the substrate W and the walls of the processing container 10 (inner tube 11 and outer tube 12) are heated by the heating unit 50 located outside the processing container 10. The walls of the processing container 10 are heated to a temperature similar to that of the substrate W.
[0056] The control unit 90 may be one or more circuits, or it may be provided as a single integrated unit or in partially separated units. The control unit 90 is an electronic circuit such as a CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). The control unit 90 may also be equipped with memory such as RAM (Random Access Memory), ROM (Read Only Member), or auxiliary storage device. The control unit 90 performs the various control operations described herein by executing instruction codes stored in memory or by circuit design for special applications.
[0057] The control unit 90 controls the lifting mechanism 25 to load the boat 16 holding multiple substrates W into the processing container 10, and then seals the opening at the lower end of the processing container 10 airtight with the lid 21. Subsequently, the control unit 90 controls the exhaust unit 40 to reduce the pressure inside the processing container 10 and controls the heating unit 50 to adjust the temperature of the substrates W.
[0058] When the film deposition method according to this embodiment is carried out using a hot-wall type film deposition apparatus 1H, it is preferable that the control unit 90 controls the temperature of the substrate W to 600°C or less. More specifically, when O is used in the processing container 10 ２ When an oxidizing gas containing molecules is supplied, it is preferable for the control unit 90 to control the temperature of the substrate W to 450°C or more and 600°C or less. Also, when an oxidizing gas containing molecules is supplied to the processing container 10, ３ When an oxidizing gas containing molecules and oxygen radicals is supplied, the control unit 90 preferably controls the temperature of the substrate W to between 200°C and 600°C. This allows the silicon oxide film 101 to be formed by the ALD process. As a result, a high-quality silicon oxide film 101 with high step coverage can be obtained.
[0059] The control unit 90 controls the gas supply unit 30, exhaust unit 40, and heating unit 50 to perform the film deposition method according to the embodiment on each substrate W housed in the processing container 10. The control unit 90 executes steps S11 and S12, for example, by controlling the gas supply unit 30 and heating unit 50. The control unit 90 also controls the gas supply unit 30 and heating unit 50, for example, to perform steps S11 and S12 alternately, that is, to perform step S13. The control unit 90 may further execute step S14. The control unit 90 controls the silicon raw material gas supply unit 31 to supply silicon raw material gas into the processing container 10. The control unit 90 controls the oxidation gas supply unit 32 to supply oxidation gas into the processing container 10. The control unit 90 controls the purge gas supply unit 33 to supply purge gas into the processing container 10. As a result, a silicon oxide film 101 is formed on the surface of the substrate W.
[0060] After the silicon oxide film 101 is formed on the surface of the substrate W, the control unit 90 may control the heating unit 50 to raise the temperature of the substrate W and anneal the silicon oxide film 101.
[0061] The control unit 90 increases the pressure inside the processing container 10 to atmospheric pressure, then lowers the temperature inside the processing container 10 to the discharge temperature, and then controls the lifting mechanism 25 to discharge the boat 16 from inside the processing container 10.
[0062] As described above, the film deposition method according to the embodiment can be carried out using the film deposition apparatus 1H. In the above example, the case in which the deposition of the silicon oxide film 101 and the annealing of the silicon oxide film 101 are carried out in the same processing container 10 of the film deposition apparatus 1H was described, but the deposition of the silicon oxide film 101 and the annealing of the silicon oxide film 101 may be carried out in separate apparatuses.
[0063] Next, with reference to Figure 6, an example of the configuration of a cold-wall type film deposition apparatus 1C according to the embodiment will be described. Figure 6 is a vertical cross-sectional view showing a cold-wall type film deposition apparatus 1C according to the embodiment.
[0064] The cold wall type film deposition apparatus 1C comprises a processing container 1, a mounting table 2, a shower head 3, an exhaust unit 4, a gas supply mechanism 5, an RF power supply unit 8, and a control unit 9. Note that the gas supply mechanism 5 is an example of a "gas supply unit".
[0065] The processing container 1 is configured to accommodate a substrate W. The processing container 1 is made of a metal such as aluminum and has a substantially cylindrical shape. The processing container 1 accommodates the substrate W. An inlet / outlet 11C for loading or unloading the substrate W is formed in the side wall (wall portion) of the processing container 1. The inlet / outlet 11C is opened and closed by a gate valve 12C. An annular exhaust duct 13C with a rectangular cross-section is provided on the main body of the processing container 1. A slit 13a is formed in the exhaust duct 13C along its inner circumference. An exhaust port 13b is formed in the outer wall of the exhaust duct 13C. A top wall 14C (wall portion) is provided on the upper surface of the exhaust duct 13C so as to close the upper opening of the processing container 1 via an insulating member 16C. The space between the exhaust duct 13C and the insulating member 16C is airtightly sealed with a sealing member 15C. The sealing member 15C may be, for example, an O-ring. The partition member 17C divides the inside of the processing container 1 vertically when the mounting platform 2 (and cover member 22C) rises to the processing position described later.
[0066] The mounting table 2 horizontally supports the substrate W within the processing container 1. The mounting table 2 has a disc shape. The outer diameter of the mounting table 2 is larger than, for example, the outer diameter of the substrate W. The mounting table 2 is made of a ceramic material such as aluminum nitride (AlN) or a metallic material such as aluminum or nickel alloy. A heating unit 21C (e.g., a heater) for heating the substrate W is embedded inside the mounting table 2. The heating unit 21C is powered by a power source (not shown) and generates heat. The heating unit 21C is configured to raise the temperature of the substrate W. A thermocouple (not shown) is provided near the upper surface of the mounting table 2. By controlling the output of the heating unit 21C with the temperature signal of the thermocouple, the substrate W is controlled to a predetermined temperature. The mounting table 2 is provided with a cover member 22C made of ceramic material such as alumina so as to cover the outer peripheral region of the upper surface and the sides.
[0067] When the film deposition method according to the embodiment is carried out using a cold-wall type film deposition apparatus 1C, the substrate W is heated by a heating unit 21C located inside the processing container 1. On the other hand, the walls of the processing container 1 (side walls, bottom wall, and top wall 14C) are not directly heated by the heating unit 21C. Therefore, the temperature change in the walls of the processing container 1 before and after the operation of the heating unit 21C is sufficiently small compared to the temperature change of the substrate W.
[0068] A support member 23C is provided on the bottom surface of the mounting table 2. The support member 23C supports the mounting table 2. The support member 23C extends from the center of the bottom surface of the mounting table 2, through a hole formed in the bottom wall of the processing container 1, and downward to the processing container 1. The lower end of the support member 23C is connected to a lifting mechanism 24C. The lifting mechanism 24C raises and lowers the mounting table 2 via the support member 23C between the processing position shown in Figure 6 and the transport position below it, indicated by the dashed line, where the substrate W can be transported. A flange portion 25C is attached below the support member 23C of the processing container 1. A bellows 26C is provided between the bottom surface of the processing container 1 and the flange portion 25C. The bellows 26C partitions the atmosphere inside the processing container 1 from the outside air and expands and contracts in accordance with the lifting and lowering operation of the mounting table 2.
[0069] Three support pins 27C (only two are shown) are provided near the bottom of the processing container 1, protruding upward from the lifting plate 27a. The support pins 27C are raised and lowered via the lifting plate 27a by a lifting mechanism 28C located below the processing container 1. The support pins 27C are inserted through holes 2a provided in the mounting table 2 at the transport position, and are able to protrude and retract relative to the upper surface of the mounting table 2. By raising and lowering the support pins 27C, the substrate W is transferred between the mounting table 2 and a transport device (not shown) located in a vacuum transport chamber (not shown) connected to the film deposition apparatus 1C.
[0070] The shower head 3 supplies processing gas into the processing container 1 in a shower-like manner. The shower head 3 is made of metal and is installed facing the mounting base 2. The shower head 3 has approximately the same diameter as the mounting base 2. The shower head 3 has a main body 31C and a shower plate 32C. The main body 31C is fixed to the top wall 14C of the processing container 1. The shower plate 32C is connected below the main body 31C. A gas diffusion space 33C is formed between the main body 31C and the shower plate 32C. A gas introduction hole 36 is provided in the gas diffusion space 33C so as to penetrate the center of the top wall 14C and the main body 31C. An annular projection 34 protruding downward is formed on the periphery of the shower plate 32C. A gas discharge hole 35 is formed in the flat part inside the annular projection 34. When the mounting table 2 is in the processing position, a processing space 38 is formed between the mounting table 2 and the shower plate 32C, and the upper surface of the cover member 22C and the annular projection 34 are in close proximity to form an annular gap 39.
[0071] The exhaust unit 4 exhausts the inside of the processing container 1. The exhaust unit 4 has an exhaust pipe 41C and an exhaust mechanism 42C. The exhaust pipe 41C is connected to the exhaust port 13b. The exhaust mechanism 42C has a vacuum pump connected to the exhaust pipe 41C and a pressure control valve. During processing, the gas inside the processing container 1 reaches the exhaust duct 13C through the slit 13a, and is exhausted from the exhaust duct 13C through the exhaust pipe 41C by the exhaust mechanism 42C.
[0072] The gas supply mechanism 5 supplies gas into the processing container 1. Specifically, the gas supply mechanism 5 supplies various processing gases to the shower head 3. The gas supply mechanism 5 includes a silicon raw material gas supply unit 51, an oxidation gas supply unit 52, and a purge gas supply unit 53.
[0073] One end of the gas line 51b is connected to the gas supply source 51a of the silicon raw material gas supply unit 51. A valve 51c, a fill tank 51d, and a mass flow controller 51e are arranged in the gas line 51b from the downstream side in the direction of gas flow. The valve 51c switches the supply of silicon raw material gas on and off. The fill tank 51d temporarily stores the silicon raw material gas and supplies the required silicon raw material gas in a short time. The mass flow controller 51e controls the flow rate of the silicon raw material gas flowing through the gas line 51b. The silicon raw material gas is introduced into the gas diffusion space 33C through the gas line 51b and the common line 59. The fill tank 51d may be provided as needed.
[0074] One end of the gas line 52b is connected to the gas supply source 52a of the oxidizing gas supply unit 52. A valve 52c, a fill tank 52d, and a mass flow controller 52e are arranged in the gas line 52b from downstream in the direction of gas flow. The valve 52c switches between supplying and stopping the oxidizing gas. The fill tank 52d temporarily stores the oxidizing gas and supplies the required amount of oxidizing gas in a short time. The mass flow controller 52e controls the flow rate of the oxidizing gas flowing through the gas line 52b. The oxidizing gas is introduced into the gas diffusion space 33C through the gas line 52b and the common line 59. The fill tank 52d may be provided as needed.
[0075] Oxidizing agent OA contained in oxidizing gas ２ When molecules are used, it is preferable that a heater 52h is provided in the gas line 52b of the oxidizing gas supply unit 52 to heat the oxidizing gas flowing from the gas supply source 52a. By providing a heater 52h in the gas line 52b, for example, a high temperature O50°C or higher can be heated. ２ Molecules can be supplied to the substrate W. This allows O ２The molecules can reach deep into the recesses R of the substrate W while maintaining a highly reactive state. As a result, the step coverage of the silicon oxide film 101 can be increased. Note that the position of the heater 52h for heating the oxidizing gas is not limited to the gas line 52b. The heater 52h for heating the oxidizing gas may be placed in other locations, such as the shower head 3.
[0076] One end of the gas line 53b is connected to the gas supply source 53a of the purge gas supply unit 53. A valve 53c and a mass flow controller 53e are arranged in the gas line 53b from the downstream side in the direction of gas flow. The valve 53c switches the supply and stop of purge gas. The mass flow controller 53e controls the flow rate of purge gas flowing through the gas line 53b. The purge gas is introduced into the gas diffusion space 33C through the gas line 53b and the common line 59.
[0077] The cold-wall type film deposition apparatus 1C may be, for example, a capacitively coupled plasma apparatus, configured such that the mounting stage 2 functions as the lower electrode and the showerhead 3 functions as the upper electrode. The mounting stage 2 is grounded. The showerhead 3 is connected to the RF power supply unit 8.
[0078] The RF power supply unit 8 supplies high-frequency power (hereinafter also referred to as "RF power") to the shower head 3. The RF power supply unit 8 includes an RF power supply 81, a matching unit 82, and a power supply line 83. The RF power supply 81 is a power source that generates RF power. The RF power has a frequency suitable for plasma generation. The frequency of the RF power is, for example, within the range of 450 kHz in the low frequency band to 2.45 GHz in the microwave band. The RF power supply 81 is connected to the main unit 31C via the matching unit 82 and the power supply line 83. The matching unit 82 has a circuit for matching the load impedance to the internal impedance of the RF power supply 81. The RF power supply unit 8 may also be configured to supply RF power to the mounting base 2.
[0079] The control unit 9 may be one or more circuits, or it may be provided as a single unit or in separate parts. The control unit 9 may be, for example, a computer. The control unit 9 includes a CPU, RAM, ROM, auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or auxiliary storage device and controls the operation of the film deposition apparatus 1C. The control unit 9 may be provided inside or outside the film deposition apparatus 1C. If the control unit 9 is provided outside the film deposition apparatus 1C, the control unit 9 can control the film deposition apparatus 1C by communication means such as wired or wireless.
[0080] The control unit 9 controls the gas supply mechanism 5, the exhaust unit 4, and the heating unit 21C to perform the film deposition method according to the embodiment on the substrate W housed in the processing container 1. The control unit 9 executes steps S11 and S12, for example, by controlling the gas supply mechanism 5 and the heating unit 21C. The control unit 9 also controls the gas supply mechanism 5 and the heating unit 21C, for example, to perform steps S11 and S12 alternately, that is, to perform step S13. The control unit 9 may further execute step S14. The control unit 9 controls the silicon raw material gas supply unit 51 to supply silicon raw material gas into the processing container 1. The control unit 9 controls the oxidation gas supply unit 52 to supply oxidation gas into the processing container 1. The control unit 90 controls the purge gas supply unit 53 to supply purge gas into the processing container 1. As a result, a silicon oxide film 101 is formed on the surface of the substrate W.
[0081] When the film deposition method according to this embodiment is carried out using a cold wall type film deposition apparatus 1C, it is preferable that the control unit 9 controls the temperature of the substrate W to 700°C or less. More specifically, when O is placed in the processing container 1 ２ When an oxidizing gas containing molecules is supplied, it is preferable for the control unit 9 to control the temperature of the substrate W to 450°C or more and 700°C or less. Also, when an oxidizing gas containing molecules is supplied to the processing container 1, ３When an oxidizing gas containing molecules and oxygen radicals is supplied, the control unit 9 preferably controls the temperature of the substrate W to between 200°C and 700°C. This allows the silicon oxide film 101 to be formed by the ALD process. As a result, a high-quality silicon oxide film 101 with high step coverage can be obtained.
[0082] After the silicon oxide film 101 is formed on the surface of the substrate W, the control unit 9 may control the heating unit 21C to raise the temperature of the substrate W and anneal the silicon oxide film 101. For example, after the annealing of the silicon oxide film 101 is completed, the control unit 90 controls the transport device (not shown) to transport the substrate W from the processing container 1 to a vacuum transport chamber (not shown).
[0083] As described above, the film deposition method according to the embodiment can be carried out using the film deposition apparatus 1C. In the above example, the case in which the deposition of the silicon oxide film 101 and the annealing of the silicon oxide film 101 are carried out in the same processing container 1 of the film deposition apparatus 1C was described, but the deposition of the silicon oxide film 101 and the annealing of the silicon oxide film 101 may be carried out in separate apparatuses.
[0084] [Examples] Next, examples of the film formation method according to the embodiment will be described. However, the film formation method of this disclosure is not limited to these examples. In the following description, the chemical reaction of the raw materials that occurs during the thin film formation process in the ALD process will be referred to as the "ALD reaction". Also, the chemical reaction of the raw materials that occurs during the thin film formation process in the CVD (Chemical Vapor Deposition) method (CVD process) will be referred to as the "CVD reaction".
[0085] (Relationship between substrate W temperature and silicon oxide film 101 growth rate) An example of the relationship between substrate W temperature and silicon oxide film 101 growth rate will be explained with reference to Figure 7. Figure 7 is a graph showing an example of the relationship between substrate W temperature and silicon oxide film 101 growth rate for Examples 1 and 2. The horizontal axis of Figure 7 is the temperature of substrate W [°C] when the silicon oxide film 101 was deposited. The vertical axis of Figure 7 is the growth rate of silicon oxide film 101 per cycle [Å / cycle] when the temperature of substrate W is changed. In Figure 7, the symbol "Ex1" indicates the results for Example 1. The symbol "Ex2" indicates the results for Example 2.
[0086] Each embodiment shown in Figure 7 is as follows:
[0087] <Example 1> In Example 1, a substrate W placed in the processing container 10 of a hot-wall type film deposition apparatus 1H is subjected to silicon raw material gas and an oxidizing agent OA as O ２ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 1, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC.
[0088] <Example 2> In Example 2, a substrate W placed in the processing container 1 of a cold wall type film deposition apparatus 1C is subjected to silicon raw material gas and an oxidizing agent OA as O ２ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 2, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC.
[0089] When the silicon oxide film 101 in Example 1 is formed, the walls of the processing container 10 are heated to a temperature similar to that of the substrate W. In Example 1, in one cycle of steps S11 and S12, silicon raw material gas and oxidizing gas with pressures of approximately 1 Torr and approximately 10 Torr, respectively, were supplied to the substrate W for 60 seconds each. In Example 1, the temperature range of the substrate W from 400°C to 700°C was used for measurement.
[0090] In Example 2, when the silicon oxide film 101 is formed, the substrate W is heated, while the walls of the processing container 1 are hardly heated. The temperature of the walls of the processing container 1 is maintained at a low temperature even while the film formation method according to the embodiment is being carried out. In Example 2, in one cycle of step S11 and step S12, silicon raw material gas and oxidizing gas with pressures of approximately 1 Torr and approximately 10 Torr, respectively, were supplied to the substrate W for 60 seconds each. In Example 2, the temperature range of the substrate W from 500°C to 700°C was used for measurement.
[0091] In Example 1, the formation of the silicon oxide film 101 was confirmed throughout the entire measurement range. Specifically, the growth rate of the silicon oxide film 101 increased when the substrate temperature W was in the range of 400°C to 450°C. Around 400°C, O ２ The oxidizing power of the oxidizing gas containing the molecules was weak, and the growth rate was considered to be low. Furthermore, the growth rate of the silicon oxide film 101 was almost constant in the range of 450°C to 600°C when the temperature of the substrate W was between 450°C and 600°C. In the range of 450°C to 600°C when the temperature of the substrate W was between 450°C and 600°C, it is considered that the silicon oxide film 101 was formed by an ideal ALD reaction. Furthermore, in the range where the temperature of the substrate W was above 600°C, the growth rate of the silicon oxide film 101 increased sharply. In the range where the temperature of the substrate W was above 600°C, the temperature of the wall of the processing container 10 was also raised to a temperature above 600°C, so it is considered that conditions were created in which thermal decomposition of the silicon-containing compound SC was likely to occur. Therefore, in the range where the temperature of the substrate W was above 600°C, the CVD reaction of the silicon-containing compound SC proceeded, and it is considered that a silicon-rich silicon oxide film 101 was formed.
[0092] The process window in Example 1 is considered to be between 450°C and 600°C, considering the growth rate and the thermal decomposition of the silicon-containing compound SC. In Example 1, the process window was broadened compared to Example 2, which will be described later.
[0093] In Example 2, the formation of the silicon oxide film 101 was confirmed across the entire measurement range. Specifically, the growth rate of the silicon oxide film 101 increased gradually when the temperature of the substrate W was in the range of 500°C to 650°C. The wall portion of the processing container 1 of the cold-wall type film deposition apparatus 1C was hardly heated. Therefore, the O2O ２ The oxidizing power of the oxidizing gas containing molecules is weak, and the growth rate is low. As the temperature of the substrate W increases, ２ It is thought that the heat received by the molecules from the substrate W increases, leading to an increase in oxidizing power and, as a result, an increase in the growth rate. Furthermore, the growth rate of the silicon oxide film 101 was almost constant when the temperature of the substrate W was in the range of 650°C to 700°C. It is thought that the silicon oxide film 101 was formed by an ideal ALD reaction when the temperature of the substrate W was in the range of 650°C to 700°C. In addition, in Example 2, since the wall portion of the processing container 1 of the cold wall type film deposition apparatus 1C is hardly heated, it is thought that the silicon-containing compound SC is less likely to thermally decompose before reaching the substrate W even when the temperature of the substrate W is 700°C.
[0094] The process window in Example 2 is considered to be 550°C to 700°C, considering the growth rate and the thermal decomposition of the silicon-containing compound SC. In Example 1, it is highly probable that the silicon oxide film 101 could be formed by an ideal ALD reaction when the substrate W temperature was 450°C. Therefore, in Example 2 as well, O ２ If an oxidizing gas containing molecules is heated to over 450°C and supplied, it is thought that a silicon oxide film 101 can be formed by an ideal ALD reaction even when the substrate W temperature is 450°C. In other words, O ２ If the oxidizing gas containing molecules is preheated to 450°C or higher before being supplied to the substrate W, the process window in Example 2 is considered to be from 450°C to 700°C.
[0095] Next, with reference to Figure 8, other examples of the relationship between the temperature of the substrate W and the growth rate of the silicon oxide film 101 will be described. Figure 8 is a graph showing other examples of the relationship between the temperature of the substrate W and the growth rate of the silicon oxide film 101 for Examples 3 and 4. The horizontal axis of Figure 8 is the temperature of the substrate W [°C] when the silicon oxide film 101 was deposited. The vertical axis of Figure 8 is the growth rate of the silicon oxide film 101 per cycle [Å / cycle] when the temperature of the substrate W is changed. In Figure 8, the symbol "Ex3" indicates the results for Example 3. The symbol "Ex4" indicates the results for Example 4.
[0096] Each embodiment shown in Figure 8 is as follows:
[0097] <Example 3> In Example 3, a substrate W is placed in the processing container 10 of a hot-wall type film deposition apparatus 1H, and silicon raw material gas and oxidizing agent OA are added. ３ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 3, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC.
[0098] <Example 4> In Example 4, a substrate W is placed in the processing container 1 of a cold wall type film deposition apparatus 1C, and silicon raw material gas and oxidizing agent OA are added. ３ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 4, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC.
[0099] In Example 3, when the silicon oxide film 101 is formed, the walls of the processing container 10 are heated to a temperature similar to that of the substrate W. In Example 3, in one cycle of steps S11 and S12, silicon raw material gas and oxidizing gas with pressures of approximately 1 Torr and approximately 10 Torr, respectively, were supplied to the substrate W for 60 seconds each. In Example 3, the temperature range of the substrate W from 130°C to 650°C was used for measurement.
[0100] In Example 4, when the silicon oxide film 101 is formed, the substrate W is heated, while the walls of the processing container 1 are hardly heated. The temperature of the walls of the processing container 1 is maintained at a low temperature even after the film formation method is carried out. In Example 4, in one cycle of step S11 and step S12, silicon raw material gas and oxidizing gas with pressures of approximately 1 Torr and approximately 10 Torr, respectively, were supplied to the substrate W for 60 seconds each. In Example 4, the temperature range of the substrate W from 130°C to 700°C was used for measurement.
[0101] In Example 3, the formation of the silicon oxide film 101 was confirmed across the entire measurement range. Specifically, the growth rate of the silicon oxide film 101 increased when the temperature of the substrate W was in the range of 130°C to 200°C. Furthermore, the growth rate of the silicon oxide film 101 remained almost constant when the temperature of the substrate W was in the range of 200°C to 600°C. It is considered that the silicon oxide film 101 was formed by an ideal ALD reaction when the temperature of the substrate W was in the range of 200°C to 600°C. Moreover, the growth rate of the silicon oxide film 101 increased sharply when the temperature of the substrate W exceeded 600°C. Since the temperature of the walls of the processing container 10 also rose to a temperature above 600°C when the temperature of the substrate W was above 600°C, it is considered that conditions were created in which thermal decomposition of the silicon-containing compound SC was likely to occur. Therefore, it is considered that the CVD reaction of the silicon-containing compound SC proceeded when the temperature of the substrate W exceeded 600°C, resulting in the formation of a silicon-rich silicon oxide film 101.
[0102] The process window in Example 3 is considered to be between 200°C and 600°C, from the viewpoint of the growth rate and the thermal decomposition of the silicon-containing compound SC.
[0103] In Example 4, the formation of the silicon oxide film 101 was confirmed across the entire measurement range. Specifically, the growth rate of the silicon oxide film 101 increased when the temperature of the substrate W was in the range of 130°C to 200°C. Furthermore, the growth rate of the silicon oxide film 101 remained almost constant when the temperature of the substrate W was in the range of 200°C to 700°C.
[0104] The process window in Example 4 is considered to be between 200°C and 700°C, considering the growth rate and the thermal decomposition of the silicon-containing compound SC. In Example 4, the process window of the ALD process was broadened compared to Example 3.
[0105] (Step coverage of silicon oxide film 101) An example of step coverage of silicon oxide film 101 will be explained with reference to Figure 9. Figure 9 is a graph showing an example of step coverage of silicon oxide film 101 for Examples 5 to 7. The horizontal axis of Figure 9 is the depth [μm] of the recess R in the substrate W. The vertical axis of Figure 9 is the film thickness of silicon oxide film 101 at multiple depth positions in the recess R of the substrate W. The values on the vertical axis of Figure 9 are normalized by the film thickness of silicon oxide film 101 deposited at a recess R 0.1 μm deep from the top surface U of the substrate W (reference position). In Figure 9, the symbol "Ex5" indicates the result of Example 5. The symbol "Ex6" indicates the result of Example 6. The symbol "Ex7" indicates the result of Example 7.
[0106] Each embodiment shown in Figure 9 is as follows:
[0107] <Example 5> In Example 5, a substrate W is placed in the processing container 10 of a hot-wall type film deposition apparatus 1H, and silicon raw material gas and oxidizing agent OA are added. ２ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 5, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC. The temperature of the substrate W was adjusted to 600°C.
[0108] <Example 6> In Example 6, a substrate W is placed in the processing container 1 of a cold wall type film deposition apparatus 1C, and silicon raw material gas and oxidizing agent OA are added. ２ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 6, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC. The temperature of the substrate W was adjusted to 600°C.
[0109] <Example 7> In Example 7, a substrate W is placed in the processing container 1 of a cold wall type film deposition apparatus 1C, and silicon raw material gas and oxidizing agent OA are added. ２ This is an example in which a silicon oxide film 101 was formed by alternately supplying an oxidizing gas containing molecules and generating oxygen plasma in the processing container 1. In Example 7, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC. The temperature of the substrate W was adjusted to 300°C.
[0110] In each of Examples 5 to 7, the maximum depth of the recess R was set to 3 μm, and the opening width of the recess R was set to 80 nm. That is, in each of Examples 5 to 7, the aspect ratio of the recess R was set to 37.5 (3 μm / 80 nm).
[0111] In Example 5, the thickness of the silicon oxide film 101 was almost constant regardless of the depth of the recess R. In Example 5, the wall of the processing container 10 was also heated to about 600°C. Therefore, the O supplied into the processing container 10 ２ It is believed that the molecules received high thermal energy from the walls of the processing container 10 and reached the deeper parts of the recess R in a highly reactive state. As a result, it is believed that a silicon oxide film 101 with a thickness similar to that of the reference position was formed in the deeper parts of the recess R. In Example 5, a silicon oxide film 101 with high step coverage was obtained.
[0112] In Example 6, the thickness of the silicon oxide film 101 decreased as the depth of the recess R increased. In Example 6, the temperature of the wall of the processing container 1 was maintained at a low temperature. Therefore, the O supplied into the processing container 1 ２It is thought that the molecules were unable to receive thermal energy from the wall of the processing container 1 and therefore could not reach the deeper parts of the recess R in a highly reactive state. As a result, it is thought that the thickness of the silicon oxide film 101 at the deeper parts of the recess R was reduced. However, referring to the results of Example 5, it is possible to increase the step coverage of the silicon oxide film 101 by supplying an oxidizing gas that has been preheated to a high temperature (for example, a temperature of 600°C or higher) to the substrate W. Furthermore, referring to the results of Example 1, it is thought that it is possible to increase the step coverage of the silicon oxide film 101 even when using a cold-wall type film deposition apparatus 1C by supplying an oxidizing gas heated to 450°C or higher to the substrate W.
[0113] In Example 7, the thickness of the silicon oxide film 101 was almost constant regardless of the depth of the recess R. In Example 7, highly reactive oxygen radicals acted as the oxidizing agent OA. Therefore, even if the temperature of the wall of the processing container 1 was maintained at a low temperature, it is thought that the oxygen radicals were able to reach the deeper parts of the recess R while maintaining a highly reactive state. As a result, it is thought that a silicon oxide film 101 with a thickness similar to that of the reference position was formed even in the deeper parts of the recess R. In Example 7, a silicon oxide film 101 with high step coverage was obtained.
[0114] Referring to Figure 10, other examples of step coverage of the silicon oxide film 101 will be described. Figure 10 is a graph showing other examples of step coverage of the silicon oxide film 101 for Examples 8 to 11. The horizontal axis of Figure 10 is the depth [μm] of the recess R in the substrate W. The vertical axis of Figure 10 is the film thickness of the silicon oxide film 101 at multiple depth positions in the recess R of the substrate W. Note that the values on the vertical axis of Figure 10 are normalized by the film thickness of the silicon oxide film 101 deposited at a reference position in the recess R. In Figure 10, the symbol "Ex8" indicates the result for Example 8. The symbol "Ex9" indicates the result for Example 9. The symbol "Ex10" indicates the result for Example 10. The symbol "Ex11" indicates the result for Example 11.
[0115] Each embodiment shown in Figure 10 is as follows:
[0116] <Example 8> In Example 8, a substrate W is placed in the processing container 10 of a hot-wall type film deposition apparatus 1H, and silicon raw material gas and oxidizing agent OA are added. ３ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 8, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC. The temperature of the substrate W was adjusted to 300°C.
[0117] <Example 9> In Example 9, a substrate W is placed in the processing container 10 of a hot-wall type film deposition apparatus 1H, and silicon raw material gas and oxidizing agent OA are added. ３ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 9, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC. The temperature of the substrate W was adjusted to 600°C.
[0118] <Example 10> In Example 10, a substrate W is placed in the processing container 1 of a cold wall type film deposition apparatus 1C, and silicon raw material gas and oxidizing agent OA are added. ３ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 10, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC. The temperature of the substrate W was adjusted to 300°C.
[0119] <Example 11> In Example 11, a substrate W placed in the processing container 1 of a cold wall type film deposition apparatus 1C is subjected to silicon raw material gas and an oxidizing agent OA as O ３ This is an example of forming a silicon oxide film 101 by alternately supplying an oxidizing gas containing molecules. In Example 11, a silicon raw material gas containing 3,5-dimethylpyrazolyltrimethoxysilane was used as the silicon-containing compound SC. The temperature of the substrate W was adjusted to 600°C.
[0120] In each of Examples 8 to 11, a substrate W having a recess R with the same aspect ratio as in Examples 5 to 7 was used.
[0121] As shown in Figure 10, in each of Examples 8 to 11, the thickness of the silicon oxide film 101 was almost constant regardless of the depth of the recess R. In each of Examples 8 to 11, O ３ It is thought that the molecules were able to reach the deeper parts of the recess R while maintaining a highly reactive state. As a result, it is thought that a silicon oxide film 101 with a thickness similar to that of the reference position was formed even in the deeper parts of the recess R. In each of Examples 8 to 11, a silicon oxide film 101 with high step coverage was obtained.
[0122] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.
[0123] This international application claims priority based on Japanese Patent Application No. 2025-016041, filed on 3 February 2025, and the entire contents of said application are incorporated herein by reference.
[0124] 101 Silicon oxide film W Substrate R Recess R1 Inner surface of recess SC Silicon-containing compound
Claims
1. A method for forming a silicon oxide film, comprising: (a) a step of supplying a silicon raw material gas containing a silicon-containing compound represented by the following formula (1) to a substrate; and (b) a step of supplying an oxidizing gas containing an oxidizing agent to the substrate, wherein step (a) and step (b) are performed alternately. In formula (1), R1, R2, and R3 are hydrogen atoms or linear, branched, or cyclic alkyl groups, and R4, R5, and R6 are linear, branched, or cyclic alkyl groups.
2. The method for forming a film according to claim 1, wherein the steps (a) and (b) are carried out using a hot-wall type film deposition apparatus and with the temperature of the substrate set to 600°C or lower.
3. The method for forming a film according to claim 1, wherein the steps (a) and (b) are carried out using a cold-wall type film deposition apparatus and with the temperature of the substrate set to 700°C or lower.
4. The film formation method according to claim 2 or claim 3, wherein the oxidizing agent comprises oxygen molecules.
5. The method for forming a film according to claim 2 or 3, wherein the oxidizing agent comprises oxygen molecules, and step (b) comprises supplying the oxidizing gas heated to 450°C or higher.
6. The film formation method according to claim 5, wherein step (b) includes raising the temperature of the substrate to 450°C or higher.
7. The method for forming a film according to claim 2 or 3, wherein the oxidizing agent comprises oxygen molecules, and step (b) comprises generating oxygen plasma from the oxygen molecules.
8. The film formation method according to claim 2 or 3, wherein the oxidizing agent includes ozone molecules.
9. The method for forming a film according to any one of claims 1 to 3, wherein the substrate has a recess, and the silicon oxide film is formed on the inner surface of the recess.
10. A film deposition apparatus comprising: a processing container configured to accommodate a substrate; a gas supply unit for supplying gas into the processing container; a heating unit configured to raise the temperature of the substrate; and a control unit, wherein the control unit controls the gas supply unit and the heating unit to perform the following steps: supplying a silicon raw material gas containing a silicon-containing compound represented by the following formula (1) to the substrate; and supplying an oxidizing gas containing an oxidizing agent to the substrate; and controlling the gas supply unit and the heating unit so that steps (a) and (b) are performed alternately. In formula (1), R1, R2, and R3 are hydrogen atoms or linear, branched, or cyclic alkyl groups, and R4, R5, and R6 are linear, branched, or cyclic alkyl groups.