Film forming apparatus and substrate support apparatus

Abstract

To provide a deposition device and a substrate support device capable of suppressing cost and suppressing deterioration of film forming performance.SOLUTION: A deposition device includes a chamber (10). A mounting portion (20) is provided so as to be able to mount a substrate (W) in the chamber and contains aluminum nitride. A heater (30) is provided in the mounting portion. A supply portion (40) supplies process gas for film formation to the substrate on the mounting portion in the chamber. A cover film (21) covers the mounting surface of the mounting portion on which the substrate is mounted, the back surface opposite to the mounting surface, and the side surface between the mounting surface and the back surface, and contains yttrium oxide.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present embodiment relates to a film forming apparatus and a substrate supporting apparatus. [Background technology]

[0002] In film formation apparatuses using the CVD (Chemical Vapor Deposition) method, films and particles that adhere to the inner walls of the chamber or the stage during film formation are cleaned using fluorine radicals. However, in such a cleaning process, the stage may be etched by the fluorine radicals and may adhere to the shower head of the process gas as fluorides. If such fluorides accumulate on the shower head, the film formation performance during film formation deteriorates and the in-plane uniformity of the formed film is deteriorated.

[0003] Since fluoride attached to the shower head is difficult to remove, the shower head itself must be replaced periodically, which increases costs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4856978 [Patent Document 2] U.S. Patent No. 9,975,320 [Patent Document 3] U.S. Patent Publication No. 2017 / 0140902 [Patent Document 4] U.S. Patent No. 7,312,974 [Patent Document 5] U.S. Patent Publication No. 2001 / 0003271 [Patent Document 6] JP 2004-002101 A Summary of the Invention [Problem to be solved by the invention]

[0005] A film forming apparatus and a substrate supporting apparatus capable of suppressing costs and suppressing deterioration of film forming performance are provided. [Means for solving the problem]

[0006] The film forming apparatus according to the present embodiment includes a chamber. The mounting part is provided so that a substrate can be mounted in the chamber, and includes aluminum nitride. The heater is provided in the mounting part. The supply part supplies a process gas for film formation to the substrate on the mounting part in the chamber. The cover film covers the mounting surface of the mounting part on which the substrate is mounted, the back surface opposite the mounting surface, and a side surface between the mounting surface and the back surface, and includes yttrium oxide. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing an example of the configuration of a film forming apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a configuration example of a stage according to the first embodiment. [Figure 3A] 13 is a graph showing the spectral intensity peak ratio of the constituent material of the cover film to the constituent material of the mounting portion. [Figure 3B] 1 is a graph showing the relationship between the peak ratio and the number of particles. [Figure 3C] 1 is a graph showing the relationship between the peak ratio and the mass change rate due to washing. [Figure 4A] 13 is a graph showing the spectral intensity peak ratio of the constituent material of the cover film to the constituent material of the mounting portion. [Figure 4B] 1 is a graph showing the relationship between the peak ratio and the number of particles. [Figure 4C] 1 is a graph showing the relationship between the peak ratio and the mass change rate due to washing. [Diagram 5] FIG. 11 is a cross-sectional view showing an example of the configuration of a stage according to a second embodiment. [Figure 6] FIG. 4 is a partial cross-sectional view showing in detail an example of a mounting surface of a stage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment. The drawings are schematic or conceptual, and the ratio of each part is not necessarily the same as the actual one. In the specification and drawings, elements similar to those described above with respect to the previous drawings are given the same reference numerals, and detailed descriptions are omitted as appropriate.

[0009] (First embodiment) 1 is a cross-sectional view showing an example of the configuration of a film forming apparatus 1 according to the first embodiment. The film forming apparatus 1 is, for example, a plasma CVD apparatus or a thermal CVD apparatus, and is a film forming apparatus 1 that uses a halogen-based gas including fluorine in a cleaning process in a chamber 10.

[0010] The film forming apparatus 1 includes a chamber 10, a mounting unit 20, a cover film 21, a heater 30, a shower head 40, a driving unit 50, and a controller 60. When the film forming apparatus 1 is a plasma CVD apparatus, the film forming apparatus 1 may further include a high-frequency application electrode, an RF power supply, a matching box, and the like (not shown).

[0011] The chamber 10 is a hollow housing, and the inside of the chamber 10 can be depressurized by drawing a vacuum. The chamber 10 is made of a metal material such as aluminum.

[0012] The mounting part 20 is provided in the chamber 10 and is capable of mounting a semiconductor substrate W. The mounting part 20 vacuum-sucks or electromagnetically-sucks the semiconductor substrate W, and is capable of rotating about an axis 25 by receiving a driving force from a driving part 50. The mounting part 20 is mainly made of aluminum nitride.

[0013] The surface of the mounting portion 20 is covered with a cover film 21. The cover film 21 is made of yttrium oxide.

[0014] The heater 30 is provided in the mounting part 20, and is capable of heating the mounting part 20 and the semiconductor substrate W thereon to a temperature of 400° C. or higher under the control of and power supply from the controller 60. The heater 30 may be, for example, an electric heating coil such as a nichrome wire.

[0015] The mounting portion 20 and the heater 30 are sintered as a single unit, and the cover film 21 covers the mounting portion 20 to form the stage 2. The detailed structure of the stage 2 will be described later.

[0016] The showerhead 40 has a hollow member with a plurality of openings 43 formed therein, and is configured so that the openings 43 of the showerhead 40 face the stage 2 and can supply gas toward the stage 2. The showerhead 40 supplies a process gas for film formation or a cleaning gas for cleaning into the chamber 10. A pipe 41 for supplying a process gas and a pipe 42 for supplying a cleaning gas are connected to the showerhead 40.

[0017] The pipe 41 supplies a process gas to the shower head 40 as indicated by an arrow A2 when a film is formed on the semiconductor substrate W. Thus, the process gas is supplied from an opening 43 of the shower head 40 to the semiconductor substrate W on the stage 2. The process gas is, for example, TEOS (TetraEthOxySilane), silane (SiH4), tungsten fluoride (WF6), and O2, N2O as an oxidizing agent, N2, NH3, or the like as a nitriding agent, and is used to form a silicon oxide film, a silicon nitride film, or a metal film such as tungsten on the semiconductor substrate W.

[0018] When cleaning the inside of the chamber 10 after film formation, the pipe 42 supplies a cleaning gas to the shower head 40 as indicated by an arrow A3. In this way, the cleaning gas is supplied into the chamber 10 from an opening 43 of the shower head 40. The cleaning gas is, for example, fluorine radicals, and is used to clean the inner wall of the chamber 10 and the stage 2.

[0019] The driving unit 50 drives the stage 2 to rotate about the axis 25. The controller 60 controls the supply of power to the heater 30 and / or the driving unit 50.

[0020] 2 is a cross-sectional view showing an example of the configuration of the stage 2 according to the first embodiment. The stage 2 as a substrate support device includes a mounting portion 20, a cover film 21, a heater 30, and a connector portion 22.

[0021] The mounting part 20 incorporates the entire heater 30, and is sintered integrally with the heater 30 as described above. Therefore, the heater 30 is not exposed inside the chamber 10. The mounting part 20 has a mounting surface F1 on which the semiconductor substrate W is mounted, a back surface F2 opposite to the mounting surface F1, and a side surface F3 between the mounting surface F1 and the back surface F2. When viewed from above the mounting surface F1, the mounting part 20 has, for example, a substantially circular shape larger than the outer shape of the semiconductor substrate W. Also, when viewed from the side of the side surface F3, the mounting part 20 has, for example, a substantially rectangular shape as shown in FIG. 2. That is, the mounting part 20 has a substantially cylindrical shape.

[0022] The cover film 21 covers the mounting surface F1, the back surface F2, and the side surface F3 of the mounting portion 20. For example, the cover film 21 is made of a material containing yttrium oxide such as Y2O3 or YOF. The cover film 21 covers almost the entire surface of the mounting portion 20 except for at least the connector portion 22. The cover film 21 covers the mounting surface F1, the back surface F2, and the side surface F3 of the mounting portion 20 with a substantially uniform film thickness. The film thickness of the cover film 21 is, for example, 0.5 μm or more and less than 10 μm.

[0023] The connector portion 22 is connected to the shaft 25 shown in Fig. 1. By connecting the connector portion 22 to the shaft 25, the electric heating coil of the heater 30 is connected to the controller 60 via the heating wire of the shaft 25. Also, by connecting the connector portion 22 to the shaft 25, the mounting portion 20 is connected to the driving portion 50 via the shaft 25 and becomes rotatable. Note that in the stage 2, the mounting portion 20 and the shaft 25 can also be constructed by integrally sintering, in which case the cover film 21 may cover up to the circumferential surface of the shaft 25.

[0024] (Considerations regarding cover membrane 21) In a film forming apparatus 1 using a plasma CVD method, a thermal CVD method, or the like, in order to suppress the generation of dust in the film forming process, fluorine radicals are introduced into the chamber 10 in a cleaning process after the film forming process, and deposits or particles adhering to the inner wall of the chamber 10 and the stage 2 are etched. This cleans the inside of the chamber 10, and suppresses the generation of dust in the next film forming process.

[0025] In the cleaning process, if the aluminum nitride of the mounting portion 20 is exposed, the material of the mounting portion 20 is etched by fluorine radicals in an atmosphere heated to approximately 400° C. or higher. This etched material of the mounting portion 20 may adhere to the showerhead 40 as aluminum fluoride. If aluminum fluoride accumulates on the showerhead 40, the in-plane uniformity of the film thickness of the material film formed on the semiconductor substrate W in the film formation process deteriorates. Since it is difficult to remove aluminum fluoride that adheres to the showerhead 40, it has been necessary to periodically replace the showerhead in order to suppress such deterioration of the film formation performance.

[0026] In contrast, in this embodiment, the mounting portion 20 is covered with a cover film 21. The cover film 21 is made of yttrium oxide. As described later, yttrium oxide is not easily etched by fluorine radicals even in an atmosphere heated to about 400° C. or higher. Therefore, in the cleaning process, it is possible to suppress deposition of deposits such as aluminum fluoride on the shower head 40. As a result, it is possible to suppress deterioration of the film formation performance in the film formation process, and the life of the shower head 40 can be extended. In the cleaning process, the fluorine radicals isotropically clean the entire inside of the chamber 10. Therefore, the cover film 21 covers the entire surface (mounting surface F1, back surface F2, and side surface F3) of the mounting portion 20 so that the mounting portion 20 is not exposed to fluorine radicals as much as possible.

[0027] Methods for forming the cover film 21 include the ALD (Atomic Layer Deposition) method, the MOCVD (Metal-Organic CVD) method, the sputtering method, and the ion plating method. Among these, the ALD and MOCVD methods can isotropically form a Y2O3 film (yttria film) or a YOF film (yttrium oxyfluoride film) on the mounting portion 20. Therefore, the ALD and MOCVD methods can form the Y2O3 film or the YOF film substantially uniformly over the entire mounting surface F1, the back surface F2, and the side surface F3 of the mounting portion 20.

[0028] On the other hand, the sputtering method and the ion plating method form a Y2O3 film or a YOF film anisotropically on the mounting portion 20. That is, it is difficult to form a Y2O3 film or a YOF film uniformly over the entire surface of the mounting portion 20 by the sputtering method and the ion plating method.

[0029] Therefore, it can be said that the ALD method and the MOCVD method are preferable for forming a Y2O3 film or a YOF film substantially uniformly over the entire surface of the mounting part 20. When comparing the ALD method with the MOCVD method, the crystallinity of the Y2O3 film or the YOF film formed by the MOCVD method is inferior to that of the Y2O3 film or the YOF film formed by the ALD method, as described later, and there are more particles.

[0030] 3A is a graph showing the spectral intensity peak ratio of the constituent material of the cover film 21 to the constituent material of the mounting portion 20. The constituent material of the mounting portion 20 is, for example, aluminum nitride (AlN), and the constituent material of the cover film 21 is, for example, an yttria (Y2O3) film.

[0031] The horizontal axis of this graph indicates the materials of the samples S1 to S6. Sample S1 is a simple aluminum nitride (bulk AlN). Sample S2 is a simple yttria (bulk Y2O3). Sample S3 is a cover film 21 (Y2O3 film) formed on the mounting part 20 (AlN) by the ALD method. Sample S4 is a cover film 21 (Y2O3 film) formed on the mounting part 20 (AlN) by the MOCVD method. Sample S5 is a cover film 21 (Y2O3 film) formed on the mounting part 20 by the sputtering method. Sample S6 is a cover film 21 (Y2O3 film) formed on the mounting part 20 by the ion plating method.

[0032] The vertical axis shows the ratio P2 / P1 (hereinafter also referred to as the peak ratio P2 / P1) of the spectral intensity peak P2 (2θ=29.15°) of yttria (Y2O3) as the constituent material of the cover film 21 to the spectral intensity peak P1 (2θ=33.24°) of aluminum nitride (AlN) as the constituent material of the mounting portion 20 obtained by X-ray diffraction method.

[0033] Sample S1 is made of aluminum nitride alone, so almost no yttria was detected, and the peak ratio P2 / P1 is very small, close to zero. Sample S2 is made of yttria alone, so conversely, a lot of yttria was detected, and the peak ratio P2 / P1 is very large. The values ​​of samples S1 and S2 are listed as reference values.

[0034] Comparing samples S3 to S6, the peak ratios P2 / P1 of samples S5 and S6 are significantly larger than those of samples S3 and S4. This is because the thickness of the yttria film formed by the sputtering method and the ion plating method is thicker than the thickness of the yttria film formed by the ALD method and the MOCVD method.

[0035] Comparing samples S3 and S4, yttria films of approximately the same thickness are formed using the ALD method and the MOCVD method, respectively. However, the peak ratio P2 / P1 of sample S4 is smaller than the peak ratio P2 / P1 of sample S3. The yttria film formed by the MOCVD method has lower crystallinity than the yttria film formed by the ALD method. For this reason, the spectral intensity of the yttria film formed by the MOCVD method is smaller than the spectral intensity of the yttria film formed by the ALD method. Therefore, the peak ratio P2 / P1 of sample S4 formed by the MOCVD method is smaller than the peak ratio P2 / P1 of sample S3 formed by the ALD method.

[0036] 3B is a graph showing the relationship between the peak ratio P2 / P1 and the number of particles. The horizontal axis of this graph shows the peak ratio P2 / P1, and the vertical axis shows the number of particles on the surfaces of samples S1 and S3 to S6 after the cleaning process.

[0037] According to this graph, when the peak ratio P2 / P1 is 0.1 or more, the number of particles is almost zero, whereas when the peak ratio P2 / P1 is less than 0.1, the number of particles increases. Therefore, it can be said that it is preferable that the peak ratio P2 / P1 is 0.1 or more. For example, as shown in FIG. 3A, samples S1 and S4, which have a peak ratio P2 / P1 of less than 0.1, have a large number of particles. In other words, it can be seen that bulk AlN and yttria films produced by MOCVD have a large number of particles. This is because yttria films produced by MOCVD have low crystallinity.

[0038] In contrast, it is found that the yttria film of sample S3 formed by the ALD method is isotropically formed on the entire surface of the mounting portion 20 and has a small number of particles. Therefore, it can be said that the yttria film formed by the ALD method is preferable as the cover film 21.

[0039] On the other hand, as described above, the yttria film formed by the ALD method is thinner in thickness than the yttria film formed by the sputtering method and the ion plating method. This is because the deposition rate of the ALD method is slower than that of the sputtering method and the ion plating method. Therefore, it takes time and cost to form a thick yttria film by the ALD method. For example, it takes a very long time and cost to form an yttria film with a thickness of more than 1 μm by the ALD method. Therefore, it is preferable that the thickness of the yttria film formed by the ALD method is 1 μm or less.

[0040] FIG. 3C is a graph showing the relationship between the peak ratio P2 / P1 and the mass change rate due to cleaning. The horizontal axis of this graph shows the peak ratio P2 / P1. The vertical axis shows the mass change rate of stage 2 before and after the cleaning process. Zero on the vertical axis indicates that the mass of stage 2 does not change before and after the cleaning process, and that it is not etched by fluorine radicals in the cleaning process. The graph shows the results for samples S1 and S3 to S6, and the results for sample S2 containing only yttria are also omitted here. Similar results were obtained when the temperature in the cleaning process was changed.

[0041] According to this graph, the bulk AlN of sample S1 is etched by fluorine radicals, decreasing the mass of stage 2. The etched AlN adheres to the showerhead 40 as aluminum fluoride.

[0042] In samples S3 to S6 other than sample S1, the mass of stage 2 did not decrease, but rather increased. This is thought to be because in samples S3 to S6, the mounting portion 20 or cover film 21 of stage 2 was hardly etched by fluorine radicals, and instead other deposits from the outside adhered to stage 2. Therefore, it can be seen that stage 2, whose mounting portion 20 is covered with an yttria film, is not etched in the cleaning process, making it possible to suppress the accumulation of aluminum fluoride on the showerhead 40.

[0043] Thus, according to this embodiment, the peak ratio P2 / P1 is 0.1 or more, so that the generation of particles on the stage 2 can be suppressed. The film formation methods for which the peak ratio P2 / P1 is 0.1 or more are the ALD method (S3), the sputtering method (S5), and the ion plating method (S6) shown in Fig. 3A. Furthermore, in order to cover the entire surface of the mounting part 20, the ALD method, which allows isotropic film formation, is preferable.

[0044] Since the ALD method has a slower film formation rate than the sputtering method or the ion plating method, it is preferable that the thickness of the cover film 21 is as thin as possible while suppressing etching of the mounting portion 20. For example, the thickness of the cover film 21 is preferably 0.5 μm or more and less than 10 μm. By making the thickness of the cover film 21 0.5 μm or more, the cover film 21 can protect the aluminum nitride of the mounting portion 20 from fluorine radicals in the cleaning process and suppress etching of the mounting portion 20. In addition, considering the manufacturing time and manufacturing cost of the ALD method, the thickness of the cover film 21 is preferably less than 10 μm, and more preferably 1 μm or less.

[0045] Next, with reference to Figs. 4A to 4C, a case where the cover film 21 is an yttrium oxyfluoride (YOF) film will be described. Figs. 4A to 4C are different from the example shown in Figs. 3A to 3C in that the constituent material of the cover film 21 is yttrium oxyfluoride (YOF). When an yttria film is exposed to fluorine radicals in the cleaning process, most of it becomes an yttrium oxyfluoride (YOF) film. Therefore, the cover film 21 shown in Figs. 3A to 3C changes from an yttria film to a YOF film after passing through the cleaning process. The results shown in Figs. 4A to 4C are also the same for the YOF film changed from an yttria film in this way.

[0046] 4A is a graph showing the spectral intensity peak ratio of the constituent material of the cover film 21 to the constituent material of the mounting portion 20. Note that the peak ratio of yttrium oxyfluoride alone is omitted here.

[0047] The horizontal axis of the graph in FIG. 4A indicates the materials of the samples S1, S13 to S16. As described above, the sample S1 is bulk AlN. The sample S13 is a YOF film formed on the mounting part 20 (AlN) by the ALD method, or a YOF film obtained by fluoriding an yttria film formed by the ALD method. The sample S14 is a YOF film formed on the mounting part 20 (AlN) by the MOCVD method, or a YOF film obtained by fluoriding an yttria film formed by the MOCVD method. The sample S15 is a YOF film formed on the mounting part 20 by the sputtering method, or a YOF film obtained by fluoriding an yttria film formed by the sputtering method. The sample S16 is a YOF film formed on the mounting part 20 by the ion plating method, or a YOF film obtained by fluoriding an yttria film formed by the ion plating method.

[0048] The vertical axis of the graph in Fig. 4A, like the vertical axis in Fig. 3A, indicates the ratio P2 / P1 of the spectrum intensity peak P2 (2θ=28.064°) of the constituent material (YOF) of the cover film 21 to the spectrum intensity peak P1 (2θ=33.24°) of the constituent material (AlN) of the mounting portion 20 obtained by X-ray diffraction. Samples S13 to S16 have similar characteristics to samples S3 to S6, respectively. Therefore, the peak ratio P2 / P1 of sample S14 obtained by the MOCVD method is smaller than the peak ratio P2 / P1 of sample S13 obtained by the ALD method.

[0049] 4B is a graph showing the relationship between the peak ratio P2 / P1 and the number of particles. In this graph, samples S13 to S16 have the same characteristics as samples S3 to S6, respectively. That is, when the peak ratio P2 / P1 is 0.1 or more, the number of particles is almost zero, whereas when the peak ratio P2 / P1 is less than 0.1, the number of particles increases. Therefore, it can be said that it is preferable for the peak ratio P2 / P1 to be 0.1 or more.

[0050] As described above, it is found that the YOF film formed by the ALD method is isotropically formed on the entire surface of the mounting part 20 and has a small number of particles. Therefore, like the yttria film formed by the ALD method, the YOF film formed by the ALD method can be said to be preferable as the cover film 21. In contrast, the YOF film formed by the MOCVD method has a small peak ratio P2 / P1 and also has a large number of particles.

[0051] Like the thickness of the yttria film, the thickness of the YOF film is 0.5 μm or more, so that the cover film 21 can suppress etching of the mounting portion 20 by fluorine radicals in the cleaning process. In addition, in consideration of the manufacturing time and manufacturing cost of the ALD method, the thickness of the YOF film by the ALD method is also preferably less than 10 μm, and more preferably 1 μm or less, like the thickness of the yttria film by the ALD method.

[0052] 4C is a graph showing the relationship between the peak ratio P2 / P1 and the mass change rate due to cleaning. In this graph, samples S13 to S16 have the same characteristics as samples S3 to S6, respectively. That is, the bulk AlN of sample S1 is etched by fluorine radicals, and the mass of stage 2 is reduced.

[0053] In samples S13 to S16 other than sample S1, the mass of the stage 2 did not decrease, but rather increased. This is thought to be because the mounting portion 20 or cover film 21 of the stage 2 in samples S13 to S16 was hardly etched by fluorine radicals. Therefore, it is found that the stage 2 whose mounting portion 20 is covered with the YOF film is not etched in the cleaning process, making it possible to suppress the accumulation of aluminum fluoride on the showerhead 40.

[0054] In this way, even if the cover film 21 is composed of a YOF film, the generation of particles on the stage 2 can be suppressed by making the peak ratio P2 / P1 0.1 or more. The film formation methods that make the peak ratio P2 / P1 0.1 or more are the ALD method (S13), sputtering method (S15), and ion plating method (S16) shown in Fig. 4A. Furthermore, in order to cover the entire surface of the mounting part 20, it can be said that the isotropic ALD method is preferable.

[0055] According to this embodiment, the mounting portion 20 is covered with a cover film 21. The cover film 21 covers the entire surface (mounting surface F1, rear surface F2, and side surface F3) of the mounting portion 20. The cover film 21 is made of yttrium oxide. Therefore, it is possible to prevent deposits such as aluminum fluoride from adhering to the shower head 40 in the cleaning process. As a result, it is possible to suppress the generation of particles in the film formation process and suppress deterioration of film formation performance, and to extend the life of the shower head 40. This makes it possible to suppress costs and suppress deterioration of film formation performance. This also leads to an improvement in product yield.

[0056] Second embodiment FIG. 5 is a cross-sectional view showing a configuration example of the stage 2 according to the second embodiment. In the second embodiment, a laminated film of the cover film 21_1 and the cover film 21_2 covers the mounting surface F1 of the mounting part 20. When a film formation process is repeated on the semiconductor substrate W mounted on the stage 2, the mounting surface F1 side of the mounting part 20 is worn due to contact with the semiconductor substrate W, and the film covering the mounting surface F1 may become thinner. In contrast, in this embodiment, the cover film 21_2 is laminated on the cover film 21_1 on the mounting surface F1 of the mounting part 20 to suppress wear on the mounting surface F1 side of the mounting part 20 due to contact with the semiconductor substrate W. The material of the cover film 21_1 is, for example, yttria (Y2O3), yttrium oxyfluoride (YOF), or yttrium fluoride (YF3). The material of the cover film 21_2 is an yttrium oxide, for example, yttria (Y2O3) or yttrium oxyfluoride (YOF).

[0057] The cover film 21_1 covers the entire mounting surface F1, rear surface F2, and side surface F3 of the mounting portion 20. Therefore, the cover film 21_1 is formed by using an isotropic film formation method (ALD method or MOCVD method).

[0058] Here, in the second embodiment, a cover film 21_2 is further provided on the cover film 21_1 covering the mounting surface F1. Therefore, if the cover film 21_2 has few particles, even if the cover film 21_1 having a larger number of particles is used in the laminated film, it is unlikely to be a problem in the film formation process. For example, when the cover film 21_1 is formed using the MOCVD method, as described above, the peak ratio P2 / P1 is less than 0.1, and the number of particles is greater than when the cover film 21_1 is formed using the ALD method. However, since the cover film 21_2 is laminated on the cover film 21_1 on the mounting surface F1, the particles do not pose a problem. On the other hand, the cover film 21_1 is exposed on the back surface F2 and side surface F3, and it is estimated that there are more particles than on the mounting surface F1, but compared to the mounting surface F1 side facing the shower head 40, the material etched by fluorine radicals becomes a deposit on the shower head 40 and has a small effect on the film formation performance. Also, the number of particles can be reduced compared to a case where the rear surface F2 and the side surface F3 are not covered with the cover film 21_1 and the aluminum nitride of the mounting portion 20 is directly exposed.

[0059] The cover film 21_2 may be formed by using an anisotropic film forming method (for example, sputtering or ion plating) since it is sufficient to form the cover film 21_1 on the mounting surface F1 side. Since the sputtering method and the ion plating method have a faster film forming speed than the ALD method and the MOCVD method, the cover film 21_2 may be formed on the cover film 21_1 on the mounting surface F1 to be thicker than the cover film 21_1. For example, the film thickness of the cover film 21_1 is relatively thin, 0.02 μm to 1 μm, and the film thickness of the cover film 21_2 is relatively thick, 1 μm to 24 μm. The total film thickness of the cover films 21_1 and 21_2 is 1 μm to 25 μm. In this case, the spectrum intensity peak ratio P2 / P1 by X-ray diffraction may have a larger ratio value on the mounting surface F1 side than on the back surface F2 and side surface F3 sides, as shown in FIG. 3A and FIG. 4A for each film forming method.

[0060] Also, the cover film 21_2 may be formed by using the ALD method. That is, instead of the sputtering method or the ion plating method, the cover film 21_2 may be formed on the cover film 21_1 formed by the MOCVD method by using the ALD method. In this case, although the thickness of the cover film 21_2 becomes thin, the cover film 21_2 formed by the ALD method covers the entire mounting surface F1, the back surface F2 and the side surface F3 of the mounting part 20. Therefore, it is possible to suppress particles of the cover film 21_1 on the back surface F2 and the side surface F3.

[0061] In addition, when the yttria (Y2O3) film or the yttrium oxyfluoride (YOF) film formed by the MOCVD method is exposed to fluorine radicals, most of them become yttrium fluoride (YF3) films. Therefore, even if the cover film 21_1 formed by the MOCVD method is an yttria film or an yttrium oxyfluoride film at the time of manufacture, it can be transformed into an yttrium fluoride film by contacting with fluorine radicals in the cleaning process.

[0062] When the yttria film formed by the ALD method, the sputtering method, or the ion plating method is exposed to fluorine radicals, most of it becomes an yttrium oxyfluoride film. Therefore, even if the cover film 21_2 formed by the sputtering method or the ion plating method is an yttria film or an yttrium oxyfluoride film at the time of manufacture, most of it becomes an yttrium oxyfluoride film when exposed to fluorine radicals. Also, even if the cover film 21_1 or 21_2 formed by the ALD method is an yttria film or an yttrium oxyfluoride film at the time of manufacture, most of it can be transformed into an yttrium oxyfluoride film when contacted with fluorine radicals.

[0063] That is, the cover films 21_1 and 21_2 can be a laminate film of an yttria film, an yttrium oxyfluoride film, or an yttrium fluoride film and an yttria film or an yttrium oxyfluoride film.

[0064] In the second embodiment, at least the mounting surface F1 of the mounting portion 20 is provided with a cover film 21_2 having a spectrum intensity peak ratio P2 / P1 of 0.1 or more by X-ray diffraction. This makes it possible to suppress generation of particles on the stage 2. In addition, since the cover film 21_1 covers the entire surface of the mounting portion 20, etching of the mounting portion 20 can be suppressed in the cleaning process.

[0065] Other configurations of the second embodiment may be similar to the corresponding configurations of the first embodiment, so the second embodiment can achieve the same effects as the first embodiment.

[0066] FIG. 6 is a partial cross-sectional view showing an example of the mounting surface F1 of the stage 2 in detail. The mounting surface F1 of the mounting part 20 often has a large number of protrusions 70. That is, the mounting surface F1 is often embossed. The protrusions 70 protrude from the mounting surface F1 and support the semiconductor substrate W. The height of the protrusions 70 from the mounting surface F1 is 10 μm or more and 50 μm or less. When the semiconductor substrate W is released from the vacuum chuck or electromagnetic chuck after the film formation process, the protrusions 70 separate the semiconductor substrate W adsorbed to the mounting surface F1 from the mounting surface F1. This makes it easier to remove the semiconductor substrate W from the mounting part 20 after the film formation process.

[0067] 6 shows a case where the mounting surface F1 having such a protrusion 70 is covered with cover films 21_1 and 21_2 according to the second embodiment. The cover film 21_1 is formed by an isotropic film formation method (e.g., ALD method, MOCVD method), and therefore can substantially uniformly cover the upper surface and side surface of the protrusion 70. Furthermore, the cover film 21_2 is formed by an anisotropic film formation method (e.g., sputtering method or ion plating method), and therefore can thickly cover the upper surface of the protrusion 70.

[0068] The cover film 21_1 is preferably 0.02 μm or more in order to protect the side surface of the protrusion 70. The total film thickness of the cover films 21_1, 21_2 is preferably thicker than 1 μm in consideration of wear and thinning over time of the cover films 21_1, 21_2 due to contact between the mounting surface F1 of the stage 2 and the semiconductor substrate W, and is preferably 25 μm or less in order to maintain the protruding shape of the protrusion 70 without being buried.

[0069] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0070] 1 film forming apparatus, 10 chamber, 20 mounting portion, 21 cover film, 22 connector portion, 30 heater, 40 shower head, 50 drive portion, 60 controller

Claims

1. A chamber; a mounting portion that is provided in the chamber so that a substrate can be mounted thereon and that includes aluminum nitride; a heater provided in the mounting portion; a supply unit that supplies a process gas for film formation to the substrate on the mounting unit in the chamber; a cover film that contains yttrium oxide and covers a mounting surface of the mounting portion on which the substrate is mounted, a back surface opposite to the mounting surface, and a side surface between the mounting surface and the back surface; the cover film covering the mounting surface is a laminated film of a first cover film and a second cover film, the second cover film does not cover the back surface, the first and second cover films each include yttrium oxide; a ratio (P2 / P1) of a spectrum intensity peak P2 by X-ray diffraction of a constituent material of the cover film to a spectrum intensity peak P1 by X-ray diffraction of a constituent material of the mounting portion is 0.1 or more; Film deposition equipment.

2. The cover film is Y ２ O ３ The deposition apparatus according to claim 1 , further comprising:

3. A film forming apparatus as described in claim 1 or claim 2, wherein the second cover film is thicker than the first cover film.

4. a mounting portion that is provided in a chamber of the film forming apparatus so as to be capable of mounting a substrate thereon and that includes aluminum nitride; a heater provided in the mounting portion; a cover film that contains yttrium oxide and covers a mounting surface of the mounting portion on which the substrate is mounted, a back surface opposite to the mounting surface, and a side surface between the mounting surface and the back surface; the cover film covering the mounting surface is a laminated film of a first cover film and a second cover film, the second cover film does not cover the back surface, the first and second cover films each include yttrium oxide; a ratio (P2 / P1) of a spectrum intensity peak P2 by X-ray diffraction of a constituent material of the cover film to a spectrum intensity peak P1 by X-ray diffraction of a constituent material of the mounting portion is 0.1 or more; Substrate support device.

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