Substrate placement table and film forming apparatus

Abstract

To provide a substrate placement table capable of reducing the frequency of maintenance by suppressing the deposition of reactants on the substrate placement table surface during deposition, and deposition equipment.SOLUTION: In a piece of deposition equipment, a substrate placement table includes: a wafer suction part; and a susceptor 3 that supports the wafer suction part. The wafer suction part has a first circular plane 11a on which the wafer is placed and a second circular plane 11b that comes in contact with the susceptor. The diameter of the first circular plane is greater than the diameter of the second circular plane. The deposition equipment includes; the substrate placement table; and a guide ring having an extension part over a side face of the wafer suction part in a peripheral edge 3a of the susceptor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a substrate mounting stage and a film forming apparatus used in the manufacture of semiconductor devices. [Background technology]

[0002] Patent Document 1 discloses the configuration of a CVD film forming apparatus. When a film is formed on a substrate in a CVD film forming apparatus, reactants are deposited on the surface area of ​​the mounting table even in areas where the substrate is not placed. Meanwhile, due to problems with the accuracy of the transport device, the substrate may be placed in a misaligned position during substrate transport. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-142529 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the substrate is placed in an offset position, a part of the substrate rides on the accumulated reactants, forming a gap between the substrate and the stage. This causes problems such as uneven film formation due to uneven temperature distribution on the substrate, or film formation on the back side of the substrate due to reactants getting around. To maintain the quality of the film formation, it is necessary to perform maintenance to replace the stage and surrounding parts before this problem occurs. However, frequent maintenance can lead to issues such as reduced production efficiency due to equipment stoppages during operation, and quality fluctuations due to changes in the chamber environment before and after operation.

[0005] In order to solve the above-mentioned problems, Patent Document 1 discloses a technology relating to a mounting table having a recess along the outer periphery of the position where the substrate is placed. In this configuration, the reactants are first deposited in the recess, so it is possible to extend the time until problems due to the deposited reactants occur compared to conventional methods. However, this configuration does not take into consideration the suppression of the deposition of the reactants on the mounting table itself, and there is room for improvement in this regard.

[0006] Therefore, an object of the present disclosure is to provide a substrate mounting table and a film formation apparatus that can reduce the frequency of maintenance by suppressing deposition of reactants on the surface of the substrate mounting table during film formation. [Means for solving the problem]

[0007] The present disclosure First The embodiment includes a wafer suction portion and a susceptor supporting the wafer suction portion, the wafer suction portion having a first circular plane on which a substrate is placed and a second circular plane in contact with the susceptor, and the diameter of the first circular plane is larger than the diameter of the second circular plane. The susceptor has a susceptor peripheral portion which is a region excluding a region in contact with the second circular flat surface, and the susceptor peripheral portion has a concentric region having an inner periphery of the periphery of the second circular flat surface, the concentric region being thinner than the region in contact with the second circular flat surface. It is preferably a substrate mounting table. A second aspect of the present disclosure includes a substrate mounting table and a guide ring, the substrate mounting table includes a wafer suction portion and a susceptor supporting the wafer suction portion, the wafer suction portion has a first circular plane on which a substrate is mounted and a second circular plane in contact with the susceptor, the diameter of the first circular plane being larger than the diameter of the second circular plane, the guide ring has an extension portion at the periphery of the susceptor that covers the surface on the side of the wafer suction portion, Extension tip teeth The thickness of the susceptor is tapered toward the center of the susceptor. It is preferably a film forming device. Effect of the Invention

[0008] The present disclosure First and second According to the aspect, it is possible to suppress deposition of reactants on the surface of the substrate during film formation, thereby maintaining the quality of the thin film for a longer period of time than in the conventional configuration, thereby reducing the frequency of maintenance. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing the internal structure of a chamber of a film forming apparatus according to a first embodiment of the present disclosure. [Diagram 2] 2 is a diagram showing a configuration of an upper portion of the device according to the first embodiment of the present disclosure. FIG. [Diagram 3] FIG. 3 is an enlarged view of a portion of FIG. [Figure 4] FIG. 11 is a diagram showing the configuration of an upper portion of an apparatus according to a second embodiment of the present disclosure. [Diagram 5] FIG. 5 is an enlarged view of a portion of FIG. [Figure 6] FIG. 11 is a diagram showing the configuration of the upper part of an apparatus according to a third embodiment of the present disclosure. [Figure 7] FIG. 7 is an enlarged view of a portion of FIG. [Figure 8] FIG. 11 is a diagram showing the configuration of the upper part of an apparatus according to a fourth embodiment of the present disclosure. [Figure 9] FIG. 9 is an enlarged view of a portion of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First embodiment 1 is a diagram showing the internal structure of a chamber of a film formation apparatus according to a first embodiment of the present disclosure, in which the main body of the film formation apparatus of the present disclosure serves as the chamber.

[0011] The gas head 1 is installed at the bottom of the device and introduces gas into the chamber during film formation processing. Unused gas from the gas head 1 is exhausted through an exhaust pipe 9. A wafer W is placed with its surface facing down in a position facing the gas head 1. At this time, the wafer W is attracted to a suction hole in the center of the wafer suction unit 4, which is connected to a suction line 8. The suction line 8 functions as a suction path for vacuum suction and passes through the center of the wafer suction unit 4, the susceptor 3, and the heater unit 2.

[0012] The wafer suction portion 4 is supported by a susceptor 3. The susceptor 3 is in contact with a guide ring 5. The guide ring 5 is supported by a guide 6, which prevents film formation on the heater unit 2. The guides 6 and 7 raise the susceptor 3 and guide ring 5 to attach them to the heater unit 2 and transfer the heat from the heater unit 2. A drive unit 10 at the top of the device moves the substrate parallel within the chamber during film formation processing.

[0013] During the film formation process, if the area of ​​the susceptor 3 other than the area in contact with the wafer suction part 4 is the susceptor peripheral part 3a, the film is also formed on the surface of the susceptor peripheral part 3a and the guide ring 5. On the other hand, due to the accuracy of the transport device, the substrate may be placed in a misaligned position during substrate transport. Then, when the film attached to the susceptor peripheral part 3a becomes thicker than the height of the wafer suction part 4, the substrate may ride up on the film attached to the susceptor peripheral part 3a. In this case, a gap is formed between the substrate and the wafer suction part 4, which causes uneven temperature distribution on the substrate, resulting in uneven film formation and film formation on the back surface of the wafer W. Therefore, it is necessary to perform regular maintenance for replacing the susceptor before that. Maintenance requires labor to return the device to atmospheric conditions in addition to replacing parts, and the device state may change before and after replacement, which may affect the film quality, so it is ideal to reduce the frequency of maintenance as much as possible.

[0014] Another factor that requires maintenance is the generation of spherical products near the outer periphery of the susceptor peripheral portion 3a. The center of the susceptor 3 is heated by the heater unit 2, so the temperature is lower near the outer periphery. Therefore, the reactants that become a film near the boundary between the susceptor 3 and the wafer adsorption portion 4 become spherical products near the outer periphery of the susceptor 3 due to insufficient thermal reaction. The more films are formed, the larger these products become, and they may come into contact with the gas head 1 to generate dust or fall from the susceptor 3, causing contamination inside the chamber.

[0015] In order to suppress the generation of these spherical products, a guide ring 5 made of foamed quartz and having a mesh structure is used. The guide ring 5 prevents the generation of spherical products on its surface by adhering the reactants inside the mesh. If products accumulate inside the guide ring 5, the above-mentioned effect will be weakened, so regular maintenance to replace the guide ring will be necessary, but it is ideal to keep this frequency low for the same reasons as for replacing the susceptor.

[0016] As described above, in order to reduce the frequency of maintenance, it is important to suppress the generation of by-products on the entire surface of the peripheral portion 3a of the susceptor during the film formation process. An embodiment that can achieve this will be described below.

[0017] Fig. 2 is a diagram showing the configuration of an upper portion of the apparatus according to the first embodiment of the present disclosure, and Fig. 3 is an enlarged view of Fig. 2. The film forming apparatus of the first embodiment is equipped with a wafer suction part 11 having a first circular flat surface 11a for placing a substrate thereon and a second circular flat surface 11b connected to a susceptor 3, and the diameter of the first circular flat surface 11a is larger than the diameter of the second circular flat surface 11b.

[0018] With this configuration, reactants that have accumulated on the susceptor peripheral portion 3a during the film formation process are redirected around the boundary between the wafer adsorption portion 11 and the susceptor 3, dispersing the reactants' adhesion locations more than with the conventional configuration. As a result, the overall film formation speed of the thin film formed on the susceptor peripheral portion 3a is slowed down, so the time until the quality of the film formation deteriorates can be extended and the frequency of maintenance can be reduced.

[0019] The configuration of the film forming apparatus according to the following embodiment will be described with a focus on the differences from the first embodiment. Although the present embodiment shows a case where an oxide film is formed in an atmospheric pressure CVD apparatus, a different method or a film forming apparatus using a different film type may be used. Furthermore, the present embodiment shows a case where the substrate is formed from silicon, but the substrate may be formed from a wide band gap semiconductor having a larger band gap than silicon. Examples of wide band gap semiconductors include silicon carbide, gallium nitride-based materials, and diamond.

[0020] Embodiment 2 FIG. 4 is a diagram showing the configuration of the upper part of the apparatus according to the second embodiment of the present disclosure, and FIG. 5 is an enlarged view of FIG. 4. In addition to the wafer suction part 11, the film forming apparatus of the second embodiment includes a susceptor 12 having a concentric region with the periphery of the second circular flat surface 11b of the wafer suction part 11 as the inner circumference, the susceptor 12 including a region thinner than the region in contact with the second circular flat surface 11b. FIGS. 4 and 5 show the susceptor 12 having a concave groove 13 formed by thinning a part of the susceptor 12. Note that the susceptor 12 does not have to have the concave groove 13, and may have a shape in which the entire region not in contact with the second circular flat surface 11b is thinner than the region in contact with the second circular flat surface 11b.

[0021] With this configuration, reactants that have accumulated on the susceptor peripheral portion 12a during the film formation process are directed not only to the boundary between the wafer suction portion 11 and the susceptor 12, but also to the concave groove 13. This disperses the locations where the reactants adhere, slowing down the overall film formation speed of the thin film formed on the susceptor peripheral portion 12a. As a result, the time until film formation becomes ununiform can be extended, and the frequency of maintenance can be reduced.

[0022] Third embodiment Fig. 6 is a diagram showing the configuration of an upper portion of an apparatus according to a third embodiment of the present disclosure, and Fig. 7 is an enlarged view of Fig. 6. In addition to the wafer suction part 11, the film forming apparatus of the third embodiment includes a guide ring 14 that extends from the periphery of the susceptor 3 so as to cover the surface on the wafer suction part 11 side.

[0023] With this configuration, the reactants that adhere to the outer periphery of the susceptor peripheral portion 3a during the film formation process can instead adhere to the inside of the guide ring 14. As a result, spherical products are less likely to be generated around the susceptor peripheral portion 3a, which reduces the frequency of maintenance.

[0024] Fourth embodiment Fig. 8 is a diagram showing the configuration of an upper portion of an apparatus according to a fourth embodiment of the present disclosure, and Fig. 9 is an enlarged view of Fig. 8. In addition to the wafer suction portion 11, the film formation apparatus of the fourth embodiment includes a guide ring 15 that extends from the periphery of the susceptor 3 so as to cover the surface on the wafer suction portion 11 side, and the tip of the extension is tapered so as to become thinner toward the center of the susceptor 3.

[0025] This configuration makes it difficult for spherical products to be generated, with the same effect as in embodiment 3. In addition, the tapered shape of the guide ring 15 has a gas straightening effect, so it is expected that the film deposition on the peripheral portion 3a of the susceptor will be uniform. These two points make it possible to reduce the frequency of maintenance. [Explanation of symbols]

[0026] 3 susceptor, 3a peripheral portion of susceptor, 4 wafer suction portion, 5 guide ring, 8 suction line, 11 wafer suction portion, 11a first circular flat surface, 11b second circular flat surface, 12 susceptor, 12a peripheral portion of susceptor, 14 guide ring, 15 guide ring

Claims

1. Wafer suction part and a susceptor for supporting the wafer adsorption portion, The wafer suction unit includes: a first circular plane on which a substrate is placed; a second circular plane in contact with the susceptor; the diameter of the first circular plane is greater than the diameter of the second circular plane; the susceptor has a susceptor periphery that is a region excluding a region in contact with the second circular plane, The susceptor peripheral portion includes a concentric region having an inner circumference on the periphery of the second circular flat surface, the concentric region being thinner than a region in contact with the second circular flat surface. Board mounting table.

2. The substrate mounting table according to claim 1 , wherein the wafer suction portion includes a suction line that functions as a suction path for suction-fixing the substrate.

3. A substrate mounting table and a guide ring are provided, the substrate mounting table includes a wafer suction portion and a susceptor that supports the wafer suction portion, The wafer suction unit includes: a first circular plane on which a substrate is placed; a second circular plane in contact with the susceptor; the diameter of the first circular plane is greater than the diameter of the second circular plane; the guide ring has an extension portion that covers a surface of the susceptor on a side of the wafer suction portion at a periphery of the susceptor, The tip of the extension is tapered so that the thickness decreases toward the center of the susceptor. Film deposition equipment.

4. A film forming apparatus as described in Claim 3, wherein the wafer suction portion is provided with an suction line that functions as a suction path for suction-fixing the substrate.

5. 2. The substrate mounting table according to claim 1, The wafer suction portion suctions the substrate formed of a wide band gap semiconductor.

6. The wafer suction portion suctions the substrate formed of a wide band gap semiconductor. The film forming apparatus according to claim 3 .

7. The wide band gap semiconductor is silicon carbide, a gallium nitride-based material, or diamond. The film forming apparatus according to claim 5 or 6.

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