JP2009275255A - Vapor phase growth apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor phase growth apparatus capable of depositing a uniform thin film by eliminating any temperature difference on a surface of a substrate on which the thin film is deposited. <P>SOLUTION: In the vapor phase growth apparatus having a rotation/revolution structure in which a heating means (a heater 16) is provided on a back side of a loading plate 14 to be respectively held by a plate receiving stand 13 turnably provided on a susceptor 12, a center part of a bottom surface of the loading plate is ground, and the thickness of the center part of the loading plate is set to be smaller than the thickness of an outer peripheral part of the loading plate. The temperature of the upper side of the loading plate is unified, the surface temperature of the substrate to be held on the upper surface of the loading plate is uniformized to deposit a homogeneous thin film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vapor phase growth apparatus, and more particularly to a self-revolution type vapor phase growth apparatus that vapor-phase grows a thin film on a substrate surface while revolving the substrate.

A susceptor is used as a vapor phase growth apparatus for supplying a source gas into a film formation chamber in a state where a substrate held in a susceptor in a film formation chamber (chamber) is heated to a predetermined temperature by a heating means and depositing a thin film on the substrate surface. A self-revolving vapor phase growth apparatus provided with a self-revolving mechanism that allows a thin film to be uniformly formed on a plurality of substrates by rotating and revolving the substrate during film formation is known (for example, (See Patent Document 1). In addition, since the substrate temperature has a large effect on the growth of the thin film, an adjustment plate is interposed between the substrate and the susceptor, and the thickness of the adjustment plate is adjusted to equalize the temperature of multiple substrates. (For example, refer to Patent Document 2).
JP 2007-243060 A JP 2007-273660 A

  By adopting the adjustment plate described in Patent Document 2, it is possible to eliminate the temperature difference between the plurality of substrates, but to form the adjustment plate formed of sapphire or the like into a disk shape with an optimal thickness. There was a problem that it took time and effort. Further, even when the substrate revolves, the surface temperature of the substrate may become non-uniform due to the flow of the source gas introduced into the film formation chamber.

  Therefore, an object of the present invention is to provide a vapor phase growth apparatus that can eliminate a temperature difference on the surface of a substrate on which a thin film is formed and can form a uniform thin film.

  In order to achieve the above object, the vapor phase growth apparatus of the present invention is provided with a disk-shaped susceptor rotatably provided in a film forming chamber of the vapor phase growth apparatus and a plurality of rotations in the circumferential direction of the susceptor. A ring-shaped plate base, a plurality of mounting plates respectively held on the plate base, heating means provided on the back side of the susceptor, and the mounting plate described above as the susceptor rotates. A self-revolving structure that revolves and revolves the mounting plate and the substrate placed on the mounting plate by the self-revolving structure, and heats the substrate through the mounting plate by the heating means. In the vapor phase growth apparatus for introducing a source gas into the film forming chamber to form a thin film on the substrate surface, the bottom center portion of the mounting plate is ground and the thickness of the mounting plate center portion is set to the mounting plate. It is characterized in that thinner than the thickness of the bets outer peripheral portion.

  According to the vapor phase growth apparatus of the present invention, the temperature of the outer surface of the mounting plate, which tends to decrease due to contact with the plate cradle or contact with the raw material gas, is suppressed, and the temperature of the mounting plate upper surface is made uniform A uniform thin film can be formed by uniformly heating the entire substrate held on the mounting plate.

  1 is a cross-sectional front view showing an embodiment of the vapor phase growth apparatus of the present invention, FIG. 2 is a cross-sectional front view of the main part, and FIGS. 3 to 6 are cross-sectional views showing other examples of grinding shapes on the bottom of the mounting plate It is a front view.

  In this vapor phase growth apparatus, a disk-shaped susceptor 12 is rotatably provided in a film forming chamber 11 covered with quartz glass, and a plate support 13 having an external gear is provided on the outer periphery of the susceptor 12. A self-revolving vapor phase growth apparatus in which a plurality of mounting plates 14 are rotatably provided, and is formed so that a thin film can be simultaneously formed on eight substrates (not shown). The susceptor 12 is supported by a rotating shaft 15 that penetrates the center of the bottom surface of the film forming chamber 11, and a heater 16 that is a heating unit that heats the mounting plate 14 is provided below the susceptor 12. In addition, an introduction portion 17 for introducing a source gas is provided in the central portion on the surface side of the susceptor 12 in the film formation chamber 11, and a discharge portion 18 is provided in the outer peripheral portion of the film formation chamber 11.

  The plate support 13 is formed in a ring shape having an upward stepped portion 13a for mounting the mounting plate 14 on the inner periphery, and is provided on the outer periphery of the susceptor 12 on the outer peripheral surface thereof. An external gear 13b corresponding to the fixed internal gear 12a is formed. The mounting plate 14 is formed in a stepped disk shape having an upper large-diameter portion 14a and a lower small-diameter portion 14b, and is downwardly formed between the large-diameter portion 14a and the small-diameter portion 14b. The stepped portion 14c is held in a state of being placed on the upward stepped portion 13a of the plate receiving base 13.

  When a thin film is formed on the substrate using this vapor phase growth apparatus, the raw material is introduced into the film forming chamber 11 from the introduction portion 17 while the substrate is heated to a predetermined temperature by the heater 16 via the mounting plate 14. Gas is introduced, and exhaust gas is discharged from the film forming chamber 11 through the discharge unit 18. At this time, the susceptor 12 is rotationally driven by the rotation shaft 15, so that the mounting plate 14 and the substrate revolve and revolve by the revolving mechanism.

  When the thin film is formed on the substrate in this way, the amount of heat transferred from the heater 16 to the mounting plate 14 can be controlled by changing the distance between the bottom surface of the mounting plate 14 and the heat generating surface of the heater 16. . Therefore, the temperature difference between the upper surfaces of the plurality of placement plates 14 can be eliminated by appropriately setting the thicknesses of the plurality of placement plates 14 for each placement plate 14.

  In each of the mounting plates 14 as well, the outer periphery of the mounting plate 14 whose temperature tends to decrease due to contact with the plate base 13 or contact with the raw material gas introduced from the introduction portion 17. The bottom surface portion of the central portion where the temperature tends to rise is ground, the thickness of the mounting plate 14 is made thinner than the outer peripheral portion, and the bottom surface and the heater 16 at each position of the mounting plate 14 are formed. By adjusting the distance from the heat generating surface, the amount of heat transferred from the heater 16 to the mounting plate 14 can be optimized.

  In other words, by forming the bottom surface of the outer peripheral portion closer to the heater 16 and the bottom surface of the central portion being farther from the heater 16, a large amount of heat is transferred from the heater 16 to the outer peripheral portion, and the heat from the heater 16 to the central portion is increased. Since the amount of heat transfer can be reduced, the upper surface temperature of the mounting plate 14 can be made uniform as a whole, and the substrate placed on the mounting plate 14 can be heated uniformly.

  The grinding shape of the bottom surface of the mounting plate 14 is arbitrary. For example, as shown in FIG. 2, the bottom surface of the mounting plate 14 is ground stepwise from the outer peripheral portion toward the central portion, thereby grinding processing portion 20. , The thickness of the mounting plate 14 becomes thicker at the outer peripheral portion and gradually becomes thinner toward the central portion, the bottom surface of the outer peripheral portion is close to the heater 16, and the bottom surface of the central portion is It will be in the state away from the heater 16.

  Accordingly, the heating amount of the mounting plate 14 from the heater 16 can be increased in the outer peripheral portion where the temperature tends to decrease due to contact with the plate receiving base 13 and the raw material gas, and can be reduced in the central portion. Or the temperature difference of the upper surface of the mounting plate 14 caused by the contact with the raw material gas, that is, the surface temperature of the substrate mounted on the mounting plate 14 and heated via the mounting plate 14 may be made uniform. it can.

  The shape of the grinding part to be removed from the center of the bottom surface of the mounting plate 14 can be appropriately selected according to the temperature difference state of the top surface measured in advance, the conditions of the grinding tool, etc. As shown in FIG. 4, a grinding part 21 in which the central part with a small temperature drop is ground extremely thinly compared to its surroundings, or a grinding part in which the grinding part is ground conically from the outer peripheral part to the central part as shown in FIG. As shown in FIG. 5 or FIG. 5, it can be set as the grinding part 23 grind | polished spherically from the outer peripheral part toward the center part. Furthermore, as shown in FIG. 6, the grinding parts 24 having various shapes may be provided with ring-shaped slits 24 a from the bottom surface to the top surface of the mounting plate 14.

  In addition, although the material of the plate base 13 and the mounting plate 14 is arbitrary, it can be manufactured by, for example, SiC coated carbon.

  First, a heater is disposed below the mounting plate formed in a state where the upper surface and the bottom surface are parallel, the setting temperature of the heater is set to 850 ° C., and the mounting plate is heated from below, and the upper surface temperature at that time is Measurements were made at a total of five locations, the center of the mounting plate, two points at a radius of 15 mm and two points at a radius of 30 mm. As a result, as shown in FIG. 6 before processing, the upper surface temperature of the central portion of the mounting plate is about 784 ° C., and the upper surface temperatures of the outer peripheral portion are about 776 ° C. and 781 ° C. A difference of about 8 ° C. occurred.

  Therefore, as shown in FIG. 2, when the bottom surface of the mounting plate is ground stepwise in consideration of the temperature difference and heated under the same conditions, the upper surface temperature is about 760 to 600 as shown in FIG. It was within the range of about 762 ° C., and the difference between the maximum temperature and the minimum temperature on the upper surface of the mounting plate could be suppressed to 2 ° C. or less.

It is a cross-sectional front view which shows one example of the vapor phase growth apparatus of this invention. It is a cross-sectional front view of the principal part. It is a section front view showing other examples of grinding processing of a mounting plate bottom. It is a section front view showing other examples of grinding processing of a mounting plate bottom. It is a section front view showing other examples of grinding processing of a mounting plate bottom. It is a section front view showing other examples of grinding processing of a mounting plate bottom. It is a figure which shows the upper surface temperature of the mounting plate in Example 1. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Film-forming chamber, 12 ... Susceptor, 12a ... Fixed internal gear, 13 ... Plate base, 13a ... Upward stepped part, 13b ... External gear, 14 ... Mounting plate, 14a ... Large diameter part, 14b ... Small diameter part, 14c ... downward step part, 15 ... rotating shaft, 16 ... heater, 17 ... introduction part, 18 ... discharge part, 20-24 ... grinding part

Claims (1)

  A disk-shaped susceptor that is rotatably provided in a film forming chamber of a vapor phase growth apparatus, a ring-shaped plate support that is rotatably provided in a circumferential direction of the susceptor, and a plate support A plurality of holding plates, a heating means provided on the back side of the susceptor, and a self-revolving structure that revolves the mounting plate as the susceptor rotates. The mounting plate and the substrate mounted on the mounting plate are rotated and revolved, and the source gas is introduced into the film formation chamber while heating the substrate through the mounting plate by the heating means to the substrate surface. In the vapor phase growth apparatus for forming a thin film, the vapor phase characterized in that the bottom center portion of the mounting plate is ground and the thickness of the mounting plate central portion is made thinner than the thickness of the mounting plate outer peripheral portion. Length devices.

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