JP2009275254A - Vapor phase growth device - 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 in which a heating means (a heater 16) is provided on a back side of a loading plate 14 to be held by a susceptor 12, a bottom surface of the loading plate on the downstream side of the gas flow is ground, and the thickness of the loading plate on the upstream side 14d of the gas flow is set to be smaller than the thickness of the loading plate on the downstream side 14e of the gas flow. The temperature of the upper side of the loading plate is unified, and 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 specifically, a vapor phase growth apparatus that heats a substrate placed on a placement plate held by a susceptor from a heating means provided on the back side of the susceptor via the placement plate. About.

A source gas is supplied into the film forming chamber while the substrate held on the susceptor in the film forming chamber (chamber) directly or via the mounting plate is heated to a predetermined temperature by heating means, and a thin film is deposited on the substrate surface. As a vapor phase growth apparatus, an adjustment plate is interposed between a substrate and a susceptor, and the thickness of the adjustment plate is adjusted to make the temperatures of a plurality of substrates uniform (for example, Patent Document 1). reference.).
JP 2007-273660 A

  By adopting the adjustment plate described in Patent Document 1, 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, the surface temperature of the substrate may become non-uniform between the upstream side and the downstream side of the gas flow of the substrate due to the flow of the source gas introduced into the film forming 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, a vapor phase growth apparatus of the present invention is provided with a susceptor provided in a film forming chamber of the vapor phase growth apparatus, a mounting plate held by the susceptor, and a back surface side of the susceptor. A heating means for introducing a source gas into the film formation chamber while heating the substrate placed on the placement plate through the placement plate by the heating means to form a thin film on the substrate surface. In the phase growth apparatus, the bottom surface of the mounting plate on the downstream side of the gas flow is ground, and the thickness on the downstream side of the gas flow is made thinner than the thickness of the mounting plate on the upstream side of the gas flow. .

  According to the vapor phase growth apparatus of the present invention, the bottom portion of the gas flow downstream side where the temperature tends to be higher than the gas flow upstream side of the mounting plate where the temperature tends to be low due to contact with the source gas The amount of heat transferred from the heating means to the mounting plate is adjusted by adjusting the distance between the heating means and the bottom surface by reducing the thickness of the mounting plate from the upstream side of the gas flow to the downstream side of the gas flow. Can be Thereby, the upper surface temperature of the mounting plate can be made uniform, and a uniform thin film can be formed by uniformly heating the entire substrate held on the mounting plate.

  FIG. 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 5 are cross-sectional views showing other grinding examples of the mounting plate bottom surface. 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 plurality of mounting plates are disposed on the outer periphery of the susceptor 12 via a plate support 13. 14 is a revolution type vapor phase growth apparatus provided with 14 so that a thin film can be simultaneously formed on 8 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 receiving base 13 is formed in a ring shape having an upward stepped portion 13a for mounting the mounting plate 14 on the inner periphery, and the mounting plate 14 includes an upper large-diameter portion 14a and a lower portion. And a downward stepped portion 14c formed between the large diameter portion 14a and the small diameter portion 14b is placed on the upward stepped portion 13a of the plate receiving base 13. It is held in the state.

  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 rotating shaft 15 so that the mounting plate 14 and the substrate are revolved 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 mounting plate 14, the gas flow downstream side 14 e whose temperature tends to be higher than the gas flow upstream side 14 d of the mounting plate 14 whose temperature tends to decrease due to contact with the source gas. The bottom surface portion of the mounting plate 14 is ground so that the gas flow downstream side 14e is thinner than the gas flow upstream side 14d, and the bottom surface at each position of the mounting plate 14 and the heating surface of the heater 16 are formed. By adjusting the distance, the amount of heat transferred from the heater 16 to the mounting plate 14 can be optimized.

  That is, by forming the bottom surface of the gas flow upstream side 14d close to the heater 16 and the bottom surface of the gas flow downstream side 14e far from the heater 16, the amount of heat transfer from the heater 16 to the gas flow upstream side 14d is increased. Since the amount of heat transfer from the heater 16 to the gas flow downstream side 14e can be reduced, the upper surface temperature of the mounting plate 14 can be made uniform as a whole, and the substrate mounted 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 moved from the left gas flow upstream side 14d toward the right gas flow downstream side 14e. By removing the grinding portion 20 by grinding in stages, the thickness of the mounting plate 14 becomes a shape in which the gas flow upstream side 14d is thick and gradually becomes thinner toward the gas flow downstream side 14e. The bottom surface of the gas flow upstream side 14d is close to the heater 16, and the bottom surface of the gas flow downstream side 14e is separated from the heater 16.

  As a result, the heating amount of the mounting plate 14 from the heater 16 can be increased on the gas flow upstream side 14d and the gas flow downstream side 14e where the temperature tends to decrease due to contact with the source gas. It is possible to equalize the upper surface temperature difference of the mounting plate 14 caused by the flow, that is, the surface temperature of the substrate mounted on the mounting plate 14 and heated via the mounting plate 14.

  The shape of the grinding part to be removed from the bottom surface of the mounting plate 14 can be appropriately selected according to the temperature difference state of the top surface measured after manufacture, the conditions of the grinding tool, and the like, for example, as shown in FIG. As shown in FIG. 4, the slit 21a is provided between the steps of the grinding portion 21 where the bottom surface portion is ground stepwise, or is ground in a flat shape from the gas flow upstream side 14d to the gas flow downstream side 14e as shown in FIG. As shown in FIG. 5, the ground grinding part 22 can be a grinding part 23 that is ground in a curved or spherical shape from the gas flow upstream side 14 d toward the gas flow downstream side 14 e.

  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. The present invention can also be applied to horizontal and vertical vapor phase growth apparatuses that do not revolve the substrate.

  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 The center of the mounting plate, the position of 15 mm and 30 mm toward the gas flow upstream side with respect to the center, the position of 15 mm (−15 mm) and 30 mm (−30 mm) toward the gas flow downstream side with respect to the center Measurements were made at five locations. As a result, as shown in FIG. 6 before processing, the upper surface temperature of the upstream portion of the gas flow is about 775 ° C., the center is about 783 ° C., and the downstream portion of the gas flow is about 785 ° C. The difference between the temperature and the minimum temperature was about 10 ° C.

  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 top surface temperature is about 771 to 1, as shown in FIG. It was within the range of about 772 ° C., and the difference between the maximum temperature and the minimum temperature on the top 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 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, 13 ... Plate base, 13a ... Upward step part, 14 ... Mounting plate, 14a ... Large diameter part, 14b ... Small diameter part, 14c ... Downward step part, 14d ... Gas flow upstream Side, 14e ... gas flow downstream side, 15 ... rotating shaft, 16 ... heater, 17 ... introduction part, 18 ... discharge part, 20-23 ... grinding part

Claims (1)

  A susceptor provided in a film forming chamber of the vapor phase growth apparatus, a mounting plate held by the susceptor, and a heating means provided on the back side of the susceptor, and placed on the mounting plate. In the vapor phase growth apparatus for forming a thin film on the substrate surface by introducing the source gas into the film forming chamber while heating the substrate through the mounting plate by the heating means, the bottom surface of the mounting plate on the downstream side of the gas flow A gas phase growth apparatus characterized in that the thickness on the downstream side of the gas flow is made thinner than the thickness on the upstream side of the gas flow in the mounting plate.

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