JP2009188289A - Vapor growth system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-revolution type vapor growth system capable of equalizing temperatures of a plurality of substrates. <P>SOLUTION: A substrate holder 14 is held in a state that the substrate holder is assembled to a rotating gear member 15 provided rotatably on the periphery of a susceptor 13 via a spacer ring 26, and a thickness of the spacer ring is varied according to surface temperatures of a plurality of substrate holder, and thereby surface temperatures of a plurality of substrate holder are equalized and the distribution of temperatures of substrates 16 held by substrate holders is made as small as possible. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vapor phase growth apparatus, and more specifically, a substrate is rotatably provided on a susceptor via a substrate holding member and a rotating gear member, and the heating means provided on the back surface side of the susceptor is used to pass the substrate via the substrate holding member. The present invention relates to a self-revolving vapor phase growth apparatus for heating a substrate.

In a vapor phase growth apparatus for producing a thin film such as a compound semiconductor used in a gallium nitride (GaN) -based semiconductor device, which is a material for blue light emitting diodes, green light emitting diodes, and ultraviolet laser diodes, hydrogen is produced using organic metal and ammonia as raw materials. Alternatively, a source gas using nitrogen as a carrier gas is supplied onto a heated substrate, and a GaN thin film is vapor-phase grown on the substrate surface. As such a vapor phase growth apparatus, there is known a so-called self-revolution type vapor phase growth apparatus in which a substrate is rotated while revolving in order to make processing conditions such as a state of a source gas on a substrate surface uniform (for example, , See Patent Document 1). Furthermore, since the GaN thin film is greatly affected by the deposition temperature, when processing multiple substrates simultaneously, an adjustment plate is interposed between the substrate and the susceptor, and the thickness of the adjustment plate is adjusted to adjust the thickness of the multiple substrates. The temperature is also made uniform (see, for example, Patent Document 2).
JP 2007-243060 A JP 2007-273660 A

  By adopting the adjustment plate described in Patent Document 2 in the self-revolving vapor phase growth apparatus described in Patent Document 1, it is possible to equalize the temperature conditions of a plurality of substrates. Therefore, it takes a lot of labor and cost to form the adjusting plate formed in a disk shape with the optimum thickness, and there is a problem in the detachability of the adjusting plate.

  Thus, the present invention provides a self-revolution type vapor phase growth apparatus in which the distance between the heating means and the substrate holding member can be adjusted with a simple structure, and the temperature of a plurality of substrates can be made uniform. The object is to provide a device.

  In order to achieve the above object, the present invention provides a disk-shaped susceptor rotatably provided in a chamber, a plurality of cylindrical rotating gear members rotatably provided on the outer periphery of the susceptor, and the rotation A cylindrical substrate holding member held by the gear member, a fixed gear member having an internal gear meshing with an external gear provided on the outer periphery of the rotating gear member, and a raw material provided on the susceptor surface side of the chamber A gas introduction part, an inert gas introduction part provided on the susceptor back side of the chamber, an exhaust part provided on the anti-source gas introduction part side and the anti-inert gas introduction part side of the chamber, and the chamber In the vapor phase growth apparatus having a self-revolving mechanism provided with a heating means provided on the back surface side of the susceptor, the substrate holding member includes a large diameter portion provided with a substrate mounting portion on an upper surface, and a large diameter portion of the large diameter portion. Bottom The rotating gear member has a large diameter portion for accommodating the large diameter portion of the substrate holding member in the upper part of the inner periphery. A diameter storage portion, a small diameter storage portion that stores a small diameter portion of the substrate holding member at the inner periphery lower portion, and a placement for mounting the downward stepped portion of the substrate holding member between the large diameter storage portion and the small diameter storage portion A spacer ring for adjusting the height of the substrate holding member held by the rotating gear member between the downward stepped portion of the substrate holding member and the mounting step portion of the rotating gear member. The spacer ring is preferably formed of a composite material of silicon nitride and boron nitride.

  According to the vapor phase growth apparatus of the present invention, it is possible to adjust the distance between the heating means and the substrate holding member by changing the thickness of the spacer ring, and at the same time, uniformize the temperature of a plurality of substrates on which film formation processing is performed. can do. Further, by forming the spacer ring with a composite material of silicon nitride and boron nitride, it is possible to improve workability and strength.

  1 is a sectional view showing an embodiment of the vapor phase growth apparatus of the present invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a sectional view taken along the line III-III in FIG.

  In the vapor phase growth apparatus 11 shown in this embodiment, a disk-shaped susceptor 13 is rotatably provided in a flat cylindrical chamber 12 made of stainless steel, and a plurality of substrate holding members 14 are provided on the outer periphery of the susceptor 13. Is a revolving type vapor phase growth apparatus that is rotatably provided via a rotating gear member 15, and is formed so that ten substrates 16 can be processed simultaneously.

  The susceptor 13 is supported by a rotating shaft 17 that penetrates the bottom surface portion of the chamber 12. A heater 18 and a thermometer 19 are provided below the chamber 12, and a reflector 20 is provided around the heater 18. Further, a source gas introduction part 21 is provided in the central part on the susceptor surface side of the chamber 12, an exhaust part 22 is provided in the outer peripheral part, and an inert gas introduction part 23 is provided around the rotating shaft 17, An inert gas lead-out portion 24 communicating with the exhaust portion 22 is provided on the outer periphery of the reflector 20.

  On the outer periphery of the susceptor 13, there are provided storage portions 13 a having a circular shape in plan view for storing the rotating gear member 15 at equal intervals in the circumferential direction. An opening 13b is provided on the outer periphery side of the susceptor 13 of the housing portion 13a, and the external gear 15a of the rotating gear member 15 is formed so as to protrude to the outer periphery of the susceptor 13.

  The substrate holding member 14 includes a large-diameter portion 14b provided with a substrate placement portion 14a for placing the substrate 16 on the upper surface, a small-diameter portion 14c protruding from the lower surface of the large-diameter portion 14b, a large-diameter portion 14b, and a small-diameter portion. It is formed in a cylindrical shape having a horizontal downward step portion 14d between 14c.

  The rotating gear member 15 includes a large-diameter accommodating portion 15b that accommodates the large-diameter portion 14b of the substrate holding member 14 in the upper inner periphery, and a small-diameter accommodating portion 15c that accommodates the small-diameter portion 14c in the substrate holding member 14 in the lower inner periphery. And a mounting step portion 15d for mounting the downward step portion 14d of the substrate holding member 14 between the large diameter storage portion 15b and the small diameter storage portion 15c, A gear 15a is formed. The rotating gear member 15 is rotatably accommodated in the accommodating portion 13a via a large number of balls 25 formed of carbon or ceramic.

  The substrate holding member 14 is housed and held inside the rotating gear member 15 with the spacer ring 26 interposed between the downward stepped portion 14d and the mounting stepped portion 15d, and is integrated with the rotating gear member 15. Rotate. The spacer ring 26 adjusts the height of the substrate holding member 14 held by the rotating gear member 15, and a plurality of spacer rings 26 having different thickness dimensions are prepared. The spacer ring 26 can be formed of various materials such as sapphire and carbon. However, by forming the spacer ring 26 from a composite material of silicon nitride and boron nitride, it is possible to improve workability and strength.

  A ring-shaped fixed gear member 27 having an internal gear 27a meshing with the external gear 15a of the rotating gear member 15 protruding from the opening 13b is provided at the outer peripheral position of the susceptor 13.

  When the thin film is vapor-grown on the upper surface of the substrate 16 by the vapor phase growth apparatus 11 described above, when the susceptor 13 is rotated by rotating the rotating shaft 17 at a predetermined speed, the axis of the susceptor 13 is rotated by the rotation of the susceptor 13. The outer gear 15a of the rotating gear member 15 revolving around the center of the gear meshes with the inner gear 27a of the fixed gear member 27, so that the rotating gear member 15 and the substrate holding member 14 held by the rotating gear member 15 rotate about the axis. As a result, the substrate 16 is in a state of self-revolving.

  On the other hand, in a state where the heater 18 is operated and the substrate 16 is heated to a predetermined temperature, for example, 1100 ° C. via the susceptor 13 and the substrate holding member 14, a predetermined source gas, for example, trimethylgallium and ammonia, is supplied from the source gas introduction unit 21. Is introduced into the upper surface side of the susceptor in the chamber 12 and discharged from the outer exhaust portion 22, whereby a predetermined thin film can be deposited on the upper surfaces of the plurality of substrates 16. At the same time, a predetermined inert gas, for example, nitrogen gas, is introduced into the space E below the susceptor 13 from the inert gas introduction unit 23 and discharged from the exhaust unit 22 to purge the space E.

  When the thin film is formed on the upper surface of the substrate 16 in this way, the temperature of the substrate 16 placed on each substrate holding member 14 may be different due to manufacturing errors of the substrate holding member 14 or the like. Accordingly, the thickness of the spacer ring 26 is changed to adjust the height of the substrate holding member 14, and the distance between the bottom surface of the substrate holding member 14 and the heater 18 is adjusted to minimize the temperature difference between the substrates. The thin film can be vapor-phase grown under uniform temperature conditions.

  An experiment was conducted in which the surface temperatures of the ten substrate holding members 14 were made uniform using the vapor phase growth apparatus 11 shown in the embodiment. With respect to the spacer ring, 10 spacer rings each having a thickness of 0.7 to 1.3 mm in increments of 0.1 mm were prepared with a thickness of 1 mm as a reference.

  First, as a reference, a spacer ring having a thickness of 1 mm is interposed between each downward stepped portion 14d and the mounting stepped portion 15d, heater temperature (measured value): 850 ° C., gas type: nitrogen gas, gas flow rate: The surface temperature of each substrate holding member 14 was measured with a radiation thermometer under the measurement conditions of 300 SLM and reactor pressure: atmospheric pressure. The result is shown in FIG. From this measurement result, it was found that there is a temperature difference of 2.6 ° C. between the maximum temperature and the minimum temperature of the surface temperature of each substrate holding member, and the surface temperature of each substrate holding member varies within this range.

  Further, the surface temperature of each substrate holding member when each spacer ring having each thickness was interposed was measured under the same measurement conditions, and the relationship between the thickness of the spacer ring and the surface temperature of the substrate holding member was examined. The result is shown in FIG. From this result, when the spacer ring thickness increases by 1 mm, the surface temperature of the substrate holding member decreases by 6 ° C., that is, when the spacer ring thickness increases by 0.1 mm, the surface temperature of the substrate holding member decreases by about 0.6 ° C. I understood it.

Next, based on the results of FIGS. 4 and 5, as shown in Table 1, a spacer ring thicker than 1 mm is interposed in the substrate holding member having a surface temperature higher than the average temperature, and the surface higher than the average temperature. A spacer ring thinner than 1 mm was interposed in a substrate holding member having a low temperature, and the surface temperature of each substrate holding member was measured under the same measurement conditions. The result is shown in FIG.

  As shown in the measurement results of FIG. 6, the variation in the surface temperature of each substrate holding member is reduced by changing the thickness of the spacer ring, that is, by adjusting the distance between the bottom surface of each substrate holding member and the heater. It can be seen that the improvement was within the range of 5 ° C.

  With all the 10 spacer rings having a thickness of 1 mm, the LED structure was vapor-phase grown on the substrate surface with a light emission wavelength of about 450 nm under known processing conditions. About the obtained LED structure, the light emission wavelength of each board | substrate was measured by PL measurement. The result is shown in FIG. From this result, it can be seen that the wavelength distribution between the substrates is about 6 nm (max-min).

  Next, each of the spacer rings having the respective thicknesses shown in Table 1 was used, and the LED structure was vapor-phase grown on the substrate surface with the same processing condition and aiming at an emission wavelength of about 450 nm. About the obtained LED structure, the light emission wavelength of each board | substrate was measured by PL measurement similarly to the above. The result is shown in FIG. This result shows that the wavelength distribution between the substrates is about 2.2 nm (max-min), and the wavelength reproducibility between the substrates can be improved.

It is sectional drawing which shows one example of the vapor phase growth apparatus of this invention. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a figure which shows the relationship between the board | substrate holding member in Example 1, and its surface temperature. It is a figure which similarly shows the relationship between a spacer ring thickness and the surface temperature of a board | substrate holding member. It is a figure which similarly shows the relationship between a board | substrate holding member and its surface temperature. It is a figure which shows the relationship between the board | substrate holding member in Example 2, and RPM. It is a figure which similarly shows the relationship between a board | substrate holding member and RPM.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Vapor growth apparatus, 12 ... Chamber, 13 ... Susceptor, 13a ... Accommodating part, 13b ... Opening part, 14 ... Substrate holding member, 14a ... Substrate mounting part, 14b ... Large diameter part, 14c ... Small diameter part, 14d DESCRIPTION OF SYMBOLS ... Downward step part, 15 ... Rotating gear member, 15a ... External gear, 15b ... Large diameter accommodating part, 15c ... Small diameter accommodating part, 15d ... Mounting step part, 16 ... Substrate, 17 ... Rotating shaft, 18 ... Heater, 19 DESCRIPTION OF SYMBOLS ... Thermometer, 20 ... Reflector, 21 ... Raw material gas introduction part, 22 ... Exhaust part, 23 ... Inert gas introduction part, 24 ... Inert gas extraction part, 25 ... Ball, 26 ... Spacer ring, 27 ... Fixed gear member 27a ... Internal gear

Claims (2)

  A disk-shaped susceptor that is rotatably provided in the chamber, a plurality of cylindrical rotating gear members that are rotatably provided on the outer periphery of the susceptor, and a cylindrical substrate holding that is held by the rotating gear member A member, a fixed gear member having an internal gear meshing with an external gear provided on the outer periphery of the rotating gear member, a source gas introduction portion provided on the susceptor surface side of the chamber, and a susceptor back surface of the chamber An inert gas introduction part provided on the side, an exhaust part provided on the anti-raw material gas introduction part side and the anti-inert gas introduction part side of the chamber, and heating means provided on the susceptor back side of the chamber In the vapor phase growth apparatus having a self-revolution mechanism, the substrate holding member includes a large diameter portion provided with a substrate mounting portion on an upper surface, a small diameter portion protruding from the lower surface of the large diameter portion, and a large diameter Part and small diameter The rotating gear member includes a large-diameter accommodating portion that accommodates a large-diameter portion of the substrate holding member at an inner peripheral upper portion, and the substrate holding member at an inner peripheral lower portion. A small-diameter storage portion for storing the small-diameter portion, and a mounting step portion for mounting the downward step portion of the substrate holding member between the large-diameter storage portion and the small-diameter storage portion, and the substrate holding member facing downward A vapor phase growth apparatus characterized in that a spacer ring for adjusting the height of the substrate holding member held by the rotating gear member is interposed between the stepped portion and the mounting step portion of the rotating gear member. 2. The vapor phase growth apparatus according to claim 1, wherein the spacer ring is formed of a composite material of silicon nitride and boron nitride.

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