JP2011187695A - Vapor phase growth method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor phase growth method capable of obtaining a deposited film of high quality and high reproducibility, while making a susceptor rotate with a substrate mounted, at a low speed. <P>SOLUTION: The present invention relates to the vapor phase growth method that uses a rotation/revolution type vapor phase growth device that performs vapor phase growth of a thin film, on the surface of the substrate heated by a heating means, by supplying a raw material gas to the side of the susceptor surface from a raw material gas supplying section. Meanwhile, a substrate-holding member is made to rotate and revolve, following the rotation of the susceptor; and in the vapor phase growth device, the number of rotations of the susceptor is set to be no more than 60 times a minute; and for the rotating direction of the substrate, the substrate is rotated in a negative direction for a smaller amount of time, as compared with the amount of time in rotation in the forward direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vapor phase growth method, and more particularly to a method for vapor phase growth of a thin film on a substrate using a vapor phase growth apparatus having a mechanism for rotating a susceptor holding a substrate.

  As a vapor phase growth apparatus, a disk-shaped susceptor rotatably provided in a chamber, a plurality of substrate holding members rotatably provided at equal intervals in the circumferential direction of the outer periphery of the susceptor, and the substrate holding member A circular substrate holding recess provided on the surface, a raw material gas introduction portion for introducing a raw material gas radially from the central portion of the chamber to the susceptor surface side, an exhaust portion provided on an outer peripheral portion of the chamber, and the substrate Heating means for heating the substrate held in the substrate holding recess through a holding member, and the substrate holding member rotates and revolves as the susceptor rotates, and from the source gas introduction part to the susceptor surface side. A self-revolving vapor phase growth apparatus is known in which a raw material gas is introduced and a thin film is vapor-phase grown on a substrate surface heated by the heating means.

  Furthermore, when a thin film is vapor-phase grown on a substrate using a vapor phase growth apparatus of the type that rotates the substrate placed on the susceptor including this self-revolving type, the susceptor is rotated at a high speed or at regular intervals. A method of improving the film quality of the growth film by rotating the susceptor in reverse has been proposed (see, for example, Patent Document 1).

JP 2003-142416 A

  In the method described in Patent Document 1, in the problem to be solved by the invention of the document, the quality of the deposited film grown on the substrate is deteriorated in the conventional method in which the rotation speed of the susceptor is 100 rotations per minute or less. In the method of Patent Document 1, the number of rotations of the substrate on the susceptor is basically 100 rotations per minute or more, and in the embodiment, the substrate is rotated at a high speed of 720 rotations per minute. By doing so, the film quality of the growth film can be improved. Further, even when changing the rotation direction, the high speed rotation of 720 rotations per minute or 1800 rotations per minute is basically performed, and forward rotation and reverse rotation are repeated at the same time period. .

  However, in order to rotate the substrate placed on the susceptor at high speed, a high-accuracy processing technique is required for the rotation mechanism of the susceptor. The substrate placed on the susceptor may rotate irregularly on the susceptor due to slight vibration, and the substrate and the susceptor may rub against each other, resulting in damage to the substrate. There is a problem that. Furthermore, if a thin and light substrate may be lifted from the susceptor, the substrate cannot be placed at a predetermined position on the susceptor. There was also a risk of jumping out toward the outer periphery of the susceptor.

  Accordingly, an object of the present invention is to provide a vapor phase growth method capable of obtaining a deposited film having high quality and good reproducibility while rotating a susceptor on which a substrate is placed at a low speed.

  In order to achieve the above object, the vapor phase growth method of the present invention comprises a disc-shaped susceptor rotatably provided in a chamber, a substrate holding recess provided on the surface of the susceptor, and a susceptor surface side of the chamber. A source gas introduction section for introducing a source gas into the chamber, an exhaust section provided on the side opposite to the source gas introduction section of the chamber, and a heating means for heating the substrate held in the substrate holding recess. In a vapor phase growth apparatus that rotates the substrate as it rotates and introduces a source gas from the source gas introduction unit and grows a thin film on the substrate surface heated by the heating means, integrated with the susceptor The number of rotations of the rotating substrate is set to 60 or less per minute, and the rotation direction of the substrate is rotated in the negative direction for a shorter time than the time of rotating in the positive direction. It is characterized by a door.

  Further, the vapor phase growth method of the present invention includes a disc-shaped susceptor rotatably provided in the chamber, and a plurality of substrate holding members rotatably provided at equal intervals in the circumferential direction of the outer periphery of the susceptor. A substrate holding recess provided on the surface of the substrate holding member, a source gas introducing portion for introducing a source gas radially from the central portion of the chamber to the susceptor surface side, and an exhaust portion provided on an outer peripheral portion of the chamber; A heating means for heating the substrate held in the substrate holding recess, and the substrate is rotated and revolved along with the rotation of the susceptor, and a source gas is introduced from the source gas introduction part to the susceptor surface side. In a vapor phase growth method using a self-revolution type vapor phase growth apparatus for vapor phase growth of a thin film on a substrate surface heated by the heating means, the rotation speed of the susceptor is set to 60 rpm or less. With the rotation direction of the substrate, shorter than the time which is rotating in the forward direction, or is characterized in that only a small angle compared to the angle which is rotating in the forward direction is rotated in the negative direction.

  Furthermore, in the vapor phase growth method of the present invention, the rotation speed of the susceptor is 1 to 10 rotations per minute, and the substrate is rotated in the negative direction with respect to the time or angle of rotation in the positive direction or During the film forming operation, the angle is in the range of 1/8 to 1/2. In particular, when the substrate rotates 360 degrees in the positive direction, the substrate rotates 90 degrees in the negative direction and returns to the positive rotation. It is characterized by repetition.

  According to the vapor phase growth method of the present invention, by rotating the susceptor and the substrate at a low speed and by rotating the substrate in the reverse direction for a short time, the substrate in the substrate holding recess is not affected by the vibration of the rotating susceptor and the substrate holding member. Since regular rotation can be suppressed, a deposited film with high quality and good reproducibility can be obtained. Further, since it is not necessary to rotate the susceptor at a high speed, the apparatus cost does not increase, and it can be easily applied to a normal vapor phase growth apparatus.

It is sectional drawing which shows one example of the vapor phase growth apparatus of this invention. It is an II-II arrow line view of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is explanatory drawing which shows the rotation direction of a board | substrate. It is a figure which shows the relationship between the rotation angle in Example 1, and in-plane light emission distribution. It is a figure which shows the relationship between the rotation angle in Example 2, and in-plane light emission distribution.

  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. In this embodiment, it is formed so that ten substrates 16 can be processed simultaneously.

  The susceptor 13 is supported by a rotating shaft 17 penetrating the bottom surface portion of the chamber 12, and the rotating shaft 17 is driven by a pulse motor capable of controlling the rotation speed and the rotation direction. 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 holding recess 14a for holding 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 14c. It is formed in the column shape which has the downward step part 14d of the horizontal direction of between.

  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.

  The substrate holding recess 14 a provided on the upper surface of the substrate holding member 14 has a diameter corresponding to the diameter of the substrate 16 to be held, usually a diameter slightly larger than the diameter of the substrate 16, for example, several millimeters. It has a depth substantially the same as the thickness.

  When the thin film is vapor-phase grown on the upper surface of the substrate 16 by the vapor phase growth apparatus 11, 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. When the external gear 15a of the rotating gear member 15 revolving around the center meshes with the internal gear 27a of the fixed gear member 27, the rotating gear member 15 and the substrate holding member 14 held thereby rotate around its axis. As a result, the substrate 16 revolves and revolves.

  Thus, when performing the vapor phase growth operation while revolving the substrate 16 held on the substrate holding member 14, the rotation speed of the susceptor 13 is set to 60 rotations per minute or less, preferably 1 to 10 rotations per minute. At the same time, as shown by the solid line and the broken line in FIG. 4, the rotation direction of the substrate 16 is compared to the positive direction (solid arrow A in FIG. 4), for example, the time during which it rotates counterclockwise in FIG. By rotating in the negative direction (broken arrow B in FIG. 4) for a short time, that is, clockwise in FIG. 2, the acceleration generated in the substrate 16 when rotating in the positive direction, and the substrate 16 with respect to the substrate holding recess 14a. The force to be rotated can be suppressed, and the substrate 16 is irregularly rotated in the substrate holding recess 14a due to vibrations from the susceptor 13, the substrate holding member 14, and the rotating gear member 15 accompanying the rotation. It can be prevented.

  That is, by setting the number of rotations of the susceptor 13 low and rotating the substrate 16 in the negative direction for a short time, the substrate 16 during the film forming operation can be held in a stable state, and also sufficiently in the revolution direction. Therefore, it is possible to obtain a deposited film with high quality and good reproducibility.

  The ratios of the time to rotate in the positive direction and the time to rotate in the negative direction are the number of rotations of the susceptor 13 (the number of revolutions of the substrate 16), the number of rotations of the substrate holding member 14 (the number of rotations of the substrate 16), and the susceptor 13 and the substrate. What is necessary is just to select optimal conditions according to conditions, such as the magnitude | size (diameter) of 16, and the gear ratio of a rotation part and a revolution part. Usually, if the time for rotating in the negative direction is made closer to the time for rotating in the positive direction, there are too few changes in the rotation direction, and a sufficient effect cannot be obtained. On the other hand, if the rotation direction is switched too much, a slight rotation stop time at the time of switching cannot be ignored, and the film formation uniformity may be impaired. The time for rotating in the negative direction relative to the time for rotating in the positive direction is preferably in the range of 1/8 to 1/2, particularly 1/4. For example, after rotating in the positive direction for 12 seconds, it is preferable to rotate in the negative direction for 3 to 6 seconds. If this is expressed by a rotation angle, the substrate 16 is rotated in the positive direction of 360 degrees, for example, and then 45 to 45 seconds. It is preferable to rotate 180 degrees in the negative direction. For example, the susceptor 13 is rotated regardless of the number of rotations, the substrate 16 is rotated 360 degrees in the positive direction, and then the substrate 16 is rotated 90 degrees (1/4 of 360 degrees) in the negative direction. Since the rotation proceeds by 270 degrees in the revolution direction, a good deposited film can be obtained without impairing the effect of revolving the substrate 16.

  In this embodiment, the self-revolution type vapor phase growth apparatus has been described as an example. However, a disk-shaped susceptor provided rotatably in the chamber, and a substrate holding recess provided on the surface of the susceptor. A source gas introduction part for introducing a source gas into the susceptor surface side of the chamber; an exhaust part provided on the side opposite to the source gas introduction part of the chamber; and a heating means for heating the substrate held in the substrate holding recess A horizontal gas phase in which the substrate is rotated in accordance with the rotation of the susceptor, and a source gas is introduced from the source gas introduction part and a thin film is vapor-phase grown on the substrate surface heated by the heating means. It can also be applied to a growth apparatus.

  The rotation angle (rotation angle) of the substrate 16 in the negative direction is set to 1/4 of the rotation angle in the positive direction, and the rotation angle in the positive direction until the substrate 16 is rotated in the negative direction is changed to change the GaN-based semiconductor light-emitting device. A film was formed under normal conditions, and the in-plane wavelength distribution of the obtained light emitting device was measured. Note that the rotation angle in the positive direction is 0 degree means that the substrate 16 does not rotate but only revolves due to the rotation of the susceptor 13. The results are shown in FIG. From this result, when the rotation angle in the negative direction is 1/4 of the rotation angle in the positive direction, the in-plane distribution of the deposited film can be improved by changing the rotation direction of the substrate 16, and the rotation in the positive direction. It can be seen that the best results are obtained by switching the direction of rotation when the angle is 360 degrees.

  The rotation angle (rotation angle) of the substrate 16 in the positive direction is set to 360 degrees, and the rotation angle in the negative direction is changed to form a GaN-based semiconductor light emitting device, and the in-plane wavelength distribution of the obtained light emitting device Was measured. Note that the reverse rotation angle is 0 degrees when the rotation direction is not switched. The results are shown in FIG. From this result, it can be seen that when the rotation angle in the positive direction is 360 degrees, the best result is obtained at 90 degrees. In addition, in a substrate having a diameter of 100 mm, the in-plane wavelength distribution in the substrate diameter direction is about ± 1 nm when the rotation angle in the positive direction is 360 degrees and the rotation angle in the negative direction is 90 degrees. It can be seen that the wavelength distribution is improved.

  DESCRIPTION OF SYMBOLS 11 ... Vapor growth apparatus, 12 ... Chamber, 13 ... Susceptor, 13a ... Accommodating part, 13b ... Opening part, 14 ... Substrate holding member, 14a ... Substrate holding recessed part, 14b ... Large diameter part, 14c ... Small diameter part, 14d ... Downward stepped portion, 15 ... rotating gear member, 15a ... external gear, 15b ... large diameter accommodating portion, 15c ... small diameter accommodating portion, 15d ... mounting stepped portion, 16 ... substrate, 17 ... rotating shaft, 18 ... heater, 19 ... Thermometer, 20 ... reflector, 21 ... raw material gas introduction part, 22 ... exhaust part, 23 ... inert gas introduction part, 24 ... inert gas outlet part, 25 ... ball, 26 ... spacer ring, 27 ... fixed gear member, 27a ... Internal gear

Claims (4)

  A disk-shaped susceptor that is rotatably provided in the chamber, a substrate holding recess provided on the surface of the susceptor, a source gas introduction part that introduces a source gas to the susceptor surface side of the chamber, and a reaction of the chamber An exhaust part provided on the source gas introduction part side, and a heating means for heating the substrate held in the substrate holding recess, and the substrate gas is rotated as the susceptor rotates, and the source gas introduction part In the vapor phase growth apparatus that introduces the source gas from the vapor phase and vapor-deposits the thin film on the substrate surface heated by the heating means, the rotation speed of the substrate that rotates integrally with the susceptor is set to 60 rotations per minute or less. The vapor phase growth method characterized in that the rotation direction of the substrate is rotated in the negative direction for a shorter time than the time in which the substrate is rotated in the positive direction.   A disk-shaped susceptor that is rotatably provided in the chamber, a plurality of substrate holding members that are rotatably provided at equal intervals in the circumferential direction of the outer periphery of the susceptor, and a circular shape that is provided on the surface of the substrate holding member The substrate holding recess, the source gas introducing portion for introducing the source gas radially from the central portion of the chamber to the susceptor surface side, the exhaust portion provided in the outer peripheral portion of the chamber, and the substrate holding recess Heating means for heating the substrate, and the substrate surface revolves as the susceptor rotates, and a source gas is introduced from the source gas introduction part to the susceptor surface side and heated by the heating means. In a vapor phase growth method using a self-revolution type vapor phase growth apparatus for vapor phase growth of a thin film on the substrate, the rotation speed of the susceptor is set to 60 rpm or less, and the rotation of the substrate is performed. Vapor deposition method characterized by rotating the direction, the negative direction for a short time compared to the time which is rotating in the forward direction.   The number of rotations of the susceptor is 1 to 10 rotations per minute, and the rotation time of the substrate in the negative direction is in the range of 1/8 to 1/2 with respect to the rotation time in the positive direction. 3. The vapor phase growth method according to claim 1 or 2, characterized in that:   4. The substrate according to claim 1, wherein when the substrate rotates 360 degrees in the positive direction, the substrate rotates 90 degrees in the negative direction and returns to the positive rotation during the film forming operation. 5. Vapor phase growth method.

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