WO2008023697A1

WO2008023697A1 - Vapor phase growth system

Info

Publication number: WO2008023697A1
Application number: PCT/JP2007/066183
Authority: WO
Inventors: Akira Yamaguchi; Yuuichirou Kitamura
Original assignee: Taiyo Nippon Sanso Corporation
Priority date: 2006-08-23
Filing date: 2007-08-21
Publication date: 2008-02-28
Also published as: TW200818276A

Abstract

A vapor phase growth system comprising a chamber, a flow channel arranged in the chamber, a substrate arranged in the flow channel, a heating means for heating the substrate, a reaction gas supply means for supplying a reaction gas into the flow channel, and a view port provided onto the chamber. A through hole serving as an optical path when the substrate surface is observed optically through the view port is provided in the wall of the flow channel facing the substrate, a purge gas channel is provided between the outer surface of the flow channel wall provided with the through hole and a portion of the view port on the inner side of the chamber, and a purge gas introducing means for introducing a purge gas into the purge gas channel in the state of layer flow at the substantially same speed and the same pressure in the same direction as the reaction gas flowing through the flow channel is provided.

Description

Specification

Vapor growth equipment

Technical field

TECHNICAL FIELD [0001] The present invention relates to a vapor phase growth apparatus provided with a viewport for optically observing a substrate surface in a chamber containing a flow channel, and in particular, an organometallic semiconductor thin film, particularly a nitride organic film. The present invention relates to a horizontal vapor phase growth apparatus for growing a metal-based semiconductor film on a substrate surface.

This application (May 23, 2006, Japanese Patent Application No. 2006-226732, and Japanese Patent Application No. 2006-226733, filed August 23, 2006, in Japan. The content of this is used here.

Background art

[0002] As a vapor phase growth apparatus, the temperature and warpage of the substrate surface during vapor phase growth, and the thickness and composition of the thin film being grown are observed and measured by optical equipment. It is known to have an observation window (view port) fitted with quartz glass with corrosion resistance and heat resistance. In order to prevent reaction products from adhering to the inner surface of the viewport and clouding it, a purge gas is circulated, and a part of the viewport is heat-reflected in order to avoid thermal effects during substrate temperature measurement. (E.g., see Patent Document 1).

[0003] Further, as a photo-excited vapor phase growth apparatus using light energy, a double tube structure in which an inner tube having a light introduction hole (through hole) is housed inside an outer tube having a light introduction window An apparatus having the following reaction tubes has been proposed. In this apparatus, a raw material gas is flowed inside the inner tube, a carrier gas (purge gas) is flowed between the outer tube and the inner tube, and the flow rates of the raw material gas and the carrier gas are made substantially equal in the vicinity of the light introduction hole. . This prevents the raw material gas from flowing out of the inner tube through the light introduction hole and prevents the reaction product from adhering to the inner surface of the light introduction window to cause fogging (see, for example, Patent Document 2). .

[0004] When the configuration described in Patent Document 1 and the configuration described in Patent Document 2 are combined, an adverse effect of reaction products adhering to the inner surface of the flow channel is provided. In addition, it is possible to prevent the reaction product from adhering to the inner surface of the viewport by flowing the carrier gas to the outside of the through hole at a substantially constant speed relative to the flow rate of the raw material gas to prevent the raw material gas from flowing out. .

[0005] However, in the double pipe structure as described in Patent Document 2, the cross-sectional area of the flow path through which the carrier gas (purge gas) flows becomes large, and it is necessary to flow a large amount of carrier gas. Exhaust pumps that have a large capacity are also required, as well as their own cost increases. Furthermore, in a horizontal type vapor phase growth apparatus in which the substrate is heated by a heater provided on the back surface of the susceptor while the substrate is held and rotated by a susceptor (susc mark tor), the reaction tube has a heater portion and a susceptor support portion. Such a structure becomes complicated, and the cost of the equipment increases significantly.

[0006] In addition, when a thin film is formed at a pressure close to normal pressure, a gas stream (for example, thermal convection) in the chamber causes a light beam, for example, a laser beam, to fluctuate so that the substrate surface cannot be observed accurately. There was. For example, fluctuations due to the height and rotation of the substrate surface during film formation can be measured by the force measured by the reflection position of the laser beam irradiated on the substrate surface at an appropriate angle, and the noise increases when the laser beam fluctuates due to airflow. Sometimes it became impossible.

[0007] In addition, in a compound semiconductor thin film manufacturing apparatus, a film may be formed by reacting raw materials at a high temperature exceeding 800 to 1000 ° C at a pressure close to normal pressure. Under such a high temperature, the entire substrate may be warped due to the difference in thermal expansion coefficient between the films or between the substrate and the thin film. Even when trying to measure the degree of warpage of this substrate using laser light, an air flow is generated in the chamber 1 due to the temperature difference between the water-cooled chamber outer wall and the inside of the chamber. Measurement was difficult due to the large fluctuation.

[0008] In order to reduce the fluctuation of light caused by such an air flow, there is a big problem that the film forming conditions change, which can be considered to reduce the pressure in the chamber. In addition, it is possible to suppress fluctuations by forming an optical path through which one laser beam passes as much as possible. However, adjustment during installation is difficult, and there is a problem in practicality.

Patent Document 1: JP 2001-68415 A

Patent Document 2: Japanese Patent Application Laid-Open No. 62-188218

Disclosure of the invention Problems to be solved by the invention

[0009] Therefore, the present invention can efficiently prevent the reaction product from adhering to the inner surface of the viewport, and suppresses the influence of the airflow in the chamber, thereby ensuring optical observation and measurement using a laser beam or the like. The purpose is to provide a vapor phase growth apparatus that can be performed!

Means for solving the problem

[0010] To achieve the above objective,

A vapor phase growth apparatus according to a first aspect of the present invention includes a chamber, a flow channel disposed in the chamber, a substrate installed in the flow channel, and a heating unit that heats the substrate. A reaction gas supply means for supplying a reaction gas into the flow channel; and a viewport provided in the chamber. The substrate surface of the flow channel is optically disposed on the opposite wall of the flow channel via the viewport. And a purge gas flow path is provided between the outer surface of the flow channel wall provided with the through hole and the inside of the chamber of the viewport. Purge gas introduction means for flowing a purge gas in a laminar flow state in the same direction as the flow direction of the reaction gas flowing in the flow channel, at substantially the same speed and pressure. It is characterized by having established.

[0011] Further, in the vapor phase growth apparatus according to the first aspect of the present invention, the viewport is arranged near the outer surface of the flow channel wall, or the viewport is in the flow direction of the reaction gas. It is preferable that it is located downstream.

[0012] The purge gas flow path includes a pair of side plates erected on the outer surface of the flow channel wall, an end plate closing the upstream side of both side plates, and the opposite flow channel side of the end plates and both side plates. It is preferable that the end plate is provided with a purge gas introduction part, and the exhaust port is formed by opening the downstream side of both side plates! /.

[0013] Further, the cover plate has a through-hole serving as an optical path when optically observing the substrate surface through the viewport, and the cover plate is a front end on the inner side of the Puport chamber. It is preferable to have an annular protrusion covering the outer periphery of the part, or to have a through-hole through which the front end of the viewport inside the chamber passes.

[0014] A vapor phase growth apparatus according to a second aspect of the present invention includes a chamber and a chamber. A flow channel, a substrate installed in the flow channel, a heating unit for heating the substrate, a reaction gas supply unit for supplying a reaction gas into the flow channel, and a view provided in the chamber. The viewport is characterized in that the inside of the chamber of the viewport extends toward the flow channel, and the distal end surface of the extension is arranged near the outer surface of the flow channel.

[0015] In the vapor phase growth apparatus according to the second aspect of the present invention, the extension part of the viewport has a hollow structure having a hollow part inside, and the hollow part is in a vacuum state, The front end surface of the viewport is inclined with respect to the surface of the substrate, the viewport is provided so as to be adjustable with respect to the chamber, and the viewport has a flow direction of the reaction gas. It is preferable that it is located downstream.

The invention's effect

[0016] According to the vapor phase growth apparatus according to the first aspect of the present invention, optical observation of the substrate surface can be performed even if a reaction product adheres to the inner surface of the flow channel by providing a through hole in the flow channel. It can be done reliably. In addition, by flowing the purge gas under specific conditions, it is possible to prevent the reaction gas and reaction product from flowing out from the through hole to the viewport side with a small amount of purge gas, and the reaction product adheres to the inner surface of the viewport. As a result, it is possible to prevent the purge gas from flowing into the flow channel and adversely affecting the thin film being formed.

[0017] Further, since the purge gas flow path is provided only on the substrate facing wall, the amount of purge gas can be reduced, and the cost of the purge gas itself can be reduced. The equipment cost can also be reduced by downsizing the exhaust pump. Furthermore, a heater or the like for heating the susceptor holding the substrate can be arranged in the same manner as a conventional general horizontal vapor phase growth apparatus, and an increase in apparatus cost can be suppressed.

[0018] According to the vapor phase growth apparatus according to the second aspect of the present invention, since the inner side of the chamber of the viewport extends to the vicinity of the outer surface of the flow channel, the air flow in the chamber 1 is converted into laser light. It is possible to optically reliably and accurately observe and measure the state of the substrate during film formation that does not adversely affect the film.

Brief Description of Drawings FIG. 1 is a cross-sectional view of a main part showing a first embodiment of a vapor phase growth apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a cross-sectional view of a relevant part showing a second embodiment of the vapor phase growth apparatus according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view of a relevant part showing a third embodiment of the vapor phase growth apparatus according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of a main part showing a fourth embodiment of the vapor phase growth apparatus according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view of a relevant part showing a fifth embodiment of the vapor phase growth apparatus according to the first embodiment of the present invention.

FIG. 8 is a cross-sectional view of a relevant part showing a first embodiment of a vapor phase growth apparatus according to a second aspect of the present invention.

FIG. 9 is a cross-sectional view of a main part showing a second example of the vapor phase growth apparatus according to the second aspect of the present invention.

FIG. 10 is a cross-sectional view of a relevant part showing a third embodiment of the vapor phase growth apparatus according to the second aspect of the present invention.

FIG. 11 is a cross-sectional view of a relevant part showing a fourth example of the vapor phase growth apparatus according to the second aspect of the present invention.

FIG. 12 is a cross-sectional view of a relevant part showing a fifth embodiment of the vapor phase growth apparatus according to the second aspect of the present invention.

FIG. 13 is a diagram showing the result of measuring the height of the upper surface on the outer periphery side of a rotating substrate. Explanation of symbols

[0020] 11 ··· substrate, 12 ··· susceptor, 13 ··· flow channel, 13a ... upper wall, 13b ... through, 1 4 ... chamber one, 14a ... top plate, 14b ... view Port opening, 14c ... concave part, 15 ... exhaust part, 16 ... reflector, 17 ... heater, 18 ... support shaft, 20 ... viewport, 21 ... window material, 22 ... sinore material, 23 --- 24 gas nozzle, 24a -... plate, 24b- end Plate, 24c ... Cover plate, 24d ... Noge gas introduction ^ 24e ... Mouth, 24f ... Communication? 24g ... through hole, 24h ... annular protrusion, 25 ... purge gas introduction means, 26 ... exhaust pump, 31 ... view port, 31a ... same as the moon ^ 31b ... flange, 31c ... tip, 32 ················································································································································· 41b ... Window member, 41c ... Tip member, 42 ... Airtight bellows member, 42a ... Bellows part, 42b ... Mounting flange, 42c ... Sealing material, 43 ... Lid member, 43a ... Through hole for incident light, 43b ... Through hole for reflected light

111 ... Substrate, 112 ... Susceptor, 113 ... Flow channel nore, 113a ... Pass through, 114 ··· No. 114a ... Top plate, 114b ... Opening for viewport, 115 ... Exhaust , 116 ... Reflector, 117 ... Heater, 118 ... Support shaft, 120 ... Viewport, 121 ... Pewport member, 121a ... Moon joint ^ 121b ... Flange, 121c ... Tip face, 122 ... Sinole material , 123 ··· Fastening member, 131 ··· Window member, 132 ··· Hollow member, 132a ... Pipe-like member, 132b ... Disc-like member, 132c ... Tip surface, 132d ... Connection part, 133 ··· Vacuum Pump, 134 ... Exhaust pipe, 135 ... Ring member, 135a ... Connection part, 141 ... Viewport member, 141a ... Cylindrical part, 141b ... Window member, 141c ... Tip member, 142 ... Airtight 142a ... bellows part, 142b ... mounting flange, 142c ... sealing material, 143 ... lid member, 143a ... incident light through hole, 143b ... reflected light through hole, 144 ... Jigasu ^ E, 144 & ··· Roh Jigasu input ^, 144b-- your ^ ¼ ports, 144 Ji hole, 144d ... annular projection

BEST MODE FOR CARRYING OUT THE INVENTION

1 to 3 show a first embodiment of the vapor phase growth apparatus according to the first embodiment of the present invention. FIG. 1 is a cross-sectional view of the main part, and FIG. 2 is II II of FIG. Cross-sectional view, Fig. 3 is a cross-sectional view of III-III in Fig. 1.

[0022] The plurality of substrates 11 are concentrically held on the upper surface of the susceptor 12, and are flow channels.

Arranged at 13 predetermined positions. The substrate surface of the substrate 11 is substantially parallel to the upper surface of the susceptor 12. The flow channel 13 and the like are housed in a sealed chamber 14. Through a reaction gas inlet provided at one end of the chamber 14, a reaction gas A is introduced into the flow channel 13 in a laminar flow state in a direction parallel to the substrate surface from a reaction gas supply means (not shown). Gas (exhaust gas B) that has passed through the substrate surface is connected to the flow channel 13. Exhausted from the exhaust section 15. The reaction gas supply means is not particularly limited, and a known one can be used.

[0023] Below the susceptor 12, there is provided a heater 17, which is a heating means, housed in a box-shaped reflector 16. The substrate 17 is heated to a predetermined temperature via the susceptor 12 by the heater 17. To do. The susceptor 12 is supported by a support shaft 18. By rotating the susceptor 12 with the support shaft 18, the substrate 11 is rotated to average the thickness of the thin film formed on the substrate. And then,

[0024] A viewport opening 14b is provided on the downstream side in the reaction gas flow direction from the center of the susceptor 12 in the top plate portion 14a of the chamber 14, and the viewport 20 is provided in the viewport opening 14b. The window member 21 to be formed is fitted. The window member 21 is made of a disc-like light-transmitting material, for example, quartz glass having corrosion resistance and heat resistance, and is detachably fixed to the upper surface of the top plate portion 14a by a fastening member 23. . The lower surface of the outer peripheral portion of the window member 21 is hermetically sealed to the upper surface of the top plate portion 14a by the sealing material 22.

Further, a through hole 13b is provided in a position corresponding to the center of the viewport 20 on the substrate facing wall (upper wall) 13a of the flow channel 13, and the outer surface of the upper wall 13a and the pure port 20 are provided. A purge gas flow path 24 is provided between the chamber 14 and the inside of the chamber 14 so as to surround the through hole 13b.

As shown in FIGS. 1 to 3, the purge gas flow path 24 is formed on the upper surface of the upper wall 13a of the flow channel 13 with respect to the flow direction of the reaction gas in the flow channel 13. A pair of side plates 24a, 24a erected at a predetermined interval in a parallel direction, a substantially V-shaped end plate 24b extending downstream in the purge gas flow direction closing the upstream side of both side plates 24a, 24a, and the end plate 24b And the upper side of both side plates 24a, 24a, that is, the cover plate 24c covering the side opposite to the flow channel, has a flat shape with a height direction of several mm to 10 mm, and the end plate 24b A purge gas introduction part 24d is provided at the center in the width direction, an exhaust port 24e is formed by opening the downstream side of both side plates 24a, 24a, and a through hole 24f corresponding to the through hole 13b is provided in the cover plate 24c. It has been.

[0027] The purge gas P flowing through the purge gas passage 24 has a flow rate adjustment function and a pressure adjustment function. The purge gas introduction means 25 is introduced into the purge gas flow path 24 at a predetermined pressure and flow rate through the purge gas introduction section 24d, flows out from the exhaust port 24e, and exhaust gas B discharged from the exhaust section 15 of the flow channel 13 They are merged or individually sucked into the exhaust pump 26 and sent to an abatement facility.

Here, the purge gas P flowing through the purge gas flow path 24 is substantially the same in flow direction as the reaction gas flowing in a laminar flow state in the flow channel 13 in a direction parallel to the upper surface of the substrate 11. Are set to flow at the same speed, the same pressure, and laminar flow. Further, the flow path cross-sectional shape of the purge gas flow path 24 is set so as to be sufficient to satisfy these conditions.

[0029] The flow rate and pressure of the purge gas flowing in the purge gas flow path 24 are preferably the same as the flow rate and pressure of the reaction gas flowing in the flow channel 13, but the conditions of both gases, the flow channel There are appropriate ranges for the flow rate and pressure of the purge gas depending on the shape of the purge gas flow path 13 and the shape of the purge gas passage 24 and the shape and position of the through-hole 13b provided in the flow channel 13. For example, even if the flow rate and pressure of the purge gas are lower than the flow rate and pressure of the reaction gas, and the reaction gas in the flow channel 13 flows out to the purge gas flow path 24 through the through hole 13b, it is quickly discharged with the purge gas. As long as the cover plate 24c and the viewport 20 of the purge gas flow path 24 are not reached! /, The optical observation of the substrate surface and the film formation are not affected.

[0030] Conversely, even if the purge gas flow rate or pressure is higher than the reaction gas flow rate or pressure and the purge gas flows into the flow channel 13, the purge gas does not reach the substrate surface. If the flow is not significantly disturbed, the film thickness distribution and film quality will not be affected. Furthermore, by providing the through hole 13b on the downstream side of the center of the susceptor 12, the influence of the outflow of the reaction gas from the flow channel 13 and the inflow of the purge gas into the flow channel 13 can be reduced.

[0031] In addition, since the space between the two can be reduced by bringing the viewport 20 closer to the flow channel 13, it is possible to suppress the generation of airflow such as thermal convection, and to prevent the measurement light from fluctuating accurately. Measurements can be made. Furthermore, by making the purge gas flow in the purge gas passage 24 into a laminar flow state, the light generated by the airflow is less than that in the turbulent state. Fluctuation can be suppressed and more precise measurement can be performed.

FIG. 4 is a cross-sectional view of a main part showing a second embodiment of the vapor phase growth apparatus according to the first aspect of the present invention. In the following description, the same components as those shown in the first embodiment of the previous year are denoted by the same reference numerals, and detailed description thereof is omitted.

This embodiment shows a corresponding example in the case where the top plate portion 14a of the chamber 14 has to be raised to some extent due to the surrounding devices of the flow channel 13. That is, a concave portion 14c is formed at a predetermined position with respect to the susceptor 12 in the top plate portion 14a, and a viewport opening 14b is provided at the bottom of the concave portion 14c to attach the pew port member 21, whereby the view port 20 is It is lowered below the section 14a and is positioned near the outer surface of the flow channel 13.

[0034] By thus positioning the viewport 20 in the vicinity of the outer surface of the flow channel 13, the purge gas flow path 24 is formed flat in the height direction in the same manner as in the first embodiment, and the flow path is cut off. The area can be reduced, and the state of the substrate 11 can be optically observed from the outside without being affected by the gas flow in the chamber 14.

In the first and second embodiments, the cover plate 24c is provided on the side opposite to the flow channel of the purge gas passage 24! /, But this cover / plate 24c is omitted. It is also possible to use the top plate part 14a as a cover / board.

FIG. 5 is a cross-sectional view of a main part showing a third example of the vapor phase growth apparatus according to the first aspect of the present invention. This embodiment shows a corresponding example when the flow channel 13 and the top plate portion 14a of the chamber 14 are separated from each other as in the second embodiment. In this embodiment, the top 14a of the chamber 14 remains flat, and is fixed to the viewport opening 14b to the cylindrical body 31a protruding into the chamber 14 and the top 14a. A viewport member 31 made of a solid translucent material having a hat-shaped (T-shaped) longitudinal cross section having a flange 31b at the upper end of the head is attached. The front end of the body 31a protruding into the chamber 14 passes through a through hole 24g formed in the cover plate 24c of the purge gas flow path 24, and the front end surface 31c reaches the vicinity of the upper wall 13a of the flow channel 13. Yes.

FIG. 6 is a cross-sectional view of a main part showing a fourth example of the vapor phase growth apparatus according to the first aspect of the present invention. This embodiment replaces the solid viewport member 31 in the third embodiment. In addition, a disc-shaped window member 32 mounted in the viewport opening 14b and a hollow member 33 provided below the window member 32 are provided. The hollow member 33 airtightly closes both ends of the pipe-shaped member 33a made of a translucent member such as quartz glass by the disk-shaped member 33b, and exhaust pipe 34 for evacuating the hollow portion of the hollow member 33. The inside of the hollow member 33 is evacuated and kept in a vacuum state to such an extent that the air current does not affect the optical observation. The exhaust pipe 34 may be sealed after the inside of the hollow member 33 is exhausted to a predetermined degree of vacuum.

[0038] Also in this embodiment, the distal end portion of the hollow member 33 protruding into the chamber 14 penetrates the through hole 24g formed in the cover plate 24c of the purge gas flow path 24, and the distal end surface 33c is the flow channel 13. To the vicinity of the upper wall 13a.

[0039] In the third and fourth embodiments, the distal end portions of the viewport member 31 and the hollow member 33 protrude into the purge gas flow channel 24, so that the flow channel height is lowered at this portion and the flow channel is cut off. Since the area becomes small, the force that causes the flow velocity and the like to be different from the peripheral portion. The purge gas may be flowed so as to satisfy the above-described condition at the position of the through hole 13b of the flow channel 13. Further, by making the distal end surface 31c of the viewpoint member 31 and the distal end surface 33c of the hollow member 33 flush with the lower surface of the covering plate 24c, it is possible to eliminate the change in the flow path cross-sectional area.

[0040] FIG. 7 is a cross-sectional view of a relevant part showing a fifth embodiment of the vapor phase growth apparatus according to the first aspect of the present invention. The viewport member 41 shown in the present embodiment includes a conical cylindrical portion 41a having a reduced diameter on the lower side, a disk-like window member 41b that hermetically closes the upper opening of the cylindrical portion 41a, and a cylindrical shape It is a hollow member formed by a disc-shaped tip member 41c that hermetically closes the lower opening of the portion 41a, and the tip member 41c is inclined with respect to the surface of the substrate 11. In addition, the hollow portion in the viewport member 41 is evacuated by a vacuum pump and then sealed to be in a vacuum state.

[0041] The viewport member 41 is attached to the top plate portion 14a of the chamber 14 via an airtight bellows member 42 provided so as to surround the Puport opening 14b of the chamber 14. . The airtight bellows member 42 has mounting flanges 42b at both ends of the bellows portion 42a. In addition, the lower mounting flange 42b is fixed to the upper surface of the top plate portion 14a via a sealing material 42c, and the upper mounting flange 42b is fixed to the window member via the sealing material 42c. The viewport member 41 is attached to the chamber 14 by mounting the outer periphery of the 41b and fixing the lid member 43 covering the upper surface of the window member 41b to the upper mounting flange 42b.

[0042] In this manner, by attaching the viewport member 41 to the chamber 14 through the airtight bellows member 42, the mounting position of the viewport member 41 with respect to the chamber 14 using the deformation of the bellows portion 42a. The front / rear, left / right, up / down directions and mounting angle can be adjusted. Further, the tip member 41c of the Puport member 41 is close to the upper surface of the cover plate 24c of the purge gas flow path 24, and an annular protrusion 24h that covers the outer periphery of the tip of the viewport member 41 is provided on the upper surface of the cover plate 24c. Being! /

The lid member 43 is provided with two through holes, an incident light through hole 43a and a reflected light through hole 43b. Laser light La is transmitted from the incident light through hole 43a to the surface of the substrate 11. In this way, the state of the light Lb reflected on the substrate surface is received outside the reflected light through hole 43b. When the reflected light is used in this way, the light reflected by the tip member 41c and the light reflected by the substrate surface can be separated by slightly tilting the tip member 41c with respect to the substrate surface. Only reflected light from the substrate surface can be reliably received. Although the tilt direction is arbitrary, it is preferable that the tilt direction is not perpendicular to the incident light or reflected light.

[0044] Further, by providing an annular protrusion 24h covering the outer periphery of the distal end of the viewport member 41, the purge gas flowing in the purge gas flow path 24 flows from the through hole 24f into the chamber 14 through the tip member 41c portion. Conversely, the gas in the chamber 14 can be prevented from flowing into the tip member 41c. Note that the cover plate 24c and the tip member 41c of the purge gas channel 24 may be integrally formed without providing the through hole 24f of the purge gas channel 24. Furthermore, as a means for attaching the viewport member 41 to the chamber 14, an arbitrary position adjusting mechanism formed of an arbitrary material is adopted as long as it can withstand the use environment, not limited to the airtight bellows group material. can do. As a means for holding the viewport member 41 in a predetermined position, any holding means such as a bolt can be used.

[0045] In each embodiment, the type of purge gas is arbitrary, and nitrogen, hydrogen, argon, or the like that is normally used as a purge gas in this type of apparatus can be used. Also, view The position where one port is provided can be arbitrarily selected within a range where the state of the substrate surface can be observed and measured, but in order to prevent the reaction gas flow from being disturbed by the through holes, the flow of the reaction gas is as much as possible. It is preferable to arrange in the direction downstream. In addition, in order to avoid thermal influence on the measuring equipment, an infrared reflecting film should be provided outside or inside the viewport.

FIG. 8 is a cross-sectional view of a main part showing a first embodiment (embodiment) of the vapor phase growth apparatus according to the second aspect of the present invention. This vapor phase growth apparatus basically has the same configuration as the vapor phase growth apparatus described in Patent Document 1 described above.

The plurality of substrates 111 are concentrically held on the upper surface of the susceptor 112 and are arranged at predetermined positions on the flow channel 113. The substrate surface of the substrate 111 is substantially parallel to the upper surface of the susceptor 112. The flow channel 113 and the like are housed in a sealed chamber 114, and from a reaction gas supply means (not shown) through the reaction gas inlet provided at one end of the chamber 114, The reaction gas is introduced into the gas, and the gas that has passed through the substrate surface is exhausted from the exhaust part 115 connected to the flow channel 113. The reaction gas supply means is not particularly limited, and a known one can be used.

[0048] Below the susceptor 112 is provided a heater 117, which is a heating means, housed in a box-shaped reflector 116. The heater 117 causes the base plate 111 to reach a predetermined temperature via the susceptor 112. Heat. The susceptor 112 is supported by a support shaft 118. By rotating the susceptor 112 with the support shaft 118, the thickness of the thin film formed on the substrate is averaged by rotating the substrate 111. ing.

[0049] A viewport member 121 that forms a viewport 120 is fitted into a viewport opening 114b provided in the top plate portion 114a of the chamber 114. This view port member 121 has a cylindrical translucent material having a cylindrical body 121a and a flange 121b at the upper end, and a solid translucent material having a hat shape (T shape), for example, corrosion resistance and heat resistance. It is made of stone glass with The body 121a is inserted into the viewport opening 114b from above, and the viewport member 121 is fixed in a state where the bottom surface of the flange 121b is hermetically sealed to the top surface of the top plate portion 114a by the sealing material 122. Detachable by member 123 It is fixed to Noh. The front end surface 121c of the body 121a, which is an extended portion extending into the chamber 114, is disposed near the outer surface of the upper plate of the flow channel 113, that is, in the immediate vicinity of a distance of about several mm to 10 mm. The thickness of the gas layer between the front end surface 121c and the outer surface of the flow channel is made as small as possible. The thickness of the gas layer is preferably 1 mm or more and 10 mm or less, more preferably 1 mm or more and 8 mm or less, and most preferably 1 mm or more and 6 mm or less.

[0050] By forming the viewport 120 using such a viewport member 121, even if an airflow due to thermal convection is generated in the chamber 114, the front end face 121c and the flow channel are affected by the airflow. Since it is limited to a gas layer that is only slightly in contact with the outer surface, fluctuations in the laser beam for measurement can be suppressed, and the ability to perform accurate measurements in a stable state can be achieved. In addition, if necessary, the reaction product adheres to the inner surface of the flow channel 113 by providing a through hole 113a in the flow channel 113 where the measurement light such as laser light or observation light passes. However, accurate measurement can be performed.

[0051] FIG. 9 is a cross-sectional view of the main part showing a second embodiment of the vapor phase growth apparatus according to the second aspect of the present invention. In the following description, the same components as those shown in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0052] In the vapor phase growth apparatus shown in the present embodiment, the viewport 120 includes a disk-shaped window member 131 attached to the viewport opening 114b, and a hollow portion provided continuously below the window member 131. And a vacuum pump 133 for evacuating the hollow portion of the hollow member 132. As described above, the hollow member 132 is formed by sealing both ends of a pipe-shaped member 132a made of a translucent member such as quartz glass with a disk-shaped member 132b, and protrudes into the chamber 114. The distal end surface 132c of the hollow member 132 is disposed in the vicinity of the outer surface of the flow channel 113, similarly to the distal end surface 121c in the first embodiment.

[0053] Further, the hollow member 132 is provided with a connecting portion 132d of an exhaust pipe 134 connected to the vacuum pump 133. The inside of the hollow member 132 is connected to the vacuum pump 133 through the exhaust pipe 134 from the connecting portion 132d. By evacuating, the hollow member 132 is evacuated (including a reduced pressure state) so that no airflow is generated in the hollow member 132. Furthermore, a hollow structure is used. As a result, the effects of light refraction and transmission loss due to thermal expansion and vibration can be reduced compared to the case of a solid structure. The window member 131 can be attached in the same manner as the flange 121b of the first embodiment.

[0054] FIG. 10 is a cross-sectional view of a principal part showing a third example of the vapor phase growth apparatus according to the second aspect of the present invention. In this embodiment, the hollow member 132 in the second embodiment is formed by combining a light transmissive member and a non-light transmissive member. That is, a metal ring member 135 that is a non-translucent member is hermetically connected to an upper portion of a pipe-shaped member 132 a made of a translucent member, and the exhaust pipe 134 that is connected to the vacuum pump 133 is connected to the ring member 135. The connecting portion 135a is provided. Thus, by making the connection part of the exhaust pipe 134 made of metal, for example, stainless steel, the exhaust pipe connection part can be easily formed as compared with the case of quartz glass. In the present embodiment, a part of the hollow member 132 is formed of a non-translucent member, but the entire pipe-shaped member 132a may be formed of a non-translucent member.

[0055] FIG. 11 is a cross-sectional view of a principal part showing a fourth embodiment of the vapor phase growth apparatus according to the second aspect of the present invention. In this embodiment, the upper portion of the hollow member 132 in the second embodiment is formed integrally with the window member 131, and after the inside of the hollow member 132 is evacuated by a vacuum pump, the exhaust pipe connecting portion 132d is sealed. The hollow member 132 is kept in a vacuum state by cutting. The hollow member 132 can be attached to the chamber 114 in the same manner as the viewport member 121 of the first embodiment.

[0056] FIG. 12 is a cross-sectional view of a relevant part showing a fifth embodiment of the vapor phase growth apparatus according to the second aspect of the present invention. The Puport member 141 shown in the present embodiment includes a conical cylindrical portion 141a having a reduced diameter on the lower side, a disk-shaped window member 141b that hermetically closes an upper opening of the cylindrical portion 141a, and a cylindrical portion 141a. The hollow member is formed of a disc-shaped tip member 141c that hermetically closes the lower opening of the tip member 141c, and the tip member 141c is inclined with respect to the surface of the substrate 111. Further, the hollow portion in the viewport member 141 is evacuated by a vacuum pump and then sealed to be in a vacuum state.

[0057] This viewport member 141 is attached to the top plate portion 114a of the chamber 114 via an airtight bellows member 142 provided so as to surround the viewport opening 114b of the chamber 114. Yes. The airtight bellows member 142 is attached to both end openings of the bellows portion 142a. Respectively. In addition, the lower mounting flange 142b is fixed to the upper surface of the top plate portion 114a via the sealing material 142c, and the outer periphery of the window member 141b is placed on the upper mounting flange 142b via the sealing material 142c, and the window member The view port member 141 is attached to the chamber 114 by fixing the lid member 143 covering the upper surface of the 141b to the upper attachment flange 142b.

In this way, by attaching the viewport member 141 to the chamber 114 via the airtight bellows member 142, the mounting position of the viewport member 141 with respect to the chamber 114 is changed using the deformation of the bellows 142a. The front and rear, left and right, top and bottom directions and mounting angle can be adjusted. That is, the view port 120 is provided so that the position of the view port 120 can be adjusted with respect to the chamber 114.

Further, a purge gas flow path 144 is provided between the distal end member 141c of the viewport member 141 and the upper surface of the flow channel 113. This purge gas flow path 144 has a purge gas introduction part 144a on the upstream side in the reaction gas flow direction, and an exhaust port 144b opened on the downstream side. The lower part of the flow path is connected to the upper plate member of the flow channel 113. It is common and has a shape in which the upstream side, both sides, and the upper part of the flow path are surrounded by a plate member made of quartz glass. The ceiling member of the flow channel 113 and the upper member of the purge gas flow path 144 are provided with through holes 113a and 144c, respectively, in the portions through which laser light and other measurement and observation light passes. An annular protrusion 144d is provided on the upper surface of the upper member to cover the outer periphery of the distal end of the viewport member 141.

[0060] The lid member 143 is provided with two through holes, an incident light through hole 143a and a reflected light through hole 143b. Laser light La is incident on the surface of the substrate 111 from the incident light through hole 143a. It is formed so that the state of the light Lb irradiated toward and reflected by the substrate surface is received outside the anti-potential light through hole 143b. When using reflected light in this way, the light reflected by the tip member 141c and the light reflected by the substrate surface can be separated by slightly tilting the tip member 141c with respect to the substrate surface. It is possible to reliably receive only the reflected light from the substrate surface. The tilt direction is arbitrary, but it is preferable to make the direction perpendicular to the incident light or reflected light.

Further, a purge gas flow path 144 is provided between the viewport member 141 and the flow channel 113. By providing, it is possible to prevent the reaction gas reaction product flowing out from the flow hole 113a of the flow channel 113 from adhering to the tip member 141c of the viewport member 141. Furthermore, by providing an annular protrusion 144d that covers the outer periphery of the distal end of the viewport member 141, the purge gas flowing in the purge gas flow path 144 flows from the through hole 144c through the distal member 141c into the chamber 114 or vice versa. Further, the gas in the chamber 114 can be prevented from flowing into the tip member 141c. Note that it is possible to integrally form the upper member of the purge gas channel 144 and the tip member 141c without providing the through hole 144c of the purge gas channel 144. Further, the type of the noble gas is arbitrary, and nitrogen, hydrogen, argon, etc., which are usually used as a purge gas in this type of apparatus can be used. Furthermore, the means for mounting the viewport member 141 to the chamber 114 is not limited to the airtight bellows member, and an arbitrary position adjusting mechanism formed of any material can be used as long as it can withstand the use environment. Can be adopted. As a means for holding the viewport member 141 at a predetermined position, any holding means such as a bolt can be used.

[0062] In each embodiment, the position at which the viewport is provided is a force that can be arbitrarily selected within a range in which the state of the substrate surface can be observed and measured. In order to suppress the occurrence of turbulence in the gas flow, it is preferable that the gas flow be arranged as downstream as possible in the reaction gas flow direction. In addition, an infrared reflective film can be provided outside or inside the viewport to avoid thermal effects on the measurement equipment.

[0063] FIG. 13 is a schematic view of the height of the upper surface on the outer peripheral side of a substrate rotated during film formation using a laser distance meter in a vapor phase growth apparatus provided with a viewport having the structure shown in the fifth embodiment. It is a figure which shows the result of having measured the thickness. The temperature during film formation is 500 ° C and the pressure is normal pressure. As a result, as shown by line A in FIG. 13, the vertical movement synchronized with the rotation of the substrate could be observed. On the other hand, when the same top surface height was measured through a conventional viewport where the viewport did not protrude into the chamber, the noise increased as shown by line B in Fig. 13 even at a temperature of 200 ° C. It was not possible to observe the vertical movement synchronized with the rotation of.

Example [0064] In the vapor phase growth apparatus having the configuration shown in the first embodiment of the first aspect of the present invention, a through hole 13b having a diameter of 5 mm is provided in the upper wall 13a of the flow channel 13, and the internal height force A purge gas passage 24 of mm was provided. Hydrogen was passed through the purge gas flow path 24 as a purge gas so that the flow velocity and pressure were equal to the reaction gas in the flow channel 13 at the position of the through hole 13b.

[0065] Hydrogen, trimethylgallium (TMG), and ammonia are introduced as reaction gases into the flow channel 13, and the 2-inch sapphire substrate on which the buffer layer is formed is heated to 1100 ° C while rotating at lOrpm. GaN film was grown. At this time, a radiation thermometer was installed outside the viewport 20, and the temperature of the substrate 11 was measured. The temperature of the thermocouple for temperature adjustment installed on the back of the susceptor was 1100 ° C—constant for 1 hour, and then the inner surface of the viewport 20 was observed. It was stable at 1080 ° C. In addition, the film thickness distribution of the deposited GaN was Δ5%, which was similar to the case where no through hole was provided in the flow channel. The impurity level in the hole measurement was also about 7 × 10 ¹⁵ / cm ³ and there was no change.

Industrial applicability

[0066] According to the vapor phase growth apparatus of the present invention, it is possible to efficiently prevent the reaction product from adhering to the inner surface of the viewport, and to suppress the influence of the air flow in the chamber and to optically use a laser beam or the like. Observation and measurement can be performed reliably. Therefore, the present invention is industrially useful.

Yes

Claims

The scope of the claims

[1] With chamber one,

A flow channel disposed within the chamber;

A substrate installed in the flow channel;

Heating means for heating the substrate;

Reactive gas supply means for supplying a reactive gas into the flow channel;

A viewport provided in the chamber,

A through hole serving as an optical path for optically observing the substrate surface through the viewport is provided in the substrate facing wall of the flow channel,

A purge gas flow path is provided between the outer surface of the flow channel wall provided with the through hole and the inside of the chamber of the viewport.

In the purge gas flow path, purge gas introduction means for flowing the purge gas in a laminar flow state in the same direction as the flow direction of the reaction gas flowing in the flow channel at substantially the same speed and pressure is provided. Vapor growth equipment.

2. The vapor phase growth apparatus according to claim 1, wherein the viewport is disposed in the vicinity of the outer surface of the flow channel wall.

[3] The vapor phase growth apparatus according to [1], wherein the pureport is located downstream of the reactive gas in the flow direction.

[4] The purge gas flow path includes a pair of side plates erected on the outer surface of the flow channel wall, an end plate that closes the upstream side of the side plates, and a cover that covers the end plate and the opposite flow channel side of the side plates. 2. The vapor phase growth apparatus according to claim 1, wherein the end plate is provided with a purge gas introduction portion, and an exhaust port is formed by opening a downstream side of both side plates.

5. The vapor phase growth apparatus according to claim 4, wherein the cover plate has a through hole serving as an optical path when optically observing the substrate surface through the viewport.

6. The vapor phase growth apparatus according to claim 4, wherein the cover plate has an annular protrusion that covers the outer periphery of the inner end of the viewport chamber.

7. The vapor phase growth apparatus according to claim 4, wherein the cover plate has a through-hole through which a front end portion on the inside of the chamber of the viewport passes.

[8] With chamber one,

A flow channel disposed within the chamber;

A substrate installed in the flow channel;

Heating means for heating the substrate;

A reaction gas supply means for supplying a reaction gas into the flow channel; and a viewport provided in the chamber,

A vapor phase growth apparatus in which the inner side of the chamber of the viewport extends toward the flow channel, and the distal end surface of the extended portion is disposed near the outer surface of the flow channel.

9. The vapor growth apparatus according to claim 8, wherein the extension portion of the viewport has a hollow structure having a hollow portion therein, and the hollow portion is in a vacuum state.

10. The vapor phase growth apparatus according to claim 8, wherein a front end surface of the view port is inclined with respect to a surface of the substrate.

11. The vapor phase growth apparatus according to claim 8, wherein the view port is provided so that the position of the view port can be adjusted with respect to the chamber.

12. The vapor phase growth apparatus according to claim 8, wherein the viewport is located on the downstream side in the flow direction of the reaction gas! /.