JP2011096776A - Vapor deposition apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition apparatus controlling the flow rate of distributing gas more precisely. <P>SOLUTION: The vapor deposition apparatus 1 includes a susceptor 3 which holds a substrate 5 as a workpiece and can rotate, and a flow channel 10 for flowing gas for deposition on one main surface of the substrate 5. An average pore diameter of a porous body arranged on a side surface part inside the flow channel 10 is larger than an average pore diameter of a porous body arranged in a center part of the flow channel 10. The average pore diameter of the porous body arranged on the side surface part is preferably 50% larger than the average pore diameter of the porous body arranged on the center part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vapor phase growth apparatus, and more particularly to a vapor phase growth apparatus that more precisely controls the flow rate of flowing gas.

  For example, when a thin film of a compound semiconductor is formed on one main surface of an object to be processed such as a substrate using a CVD method, a source gas is supplied onto the main surface of the substrate. Here, the main surface means a main surface having the largest area among the surfaces. At this time, in order to supply a desired amount of source gas in a desired direction with high accuracy, a metal porous body may be disposed in the flow path of the supplied gas. If it does in this way, the gas which distribute | circulates the said flow path will flow through the micropores contained in many in a porous body, when passing a porous body. For this reason, the gas penetrating each of the many minute holes is less likely to cause fluctuations in the flow velocity and the like in the flow path than the gas flowing through the flow path having a thick cross section. For this reason, the said porous body is widely used in order to control the flow volume, the distribution direction, etc. of the distribute | circulating gas.

  For example, Japanese Patent Application Laid-Open No. 2008-66413 (hereinafter referred to as “Patent Document 1”) discloses a porous member (porous body) on the downstream side of a shower head that supplies a raw material gas that faces a target object to be formed. ) And a film forming processing apparatus using the same are disclosed. A plurality of shower heads each having a gas injection plate are arranged, and a raw material gas is injected from each gas injection plate. The flow rate and direction of the gas injected are controlled by the action of the gas injection plate. On the other hand, an argon gas, which is an inert gas, is sprayed toward an object to be processed facing the ejection port in a region sandwiched between a plurality of shower heads. For this reason, the argon gas suppresses a phenomenon in which the raw material gas once injected from the gas injection plate flows backward toward the injection surface of the gas injection plate, for example, and efficiently directs the raw material gas toward the object to be processed. Provide a flow to circulate. In addition, for example, since the phenomenon that the source gas flows around the gas injection surface is suppressed, a problem such as contamination of the inside of the processing apparatus is suppressed by forming a film of the material gas on the gas injection surface. be able to.

  Further, in Japanese Patent Application Laid-Open No. 8-209349 (hereinafter referred to as “Patent Document 2”), a substrate to be processed (processing object) is placed in a region (upper surface of a lower electrode) sandwiched between electrodes facing each other. There has been disclosed a plasma CVD apparatus for forming a film on one main surface of a substrate to be processed by mounting and generating plasma by applying high-frequency power between upper and lower electrodes. Here, the internal space of the upper electrode is made hollow, and the reaction gas is introduced into the hollow space. Then, the reaction gas is supplied to the substrate to be processed disposed on the lower electrode facing the lower electrode through the porous shower plate disposed near the surface facing the lower electrode of the upper electrode. Then, film formation is performed. Here, since a shower plate made of a porous body is used, for example, compared with a case where a gas is pierced and a shower plate having dispersion holes with a wide distance between adjacent holes with respect to the ejection surface of the shower plate is used. The reaction gas can be uniformly sprayed from the entire surface of the shower plate facing the substrate to be processed.

JP 2008-66413 A JP-A-8-209349

  However, all of the porous bodies disclosed in the above-mentioned patent documents are arranged for the purpose of uniformly injecting the raw material gas from the porous body, but in actuality also about the gas flowing through the porous body The amount and flow rate of gas flow differ depending on the region through which the gas penetrates in the porous body. Further, the amount and the flow rate of the flow change depending on the type of the raw material gas to be flowed. If the flow rate, flow rate, direction, etc. of the gas flowing through the porous material change due to various disturbance factors, it may be difficult to form a uniform film on the main surface of the desired processing target. is there. In patent document 1 and patent document 2, the specific description is not made about the hole diameter of each hole included in the porous body which specifically constitutes the gas injection plate and the shower plate. However, it is assumed that a porous body having almost the same pore diameter is randomly filled in the entire region of the gas injection plate and the shower plate. In this case, as described above, there is a possibility that the flow rate and flow rate of the gas penetrating the porous body greatly change between the regions of the porous body. That is, the gas injected on the surface of the gas injection plate or shower plate facing the object to be processed may not be uniform. As a result, the flow rate and flow direction of the gas supplied onto the main surface of the object to be processed may not be precisely controlled, and the film thickness and film quality of the thin film to be formed may not be precisely controlled.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vapor phase growth apparatus that more precisely controls the flow rate of flowing gas.

  A vapor phase growth apparatus according to the present invention is a vapor phase growth apparatus that includes a rotatable susceptor that holds a processing target and a flow path for flowing a film forming gas on one main surface of the processing target. is there. The average pore diameter of the porous body disposed in the side surface portion inside the flow path is set larger than the average pore diameter of the porous body disposed in the central part of the flow path.

  For example, in a normal hollow flow path in which no porous body or the like is disposed inside, the gas flowing through the side surface portion (that is, the region in the vicinity of the outer edge) crossing the gas flow direction passes through the central portion of the cross section. The flow rate tends to be slower than the circulating gas. Here, the side surface portion refers to a region where the distance from the side surface of the flow channel is within 25% of the width of the flow channel with respect to the cross section inside the flow channel. Here, the central portion refers to a region other than the side portion, that is, a region inside the side portion with respect to the cross section inside the flow path.

  The flow velocity of the gas flowing through the side surface portion is slow because the resistance of the gas flowing through the side surface portion from the structure such as piping constituting the flow path is greater than the gas flowing through the central portion. is there. For this reason, the average pore diameter of the porous body arranged in the side surface portion of the flow path is made larger than the average pore diameter of the porous body arranged in the central portion of the flow path. Here, the pore diameter of the porous body refers to the average value of the diameters of a large number of pores contained in the porous body. When the number of holes does not form a circle, the diameter of the hole is a diameter obtained by approximating the shape of the hole to a circle.

  In this way, when the gas flowing through the side surface of the flow channel passes through a large number of holes (gap portions) contained in the porous body, the resistance received from the wall of the hole is the center of the flow channel. This is smaller than the resistance received from the wall of the hole when the gas flowing through the portion penetrates the porous body. However, as described above, the resistance that the gas flowing through the side surface of the flow path receives from the structure that forms the flow path is higher than the resistance that the gas that flows through the center of the flow path receives from the structure that forms the flow path. Big.

  For this reason, if the resistance received from both is considered comprehensively, the difference in flow velocity between the gas flowing through the side surface portion of the flow path and the gas flowing through the central portion of the flow path can be reduced. Therefore, it is possible to make the flow rate and flow velocity of the gas injected from the porous body and reaching one main surface of the processing object more uniform with respect to each region on the main surface of the processing object.

  In the above-described vapor phase growth apparatus, it is more preferable that the average pore diameter of the porous body disposed in the side surface portion is 50% or more larger than the average pore diameter of the porous body disposed in the central portion. In this way, as described above, the resistance received from the wall surface of the hole in the porous body when the gas flowing through the side surface of the flow path penetrates the porous body flows through the central portion of the flow path. The effect of reducing the gas as compared with the resistance received from the hole when the gas penetrates the porous body can be sufficiently increased.

  In the gas phase treatment apparatus described above, it is more preferable that the porous body is disposed in a region of the flow path where the cross-sectional area of the flow path is changing.

  The flow velocity distribution of the gas flowing in the region, that is, the flow between the side surface portion and the central portion of the region is larger in the region where the cross-sectional area of the flow channel is changed than in the region where the cross-sectional area of the flow channel is constant. The difference in the flow velocity of the gas is likely to occur. For this reason, as described above with respect to the region where the cross-sectional area changes, it is preferable to dispose porous bodies having different average pore diameters in the side surface portion and the central portion. In this way, the flow rate and flow velocity of the gas injected from the porous body and reaching one main surface of the processing object are made more uniform with respect to each region on the main surface of the processing object. Can do.

  In the above-described gas phase treatment apparatus, it is more preferable that a porous body is provided at a terminal portion on the downstream side in the gas flow direction in the flow path.

  Here, the porous body provided in the terminal portion refers to a second porous body provided in the terminal portion and separate from the porous body provided in a region other than the terminal portion. In particular, if the cross-sectional area of the flow path is changed at the end portion, the flow velocity distribution of the gas flowing through the end portion can be more reliably reduced by providing the second porous body as described above. Therefore, it is possible to make the flow rate and flow velocity of the gas injected from the porous body and reaching one main surface of the processing object more uniform with respect to each region on the main surface of the processing object.

  ADVANTAGE OF THE INVENTION According to this invention, the vapor phase growth apparatus which can control the flow velocity of the distribute | circulating gas more precisely can be provided.

It is a schematic sectional drawing which shows the aspect of the vapor phase growth apparatus which is an example of the semiconductor manufacturing apparatus which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing in line segment II-II of FIG. It is a schematic sectional drawing in the same location as FIG. 2 in case the distribution of the hole diameter of a porous body differs. It is a schematic sectional drawing which shows the aspect of the vapor phase growth apparatus which is an example of the semiconductor manufacturing apparatus which concerns on Embodiment 2 of this invention. It is a schematic sectional drawing which shows the aspect of the vapor phase growth apparatus which is an example of the semiconductor manufacturing apparatus concerning Embodiment 3 of this invention. It is a schematic sectional drawing in line segment VI-VI of FIG. It is a schematic sectional drawing in the line segment VII-VII of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
As shown in FIG. 1, the vapor phase growth apparatus 1 according to the first embodiment of the present invention forms a thin film made of a semiconductor material on the surface of an object to be processed by supplying a gas for film formation therein. It is a device to do. A susceptor 3 for holding a substrate 5 as an object to be subjected to a film forming process and a rotating shaft 17 for allowing the susceptor 3 to rotate in a direction along the main surface are provided. The lower end of the rotating shaft 17 is connected via a motor 22 and a joint 19. The driving force generated by the motor 22 is transmitted to the susceptor 3 through the joint 19 and the rotating shaft 17. The structure of the connecting portion between the susceptor 3 and the rotating shaft 17 can be an arbitrary structure. For example, the susceptor 3 and the rotating shaft 17 are joined by a brazing material or the like, or a convex portion is provided on one of the susceptor 3 and the rotating shaft 17 at a portion where the susceptor 3 and the rotating shaft 17 face each other, A convex portion corresponding to the convex portion or a convex portion (for example, a concave portion or a convex portion in which the rotation of the rotating shaft 17 is transmitted to the susceptor 3 by contacting the convex portion with the side surface); The rotation of the rotating shaft 17 may be transmitted to the susceptor 3 by engaging the recess and the recess or the protrusion and the protrusion. That is, the connecting portion between the susceptor 3 and the rotating shaft 17 only needs to be able to transmit the rotational force of the rotating shaft 17 to the susceptor 3, and the susceptor 3 and the rotating shaft 17 may not be fixed.

  In order to make the thickness and quality of the thin film to be formed more uniform, it is more preferable to place one substrate 5 on the susceptor 3. However, depending on the design specifications of the susceptor 3, for example, two, three, or four or more substrates 5 may be placed and processed at a time.

  A heater 7 for heating the susceptor 3 is disposed below the susceptor 3 in order to heat the substrate 5 during film formation.

  A flow for flowing a source gas for film formation on the main surface of the substrate 5, that is, on the upper side inside the vapor phase growth apparatus 1 in FIG. 1 so as to extend in a direction along the main surface of the substrate 5. A path 10 is arranged. However, the channel 10 may be arranged in a direction intersecting with the main surface of the substrate 5 (that is, extending from the upper side to the lower side in FIG. 1). The flow path 10 has an equal cross-sectional area 11 in which the area of the cross section intersecting the gas flow direction (the direction from the right side to the left side in FIG. 1) is substantially constant, and the cross section from the upstream side to the downstream side with respect to the gas flow direction. And a variable cross-sectional area 12 in which the area of the area changes. The flow path 10 has a rectangular cross-sectional shape in a direction perpendicular to the direction in which the source gas flows, for example.

  The channel 10 is preferably made of, for example, quartz or a metal such as chromium, iron, nickel, stainless steel, manganese, molybdenum, tungsten, or aluminum. In this way, for example, the gas can be smoothly circulated without being damaged such as the reaction of the flow path 10 by the gas to be circulated. However, when a corrosive gas is used as the gas flowing through the flow path 10, it is preferable to use a material other than aluminum among the above-described materials.

  As shown in FIG. 1, the porous body 20 is disposed in the variable cross-sectional area 12 inside the flow path 10. For example, a porous metal body made of nickel is preferably used as the porous body 20. However, as the porous body 20, a metal film (metal sheet) of a metal porous material may be used instead of the above-described metal porous body made of nickel. Specifically, for example, chromium, iron, nickel, stainless steel, manganese, molybdenum, tungsten, and aluminum are preferably used as the metal film (metal sheet) of the metal porous material. However, when a corrosive gas is used as the gas flowing through the flow path 10, it is preferable to use a material other than aluminum among the above-described materials as the metal film (metal sheet) of the metal porous material.

  Inside the porous body 20, there are minute holes formed so as to penetrate from one region on the surface of the porous body 20 toward another region on the surface of the porous body 20. There are many.

  For example, a gas that is a raw material for film formation flowing through the flow path 10 flows along the longitudinal direction of the equal cross-sectional area 11 in the equal cross-sectional area 11 that is not filled with the porous body 20 in FIG. The way in which the gas flows inside the equal cross-sectional area 11 differs depending on how the gas is introduced into the equal cross-sectional area 11. For example, if the introduction of the gas into the equal cross-sectional area 11 has a large time change or inter-area change, or a flow with a large disturbance, the gas flowing in the equal cross-sectional area 11 is also subject to the time change or inter-area change. The flow is large and has a large disturbance. However, for example, when a gas flowing through a region where the porous body 20 is not disposed flows through a region filled with the porous body 20 as in the cross section region 12 of FIG. With this configuration, the flow is restricted. Specifically, the gas flows so as to penetrate through the inside of a large number of holes in the porous body 20. For this reason, the gas that has flowed through the porous body 20 flows out in substantially the same pressure, flow rate, and direction regardless of the flow state of the gas flowing into the porous body 20. The pressure, flow rate, direction, and the like of the gas flowing out from the porous body 20 are controlled by the size and shape of the cross-sections of a large number of holes existing in the porous body 20.

  Therefore, if the inside of the flow path 10 is filled with the porous body 20, the gas flowing out from the flow path 10 can be easily controlled to have a desired pressure, flow rate, and direction.

  However, if it is assumed that the inside of the equal cross-sectional area 11 is a space that does not include the porous body 20 or the like, the following can be said about the gas flowing through the equal cross-sectional area 11. That is, the gas flowing through the side surface portion (that is, the region near the outer edge) crossing the gas flow direction tends to have a lower flow velocity than the gas flowing through the central portion of the cross section. This is because the gas flowing through the side surface portion receives a greater resistance from a structure such as a pipe constituting the flow path 10 than the gas flowing through the central portion.

  For this reason, for example, when the gas that has flowed through the equal cross-sectional region 11 that is not filled with the porous body 20 is to flow into the porous body 20, the gas at the center of the cross section is greater than the gas that flows through the side surface of the cross section. The flow rate of the gas flowing through is faster. Therefore, in order to make the flow rate, pressure, and direction of the gas finally supplied from the flow path 10 onto the main surface of the substrate 5 almost constant in all regions on the main surface of the substrate 5, As for the raw material gas which distribute | circulates the porous body 20, it is preferable that the gas which distribute | circulates the center part of a cross section is decelerated more largely than the gas which distribute | circulates the side part of a cross section.

  Therefore, as shown in the cross-sectional view of the variable cross-sectional area 12 in FIG. 2, the average pore diameter of the porous body 20 disposed in the side surface portion of the cross section is larger than the average pore diameter of the porous body 20 disposed in the central portion of the cross section. It is preferable to arrange so that. With reference to FIG. 2, as described above, the variable cross-sectional area 12 of the flow path 10 is filled with the porous body 20. The porous body 20 includes a large diameter hole 15a having a relatively large hole diameter and a small diameter hole 13a having a relatively small hole diameter. In the variable cross-sectional area 12, it is preferable that the large-diameter hole 15a is disposed in the side surface portion 15 of the cross section and the small-diameter hole 13a is disposed in the central portion 13 of the cross section. In addition, the side surface part 15 of a cross section shall include the area | region along the side surface of the said cross section, ie, the whole outer peripheral part of a cross section. A large number of pebbles in the porous body 20 in FIGS. 1 and 2 represent holes.

  The raw material gas flows so as to penetrate through a large number of holes included in the porous body 20 and is injected from the most downstream surface of the cross-sectional area 12. As shown in FIG. 2, with respect to the gap (hole), the gap between the adjacent large-diameter holes 15a is larger than the gap between the adjacent small-diameter holes 13a. That is, the hole of the area | region comprised by the large diameter hole 15a among the porous bodies 20 is larger than the hole of the area | region comprised by the small diameter hole 13a. In other words, the gas flowing through the region (side surface portion 15) in which the large-diameter hole 15a is arranged flows through the region having a larger cross-sectional area than the gas flowing through the region (center portion 13) in which the small-diameter hole 13a is arranged. become.

  Therefore, the amount of gas flowing through the region where the small diameter hole 13a is disposed is less than the amount of gas flowing through the region where the large diameter hole 15a is disposed, and the resistance that the gas receives from the porous body 20 is large. . For this reason, the gas flowing through the region in which the small diameter hole 13a is disposed is greatly decelerated in the region than the gas flowing through the region in which the large diameter hole 15a is disposed. As described above, it is preferable that the average pore diameter of the porous body 20 disposed in the side surface portion 15 is larger than the average pore diameter of the porous body 20 disposed in the central portion 13.

  In this way, the porous body 20 filling the variable cross-sectional area 12 increases the resistance received by the gas flowing through the central portion 13 of the cross section from the surroundings compared with the gas flowing through the side surface portion 15. The flow rate can be greatly reduced. As described above, when flowing into the porous body 20, the gas flowing through the central portion has a higher flow rate than the gas flowing through the side surface portion. Accordingly, the difference in flow velocity between the gas finally injected from the side surface portion 15 of the variable cross-sectional area 12 and the gas finally injected from the central portion 13 of the variable cross-sectional area 12 is reduced, and the gas is more evenly distributed. Can be supplied on the main surface of the opposing substrate 5.

  Here, the average pore diameter of the porous body 20 disposed in the side surface portion 15 is preferably 50% or more larger than the average pore diameter of the porous body 20 disposed in the central portion 13. As described above, the pore diameter of the porous body 20 refers to an average value of the diameters of a large number of holes constituting the porous body 20. When the hole does not form a circle, the diameter of the hole is a diameter obtained by approximating the shape of the hole to a circle.

  Thus, if the average hole diameter of the holes in the side surface portion 15 of the variable cross-sectional area 12 is set to be approximately 50% or more larger than the average hole diameter of the holes in the central portion 13, the central portion and the side surface at the time of flowing into the variable cross-sectional area 12 It is possible to control so that the difference in flow velocity generated between the gas flowing through the section becomes sufficiently small. Therefore, the gas finally injected from the variable cross-sectional area 12 can be made substantially uniform over the entire surface in the direction along the cross section of the flow path 10.

  In the cross-sectional view of FIG. 2, the porous body 20 in the variable cross-sectional area 12 of the flow path 10 has a large number of holes for one row along the side surface in the up-down direction and two rows along the side surface in the left-right direction. The small-diameter hole 13a is disposed inside the large-diameter hole 15a. And the difference of the hole diameter between the large diameter hole 15a and the small diameter hole 13a is small, and the hole diameter of the porous body 20 arrange | positioned changes in the boundary of the side part 15 and the center part 13 largely.

  However, for example, as shown in the cross-sectional view of FIG. 3, the diameter of each hole in the porous body 20 filling the variable cross-sectional area 12 of the flow path 10 gradually increases from the central portion 13 toward the side portion 15. More preferably. In this way, when the flow velocity of the raw material gas flowing through the equal cross-sectional area 11 of the flow path 10 is distributed so as to gradually increase from the side surface to the center of the cross section, the porosity of the variable cross-section area 12 is increased. The mass body 20 can adjust the flow rate of the gas flowing out from the cross-sectional area 12 more precisely.

  By the way, the channel 10 described above has a configuration in which the porous body 20 is disposed only in the cross section region 12. However, the porous body 20 may also be disposed in the equal cross-sectional area 11 having a small cross-sectional area intersecting the gas flow direction in the flow path 10 in the same manner as the variable cross-sectional area 12.

  If the flow path 10 is configured to include only the equal cross-sectional area 11, the raw material gas is injected using the cross section of the equal cross-sectional area 11 having a small area as the injection port (injection surface). In this case, even if the porous body 20 is disposed inside the flow path 10, the pressure of the gas to be injected increases because the cross section of the flow path 10 is small. For this reason, for example, a large error occurs in the jetting direction and pressure, and as a result, it may be difficult to precisely control the pressure and flow velocity. For this purpose, the flow path 10 is preferably provided with a variable cross-sectional area 12 in which the area of the cross section gradually increases from the equal cross-sectional area 11 toward the downstream side in the gas flow direction.

  The source gas flowing through the flow path 10 is more likely to cause an error in which the flow velocity, pressure, flow direction, and the like are significantly different from the set values in the variable cross-sectional area 12 than in the equal cross-sectional area 11. This is because the gradual change in the cross-sectional area increases the possibility of vortices in the flowing gas and other disturbances. For this reason, it is preferable that the porous body 20 described above is preferentially disposed inside the variable cross-sectional area 12 rather than the equal cross-sectional area 11 in the flow path 10. If it does in this way, it will become easy to control uniformly the flow velocity, the pressure, etc. of the gas which distribute | circulates the porous body 20 so that it may become a desired value by the hole contained in many porous bodies 20 mentioned above.

  Here, the operation of the vapor phase growth apparatus 1 will be briefly described. In the vapor phase growth apparatus 1, the substrate 5 is disposed in the mounting recess of the susceptor 3. Then, after the susceptor 3 on which the substrate 5 is mounted is rotatably installed, the inside of the vapor phase growth apparatus 1 (inside the area surrounded by a square in FIG. 1) is set to a predetermined pressure. The pressure may be set by, for example, exhausting the atmospheric gas with an exhaust member. Then, after the inside of the apparatus reaches a predetermined set pressure, the heater 7 is operated to heat the substrate 5 to a predetermined temperature (processing temperature) via the susceptor 3. Here, as an example, it is preferable to heat the substrate 5 to a high temperature of 1000 ° C. or higher.

  At this time, the susceptor 3 is rotated via the joint 19 and the rotating shaft 17 by simultaneously driving the motor 22. In a state where the temperature of the substrate 5 reaches the processing temperature, a predetermined amount of source gas is supplied from the flow path 10 into the apparatus. In this state, the source gas is decomposed in a region facing the substrate 5, and a film (for example, a film made of gallium nitride (GaN)) using the source gas component as a source is formed on the surface of the substrate 5. The gas used for the film formation reaction is exhausted from the inside of the apparatus by the exhaust member. In this way, a predetermined film can be formed on the surface of the substrate 5.

(Embodiment 2)
As shown in FIG. 4, the vapor phase growth apparatus 1 according to the second embodiment of the present invention basically has the same mode as the vapor phase growth apparatus 1 according to the first embodiment of the present invention shown in FIG. Show. However, in the vapor phase growth apparatus 1 according to Embodiment 2 of the present invention shown in FIG. 4, the end portion 21 on the downstream side (the left side of the flow path 10 in FIG. 4) in the gas flow direction in the cross-sectional area 12. A porous body 20 is provided in the vicinity. Although not shown in FIG. 4, another porous body is disposed on the upstream side (right side in FIG. 4) of the variable cross-sectional area 12 with respect to the region in which the porous body 20 illustrated in FIG. 4 is disposed. The porous body 20 illustrated in FIG. 4 may be arranged as a second porous body different from the other porous body. Or it is good also as a structure which does not have the area | region where the two types of porous bodies mentioned above are arrange | positioned, and has arrange | positioned the porous body 20 only in the vicinity of the terminal part 21 of the flow path 10, as shown in FIG.

  For example, the first porous body disposed on the upstream side of the variable cross-sectional area 12 and the second porous body disposed on the downstream side 23 (near the end portion 21) of the variable cross-sectional area 12 are made of different materials. May be. For example, the first porous body is a metal porous body made of nickel, and the second porous body is a metal porous material metal film made of chromium, iron, nickel, stainless steel, manganese, molybdenum, tungsten, aluminum, for example. (Metal sheet) may be sufficient.

  In addition, the porous body 20 disposed in the vicinity of the terminal portion 21 is, as shown in FIG. 4, an average of the pores constituting the porous body 20 of the side surface portion 15 in the flow path 10 (the variable cross-sectional area 12). It is preferable that the pore diameter is larger than the average pore diameter of the pores constituting the porous body 20 in the central portion 13. That is, as shown in FIG. 4, it is preferable that the large-diameter hole 15 a is disposed in the side surface portion 15 and the small-diameter hole 13 a is disposed in the central portion 13. FIG. 4 shows only the pore diameter of the porous body 20 in the vertical direction of the flow path 10. However, also in other directions, for example, in the depth direction of the vapor phase growth apparatus 1, it is preferable that the large-diameter hole 15 a is disposed in the side surface portion 15 and the small-diameter hole 13 a is disposed in the central portion 13. 4, for example, as shown in FIG. 2, the large-diameter holes 15a are provided only for several rows of the side surface portions 15, and the central portion 13 inside the side surface portion 15 has a large hole diameter. The small-diameter holes 13a having different diameters may be arranged. However, the porous body 20 of FIG. 4 may also be arranged so that the pore diameter gradually changes from the central portion 13 toward the side surface portion 15, as shown in FIG.

  The porous body 20 is disposed to control the raw material gas injected from the end portion 21 of the flow path 10. For this reason, it is more preferable to arrange the porous body 20 in which the flow velocity, pressure, direction, and the like can be controlled more precisely in the vicinity of the terminal portion 21. In this way, the flow velocity of the gas flowing through the terminal portion 21 can be made more uniform, and the pressure can be controlled to be uniform at the same time. Further, if the porous body 20 is disposed only in the vicinity (downstream side 23) of the terminal portion 21, the manufacturing cost of the facility can be reduced by reducing the area in which the porous body 20 is disposed.

  The second embodiment is different from the first embodiment only in each point described above. In other words, the configuration, conditions, procedures, effects, and the like not described above for the second embodiment are all in accordance with the first embodiment.

(Embodiment 3)
As shown in FIG. 5, the vapor phase growth apparatus 1 according to Embodiment 3 of the present invention basically has the same mode as the vapor phase growth apparatus 1 according to Embodiment 1 of the present invention shown in FIG. Show. However, as shown in the cross-sectional views of FIGS. 6 and 7, in the vapor phase growth apparatus 1 according to Embodiment 3 of the present invention, two partition plates 30 are arranged inside the flow path 10. The partition plate 30 divides the cross section inside the flow path 10 into three regions. In this way, three different types of gas can be circulated through each region of the flow path 10 partitioned by the partition plate 30. Note that the number (number) of the partition plates 30 to be installed is not necessarily two as in the present embodiment, and may be an arbitrary number.

  The material of the partition plate 30 is preferably made of, for example, quartz or a metal such as chromium, iron, nickel, stainless steel, manganese, molybdenum, tungsten, or aluminum. In this way, for example, the gas can be smoothly circulated without being damaged such as the reaction of the flow path 10 by the gas to be circulated. However, when a corrosive gas is used as the gas flowing through the flow path 10, it is preferable to use a material other than aluminum among the above-described materials as the partition plate 30.

  For example, the first region (the lower region in FIG. 6, the right region in FIG. 7) in which the side surface portion 15 (see FIG. 2, FIG. 3) occupies a high proportion of each region of the divided flow path 10, and The second region (the upper region in FIG. 6 and the left region in FIG. 7) is preferably filled with a porous body 20 having a relatively large pore diameter. And it is preferable to fill the porous region 20 with a relatively small pore diameter in the third region (the central region in FIGS. 6 and 7) in which the central portion 13 (see FIGS. 2 and 3) of the cross section occupies a high ratio. . As shown in FIG. 6, the above-mentioned first region has a large-diameter hole 14a, the second region has a large-diameter hole 14c, and the third region has a small-diameter hole 14b. 12 is arranged.

  More strictly, as shown in the cross-sectional view of FIG. 7, even when the flow path 10 is divided into three regions by the partition plate 30, the side portions (regions closer to the outer edge) than the central portion in each region. It is preferable that the pore diameter of the porous body to be arranged becomes large.

  In this way, like the porous body 20 in each of the above-described embodiments, in the region where the flow rate of the gas flowing into the porous body 20 is high, the porous body 20 has a larger flow rate than the porous body 20. Receiving resistance, the gas can be greatly decelerated. For this reason, it is possible to supply each type of gas injected from each region more uniformly on the main surface of the desired substrate. Therefore, since various types of gases can be supplied in a more precisely controlled state, a higher quality thin film can be formed on the main surface of a desired substrate.

  The third embodiment is different from the first embodiment only in each point described above. That is, the configuration, conditions, procedures, effects, and the like that have not been described above for the third embodiment are all in accordance with the first embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is particularly excellent as a technique for uniformly supplying a source gas onto the surface of an object to be processed in a vapor phase growth apparatus.

  DESCRIPTION OF SYMBOLS 1 Vapor growth apparatus, 3 Susceptor, 5 Substrate, 7 Heater, 10 Flow path, 11 Equivalent cross section area, 12 Change cross section area, 13 Center part, 13a, 14b Small diameter hole, 14a, 14c, 15a Large diameter hole, 15 Side Part, 17 rotating shaft, 19 joint, 20 porous body, 21 terminal part, 22 motor, 23 downstream side, 30 partition plate.

Claims (4)

A rotatable susceptor for holding the object to be processed;
A vapor phase growth apparatus comprising a flow path for flowing a film forming gas on one main surface of the processing object;
A vapor phase growth apparatus in which an average pore diameter of a porous body disposed in a side surface portion inside the flow path is larger than an average pore diameter of a porous body disposed in a central portion of the flow path.   2. The vapor phase growth apparatus according to claim 1, wherein an average pore diameter of the porous body disposed in the side surface portion is set to be 50% or more larger than an average pore diameter of the porous body disposed in the central portion.   The vapor phase growth apparatus according to claim 1 or 2, wherein a porous body is disposed in a region of the flow path where the cross-sectional area of the flow path is changing.   The vapor phase growth apparatus of any one of Claims 1-3 provided with a porous body in the termination | terminus part which is the downstream regarding the distribution direction of gas among the said flow paths.

Images