JP2018037457A - Vapor growth device and manufacturing method of epitaxial wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vapor growth device capable of stabilizing a flow of a material gas.SOLUTION: A vapor growth device 1 comprises: a reactor 2; an introduction passage 8; a step part 8c; a tubular flow path 16a; and a baffle 14. The introduction passage 8 includes an inlet 8a connected to the reactor 2, and an outlet 8b reaching the inside of the reactor 2, and introduces a material gas into the reactor 2. The step part 8c includes a first surface 8c1 that is positioned in the introduction passage 8 and is opposite to the inlet 8a a second surface 8c2 extended to the outlet 8b from an upper end of the first surface 8c1. The flow path 16a includes: a first opening O1 opposite to the inlet 8a; and a second opening O2 positioned at a place extended toward an external side of the inlet 8a from the first opening O1, and introduces the material gas into the inlet 8a. The baffle 14 includes a shape corresponded to the second opening O2 and a penetration hole H communicated to the second opening O2, and introduces the material gas from the penetration hole H to the flow path 16a.SELECTED DRAWING: Figure 1B

Description

  The present invention relates to a vapor phase growth apparatus and an epitaxial wafer manufacturing method.

  A silicon epitaxial wafer in which an epitaxial layer, which is a silicon single crystal thin film, is grown on the main surface of a silicon single crystal substrate by a vapor phase growth method is widely used in electronic devices such as bipolar ICs and MOS-ICs. With such miniaturization of electronic devices, demands on the flatness of the main surface of the epitaxial wafer on which elements are formed are becoming stricter.

  As an apparatus for manufacturing an epitaxial wafer, there are a vapor phase growth apparatus that processes a plurality of wafers in a batch mode and a vapor phase growth apparatus that processes a single wafer in a single wafer mode. In general, an epitaxial wafer manufactured using a single-wafer type vapor phase growth apparatus has a higher flatness of the main surface of the epitaxial wafer than an epitaxial wafer manufactured using a batch type vapor phase growth apparatus. It is thought that Therefore, as an apparatus for manufacturing an epitaxial wafer having a diameter of 200 mm or more, a single-wafer type vapor phase growth apparatus has become mainstream.

  Examples of the configuration of such a single wafer type vapor phase growth apparatus are disclosed in Patent Documents 1 to 5, for example. As an example of such a vapor phase growth apparatus, a vapor phase growth apparatus 101 is shown in FIGS. 7A and 7B. The vapor phase growth apparatus 101 includes a reaction furnace 102 for growing an epitaxial layer on a substrate, a gas supply pipe 103 for supplying a raw material gas as a raw material for the epitaxial layer grown on the substrate into the reaction furnace 102, A gas exhaust pipe 104 for exhausting gas is provided. The vapor phase growth apparatus 101 supplies the source gas into the reaction furnace 102 through the gas supply pipe 103, and the supplied source gas flows along the surface of the substrate W, and then is discharged from the gas discharge pipe 104. When the film thickness of the epitaxial layer grown on the substrate is made uniform by such a vapor phase growth apparatus, the flow rate distribution of the source gas flowing in the reaction furnace becomes an important factor.

  Thus, for example, Patent Document 6 proposes an apparatus that reduces unevenness in the flow rate of the source gas flowing in the reactor. Specifically, a vapor phase growth apparatus provided with a plurality of baffle plates for adjusting the flow of the raw material gas toward the reactor and a partition plate extending along the flow direction of the raw material gas along the width direction of the raw material gas Is disclosed in Patent Document 6. The reaction furnace of such an apparatus includes an inlet through which the raw material gas flowing from the gas supply pipe flows into the reaction furnace, an outlet located above the inlet and closer to the reaction furnace than the inlet and reaching the reaction furnace, and an inlet And a passage connecting the outlet and a step portion located in the passage. Then, the raw material gas is introduced into the reaction furnace from the gas supply pipe, and the raw material gas is supplied to the surface of the substrate in the reaction furnace so as to get over the stepped portion of the passage leading to the inside of the reaction furnace. The raw material gas introduced into the reaction furnace is made into a plurality of jets by a baffle plate having a plurality of through holes through which the raw material gas passes, and each of the jets collides with a step portion of a passage leading to the inside of the reaction furnace to disperse. The unevenness in the flow rate of the source gas supplied to the substrate is eliminated.

JP 2014-110414 A JP 2009-277730 A JP 2005-183510 A JP 2004-200603 A JP 2003-168650 A JP 2003-203866 A

  However, some of the jets that collide and collide with the stepped part form a flow that circulates between the jets and flows backward. An example of a jet forming this circulating flow is shown in FIG. In FIG. 8, a plurality of jets J flow from the lower end of the figure toward the step portion 108 c, and a part of the jet J that collides and is dispersed at the step portion 108 c circulates between the jet J and the jet J in a reverse flow. . Here, the member constituting the step portion (passage) with which the jet of the raw material gas collides is required to have heat resistance and has a restriction that it does not become an impurity with respect to silicon. For this reason, the material of the members constituting the passage having the step portion is almost limited to quartz. Then, the source gas is repeatedly introduced into the passage having the step portion, so that deposits resulting from the source gas are deposited on the step portion, and the step portion is periodically formed with hydrofluoric acid to remove the deposit. Washed. As a result, some unevenness is generated on the surface of the stepped portion after the hydrofluoric acid cleaning. When the jet of the raw material gas collides with the unevenness, the flow of the jet J shown in FIG. Will affect the flow. As a result, the flow rate distribution of the source gas flowing toward the surface of the substrate is affected, so that the film thickness distribution of the epitaxial layer grown on the substrate is also affected.

  These effects are caused by the uneven shape of the surface at the step portion of the passage leading to the inside of the reactor. Therefore, the following problem arises even if the member constituting the passage is removed by maintenance, cleaned, etc., and then installed again. In other words, problems such as inability to reproduce the thickness distribution of the epitaxial layer achieved before maintenance due to slight differences in the arrangement of members constituting the passage having the stepped portions and slight changes in the surface shape of the stepped portions, etc. Occurs. Therefore, it is necessary to stabilize the flow of the raw material gas so that the flow of the raw material gas is not affected by the uneven shape on the surface of the stepped portion that causes the above-described effects and problems, the arrangement of the stepped portion, and the like.

  An object of the present invention is to provide a vapor phase growth apparatus and an epitaxial wafer manufacturing method capable of stabilizing the flow of a source gas.

Means for Solving the Problems and Effects of the Invention

The vapor phase growth apparatus of the present invention is
A reactor for vapor-phase growth of an epitaxial layer on a substrate with a source gas;
A passage having an inlet communicating with the reactor and an outlet located above the inlet and on the reactor side from the inlet and reaching the reactor, and connecting the inlet and the outlet to introduce the raw material gas into the reactor When,
A step portion having a first surface located in the passage and facing the inlet, and a second surface extending from the upper end of the first surface to the outlet;
A tubular flow path having a first opening facing the inlet and a second opening located ahead extending from the first opening toward the outside of the inlet and guiding the source gas to the inlet;
A baffle that has a shape corresponding to the second opening, and has a through hole that communicates with the second opening and guides the source gas from the through hole to the flow path;
It is characterized by providing.

  The vapor phase growth apparatus of the present invention includes a tubular flow path having a second opening having a shape corresponding to the through hole of the baffle. Therefore, the raw material gas that has passed through the through hole of the baffle and reached the tubular flow channel spreads over the tubular flow channel and flows through the tubular flow channel, and then flows into the passage and collides with the stepped portion. Here, a part of the raw material gas that collided with the step portion tries to flow backward, but later, the raw material gas that spreads to the full flow path flows one after another, and the flow of the raw material gas that tries to flow backward is swallowed by the later flow Will be countered. Therefore, even if some unevenness on the surface of the step part is formed during maintenance, or the arrangement of the step part slightly shifts before and after maintenance, the flow of the raw material gas that tries to flow backward due to the collision of the step part may be affected. The flow is canceled out. As a result, the arrangement of the stepped portion and the shape of the surface of the stepped portion do not greatly affect the flow of the entire raw material gas. Therefore, the flow of the source gas can be stabilized before and after the maintenance, and the same source gas can be guided toward the substrate before and after the maintenance.

  In the embodiment of the present invention, the flow path is connected to the curved curved pipe line positioned between the first opening and the second opening, and is connected to the curved pipe line, and is located at the end of the flow path on the first opening side. And an end pipe line.

  According to this, it is possible to guide the direction in which the raw material gas is guided by the curved pipe line.

  In the embodiment of the present invention, the first surface is an arcuate curved surface centering on an axis extending in the vertical direction from the reactor side, and the end pipe line is located along a direction orthogonal to the axis.

  Specifically, at least a part of the source gas is guided perpendicularly to the first surface by the flow path.

  According to this, reproducibility can be improved when trying to reproduce the film thickness distribution of the epitaxial layer produced before maintenance with the epitaxial wafer produced after maintenance. Moreover, even if the flow rate of the source gas is increased or decreased, the flow rate distribution of the source gas can be prevented from changing greatly.

  In an embodiment of the present invention, the substrate is a silicon single crystal substrate, the epitaxial layer is a silicon epitaxial layer, and the flow path is made of quartz.

  According to this, it can suppress that a flow path becomes a contamination source of a silicon epitaxial wafer.

  In an embodiment of the present invention, the flow path has a cross section of a square, a rectangle, or a shape with rounded corners of a square or rectangle.

In addition, the manufacturing method of the epitaxial wafer of the present invention,
Opposite the inlet in a passage connecting the inlet leading to the reactor for vapor-phase growth of the epitaxial layer on the substrate with the source gas and the outlet located above the inlet and on the reactor side from the inlet to the reactor. Introducing a source gas toward a step portion having a first surface and a second surface extending from the upper end of the first surface to the outlet;
A step of growing an epitaxial layer on the substrate by the source gas introduced by the step of introducing;
With
The process to introduce is
A tubular flow path having a first opening facing the inlet and a second opening located ahead extending from the first opening toward the outside of the inlet and guiding the source gas to the inlet;
A baffle that has a shape corresponding to the second opening, and has a through hole that communicates with the second opening and guides the source gas from the through hole to the flow path;
Is used to introduce the raw material gas into the stepped portion.

  In the epitaxial wafer manufacturing method of the present invention, the raw material gas is introduced into the step portion of the reactor using a tubular flow path having a second opening having a shape corresponding to the through hole of the baffle. Therefore, it is possible to stabilize the flow of the source gas as in the above-described vapor phase vapor deposition apparatus. Therefore, there is a possibility that an epitaxial wafer with high reproducibility of the film thickness distribution of the epitaxial layer can be manufactured.

  In the embodiment of the present invention, the flow path fuses the fusion surface of the first member and the second member after forming a groove in the fusion surface of at least one of the first member and the second member having the fusion surfaces to be fused with each other. Thus, a channel in which the groove is formed in a tubular shape is used as the channel.

  According to this, it becomes easy to produce the flow path which guides source gas.

1 is a schematic cross-sectional view showing a vapor phase growth apparatus as an example of the present invention. FIG. 1B is a schematic plan view showing a member through which gas passes toward the substrate of the vapor phase growth apparatus of FIG. 1A. The model perspective view which shows the injection insert of FIG. 1A. FIG. 2B is a schematic plan view of FIG. 2A. The schematic front view of FIG. 2B. The schematic plan view which shows the injection insert used by the comparative example. The schematic front view of FIG. 3A. The contour map of Example 1 which shows the film thickness distribution of the epitaxial wafer produced before the maintenance. The contour map of Example 1 which shows the film thickness distribution of the epitaxial wafer produced after the maintenance. The contour map of the comparative example which shows the film thickness distribution of the epitaxial wafer produced before the maintenance. The contour map of the comparative example which shows the film thickness distribution of the epitaxial wafer produced after the maintenance. The contour map of Example 2 which shows the film thickness distribution of the epitaxial wafer produced with the flow volume which normally uses hydrogen which is carrier gas. The contour map of Example 2 which shows the film thickness distribution of the epitaxial wafer produced by making twice the flow volume (2 times of FIG. 6A) which normally uses hydrogen which is carrier gas. The schematic cross section which shows an example of the conventional vapor phase growth apparatus. The schematic diagram which showed each member of FIG. 7A planarly. The flow path figure which shows the flow of the jet flow of the source gas which goes to the reaction furnace in the conventional vapor phase growth apparatus.

  FIG. 1A shows a single wafer type vapor phase growth apparatus 1 which is an example of the present invention. The epitaxial layer is vapor-phase grown on the substrate W by the vapor phase growth apparatus 1, and an epitaxial wafer is manufactured.

  The vapor phase growth apparatus 1 includes a reaction furnace 2 that accommodates a substrate W. The reaction furnace 2 is formed in a container shape. The reactor 2 has a cylindrical or annular base ring 3, an upper dome 4 that covers the base ring 3 from the upper side and forms the ceiling of the reactor 2, and a base ring 3 that is covered from the lower side. Rowardome 5 constituting the bottom side of the furnace 2.

  The base ring 3 is a member serving as a base constituting the reaction furnace 2. The base ring 3 includes an introduction port 3 a for introducing gas into the base ring 3 and a discharge port 3 b for discharging the gas inside the base ring 3 to the outside of the base ring 3. The introduction port 3a and the discharge port 3b are formed as a center line of the base ring 3, for example, an opening having a curved surface with an axis O extending in the vertical direction as an axis, that is, an opening formed in an arch shape. .

  An upper liner 6 and a lower liner 7 are located inside the base ring 3. The upper liner 6 and the lower liner 7 are an introduction passage 8 for introducing the gas introduced from the introduction port 3 a into the reaction furnace 2, and a discharge passage for guiding the gas in the reaction furnace 2 to the discharge port 3 b for discharging the gas inside the reaction furnace 2 to the outside. 9 is a member for forming.

  The upper liner 6 is a quartz member formed in an annular shape that can be fitted into the inner periphery of the base ring 3. The upper liner 6 is positioned on the upper dome 4 side in a state of being fitted inside the base ring 3.

  The lower liner 7 is a quartz member formed in an annular shape that can be fitted inside the base ring 3. The lower liner 7 is placed on the lower ward 5 while being fitted inside the base ring 3.

  The introduction passage 8 formed by the upper liner 6 and the lower liner 7 includes an inlet 8a that communicates with the reactor 2, and an outlet 8b that is located above the inlet 8a and closer to the reactor 2 than the inlet 8a and reaches the reactor 2. And a step portion 8c located in a passage connecting the inlet 8a and the outlet 8b. The step portion 8c includes a first surface 8c1 facing the inlet 8a and a second surface 8c2 extending from the upper end of the first surface 8c1 to the outlet 8b. The first surface 8c1 is an arcuate curved surface with the axis O as an axis, and the second surface 8c2 is a horizontal plane. The introduction passage 8 corresponds to the “passage” of the present invention. The discharge passage 9 formed by the upper liner 6 and the lower liner 7 is the same as the introduction passage 8 and will not be described.

  Inside the reaction furnace 2, a susceptor 10 on which the substrate W is placed, a support part 11 that supports the susceptor 10, and a preheat ring 12 that surrounds the susceptor 10 are provided. The support part 11 can be rotated around the axis O by a driving means (not shown).

  Lamps 13 serving as heating sources are arranged above and below the reaction furnace 2 in FIG. 1A, and a mechanism for supplying gas into the reaction furnace 2 and gas inside the reaction furnace 2 are arranged on the left and right sides outside the reaction furnace 2. A discharging mechanism is located.

  FIG. 1B is a schematic diagram for explaining a mechanism for supplying various gases for growing an epitaxial layer on the substrate W. FIG. FIG. 1B is a schematic plan view showing each member through which gas toward the substrate W passes. The gas to be supplied passes through each member in the order of the baffle 14 on the left side of FIG. 1B, the injection insert 15 (hereinafter referred to as “insert 15”), the lower liner 7, the preheat ring 12, and the susceptor 10. To reach. Then, after passing each member in the order of the susceptor 10, the preheat ring 12, and the lower liner 7, it is discharged out of the reaction furnace 2. In FIG. 1B, the substrate W, the susceptor 10, the preheat ring 12, and the lower liner 7 are shown in a circular shape.

  The baffle 14 has a plate shape and includes a plurality of through holes H through which gas passes. Twelve through holes H are formed in the entire baffle, and each through hole H has a rectangular opening. A gas to be supplied to the substrate W is guided toward the baffle 14 by a mass flow controller (not shown), and the gas flow is adjusted by the guided gas passing through the through-hole H to reach the insert 15.

  2A to 2C show schematic views of the insert 15. As shown in FIGS. 2A and 2B, the insert 15 has a pair of plates 16 each having an arcuate side S1 and an opposing side S2 facing the side S1. Each plate 16 includes a plurality (six) of flow paths 16a to 16f penetrating from the opposite side S2 toward the side S1. Each of the flow paths 16a to 16f is formed as a tubular pipe line having a rectangular cross section (for example, a square, a rectangle, or a cross section having a rounded shape of a square or a rectangle), and baffles 14 at both ends. Corresponding to the through-holes H (FIG. 1B), which are formed in a rectangular shape (opening O1 on the side S1 side and opening O2 on the opposite side S2 side). The flow paths 16a to 16d are provided with a curved curved pipe line 17 positioned between the opening O1 and the opening O2, and an end pipe line 18 connected to the curved pipe line 17 and positioned at the end on the opening O1 side. . The curved conduit 17 is formed in a partially curved tubular shape, and as shown in FIG. 1B, the end conduit 18 is along the normal direction of the arc-shaped first surface 8c1 of the introduction passage 8 (on the axis O). Bend (to be along an orthogonal direction). The end pipe line 18 is formed in a straight line and is positioned along a direction orthogonal to the axis O. The flow paths 16e and 16f are formed in a straight line and are positioned along a direction orthogonal to the axis O. The set of plates 16 has a total of 12 openings O2 corresponding to the through holes H of the baffle 14. The baffle 14 is attached so that each opening O2 communicates with the opposing through hole H. In the insert 15, the flow paths 16 a to 16 f extend in the horizontal direction from the inlet 8 a side to the outside of the inlet 8 a (outside of the reaction furnace 2) so as to face the inlet 8 a of the introduction passage 8. The insert 15 is inserted into the inlet 3a of FIG. As illustrated in FIG. 1B, the flow paths 16a to 16f are arranged in parallel along the horizontal plane, and the flow paths 16a to 16f are adjacently positioned along the horizontal plane. The insert 15 (both plates 16) is made of quartz. Each plate 16 is produced as follows, for example. First, two quartz blocks are prepared. The two prepared quartz blocks each have a fusion surface to be fused together. Next, a groove corresponding to the through hole H is formed on at least one fusion surface of the prepared quartz block. Then, the fused surfaces of the two quartz blocks are stacked face to face, put in an electric furnace with a load applied by a graphite block, and heated to fuse. The plate 16 is manufactured by adjusting the outer shape of the integrated quartz block by a machining center. Similarly, a set of plates 16 is produced, and the produced set of plates 16 is attached as an insert 15 between the baffle 14 and the introduction passage 8 as shown in FIG. 1B.

  After passing through the baffle 14 and the insert 15, gas is supplied to the substrate W through the lower liner 7, the preheat ring 12, and the susceptor 10. For example, vapor phase growth gas is supplied into the reaction furnace 2 during vapor phase growth. As the vapor phase growth gas, for example, a raw material gas that is a raw material of the silicon single crystal film, a carrier gas that dilutes the raw material gas, and a dopant gas that imparts conductivity to the silicon single crystal film are provided.

  The main parts of the vapor phase growth apparatus 1 have been described above. In the case of manufacturing an epitaxial wafer by growing an epitaxial layer on the substrate W by the vapor phase growth apparatus 1, first, the substrate W is placed on the susceptor 10 of the reaction furnace 2. Then, a vapor growth gas whose flow rate is controlled by a mass flow controller (not shown) is supplied toward the reaction furnace 2. Then, the vapor growth gas passes through the through holes H of the baffle 14 shown in FIG. 1B and flows into the flow paths 16a to 16f. The vapor phase growth gas that has passed through the flow paths 16 a to 16 f is introduced into the reaction furnace 2 through the introduction passage 8. A silicon single crystal thin film is vapor-grown on the substrate W by the introduced vapor growth gas, and a silicon epitaxial wafer is manufactured.

  The embodiment of the present invention includes tubular channels 16a to 16f having openings O2 having shapes corresponding to the plurality of through holes H of the baffle 14 shown in FIG. 1B. Therefore, after the vapor phase growth gas that has passed through the through-hole H of the baffle 14 and reached the flow paths 16a to 16f flows through the respective flow paths 16a to f so as to spread over the tubular flow paths 16a to 16f. Then, it flows into the introduction passage 8 and collides with the step portion 8c. Here, although a part of the vapor phase growth gas colliding with the step portion 8c tries to flow backward, the vapor phase growth gas spreading to the full flow paths 16a to 16f flows one after another, and the vapor phase growth that tries to flow backward. The gas flow is swallowed by the later flow and canceled. Therefore, some unevenness is formed on the surface of the step portion 8c during maintenance, or the arrangement of the step portion 8c slightly shifts before and after maintenance, resulting in a flow of vapor growth gas that tends to flow backward due to the collision of the step portion 8c. Even if an effect occurs, the flow is canceled. As a result, the arrangement of the stepped portion 8c and the shape of the surface of the stepped portion 8c do not significantly affect the flow of the vapor phase growth gas as a whole. Therefore, the flow of the vapor growth gas can be stabilized before and after the maintenance, and the same vapor growth gas can be guided toward the substrate W before and after the maintenance. Therefore, reproducibility can be improved when trying to reproduce the film thickness distribution of the epitaxial layer produced before maintenance with the epitaxial wafer produced after maintenance.

  In order to confirm the effect of the present invention, the following experiment was conducted. EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, these do not limit this invention.

(Example)
In the first embodiment, the susceptor 10 on which a silicon single crystal substrate having a diameter of 200 mm and a crystal orientation (100) is mounted using the vapor phase growth apparatus 1 is not rotated around the axis O, but the rotation is stopped on the substrate. A silicon epitaxial wafer was produced by growing a silicon epitaxial layer, and the film thickness distribution of the produced silicon epitaxial wafer was measured. And after removing and cleaning (maintenance) the upper liner 6 and the lower liner 7 from the reactor 2 of the vapor phase growth apparatus 1, a silicon epitaxial wafer is produced under the same conditions as above by attaching it to the original position again. The film thickness distribution of the produced silicon epitaxial wafer was measured.

  In Example 2, the susceptor 10 on which a silicon single crystal substrate having a diameter of 200 mm and a crystal orientation (100) is mounted using the vapor phase growth apparatus 1 is not rotated around the axis O, but the rotation is stopped on the substrate. A silicon epitaxial wafer was produced by growing a silicon epitaxial layer, and the film thickness distribution of the produced silicon epitaxial wafer was measured. Next, a silicon epitaxial wafer was produced using the vapor phase growth apparatus 1 as before, and the film thickness distribution of the produced silicon epitaxial wafer was measured. However, when the silicon epitaxial wafer was first manufactured, the flow rate of hydrogen as a carrier gas was set to a normal flow rate, whereas when the silicon epitaxial wafer was manufactured later, it was twice the flow rate of the previous hydrogen. A silicon epitaxial wafer was fabricated at a flow rate of 5.

  In the comparative example, a substrate having a diameter of 200 mm and a crystal orientation (100) was used in the same manner as in Example 1 except that the insert 115 shown in FIGS. 3A and 3B was used instead of the insert 15 of the vapor phase growth apparatus 1. Two silicon epitaxial wafers were produced, and the film thickness distribution of each produced silicon epitaxial wafer was measured. Next, the insert 115 will be specifically described. The same components as those of the insert 15 are denoted by the same reference numerals and description thereof is omitted. As shown in FIGS. 3A and 3B, the insert 115 includes a pair of plates 116 having sides S1 and opposed sides S2 facing the sides S1. Each plate 116 includes a plurality (two) of flow paths 116a and 116b penetrating from the opposite side S2 toward the side S1. Each of the flow paths 116a and 116b is formed as a pipe line having a wide cross section, and has openings (opening O11 on the side S1 side and opening O12 on the opposite side S2 side) at both ends. The opening O12 is formed larger than the through hole H of the baffle 14, and a plurality of jets flow from the baffle 14 into each opening O12. In the comparative example, a vapor phase growth apparatus similar to the vapor phase growth apparatus 1 was used except for the above configuration.

  4A and 4B, FIG. 5A and FIG. 5B, and FIG. 6A and FIG. 6B show contour diagrams of the film thickness distribution of the epitaxial layer grown without rotating the substrate. In each figure, the lower side is the upstream side of the vapor deposition gas to be supplied (the upper side is the downstream side of the vapor deposition gas to be supplied), and the thickness of the epitaxial layer increases as the contour line goes from the upper side to the lower side in the drawing. . In the case of growing a silicon epitaxial layer on a silicon single crystal substrate with an epitaxial growth apparatus such as the vapor phase growth apparatus 1, the layer thickness of the epitaxial layer is usually limited by the supply amount of the vapor phase growth gas, and the part having a high flow rate is used. The growth rate is high. Therefore, each figure may be considered to show the flow rate distribution of the vapor phase growth gas.

  4A shows the film thickness distribution of the epitaxial wafer produced before maintenance in Example 1, and FIG. 4B shows the film thickness distribution of the epitaxial wafer produced after maintenance in Example 1. 4A and 4B have almost the same shape, it can be seen that the influence on the flow rate distribution of the vapor growth gas is small even if the mounting position of the member is changed by maintenance. 4A and 4B show that the flow rate distribution of each vapor phase growth gas is relatively uniform. On the other hand, FIG. 5A shows the film thickness distribution of the epitaxial wafer produced before maintenance in the comparative example, and FIG. 5B shows the film thickness distribution of the epitaxial wafer produced after maintenance in the comparative example. 5A and 5B, since the contour lines are greatly different, it can be seen that the flow position distribution of the vapor growth gas is greatly affected by the change of the attachment position of the member due to the maintenance. From comparison between Example 1 and the comparative example, it can be seen that the flow paths 16a to 16f of the insert 15 of Example 1 enhance the reproducibility of the flow rate distribution of the vapor growth gas before and after the maintenance.

  6A shows the film thickness distribution of the epitaxial wafer produced by flowing a normal flow rate carrier gas in Example 2, and FIG. 6B shows the flow rate produced by flowing a normal double flow rate carrier gas in Example 2. The film thickness distribution of the epitaxial wafer is shown. 6A and 6B, since the shape of the contour line does not change greatly, it can be seen that the flow rate distribution of the vapor phase growth gas does not change greatly even if the flow rate of the carrier gas is increased or decreased in the vapor phase growth apparatus 1.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the specific description, and the illustrated configurations and the like can be appropriately combined within a technically consistent range. In addition, certain elements and processes may be replaced with known forms.

DESCRIPTION OF SYMBOLS 1 Vapor growth apparatus 2 Reactor 3 Base ring 6 Upper liner 7 Lower liner 8 Introduction passage (passage)
8a Inlet 8b Outlet 8c Stepped portion 8c1 First surface 8c2 Second surface 10 Susceptor 14 Baffle H Through hole 15 Injection insert 16 Plate 16a to 16f Flow path O1 Opening (first opening)
O2 opening (second opening) 17 curved pipe 18 end pipe W substrate

Claims (8)

A reactor for vapor-phase growth of an epitaxial layer on a substrate with a source gas;
The reactor having an inlet communicating with the reactor, and an outlet located above the inlet and on the reactor side from the inlet and reaching the reactor, and connecting the inlet and the outlet to the reactor A passage for introducing the raw material gas therein,
A step portion having a first surface located in the passage and facing the inlet, and a second surface extending from an upper end of the first surface to the outlet;
A tubular flow path having a first opening facing the inlet and a second opening located at the tip extending from the first opening toward the outside of the inlet and guiding the source gas to the inlet. ,
A baffle that has a shape corresponding to the second opening and has a through hole that communicates with the second opening and guides the source gas from the through hole to the flow path;
A vapor phase growth apparatus comprising:   The flow path is connected to the curved curved line located between the first opening and the second opening, and the end located at the end of the flow path on the first opening side. The vapor phase growth apparatus according to claim 1, further comprising a conduit. The first surface is an arcuate curved surface centering on an axis extending in the vertical direction from the reactor side,
The vapor phase growth apparatus according to claim 2, wherein the end pipe line is located along a direction orthogonal to the axis.   4. The vapor phase growth apparatus according to claim 1, wherein at least a part of the source gas is guided perpendicularly to the first surface by the flow path. 5. The substrate is a silicon single crystal substrate;
The epitaxial layer is a silicon epitaxial layer;
The vapor phase growth apparatus according to any one of claims 1 to 4, wherein the flow path is made of quartz.   6. The vapor phase growth apparatus according to claim 1, wherein the flow path has a cross section having a square shape, a rectangular shape, or a shape having rounded corners of the square shape or the rectangular shape. In a passage connecting an inlet leading to a reactor for vapor-phase growth of an epitaxial layer on a substrate with a source gas, and an outlet located above the inlet and on the reactor side from the inlet and reaching the reactor The step of introducing the source gas while suppressing the jet of the source gas toward a step portion having a first surface facing the inlet and a second surface extending from the upper end of the first surface to the outlet;
Growing the epitaxial layer on the substrate with the source gas introduced in the introducing step;
With
The introducing step includes
A tubular flow path having a first opening facing the inlet and a second opening located at the tip extending from the first opening toward the outside of the inlet and guiding the source gas to the inlet. ,
A baffle that has a shape corresponding to the second opening and has a through hole that communicates with the second opening and guides the source gas from the through hole to the flow path;
A method for producing an epitaxial wafer, wherein the raw material gas is introduced into the step portion by using a material.   The flow path is formed by forming a groove in the fusion surface of at least one of the first member and the second member having a fusion surface to be fused with each other, and then fusing the fusion surface of the first member and the second member. The method for producing an epitaxial wafer according to claim 7, wherein the groove is formed in a tubular shape as the flow path.