JP2017011182A - Silicon carbide semiconductor epitaxial growth apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a SiC semiconductor epitaxial growth apparatus capable of forming an epitaxially grown SiC semiconductor layer to achieve highly controllable carrier concentration.SOLUTION: In a SiC semiconductor epitaxial growth apparatus, a wall surface out of first through third component parts 34a-34c, which composes first through fourth introduction ports 31a-31d is inclined on a growth chamber side and an opening width of each of the first through fourth introduction ports 31a-31d gradually increases with the decreasing distance from the growth chamber. This can increase an introduction range of various gases. Accordingly, various gases can be uniformly supplied to a surface of a SiC semiconductor substrate 70 substantially without causing an in-plane distribution.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an epitaxial growth apparatus capable of epitaxially growing a silicon carbide (hereinafter referred to as SiC) semiconductor.

  Conventionally, Patent Document 1 proposes a chemical vapor deposition (CVD) apparatus that can reduce the maintenance frequency while supplying gas uniformly to the surface of a SiC semiconductor substrate. In this CVD apparatus, a plate-like inlet provided with a cooling mechanism is used so that the maintenance frequency can be lowered by minimizing deposits on the inlet.

  Specifically, as shown in FIG. 9, a plurality of holes are provided in a flat inlet J1 to form a gas introduction hole J2, and Si (silicon) is formed from each gas introduction hole J2 into a reaction chamber in which epitaxial growth is performed. Si source gas containing C and C source gas containing C (carbon) are supplied. Further, the dopant gas of the p-type impurity is supplied from a different gas introduction hole J2 from that into which Si source gas or C source gas is introduced. A cooling water passage J4 through which the cooling water J3 flows is provided inside the inlet J1 in which the gas introduction hole J2 is formed, so that the inlet J1 is cooled.

Special table 2008-508744

  However, as shown in FIG. 9, the tip of the reaction chamber side of the inlet J1 has a flat shape, so that gas flow stagnation as indicated by the broken-line arrows in the figure may occur. Thereby, there exists a problem that the controllability of the carrier concentration in the depth direction of the SiC semiconductor layer to which the dopant gas is convected and epitaxially grown is deteriorated. That is, it is difficult to realize a structure in which the carrier concentration is sharply changed in the depth direction of the SiC semiconductor layer to be epitaxially grown. In particular, in the case where epitaxial growth is performed in a high-temperature atmosphere such as a SiC semiconductor, the temperature gradient in the vicinity of the inlet is large and gas flow stagnation is likely to occur.

  An object of the present invention is to provide an epitaxial growth apparatus in an SiC semiconductor capable of forming the carrier concentration of an SiC semiconductor layer to be epitaxially grown with good controllability.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a chamber (20) constituting a growth chamber and an installation in which a SiC semiconductor substrate (70) is provided in the growth chamber constituted in the chamber. The susceptor part (50) constituting the surface and a plurality of separation chambers (40) into which a dopant gas containing an element that becomes an impurity of the SiC semiconductor is formed, including the Si raw material containing gas, the C raw material containing gas, and the separation An inlet (30) having gas inlets (31a to 31d) for introducing a gas introduced into the chamber into the growth chamber, and a heater (60) for heating the SiC semiconductor substrate. While heating the silicon, the Si raw material containing gas, the C raw material containing gas, and the dopant gas are introduced into the growth chamber through the gas inlet, so that the SiC semi-conductor is formed on the SiC semiconductor substrate. An epitaxial growth apparatus for epitaxially growing a body layer, wherein an inlet partitions a plurality of separation chambers and a growth chamber, constitutes a gas inlet, and has an inlet opening portion (34) provided with a cooling mechanism (35) inside. ) And the introduction port component is configured to have a plurality of frame-shaped components (34a to 34c) arranged concentrically, and a gas introduction port is provided between the plurality of components. And the plurality of components are tapered by tilting the wall surface constituting the gas inlet among the plurality of components with respect to the direction from each of the plurality of separation chambers toward the growth chamber. And the wall surface is inclined to the tip of the growth chamber most among the plurality of components.

  In this way, the wall surface is inclined to the tip on the growth chamber side among the plurality of constituent portions. That is, it is set as the structure without a flat surface at the front-end | tip of a some structure part. For this reason, it is possible to suppress the occurrence of gas flow stagnation at the tip of the component. For this reason, it can suppress that a dopant gas convects, and it becomes possible to adjust the carrier concentration contained in a SiC semiconductor layer with sufficient controllability.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is a cross-sectional view of an epitaxial growth apparatus 10 according to a first embodiment of the present invention. It is II-II sectional drawing of FIG. It is sectional drawing which showed the gas flow from the inlet 30 in FIG. It is the figure which showed the relationship between carrier concentration and depth. It is sectional drawing of the epitaxial growth apparatus 10 concerning 2nd Embodiment of this invention. It is sectional drawing of the epitaxial growth apparatus 10 concerning 3rd Embodiment of this invention. It is sectional drawing of the epitaxial growth apparatus 10 concerning 4th Embodiment of this invention. It is sectional drawing which showed the front-end | tip shape of the introduction port structure parts 34a-34c demonstrated by other embodiment. It is sectional drawing which showed the gas flow from the conventional inlet J1.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
With reference to FIG. 1 and FIG. 2, the epitaxial growth apparatus 10 of the SiC semiconductor concerning 1st Embodiment of this invention is demonstrated. 2 corresponds to the II-II cross-sectional view of FIG. 1, and FIG. 1 corresponds to the II cross-sectional view of FIG.

  As shown in FIG. 1, the SiC semiconductor epitaxial growth apparatus 10 includes a chamber 20, an inlet 30, a separation chamber 40, a susceptor unit 50, and a heater 60. The epitaxial growth apparatus 10 is installed so that the vertical direction of the drawing in FIG.

  The chamber 20 is made of, for example, a metal such as SUS, and is made of a cylindrical member having a hollow portion that forms a growth chamber. The epitaxial growth apparatus 10 includes a separation chamber 40 constituted by an inlet 30 at an upper position inside the chamber 20, and a susceptor portion 50 at a lower position of the separation chamber 40, and an SiC installed in the susceptor portion 50. SiC semiconductor layer 80 is epitaxially grown on the surface of semiconductor substrate 70.

  The chamber 20 is provided with a cooling mechanism 21. The cooling mechanism 21 constitutes a flowing water path through which, for example, the cooling water 22 is circulated. A cooling water inlet and a flowing water outlet (not shown) are formed, and the cooling water 22 is introduced from the flowing water inlet and discharged from the flowing water outlet. Thus, the chamber 20 can always be cooled. For example, the side wall 23 of the chamber 20 is provided with a partition wall extending in the vertical direction to partition the chilled water path, and a running water inlet and a running water outlet are provided on both sides of the partition wall, thereby 22 is made to flow along the circumferential direction of the side wall 23 of the chamber 20. Further, in the figure, the bottom surface 24 of the chamber 20 is shown as a structure in which a flowing water path is provided in substantially the entire region, but for example, a flowing water path is provided in a spiral shape, and a flowing water inlet and a flowing water outlet are provided at both ends of the spiral. Thus, the cooling water 22 is allowed to flow spirally.

  A gas discharge port 25 is provided in the bottom surface 24 of the chamber 20, and gas is discharged from the chamber 20 through the gas discharge port 25.

  The inlet 30 introduces gas while constituting the upper lid of the chamber 20, and is made of a metal such as SUS, for example. The inlet 30 forms first to fourth chambers 40a to 40d as separation chambers 40 and introduces gas by communicating each of the first to fourth chambers 40a to 40d with an internal space provided in the chamber 20. Gas inlets 31a to 31d are provided. Specifically, the inlet 30 includes a plate-like portion 32, a partition wall portion 33 disposed on the lower surface of the plate-like portion 32 (inside the chamber 20), and an inlet configuration provided at the tip of the partition wall portion 33. And a portion 34.

  The plate-like portion 32 constitutes the upper lid of the chamber 20, and in the case of this embodiment, is constituted by a disk-like member. Gas inflow holes 32a to 32d are formed at positions corresponding to the first to fourth chambers 40a to 40d in the plate-like portion 32, and gas to the first to fourth chambers 40a to 40d is formed through the gas inflow holes 32a to 32d. Inflow takes place.

  The partition wall part 33 plays a role of partitioning the first to fourth rooms 40a to 40b as a space. Specifically, the partition wall portion 33 is configured by a circular frame-shaped projection portion arranged concentrically from the center of the plate-like portion 32. The partition wall 33 includes a first partition wall 33a that surrounds the periphery of the first room 40a, a second partition wall 33b that surrounds the first partition wall 33a and forms the second chamber 40b between the first partition wall 33a, A third partition wall 33c that surrounds the second partition wall 33b and forms the third chamber 40c between the second partition wall 33b, and a fourth chamber 40d that surrounds the third partition wall 33c and between the third partition wall 33c The fourth partition wall 33d is provided. Since each of the first to fourth partition walls 33a to 33d has a circular frame shape, the first room 40a is a circular shape, and the second to fourth rooms 40b to 40d are each an annular room.

  The introduction port constituting unit 34 partitions the first to fourth chambers 40a to 40d and the growth chamber in the chamber 20 and introduces various gases that have flowed into the first to fourth chambers 40a to 40d into the growth chamber. Gas inlets 31a to 31d are provided. As shown in FIG. 2, in this embodiment, the gas inlets 31a to 31d are a first inlet 31a that is circular, and an annular first that is concentrically provided around the first inlet 31a. 2 to 4th introduction ports 31b to 31d. The first to fourth introduction ports 31a to 31d have the same opening width, specifically the radial dimension. However, the opening width is arbitrary, and different opening widths may be used. For example, the opening width increases sequentially from the first introduction port 31a located in the center to the fourth introduction port 31d located on the outermost peripheral side. It may be reduced.

  The introduction port component 34 is provided with a cooling mechanism 35 therein, and for example, the introduction port component 34 can be cooled to 200 ° C. or lower. The cooling mechanism 35 cools various gases introduced through the wall surfaces constituting the first to fourth introduction ports 31a to 31d and the first to fourth introduction ports 31a to 31d in the introduction port constituting portion 34. Thus, adhesion of deposits to the introduction port component 34 is suppressed. Here, the deposit corresponds to SiC or Al used as a dopant. Specifically, the introduction port configuration unit 34 is divided into first to third configuration units 34a to 34c by first to fourth introduction ports 31a to 31d, and each of the first to third configuration units 34a to 34c. Is provided with a cooling mechanism 35.

  The cooling mechanism 35 constitutes a flowing water path through which, for example, the cooling water 36 is circulated, and a flowing water inlet and a flowing water outlet (not shown) are formed. And the cooling water 36 is introduce | transduced from the flowing water inlet with which the cooling mechanism 35 was equipped, and is discharged | emitted from a flowing water outlet, so that it can always cool the 1st-3rd components 34a-34c during epitaxial growth. . For example, a part of a path through which the cooling water 36 is introduced is provided in the plate-like portion 32 and the partition wall portion 33, and the cooling water 36 is caused to flow in the first to third constituent portions 34a to 34c. Yes. In that case, for example, it is possible to use an annular water flow path with a part cut away in the first to third components 34a to 34c, and use one end of the cut as a water flow inlet and the other end as a water flow outlet.

  The first to third component parts 34 a to 34 c each have a tapered tip at the growth chamber side in the chamber 20. More specifically, among the first to third components 34a to 34c, the first to fourth introduction ports 31a with respect to the direction from the respective chambers 40a to 40d toward the growth chamber (normal direction with respect to the surface of the susceptor unit 50). Wall surfaces (side surfaces) constituting ˜31d are inclined, and the opening widths of the first to fourth introduction ports 31a to 31d are gradually widened toward the growth chamber side. In the case of the present embodiment, in the cross section shown in FIG. 1, a portion on the growth chamber side of the wall surface is linearly inclined to form a tapered surface. The wall surface is inclined to the most distal end on the susceptor unit 50 side among the first to third component portions 34a to 34c, and has a structure without a flat surface at the distal end.

  The gas inflow holes 32a to 32d serve as inlets for separately introducing a gas containing a SiC semiconductor material, a carrier gas, or the like into each of the first to fourth chambers 40a to 40d. In the case of this embodiment, four types of first to fourth inflow holes 32a to 32d are provided as the gas inflow holes 32a to 32d, and various gases are supplied from the first to fourth inflow holes 32a to 32d, respectively. Introduce. Specifically, the first to fourth inflow holes 32a to 32d are formed at positions corresponding to the first to fourth chambers 40a to 40d, respectively. Each of the first to fourth inflow holes 32a to 32d may be single or plural. In the case of the present embodiment, for example, a plurality of second to fourth inflow holes 32a to 32d are arranged concentrically with respect to the second to fourth chambers 40b to 40d having an annular shape.

  Gas pipes 41 to 44 are connected to the first to fourth inflow holes 32 a to 32 d, and various gases are introduced through the gas pipes 41 to 44. Gas cylinders 45 to 48 are connected to the gas pipes 41 to 44, and flow control can be performed by mass flow controllers (hereinafter referred to as MFC) 41a to 41d, 42a to 42d, 43a to 43d, and 44a to 44d. Yes.

The gas cylinder 45 contains Si source gas and supplies a silane-based gas (for example, TCS (trichlorosilane)). The gas cylinder 46 contains C source gas and supplies propane-based gas (for example, C ₃ H ₈ (propane)). The gas cylinder 47 supplies a dopant gas containing p-type impurities (for example, TMA (trimethylaluminum)). The gas cylinder 48 contains a carrier gas and supplies, for example, H ₂ (hydrogen) or an inert gas.

  Here, although an example of Si source gas, C source gas, dopant gas, and carrier gas is shown, other gas may be used as a matter of course.

  The separation chamber 40 is configured to be separated into a plurality of portions in the horizontal direction in the upper part of the growth chamber configured in the chamber 20, and can be introduced in a state where the gases from the first to fourth inflow holes 32a to 32d are separated. is there. In the case of this embodiment, the separation room 40 is configured by first to fourth rooms 40a to 40d, and the first to fourth rooms 40a to 40d are formed by the first to fourth partition walls 33a to 33d described above. It is partitioned. Thus, the first room 40a has a circular shape, and the second to fourth rooms 40b to 40c have an annular shape arranged concentrically so as to surround the first room 40a.

  The susceptor portion 50 is a member that becomes a mount portion on which the SiC semiconductor substrate 70 is installed. The upper surface of the susceptor unit 50 is an installation surface of the SiC semiconductor substrate 70. In the present embodiment, the susceptor unit 50 has a disk shape. The susceptor part 50 is provided with a rod-like support shaft 51 extending downward. Although not shown, the support shaft 51 is drawn from the bottom surface 24 of the chamber 20 to the outside, and can be rotated by being connected to a rotation mechanism (not shown).

  The heater 60 is configured by a disk-shaped heater or the like facing the installation surface of the SiC semiconductor substrate 70 in the susceptor unit 50. The heater 60 is energized from outside through wiring (not shown). As a result, the heater 60 heats the SiC semiconductor substrate 70 from the back side of the susceptor unit 50 to a temperature suitable for the growth of the SiC semiconductor layer 80.

  Although not shown in the drawing, the inside of the chamber 20 can be controlled to a reduced pressure atmosphere by a pressure reducing device, and only the gas species from the gas cylinders 45 to 48 except for air are used when the SiC semiconductor layer 80 is grown. The growth chamber can be filled.

  The epitaxial growth apparatus 10 is configured as described above. Using the epitaxial growth apparatus 10 configured as described above, the SiC semiconductor layer 80 is formed on the surface of the SiC semiconductor substrate 70 as follows.

  Specifically, while the SiC semiconductor substrate 70 is heated (for example, 1600 ° C.) by the heater 60, a reduced pressure atmosphere (for example, 13.3 kPa = 100 Torr) is set, and the MFCs 41a to 41d, 42a to 42d, 43a to 43d, and 44a to 44d. Various gases are supplied from the gas cylinders 45 to 48 while controlling the flow rate control. Various gases are introduced into the first to fourth chambers 40a to 40d through the gas pipes 41 to 44 and introduced into the growth chamber of the chamber 20 through the first to fourth introduction ports 31a to 31d. This gas is thermally decomposed in the vicinity of the heated SiC semiconductor substrate 70, so that the SiC semiconductor layer 80 is epitaxially grown on the surface of the SiC semiconductor substrate 70. At this time, when TMA containing Al as an element serving as a dopant is introduced, a p-type epitaxial layer can be grown as the SiC semiconductor layer 80. Thereby, an epitaxial substrate obtained by epitaxially growing a p-type SiC semiconductor having a desired impurity concentration on SiC semiconductor substrate 70 can be obtained.

  Here, as described above, among the first to third components 34a to 34c, the wall surfaces constituting the first to fourth introduction ports 31a to 31d are inclined on the growth chamber side, and the first to fourth introduction ports are formed. The opening widths 31a to 31d are gradually widened toward the growth chamber side. For this reason, as shown by the arrows in FIG. 3, the introduction range of various gases can be expanded. Therefore, various gases can be uniformly supplied to the surface of SiC semiconductor substrate 70 with almost no in-plane distribution.

  Moreover, the wall surface which comprises the 1st-4th inlet ports 31a-31d among the 1st-3rd structure parts 34a-34c is the front-end | tip of the susceptor part 50 side most among the 1st-3rd structure parts 34a-34c. It is made to have a structure with no flat surface at the tip. For this reason, it is possible to suppress the occurrence of gas flow stagnation at the tip of the wall surface. For this reason, it is possible to suppress the convection of the dopant gas, and it is possible to adjust the carrier concentration (impurity concentration of the p-type impurity in the present embodiment) contained in the SiC semiconductor layer 80 with good controllability. Therefore, it is possible to realize a structure that sharply changes the carrier concentration in the depth direction of SiC semiconductor layer 80 to be epitaxially grown. Specifically, as indicated by the solid line in FIG. 4, the change in the carrier concentration with respect to the depth direction of the SiC semiconductor layer 80 changes suddenly and does not become a gradual change as indicated by the broken line in FIG. Can be.

(Second Embodiment)
A second embodiment of the present invention will be described. In the present embodiment, the configuration of the inlet 30 is changed with respect to the first embodiment, and the other parts are the same as those in the first embodiment. Therefore, only different portions from the first embodiment will be described.

  In the first embodiment, the various gases are introduced in a mixed state from the gas inlets 31a to 31d. However, in the present embodiment, at least a part of the various gases is introduced separately.

  As shown in FIG. 5, pipe members 31aa to 31da are arranged in the gas inlets 31a to 31d. The tips of the pipe members 31aa to 31da are root positions of the inclined portions of the wall surfaces constituting the first to fourth introduction ports 31a to 31d in the first to third constituent portions 34a to 34c (mostly with the growth chamber). It protrudes from the opposite side).

In such a configuration, Si source gas (for example, TCS), C source gas (for example, C ₃ H ₈ ), dopant gas (for example, TMA), and carrier gas (for example, H ₂ , inert gas) from the inside of the pipe members 31aa to 31da. ). Also, introducing a purge gas (e.g., H ₂₎ from the outside than the pipe member 31aa~31da of gas inlets 31 a to 31 d. Although the purge gas is the same as the carrier gas here, a different gas may be used.

  Thus, the purge gas may be introduced around the Si source gas, the C source gas, the dopant gas, and the carrier gas. With such a structure, it is possible to further suppress adhesion of deposits to the introduction port constituting portion 34.

  In the case of such a configuration, various gases are not mixed in the gas pipes 41 to 44, but at least a Si raw material gas, a C raw material gas, a dopant gas, a carrier gas, and a purge gas are separate pipes. Need to be supplied at. Also, in the first to fourth chambers 40a to 40d, the Si source gas, the C source gas, the dopant gas, and the carrier gas are introduced, the chamber connected to the inside of the pipe members 31aa to 31da, and the purge gas are introduced, and the pipe member 31aa. It is necessary to divide it into a room connected to the outside of ~ 31da.

(Third embodiment)
A third embodiment of the present invention will be described. In this embodiment, the configuration of the inlet 30 is changed with respect to the first embodiment, and the other parts are the same as those in the first embodiment. Therefore, only different portions from the first embodiment will be described.

In the present embodiment, as shown in FIG. 6, the gas introduction ports 31 a to 31 d arranged on the base side opposite to the distal end side of the introduction port constituting portions 34 a to 34 c are arranged on the base side. In addition, in addition to these, the fifth to seventh gas introduction ports 31e to 31g on the distal end side that pass through the distal end portion closest to the susceptor portion 50 among the introduction port constituting portions 34a to 34c are formed. Then, Si source gas (for example, TCS), C source gas (for example, C ₃ H ₈ ), dopant gas (for example, TMA), and carrier gas (for example, H ₂ , inert gas) from the fifth to seventh gas introduction ports 31e to 31g. ). Further, a purge gas (for example, H ₂ ) is introduced from the first to fourth gas introduction ports 31a to 31d.

  As described above, the fifth to seventh gas introduction ports 31e to 31g are formed so as to pass on the line passing through the tip portion closest to the susceptor 50 among the introduction port constituting portions 34a to 34c, and the Si raw material is formed therefrom. A purge gas may be introduced around the gas, the C source gas, the dopant gas, and the carrier gas. With such a structure, the surroundings of the Si source gas, the C source gas, the dopant gas, and the carrier gas do not pass through the inclined wall surfaces in the inlet port constituent portions 34a to 34c. It becomes possible to suppress adhesion of deposits to the surface.

  Even in such a configuration, various gases are not mixed in the gas pipes 41 to 42, but at least the Si source gas, the C source gas, the dopant gas, the carrier gas, and the purge gas are separated. It needs to be supplied by piping. Further, in addition to the first to fourth chambers 40a to 40d, fifth to seventh chambers 40e to 40f are provided, and Si source gas, C source gas, dopant gas and carrier gas are provided in the fifth to seventh chambers 40e to 40f. Need to be introduced.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. In this embodiment, the configuration of the inlet 30 is changed with respect to the second embodiment, and the other parts are the same as those in the second embodiment. Therefore, only the parts different from the second embodiment will be described.

  In the present embodiment, the leading ends of the introduction port constituting portions 34a to 34c are structured to have heating means. Specifically, as shown in FIG. 7, a heater 37 by resistance heating is provided as a heating means at the tip of each of the introduction port constituting portions 34a to 34c. Thus, by providing the heater 37, for example, the tips of the introduction port constituent portions 34a to 34c, specifically, are inclined to a temperature equal to or higher than the adhesion temperature (for example, 1200 ° C.) of Al contained in the dopant gas. Heat the wall. In this way, it is possible to further suppress the deposits from adhering to the introduction port component 34.

  Here, the tips of the introduction port constituting portions 34a to 34c are made of a material different from the root portion (SUS) so that the cooling by the cooling mechanism 35 and the heating by the heater 37 can be thermally separated. . In this case, since it is necessary to prevent sublimation by SiC at a high temperature to form a pollutant for SiC, for example, carbon and high melting point metal carbide (TaC (tantalum carbide), NbC (niobium carbide), etc.) Is used to configure the leading ends of the introduction port constituting portions 34a to 34c.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims.

  For example, as for the inclination of the tip of each introduction port constituent part 34a-34c, the cross-sectional shape does not necessarily have to be a straight line shape, but a swollen curved shape as shown in FIG. 8 (a) or FIG. 8 (b). A concave curved shape as shown in FIG. In addition, the leading ends of the introduction port constituting portions 34a to 34c are not required to have a flat surface, and may be rounded as shown in FIG. 8C, for example.

  Moreover, what can be combined between each embodiment can also be combined. For example, the heater 37 of the fourth embodiment can be applied to the structures of the first and third embodiments.

  Moreover, in each said embodiment, although it is set as the structure where the inlet-port structure parts 34a-34c were isolate | separated, the gas inlet ports 31a-31d are dotted instead of making it a line form, and each inlet-port structure parts 34a-34c. It can also be set as the structure which connected. However, in that case, a flat surface is formed between the gas inlets 31a to 31d, and deposits may be generated in the portion, or convection of the gas flow may occur. The inlets 31a to 31d are preferably formed in a line shape.

  Further, in each of the above embodiments, the introduction port components 34a to 34c are annular members arranged concentrically. However, this is merely an example, and it may be a concentric frame member. .

DESCRIPTION OF SYMBOLS 10 Epitaxial growth apparatus 20 Chamber 30 Inlet 31a-31g Gas introduction port 34 Introduction port structure part 35 Cooling mechanism 37 Heater 40 Separation room 50 Susceptor part 70 SiC semiconductor substrate 80 SiC semiconductor layer

Claims (8)

A chamber (20) constituting a growth chamber;
A susceptor part (50) provided in the growth chamber configured in the chamber and constituting an installation surface on which the silicon carbide semiconductor substrate (70) is installed;
A plurality of separation chambers (40) into which a Si raw material containing gas, a C raw material containing gas, and a dopant gas containing an element that becomes an impurity of a silicon carbide semiconductor are introduced, and the gases introduced into the separation chamber are introduced into the growth chamber An inlet (30) having gas inlets (31a to 31d) to be introduced into
A heater (60) for heating the silicon carbide semiconductor substrate,
While heating the silicon carbide semiconductor substrate with the heater, the Si raw material containing gas, the C raw material containing gas, and the dopant gas are introduced into the growth chamber through the gas inlet, thereby the silicon carbide semiconductor substrate. An epitaxial growth apparatus for epitaxially growing a silicon carbide semiconductor layer on the substrate,
The inlet defines the gas introduction port while partitioning the plurality of separation chambers and the growth chamber, and has an introduction port configuration part (34) provided with a cooling mechanism (35) inside,
The introduction port component is configured to have a plurality of frame-shaped components (34a to 34c) arranged concentrically, and the gas inlet is configured between the plurality of components. And the wall constituting the gas inlet among the plurality of components is inclined with respect to the direction from each of the plurality of separation chambers toward the growth chamber so that the plurality of components are tapered. An epitaxial growth apparatus characterized in that the wall surface is inclined to reach the tip on the growth chamber side among the plurality of constituent parts.   2. The epitaxial growth apparatus according to claim 1, wherein the plurality of components are annularly arranged concentrically.   The epitaxial growth apparatus according to claim 1, wherein the introduction port component is cooled to 200 ° C. or less by the cooling mechanism.   Pipe members (31aa to 31da) are arranged at the gas inlet, and the Si raw material containing gas, the C raw material containing gas, the dopant gas and the carrier gas are introduced from the inside of the pipe member of the gas inlet. 4. The epitaxial growth apparatus according to claim 1, wherein a purge gas is introduced from the outside of the pipe member.   5. The epitaxial growth apparatus according to claim 4, wherein the pipe member protrudes closer to the growth chamber than a position on the opposite side of the growth chamber in a portion where the tip is inclined in the wall surface. 6. . In the introduction port configuration portion, the gas introduction port is added to the base side gas introduction port as a root side gas introduction port arranged on the root side opposite to the tip side of the introduction port configuration portion. The gas inlets (31e to 31g) on the distal end side are formed so as to pass through the distal end portion on the susceptor part side most of the inlet configuration parts,
The purge gas is introduced from the gas inlet on the base side, and the Si raw material containing gas, the C raw material containing gas, the dopant gas and the carrier gas are introduced from the gas inlet on the tip side. Item 4. The epitaxial growth apparatus according to any one of Items 1 to 3.   The epitaxial growth apparatus according to any one of claims 1 to 6, wherein a heating means (37) for heating an inclined portion of the wall surface is provided at a distal end of the introduction port component.   The epitaxial growth apparatus according to claim 7, wherein the inclined portion of the wall surface is heated to 1200 ° C. or more by the heating means.

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