JP2007123829A - Semiconductor epitaxial wafer and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cleanly maintain the orientation flat of a mirror finished surface without a process that forms and removes a new protective film in growing an epitaxial layer on a substrate. <P>SOLUTION: A semiconductor epitaxial wafer comprising the substrate 1 having the orientation flat 2 formed by cleavage and a semiconductor epitaxial layer formed on the substrate 1, the epitaxial layer is formed on the substrate 1 with both ends 2a of the orientation flat 2 of the substrate 1 covered with a coating member 15 extended up to a region in a predetermined distance inwardly of the substrate, and an ungrown section where the epitaxial layer is not formed is present at both ends 2a of the orientation flat 2 when the coating member 15 is removed from the substrate 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor epitaxial wafer and a method for manufacturing the same.

  In order to fabricate a semiconductor device, for example, a compound semiconductor laser element, a vapor phase growth method such as MOVPE (metal organic vapor phase epitaxy) or MBE (molecular beam epitaxy) is used on a semiconductor substrate such as GaAs. Epitaxial wafers are produced by sequentially epitaxially growing compound semiconductor crystals of composition and thickness. The epitaxial wafer is cut into chips along the cleavage plane, and a semiconductor laser element is formed through an element formation process such as etching and electrode formation.

  A substrate used for epitaxial crystal growth of this semiconductor laser element generally has a short line segment called an orientation flat (OF) in order to indicate the crystal orientation of the substrate. FIG. 7 shows a GaAs substrate 1 having such an orientation flat 2. In the case of a Si substrate having a diamond structure, there is no distinction between the front and the back, but in the case of a GaAs substrate having a zinc blende structure, the crystal mesa shape differs between the front and back, so that the orientation flat (OF) 2 showing the cleavage plane Is attached with an index flat (IF) 3 for indicating the direction of the surface at right angles thereto.

  This orientation flat 2 is formed by naturally cleaving a part of the periphery of the circular substrate with a specific crystal plane to form a string of a certain length and exposing the surface along the natural cleavage of the string. The reason why the cleavage plane of the crystal is oriented flat is that, in a semiconductor laser element or the like, the resonant surface needs to have good flatness, and it is used as a reference plane for reasons such as crystal orientation discrimination, alignment, and focusing. A cleavage plane is required. Therefore, when manufacturing a semiconductor laser device, after forming an epitaxial layer or the like on the substrate, it is necessary to accurately cut into a chip along the cleavage plane, and with reference to the orientation flat formed on the cleavage plane, mask alignment or This is because it is important to adjust the angle.

  By the way, in order to determine the crystal orientation strictly in the formation process of the semiconductor laser device, the orientation flat (OF) is formed even after the epitaxial layer of the III-V compound semiconductor is grown on the substrate by the vapor phase growth method. It must be clean and have a mirrored cleavage plane.

  However, conventionally, the raw material comes into contact with the orientation flat portion during epitaxial growth to form crystals, and it is difficult to obtain a clean and mirror-oriented orientation flat portion even after epitaxial growth.

  Therefore, as a means for solving this problem, a method of growing an epitaxial layer in a state where a protective film is formed around the orientation flat of the substrate (wafer) has been proposed (for example, see Patent Document 1).

In this patent document 1, first, in a state where a plurality of round wafers 10 in a bare wafer state shown in the plan view of FIG. 8A and the side view of FIG. Then, as shown in FIG. 8C, a protective film 13 made of a SiO ₂ film is formed around the orientation flat 11 by electron beam evaporation.

Next, as shown in FIG. 8D, an epitaxial crystal growth layer 12 composed of an n-type semiconductor layer and a p-type semiconductor layer is formed on the wafer 10 by using the MOVPE method to form a pn junction. After the crystal growth, the SiO ₂ protective film 13 is removed using hydrofluoric acid (FIG. 8E).

According to the method of Patent Document 1, when the epitaxial crystal growth layer 12 is formed on the wafer 10 by using the MOVPE method, the SiO ₂ protective film 13 is provided on the wafer. Does not grow. Therefore, a crystal growth wafer is obtained in which the peripheral portion of the orientation flat 11 is maintained in the same state as before crystal growth.

  However, in the method of Patent Document 1, a protective film must be formed on the orientation flat portion, and after the growth of a desired epitaxial crystal, the protective film must be removed by etching. In short, the method of Patent Document 1 requires a process for forming and removing a new protective film separately from the conventional manufacturing method. Therefore, a processing facility for realizing the formation and removal of the protective film is necessary, a new equipment investment is required, and the process load increases. In addition, the surface of the substrate may become dirty in the process of removing the protective film by etching.

  Therefore, a method as shown in FIG. 9 is conceivable as a method for increasing the process load as in Patent Document 1 and preventing the surface from becoming dirty. In FIG. 9, reference numeral 1 denotes a GaAs substrate as a III-V group compound semiconductor substrate, and has an orientation flat (OF) 2 in a part of the periphery thereof. This orientation flat 2 is formed by naturally cleaving a part of the periphery of the circular substrate with a specific crystal plane to form a string of a certain length and exposing the surface along the natural cleavage. The GaAs substrate 1 also has an index flat (IF) 3.

  When an epitaxial crystal is grown on the substrate 1 by the MOVPE method (metal organic vapor phase epitaxy), the peripheral portion of the orientation flat 2 (simply referred to as a portion) is the edge of the metal fitting 4 as a covering member as shown in FIG. Concealed in the subregion.

  The metal fitting 4 is made of a rectangular metal plate having a straight edge 4a parallel to the orientation flat 2 portion. The metal can be made of a material that is strong in strength and thermal history and does not react with the raw material used for crystal growth, such as molybdenum, SUS, silicon carbide, and carbon, which are heat resistant materials. Here, a metal plate made of molybdenum is used as the metal fitting 4.

  The rectangular metal fitting 4 is set on a carbon susceptor (not shown), and the metal fitting 4 is fixed with a bolt 5. At this time, as shown in an enlarged view in FIG. 10, the portion of the straight edge 4 a of the metal fitting 4 (the straight edge 4 a portion) is parallel to the orientation flat 2 from the orientation flat 2 of the substrate 1, and The substrate area from the orientation flat 2 to the inside of the substrate 1 at a predetermined distance D is covered. FIG. 10 shows the substrate region up to the predetermined distance D, that is, the covering region A, by hatching. The predetermined distance D for forming the covering region A of the substrate 1 is set to a slight value, for example, on the order of mm or less than 1 mm.

  Thus, with the portion of the orientation flat 2 of the GaAs substrate 1 covered and covered, an epitaxial layer of a III-V compound semiconductor such as Al, Ga, An epitaxial layer of In, As, and P-based semiconductor is grown.

During the growth of the epitaxial layer, the orientation flat 2 portion of the substrate 1 is covered with the metal fitting 4 so that the epitaxial layer is formed on the substrate 1. Therefore, when the metal fitting 4 is removed from the substrate 1, the epitaxial layer is formed. It is possible to form an LD semiconductor epitaxial wafer in which an ungrown portion that is not formed exists in the orientation flat 2 portion. Therefore, the problem that the growth raw material reaches and contacts the orientation flat 2 portion and crystals are formed on the cleavage plane can be solved. As a result, the orientation flat 2 is clean and maintained in a mirror surface.
JP-A-5-55143

  However, in the method described in FIG. 9, the cleanliness of the periphery of the OF can be obtained. However, if the metal fitting 4 that covers the orientation flat 2 portion of the substrate 1 is too large, an epitaxial growth region for element formation on the substrate 1 is formed. There is a problem that the device yield is reduced, and there is a problem that the film thickness of the epitaxial layer becomes thin in the vicinity of the OF, and as a result, the film of the epitaxial layer in the wafer surface in the direction perpendicular to the OF. There is a problem that the thickness distribution becomes worse.

  As described above, according to the embodiment of FIG. 9, the epitaxial layer of the III-V compound semiconductor is grown in a vapor phase in a state where the orientation flat 2 portion of the substrate 1 is covered with the metal fitting 4, so that In addition, the cleavage plane of the orientation flat 2 can be maintained on a clean mirror surface very easily using an existing manufacturing process without requiring a process for forming and removing a new protective film. Thus, there is a problem that the film thickness distribution of the epitaxial layer in the vertical direction is deteriorated, and as a result, the element acquisition yield is lowered.

  In addition, the form which covers the orientation flat 2 of the board | substrate 1 with a coating | coated member is divided roughly into the following two. The first is a form (FIG. 10) in which the orientation flat in a square or circular substrate is covered with a covering member having a straight edge. The second is a form (FIG. 11) in which the orientation flat 2 on the circular substrate is covered with a covering member having a substantially arc-shaped recess edge. In any form, by covering the orientation flat 2 of the substrate 1 with a covering member, it is possible to prevent a problem that a raw material comes into contact with the orientation flat 2 during epitaxial growth and a crystal is formed. Even if this method is used, there is a problem that the film thickness distribution of the epitaxial layer in the direction perpendicular to the OF deteriorates.

  Accordingly, an object of the present invention is to solve the above-mentioned problems and maintain a clean and mirror-oriented orientation flat without requiring a new protective film formation and removal process as in the prior art. An object of the present invention is to provide a semiconductor epitaxial wafer capable of maintaining a good epitaxial film thickness distribution and increasing an element acquisition rate and a method for manufacturing the same.

  According to one aspect of the present invention, a substrate having an orientation flat formed by cleavage and a semiconductor epitaxial layer formed on the substrate is formed, and both ends of the orientation flat of the substrate are predetermined inside the substrate. An epitaxial layer is formed on the substrate in a state where it is covered with a covering member up to a region within a distance, and an ungrown portion where the epitaxial layer is not formed in a state where the covering member is removed from the substrate is the orientation flat. Semiconductor epitaxial wafers present at both ends of the substrate are provided.

  According to another aspect of the present invention, there is provided a method for growing a semiconductor epitaxial layer on a substrate having an orientation flat formed by cleavage, wherein both ends of the orientation flat of the substrate are covered with a covering member. A method for manufacturing a semiconductor epitaxial wafer is provided in which an epitaxial layer is grown by covering up to a region within a predetermined distance inside a substrate.

  According to the present invention, it is possible to manufacture an epitaxial wafer in which the orientation flat can be maintained on a clean mirror surface and the element acquisition efficiency is improved without requiring the steps of forming and removing the protective film as in the conventional example. It becomes possible.

  Embodiments of the present invention will be described below in the case where a semiconductor epitaxial wafer for a laser diode element is manufactured by growing an epitaxial layer of a III-V group compound semiconductor on a GaAs substrate.

  As shown in FIG. 1, the semiconductor epitaxial wafer is composed of a GaAs substrate 1 having an orientation flat 2 formed by cleavage and a semiconductor epitaxial layer formed on the substrate 1. In this semiconductor epitaxial wafer, an epitaxial layer is formed on the substrate 1 in a state where a part of the orientation flat 2 of the substrate 1, for example, both ends 2 a are covered with a covering member up to a region within a predetermined distance inside the substrate. In a state where the member is removed from the substrate 1, an ungrown portion where no epitaxial layer is formed exists at both ends 2 a of the orientation flat 2.

  In such a method of manufacturing a semiconductor epitaxial wafer, a part of the orientation flat 2 of the GaAs substrate 1, for example, both ends 2a are covered with a metal fitting 15 as a covering member. This is because mask alignment or angle alignment can be performed only at both ends 2 a of the orientation flat 2. In a form in which a part of the orientation flat 2 is covered with a covering member, both ends 2a of the orientation flat 2 of the substrate 1 are covered with a metal fitting 15 to a region within a predetermined distance inside the substrate. Then, an epitaxial layer of a III-V compound semiconductor, for example, an epitaxial layer using Al, Ga, In, As, and P elements is formed on the substrate 1 by vapor phase growth, for example, MOVPE, so that a laser diode is formed. A semiconductor epitaxial wafer for the device is manufactured.

  Thus, by covering both ends 2a of the orientation flat 2 of the substrate 1 with the covering member, it is possible to prevent a problem that the raw material contacts the both ends 2a of the orientation flat 2 during the epitaxial growth and crystals are formed. Particularly, since not all of the orientation flat 2 is covered with the covering member, the element yield is improved as compared with the case where the whole is covered.

Moreover, although the case where the epitaxial layer of the III-V group compound semiconductor was grown on the GaAs substrate was explained in the above-mentioned embodiment, the present invention uses a GaN, SiC, sapphire, Si substrate, and a nitride semiconductor. The present invention can also be applied to the formation of the epitaxial layer.
In the above embodiment, the case where the semiconductor epitaxial layer is formed by the MOVPE method has been described. However, in the present invention, the semiconductor epitaxial layer is formed by another vapor phase growth method such as the hydride VPE method or the MBE method. It can also be applied to cases.
Moreover, although the said embodiment demonstrated the case where the semiconductor epitaxial wafer for laser diode elements was produced, it is applicable also to the semiconductor epitaxial wafer for LED elements, for example.

[Example 1]
As a specific example, the manufacturing method of covering both ends of the orientation flat 2 portion of the present invention with a covering member in FIG. 1 was applied to the production of an III-V group compound semiconductor epitaxial wafer having a laser diode structure. The GaAs substrate 1 used has a diameter of about 50 mm (2 inches) and the length of the orientation flat 2 is 16 mm.

  As shown in FIG. 1, rectangular metal fittings 15 were installed so as to cover both end portions of the orientation flat 2 of the substrate 1. The length of the metal fitting 15 and the position of the bolt 5 are designed to be a predetermined distance D = 1 mm from the orientation flat 2 to the inside of the substrate.

With this setting, an epitaxial crystal film of a III-V group compound semiconductor composed of a desired n-type semiconductor layer and a p-type semiconductor layer is sequentially grown on the substrate 1 by the MOVPE method based on the structural design of the laser diode. A pn junction was formed. Any of AsH ₃ , As (CH ₃ ) ₃ , and PH ₃ is used as the group V source, and Al (CH ₃ ) ₃ , Ga (CH ₃ ) ₃ , In (CH ₃ ) ₃ , as the group III source, Either Al (CH ₃ CH ₂ ) ₃ or Ga (CH ₃ CH ₂ ) ₃ was used. At this time, the substrate temperature during growth was set to 650 ° C., the pressure in the growth furnace was set to about 6,650 Pa (50 Torr), and the temperature was raised, the temperature was increased, the interval, and the raw material flow rate were changed in order to sequentially grow a desired crystal film.

  The orientation flat 2 surface of each substrate 1 on which the epitaxial crystal film was grown in this way was observed. As a result, both ends of the orientation flat 2 had extremely clean cleavage planes even after the growth of the crystal film. I kept it.

FIG. 2 shows the film thickness measurement results of the epitaxial crystal film in the direction perpendicular to the OF in Example 1. The vertical axis in FIG. 2 represents the thickness of the epitaxial crystal film. The horizontal axis in FIG. 2 represents the distance on the substrate from the orientation flat 2 toward the inner side of the substrate 1 (different from the predetermined distance D). In a substrate region from a distance of 0 to 25 mm (approximately the center of the substrate), measurement was performed at 3 mm, 7 mm, and 22 mm, and it was confirmed that the target epitaxial crystal film thickness was approximately 550 nm at each position. That is, there is no adverse effect such as a decrease in film thickness near the periphery of the metal fitting 15. That is, since both ends 2a of the orientation flat 2 are covered with the covering member 15, the elements on the substrate 1 are compared with those of Comparative Examples 1 and 2 in which the entire peripheral portion of the orientation flat 2 is covered with the covering member. The epitaxial growth region for formation increases and the device yield can be improved.
[Example 2]

In Example 1, the fixing method of the substrate 1 was not particularly limited. However, in the MOVPE method, a face-up method in which the crystal growth surface (surface) of the substrate is fixed upward, and the crystal growth surface of the substrate is downward. There is a face-down method to fix so that. In the face-down method, since the substrate cannot be supported by the susceptor, a substrate holding metal fitting is required as a substrate holding member. On the other hand, the face-up method can support the substrate on the susceptor and does not require a substrate holding bracket. Here, a second embodiment applied to the face-down method will be described.
In the conventional MOVPE method, as shown in FIG. 3, the substrate 1 accommodated in the susceptor is held at its outer peripheral portion by substrate holding metal fittings 9 as three substrate holding members made of metal fittings. In Example 2 shown in FIG. 4, two of the substrate holding metal fittings 9 are additionally disposed as covering members at positions corresponding to both ends of the orientation flat 2 so as to conceal both ends 2 a of the orientation flat 2. In this case, as shown in FIG. 4, the two board holding metal fittings 9 a close to the orientation flat 2 in the original board holding metal fittings 9 are deformed to be smaller than the other board holding metal fittings 9. May be. This is because the two ends 2a of the orientation flat 2 are held by the two board holding brackets 9, so that there is no problem in stability in holding the board 1.

[Comparative Example 1]
FIG. 9 shows Comparative Example 1. In the comparative example 1, the covering member 4 is arranged on the entire orientation flat 2 so that the entire orientation flat 2 is covered.
According to Comparative Example 1, since the entire peripheral portion of the orientation flat 2 was covered with the covering member, the cleanliness at the peripheral portion of the OF was obtained.
However, the film thickness measurement result of the epitaxial crystal film in the direction perpendicular to the OF of the epitaxial wafer manufactured in Comparative Example 1 is as shown in FIG. The horizontal axis in FIG. 5 represents the distance on the substrate from the orientation flat 2 toward the inside of the substrate 1 (different from the predetermined distance D). In the substrate region from a distance of 0 to 25 mm (approximately the center of the substrate), measurement was performed at 3 mm, 7 mm, and 22 mm positions. Thus, it was confirmed that the film thickness was greatly shifted in the vicinity of the OF. That is, it was found that the epitaxial film thickness in the vicinity of the OF is extremely thin due to the metal fitting 4, and this region cannot be used as an element, and the element acquisition efficiency is greatly reduced.
[Comparative Example 2]

  FIG. 11 shows Comparative Example 2. In this configuration, the orientation flat 2 portion of the circular substrate is covered with a metal fitting 6 as a covering member made of a metal plate made of molybdenum having a substantially arc-shaped recess edge as a covering member.

  FIG. 6 shows the shape of the recess edge of the metal fitting 6. The concave edge of the metal fitting 6 has a substantially arcuate shape having a linear portion 7a and an arc portion 7b by cutting the straight edge 4a of the rectangular metal fitting 4 shown in FIG. 10 inward by the maximum depth d1. The shape is formed on the edge of the recess.

As shown in FIG. 11, the metal fitting 6 of this embodiment is a straight line comprising a straight part 7a parallel to the orientation flat 2 part of the substrate 1 and a circular arc part 7b connected to both sides of the straight part at the point p. It has an arcuate edge 7. Here, the arc portion 7b may be an inclined line along the arc. The straight-arc-shaped edge 7 is a straight-arc-shaped substrate having a straight portion 8a of the orientation flat 2 on the substrate 1 and a slightly long arc portion 8b connected to both sides of the straight portion at the point S. The shape is adapted to the edge 8 of the.
A straight-arc-shaped edge 7 is formed in a similar shape to the straight-arc-shaped edge 8 of the substrate 1. Since the straight line-arc-shaped edge 7 of the metal fitting 6 is shifted and overlapped in parallel with the straight-arc-shaped edge 8 of the orientation flat 2, the arc portion 7 b of the straight-arc-shaped edge 7 of the metal fitting 6 is formed on the substrate 1. The straight line-arc-shaped edge 8 intersects the arc portion 8b at the edge 8 instead of being parallel.

  By the straight-arc-shaped edge 7 of the metal fitting 6 formed as described above, from the orientation flat 2 of the substrate to a predetermined distance d2 slightly inside the substrate and to a predetermined distance D of the intersection near the both ends of the orientation flat 2. The substrate region is covered with a substantially similar shape. FIG. 11 shows a substrate region, that is, a covering region B, which is covered by the straight-arc-shaped edge 7 of the metal fitting 6 at the shaded portion.

  According to the comparative example 2, the straight line-arc-shaped edge 7 of the metal fitting 6 causes the substrate region (for example, the coating distance shown in FIG. 11) to be slightly inside the substrate from the orientation flat 2 portion of the substrate, for example, a predetermined distance d2 = about 0.5 mm. Since the area B) is obscured, the orientation flat 2 can be obscured more evenly compared to the case of covering up to the predetermined distance D using the metal fitting 4 having the parallel linear edges 4a as shown in FIG. it can. However, although the epitaxial film thickness distribution in the direction perpendicular to the OF was slightly improved as compared with Comparative Example 1, a region that could not be used as an element in the vicinity of the OF still occurred, resulting in a decrease in element acquisition efficiency.

  Hereinafter, preferred embodiments of the present invention will be additionally described.

The first aspect includes a substrate having an orientation flat formed by cleavage and a semiconductor epitaxial layer formed on the substrate, and both ends of the orientation flat of the substrate enter a predetermined distance inside the substrate. An epitaxial layer is formed on the substrate in a state of being covered with a covering member up to a region, and an ungrown portion where the epitaxial layer is not formed in a state where the covering member is removed from the substrate is at both ends of the orientation flat. It is an existing semiconductor epitaxial wafer.
Since the epitaxial layer of the semiconductor is formed by covering both ends of the orientation flat of the substrate to a region within a predetermined distance inside the substrate using a covering member, formation of a protective film as in the conventional example, Without requiring a removal step, the orientation flat portion can be maintained on a clean mirror surface, and an epitaxial wafer with improved element acquisition efficiency can be manufactured.

A second aspect is the semiconductor epitaxial wafer according to the first aspect, wherein the predetermined distance is about 0.5 mm to 1.0 mm.
Since the predetermined distance is about 0.5 mm to 1.0 mm, it is possible to secure a large effective element creation region.

In a third aspect, the semiconductor epitaxial wafer of the first aspect or the second aspect is a group III-V compound semiconductor epitaxial wafer for a laser diode, and the substrate is a GaAs substrate, on the GaAs substrate, This is a semiconductor epitaxial wafer in which an epitaxial layer using Al, Ga, In, As, and P elements is formed by a vapor phase growth method.
When the semiconductor epitaxial wafer is a group III-V compound semiconductor epitaxial wafer for a laser diode, it is particularly required that the orientation flat portion be maintained in a clean mirror surface. According to the present invention, this requirement is met. be able to.

A fourth aspect is a method of growing an epitaxial layer of a semiconductor on a substrate having an orientation flat formed by cleavage, wherein both ends of the orientation flat of the substrate are predetermined inside the substrate using a covering member. This is a method for manufacturing a semiconductor epitaxial wafer in which an epitaxial layer is grown by covering up to a region within a distance.
Since both ends of the orientation flat are covered with the covering member, the device yield is improved compared to the case where the whole is covered, and the substrate holding member is used for the covering member, and the configuration is simple. Become.

A fifth aspect is a method of manufacturing a semiconductor epitaxial wafer according to the fourth aspect, wherein the covering member is a substrate holding member that holds the substrate.
Since the substrate holding member is used as the covering member, the method is simpler than the method in which the covering member is prepared separately.

A sixth aspect is a method for manufacturing a semiconductor epitaxial wafer according to the fourth or fifth aspect, wherein the predetermined distance is about 0.5 mm to 1.0 mm.
Since the predetermined distance is about 0.5 mm to 1.0 mm, it is possible to secure a large effective element creation region.

In a seventh aspect, the semiconductor epitaxial wafer according to the fourth to sixth aspects is a method for producing a group III-V compound semiconductor epitaxial wafer for LD, wherein the substrate is a GaAs substrate, and on the GaAs substrate, This is a method for manufacturing a semiconductor epitaxial wafer in which an epitaxial layer using Al, Ga, In, As, and P elements is formed by a vapor phase growth method.
When the semiconductor epitaxial wafer is a group III-V compound semiconductor epitaxial wafer for LD, it is particularly required that the orientation flat portion be maintained in a clean mirror surface. According to the present invention, this requirement is met. Can do.

An eighth aspect is a method for manufacturing a semiconductor epitaxial wafer according to any one of the fourth to seventh aspects, wherein the covering member is formed of a heat resistant material made of any one of molybdenum, SUS, silicon carbide, and carbon. .
Since the covering member is made of a heat resistant material such as molybdenum, contamination of the epitaxial layer can be effectively prevented.

In the ninth aspect, when an epitaxial layer of a group III-V compound semiconductor is grown by vapor deposition on a substrate having an orientation flat formed by cleavage, both end portions of the orientation flat of the substrate are covered with a covering member. It is a manufacturing method of the III-V compound semiconductor epitaxial wafer which covers.
By covering both end portions of the orientation flat of the substrate with the covering member, it is possible to prevent the problem that the raw material comes into contact with the orientation flat portion during epitaxial growth and crystals are formed.

It is the top view which showed Example 1 of this invention. It is a figure which shows the evaluation result of the film thickness at the time of forming an epitaxial crystal film with the manufacturing method of Example 1 of this invention. It is a top view which shows the substrate holding state in the conventional crystal growth method. It is the top view which showed Example 2 of this invention. It is a measurement result of comparative example 1. It is the top view which showed the outline of the metal fitting as a coating | coated member used in the comparative example 2 of this invention. It is the top view which showed the shape of the board | substrate used for the epitaxial crystal growth of a semiconductor laser element. It is process drawing which shows the manufacturing method of the conventional III-V group compound semiconductor. It is the top view which shows the manufacturing method in the comparative example 1 of this invention, and shows the state which covered the orientation flat with the metal fittings as a rectangular covering member during growth. It is the elements on larger scale which show the state which covered the orientation flat with the metal fitting as a coating | coated member used in the comparative example 1 of this invention. It is the elements on larger scale which showed the comparative example 2 of this invention, and showed the form which covered the orientation flat with the metal fitting as a coating | coated member which has a recessed part edge during growth.

Explanation of symbols

1 Substrate 2 Orientation flat (OF)
3 Index flat (IF)
4 Bracket (Coating material)
4a Straight edge 5 Bolt 6 Metal fitting (covering member)
7 linear-arc-shaped edge 7a linear-shaped portion 7b circular-arc portion 8 linear-arc-shaped edge 8a linear-shaped portion 8b circular-arc portion 15 coating member A coating region B coating region D predetermined distance d2 predetermined distance P continuous contact S continuous point

Claims (8)

A substrate having an orientation flat formed by cleavage, and a semiconductor epitaxial layer formed on the substrate,
An epitaxial layer is formed on the substrate in a state where both ends of the orientation flat of the substrate are covered with a covering member up to a region within a predetermined distance to the inside of the substrate, and the covering member is removed from the substrate. A semiconductor epitaxial wafer in which an ungrown portion in which no epitaxial layer is formed exists at both ends of the orientation flat. The semiconductor epitaxial wafer according to claim 1,
A semiconductor epitaxial wafer in which the predetermined distance is about 0.5 mm to 1.0 mm. The semiconductor epitaxial wafer according to claim 1 or 2 is a III-V group compound semiconductor epitaxial wafer for a laser diode,
The substrate is a GaAs substrate;
A semiconductor epitaxial wafer in which an epitaxial layer using Al, Ga, In, As, and P elements is formed on this GaAs substrate by a vapor phase growth method. A method of growing a semiconductor epitaxial layer on a substrate having an orientation flat formed by cleavage,
A method of manufacturing a semiconductor epitaxial wafer, wherein an epitaxial layer is grown by covering both ends of an orientation flat of the substrate to a region within a predetermined distance inside the substrate using a covering member. In the manufacturing method of the semiconductor epitaxial wafer of Claim 4,
A method for manufacturing a semiconductor epitaxial wafer, wherein the covering member is a substrate holding member for holding the substrate. In the manufacturing method of the semiconductor epitaxial wafer of Claim 4 or 5,
A method for producing a semiconductor epitaxial wafer, wherein the predetermined distance is about 0.5 mm to 1.0 mm. The semiconductor epitaxial wafer according to any one of claims 4 to 6 is a method for producing a group III-V compound semiconductor epitaxial wafer for a laser diode,
The substrate is a GaAs substrate;
A method of manufacturing a semiconductor epitaxial wafer in which an epitaxial layer using Al, Ga, In, As, and P elements is formed on this GaAs substrate by a vapor phase growth method. In the manufacturing method of the semiconductor epitaxial wafer in any one of Claim 4 thru | or 7,
A method for manufacturing a semiconductor epitaxial wafer, wherein the covering member is formed of a heat-resistant material made of any one of molybdenum, SUS, silicon carbide, and carbon.

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