JP2008016772A - Nitride semiconductor substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nitride semiconductor substrate which identifies kinds of articles. <P>SOLUTION: The nitride semiconductor substrate 1 has a principal surface of (0001) plane, and includes on an outer periphery an arcuate part 2 and an orientation flat 3. The substrate further includes a kind-of-article identification flat 4 formed between the arcuate part 2 and the orientation flat 3 and having an angle with respect to the orientation flat 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a nitride semiconductor substrate capable of identifying a product type.

  A nitride semiconductor substrate (GaN single crystal substrate) used for a blue semiconductor laser, a blue / blue-violet light emitting diode, or the like is basically formed with a circular outer periphery. However, in the device process, a straight line portion called an orientation flat is formed when it is necessary to recognize a cleavage plane (for example, (1-100) plane). That is, as shown in FIGS. 2A and 2B, the nitride semiconductor substrates 21a and 21b are formed with arc-shaped portions 22 and orientation flats 23a and 23b on the outer periphery.

  In the device process, the cleavage planes can be recognized and positioned by using the orientation flats 23a and 23b as a reference.

JP 2002-222746 A

  By the way, depending on the device manufacturer, the nitride semiconductor substrate 21a having the orientation flat 23a formed on the cleavage plane as shown in FIG. Nitride semiconductor substrate 21b (B) formed on a plane (for example, (11-20) plane) perpendicular to the cleavage plane as shown in FIG. 2B. I want to call it a type).

  In response to the demands of each device manufacturer, the substrate manufacturer manufactures A-type and B-type nitride semiconductor substrates having different orientation flat orientations. As described above, two or more kinds of nitride semiconductor substrates having different orientation flat orientations exist. The two types of nitride semiconductor substrates 21a and 21b shown in the figure have the same diameter and circumference of the arc-shaped portion 22, and the lengths of the orientation flats 23 and 23b, and there is no difference in appearance.

  The substrate manufacturer identifies nitride semiconductor substrates 21a and 21b of different varieties, manufactures record slips bundled with the nitride semiconductor substrates 21a and 21b, containers for storing the nitride semiconductor substrates 21a and 21b, nitrides This can be done by dividing the location where the semiconductor substrates 21a and 21b are stored.

  However, it is difficult for the device manufacturer to identify the type of the nitride semiconductor substrates 21a and 21b (which are called actual substrates) taken out from the package or container. Even a board manufacturer cannot distinguish the type of the actual board by itself.

  Accordingly, an object of the present invention is to provide a nitride semiconductor substrate that can solve the above-described problems and that can identify the type.

  In order to achieve the above object, the present invention provides a nitride semiconductor substrate having a (0001) plane as a main surface and an arcuate portion and an orientation flat formed on the outer periphery, the gap between the arcuate portion and the orientation flat. A product identification flat having an angle with respect to the orientation flat is formed.

  The product identification flat may have a length of 2 mm or more.

  The angle may be 140 degrees to 160 degrees.

  The orientation flat may be formed on a cleavage plane.

  The orientation flat may be formed on a plane perpendicular to the cleavage plane.

  The present invention exhibits the following excellent effects.

  (1) The product type can be identified.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1A, a nitride semiconductor substrate 1 according to the present invention is a nitride semiconductor substrate having a main surface of (0001) plane and an arcuate portion 2 and an orientation flat 3 formed on the outer periphery. In FIG. 1, a product identification flat 4 having an angle with respect to the orientation flat 3 is formed between the arc-shaped portion 2 and the orientation flat 3.

  The product type identification flat 4 is a straight line portion like the orientation flat 3 and is formed separately from the orientation flat 3 for the purpose of product type identification.

  In this embodiment, the orientation flat 3 is formed on a (11-20) plane that is a plane perpendicular to the (1-100) plane that is a cleavage plane. That is, this nitride semiconductor substrate is a B type defined in this specification.

  In this embodiment, the product type identification flat 4 is formed between the counterclockwise end of the orientation flat 3 and the arcuate portion 2.

  FIG. 1B shows an enlarged view of the vicinity of the product type identification flat 4. Since it is reduced in FIG. 1 (a), it is difficult to visually determine where and how the product identification flat 4 is formed, but in FIG. 1 (b) it is enlarged, so the product identification flat 4 is linear. The details such as the fact that the product identification flat 4 has an angle with respect to the orientation flat 3 are clearly visible.

  In the actual nitride semiconductor substrate 1, the product type identification flat 4 can be easily visually recognized, and the product type identification flat 4 can be detected by a known technique such as an optical sensor or a mechanical sensor of a device process apparatus.

  The length of the product identification flat 4 is preferably 2 mm or more. This is to make it easier to see when the type is visually identified. If it is less than 2 mm, it may be difficult to visually identify the variety due to individual differences such as skill level and visual acuity.

  The angle of the product identification flat 4 with respect to the orientation flat 3 is preferably 140 to 160 degrees. The reason why the angle is set to 160 degrees or less is to make it easy to see when the type is visually identified. When the angle exceeds 160 degrees, the orientation flat 3 and the product identification flat 4 are close to a straight line, and it may be difficult to identify the product visually. The reason why the angle is 140 degrees or more is to prevent the substrate area from being reduced by forming the product type identification flat 4.

  With the above configuration, the nitride semiconductor substrate 1 of the present invention has the following operational effects.

  The nitride semiconductor substrate 1 of the present invention has a product type identification flat 4 formed, and since this product type identification flat 4 can be confirmed visually or with a sensor, the conventional nitride semiconductor substrate in which the product type identification flat 4 is not formed Can be distinguished.

  Furthermore, in the nitride semiconductor substrate 1 of the present invention, the product type identification flat 4 is formed between the arcuate portion 2 and the orientation flat 3, and the product type identification flat 4 has an angle with respect to the orientation flat 3. Therefore, the difference in shape between both flats becomes remarkable, and it is easy to confirm visually or with a sensor.

  In this embodiment, since the product type identification flat 4 is formed on the B-type nitride semiconductor substrate 1 in which the orientation flat 3 is formed on the (11-20) plane, the actual substrate of the nitride semiconductor substrate 1 is A viewer (or a device process apparatus) can identify that the actual product substrate is the nitride semiconductor substrate 1 of the present invention and at the same time identify that the product type is B type.

  On the other hand, when the type identification flat is formed on the A type nitride semiconductor substrate having the orientation flat formed on the (1-100) plane, the type of the actual substrate of the nitride semiconductor substrate is A type. Can be identified. Of course, if the same type identification flat is formed on the A-type and B-type nitride semiconductor substrates, the two types cannot be discriminated, but the type identification flat 4 is provided at the counterclockwise end of the orientation flat 3 in the B type. If a product type identification flat (not shown) is formed at the clockwise end of the orientation flat 3 in the A type, the present invention can be applied to both types, and discrimination between both types can be performed.

  Furthermore, the nitride semiconductor substrate 1 of the present invention can be manufactured by making it easy to identify the type of the actual substrate by the device manufacturer as well as reducing the work mistakes such as the mistake of the type of the substrate manufacturer. It can be used to improve the efficiency of process management such as recording slips, containers and storage locations.

  Further, although the purpose is different from the type identification, the nitride semiconductor substrate 1 in which the type identification flat 4 of the present invention is formed in the nitride semiconductor substrate having the double-sided mirror finish is positioned in the type identification flat 4 (orientation). The front and back can be discriminated by the relative position with respect to the flat 3. Thereby, the index flat conventionally provided in the double-sided mirror finish substrate can be eliminated, and thereby the effective area of the nitride semiconductor substrate can be increased.

  In addition, when performing product type identification with a nitride semiconductor substrate having a double-sided mirror finish, front / back identification is performed using an index flat, and product type identification is performed using a product type identification flat 4.

(A) is a top view of the nitride semiconductor substrate which shows one Embodiment of this invention, (b) is the principal part enlarged view in the broken-line circle | round | yen. (A), (b) is a top view of the conventional nitride semiconductor substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nitride semiconductor substrate 2 Arc-shaped part 3 Orientation flat 4 Kind identification flat

Claims (5)

  A nitride semiconductor substrate having a main surface of the (0001) plane and an arcuate portion and an orientation flat formed on the outer periphery, and a product having an angle with respect to the orientation flat between the arcuate portion and the orientation flat A nitride semiconductor substrate having an identification flat formed thereon.   2. The nitride semiconductor substrate according to claim 1, wherein a length of the product type identification flat is 2 mm or more.   The nitride semiconductor substrate according to claim 1 or 2, wherein the angle is set to 140 to 160 degrees.   The nitride semiconductor substrate according to claim 1, wherein the orientation flat is formed on a cleavage plane. 4. The nitride semiconductor substrate according to claim 1, wherein the orientation flat is formed on a plane perpendicular to the cleavage plane.

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