JPH11238913A - Semiconductor light-emitting device chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of elements and simplify the manufacturing process by the omission of etching steps for forming electrodes and eliminating the loss of a sapphire substrate at this part in a structure of a nitride semiconductor single-crystal layer utilized for light-emitting devices, such as infrared and blue light-emitting diodes, and laser diodes. SOLUTION: In a nitride semiconductor single crystal having a GaN layer laminated on a sapphire substrate 11 by chemical vapor deposition, the sapphire substrate and a GaN buffer layer 12 are ground and removed, an n-type electrode 8 is formed on the exposed n-type GaN buffer layer 8 and p-type electrode 7 and the n-type electrode 8 are formed on the opposite end faces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a nitride semiconductor single crystal layer used for a light emitting device such as an ultraviolet, blue light emitting diode, and a laser diode.

[0002]

2. Description of the Related Art As a blue light emitting device, recently, a gallium nitride-based compound semiconductor has been put to practical use to exhibit excellent light emission at room temperature. As the structure of the blue light-emitting device, the structure of an InGaN single quantum well blue LED is such that a GaN buffer layer is grown on the C-plane of the sapphire substrate 1 as shown in FIG. As the active layer, an InGaN layer 4, a p-type AlGaN layer 5, and a p-type GaN layer 6 doped with Si and Zn as donors and acceptors are sequentially vapor-phase grown, and then a part of the p-type GaN layer 6 is replaced with an n-type. GaN layer 3
Are etched until p is exposed, and p-type GaN6, n-type GaN3
Then, a p-type electrode 7 and an n-type electrode 8 are formed on the surface, respectively, and then this chip is placed on a lead frame and molded with epoxy to complete a light emitting element.

As the same blue light emitting device, a similar gallium nitride compound is vapor-phase grown on a conductive SiC substrate instead of a sapphire substrate as an insulator,
A nitride semiconductor single crystal in which an n-type electrode is formed on an end surface facing a p-type electrode has been proposed.

[0004]

However, in this structure, in order to form an n-type electrode, part of the p-type GaN is replaced with an n-type electrode.
Etching must be performed until GaN is exposed, and this portion wastes the sapphire substrate and requires an etching step, resulting in a problem that the element is increased in size and the number of manufacturing steps is increased.

[0005]

According to the present invention, since a sapphire substrate as an insulator is present, a part of a vapor growth layer is removed to form an n-type GaN layer as a conductive layer. In a nitride semiconductor single crystal in which a gallium nitride layer is stacked on a sapphire substrate by vapor phase growth, the sapphire substrate and the GaN buffer layer are all removed by grinding, and the exposed n-type GaN surface An n-type electrode is formed on
This is a semiconductor light emitting device chip having a structure in which a mold electrode and an n-type electrode are formed on both opposite end faces.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a semiconductor light emitting device chip according to the present invention is shown in FIG.
A 200 nm GaN buffer layer 22 is formed on the surface, then a 4 μm Si-doped n-type GaN layer 33 is grown, followed by a 0.1 μm Si-doped n-type InGaN active layer 44, and then a Mg layer. The p-type cladding layer 55 made of doped p-type AlGaN is
grow μm. By forming the p-type GaN layer 66 doped with Mg, it becomes a base material of the gallium nitride-based compound semiconductor.

Sapphire substrate 11 and GaN buffer layer 22
Grinding method of p-type on the opposite side of sapphire substrate
The sapphire base is adhered to the GaN layer 66 with a wax-based bond, and then the sapphire substrate 11 is removed by grinding and polishing while leaving the sapphire substrate 11 at 0.05 μm.
It is formed so that the layer 33 is exposed. And adjust the thickness to 0.01
By applying a thickness of not more than μm, parallelism is obtained, and thereafter, an n-type electrode 8 and a p-type electrode 7 are formed, and divided and separated into chips to obtain a light-emitting element.

[0008]

As described above, according to the present invention, the portion where the n-type electrode is formed can be moved from the side of the n-type GaN and the sapphire substrate can be removed, so that the thickness can be greatly reduced and the whole chip can be miniaturized. Since the formation of the n-type electrode portion is not required, the required area of the sapphire substrate is reduced, and the yield from one substrate is improved.

Further, the whole substrate is epitaxially grown.
After the formation of the GaN layer, the insulating portion including the sapphire substrate is removed by grinding, and after cutting and dividing into chip pieces, the upper and lower electrode layers may be formed, so that the manufacturing process can be simplified and such a structure can be achieved. Therefore, the current flow does not bend to the conventional n-type electrode portion and can be made uniform, so that a favorable effect on light emission can be expected, and the life of the light emitting element can be extended.

[Brief description of the drawings]

FIG. 1 is a schematic view of a nitride semiconductor single crystal layer of the present invention.

FIG. 2 is a schematic view of a conventional nitride semiconductor single crystal layer.

[Explanation of symbols]

 1,11 sapphire substrate 2,12 GaN buffer layer 3,13 n-type GaN barrier layer 4,14 InGaN layer 5,15 p-type AlGaN layer 6,16 p-type GaN 7 p-type electrode 8 n-type electrode

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 19, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor light emitting device chip according to the present invention has a structure in which a GaN buffer layer 12 is formed on a C-plane of a φ7 ″ sapphire substrate 200 at 200 ° as shown in FIG. A layer 13 is grown to a thickness of 4 μm, followed by a Si-doped n-type InGaN active layer 14.
Formed at 0.1 μm and then p-type AlG doped with Mg
A p-type cladding layer 15 made of aN is grown by 0.2 μm. By forming the p-type GaN layer 16 doped with Mg, it becomes a base material of the gallium nitride-based compound semiconductor.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

As a method of grinding and removing the sapphire substrate 11 and the GaN buffer layer 12 , a sapphire base is bonded to the p-type GaN layer 16 on the opposite side of the sapphire substrate with a wax-based bond, and then the sapphire substrate 11 is 0.05 μm thick.
After grinding , the remaining sapphire substrate 11 and GaN buffer layer 12 are removed by further polishing, and n
The GaN layer 13 is formed so as to be exposed. Then, the thickness is corrected to 0.01 μm or less to obtain a degree of parallelism. Thereafter, the n-type electrode 8 and the p-type electrode 7 are formed, and the light-emitting element is obtained by dividing and separating into chips.

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuru Watanabe 3-8-22 Nitta, Adachi-ku, Tokyo Namiki Seiki Co., Ltd.

Claims (1)

[Claims] 1. In a nitride semiconductor single crystal in which a gallium nitride layer is laminated on a sapphire substrate by vapor phase growth, the sapphire substrate and the GaN buffer layer are removed by grinding.
An n-type electrode is formed on the exposed n-type GaN surface,
A semiconductor light-emitting device chip, wherein a mold electrode is formed on both end faces facing each other.