Semiconductor laser and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9979159-B2
Application number	US-201514873659-A
Country	US
Kind code	B2
Filing date	Oct 2, 2015
Priority date	Oct 31, 2014
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

In a semiconductor laser, a block layer is provided on both sides of a mesa-type semiconductor part having an n-type cladding layer, an active layer, and a p-type cladding layer. The block layer has: a p-type block layer formed on the side surface of the mesa-type semiconductor part and over a p-type semiconductor substrate; a high-resistance layer formed over the p-type block layer; and an n-type block layer formed over the high-resistance layer, which has a higher resistance than that of the p-type block layer. By providing the high-resistance layer between the p-type block layer and the n-type block layer, the thickness of the p-type block layer can be controlled and a leakage current (flow of a hole) can be reduced. Further, the distance between the n-type cladding layer and the n-type block layer can be secured, and hence a leakage current (flow of an electron) can be prevented.

First claim

What is claimed is:

1. A semiconductor laser comprising:
a p-type semiconductor substrate;
a convex part provided over the semiconductor substrate;
a block layer provided on both sides of the convex part;
wherein the convex part has:
a p-type compound semiconductor layer formed over the semiconductor substrate;
an active layer formed over the p-type compound semiconductor layer; and
an n-type compound semiconductor layer formed over the active layer, and
wherein the block layer includes:
a p-type block layer including a p-type compound semiconductor formed over a side surface of the convex part and over the semiconductor substrate;
a first resistive layer formed over the p-type block layer;
an n-type block layer including an n-type compound semiconductor formed over the first resistive layer; and
a second resistive layer formed over the n-type block layer that contacts and covers a portion of the n-type compound semiconductor layer,
wherein the first resistive layer has a resistance larger than that of the p-type block layer, and
wherein the n-type compound semiconductor layer covers entire side surfaces of the active layer and a portion of side surfaces of the p-type compound semiconductor layer formed over the substrate.

2. The semiconductor laser according to claim 1 ,
wherein the first resistive layer is a compound semiconductor into which Fe (iron) has been introduced.

3. The semiconductor laser according to claim 1 ,
wherein the second resistive layer is a compound semiconductor into which Fe (iron) has been introduced.

4. The semiconductor laser according to claim 1 ,
wherein a thickness of the p-type block layer is 0.2 μm or less.

5. The semiconductor laser according to claim 1 ,
wherein a thickness of the p-type block layer is 0.1 μm or less.

6. The semiconductor laser according to claim 1 ,
wherein each of the p-type compound semiconductor layer and the p-type block layer is InP including a p-type impurity, and
wherein each of the n-type compound semiconductor layer and the n-type block layer is InP including an n-type impurity, and
wherein the first resistive layer is InP into which Fe (iron) has been introduced.

7. The semiconductor laser according to claim 1 comprising:
a layer including an n-type compound semiconductor formed over the convex part and the block layer,
wherein a first electrode is formed above the layer, and
wherein a second electrode is formed in a rear surface of the semiconductor substrate.

8. The semiconductor laser according to claim 1 ,
wherein the block layer includes a semiconductor layer selectively grown over the semiconductor substrate.

Assignees

• Renesas Electronics Corp

Inventors

• Okuda Tetsuro

Classifications

• H01S5/2224

  semi-insulating semiconductors · CPC title

• H01S2304/04

  MOCVD or MOVPE · CPC title

• H01S5/06226

  Modulation at ultra-high frequencies · CPC title

• H01S5/2275 Primary

  mesa created by etching · CPC title

• H01S5/222

  having a refractive index lower than that of the cladding layers or outer guiding layers · CPC title