Optical semiconductor device and method for fabricating the optical semiconductor device

Patent metadata

Field	Value
Publication number	US-9184558-B2
Application number	US-201414331158-A
Country	US
Kind code	B2
Filing date	Jul 14, 2014
Priority date	Mar 19, 2010
Publication date	Nov 10, 2015
Grant date	Nov 10, 2015

Abstract

An optical semiconductor device, includes: a plurality of first diffraction grating layers disposed at a spacing from each other along first direction above first semiconductor layer, length of a lower surface of each of a plurality of first diffraction gratings along first direction being longer than a length of an upper surface of first diffraction grating; second diffraction grating layer disposed along first direction above first semiconductor layer, first and second diffraction grating layers being alternately disposed at a spacing from each other, a length of an upper surface of second diffraction grating layer along first direction being longer than the length of a lower surface of second diffraction layer; a diffraction grating including first and second diffraction grating layers; a second semiconductor layer disposed between first and second diffraction grating layers and under second diffraction grating layer; and third semiconductor layer disposed on first and second diffraction grating layers.

First claim

What is claimed is:

1. An optical semiconductor device, comprising:
a first semiconductor layer including a plurality of first grooves and a plurality of ridges formed along a first direction, each of the plurality of first grooves being between the ridges;
a plurality of first diffraction grating layers disposed at a spacing from each other along the first direction above the first semiconductor layer, the width of a lower surface of each of the plurality of first diffraction gratings along the first direction being wider than or equal to the width of an upper surface of the first diffraction grating;
a second diffraction grating layer disposed along the first direction, the first and second diffraction grating layers being alternately disposed at a spacing from each other, the width of an upper surface of the second diffraction grating layer along the first direction being wider than the width of a lower surface of the second diffraction layer;
a diffraction grating including the first and the second diffraction grating layers;
a second semiconductor layer disposed between the first and the second diffraction grating layers and under the second diffraction grating layer, the second semiconductor layer having a refractive index different from any of the first and the second diffraction grating layers and being contact with the upper surface of the first diffraction grating layers, wherein the second diffraction grating layer is disposed in second grooves in the second semiconductor layer, the second grooves in the second semiconductor layer being above the first grooves; and
a third semiconductor layer disposed over the first and the second diffraction grating layers, the third semiconductor layer having a refractive index different from any of the first and the second diffraction layers, the third semiconductor layer being in contact with the upper surface of the second diffraction grating layers.

2. The optical semiconductor device according to claim 1 , wherein sides of each of the plurality of the first diffraction grating layers is a plane indicated by (111) A plane or (011) plane.

3. The optical semiconductor device according to claim 1 , wherein quantum dots are disposed below the diffraction grating.

4. The optical semiconductor device according to claim 1 , wherein an intermediate semiconductor layer is disposed between the first and the second diffraction grating layers, the intermediate semiconductor layer being disposed on the upper surface of the first diffraction layers, and under the lower surface of the second diffraction layers, and wherein the intermediate semiconductor layer includes a surface joining a side of the second diffraction layer, and the surface is a plane indicated by (311) A plane.

5. The optical semiconductor device according to claim 1 , wherein the first and the second diffraction grating layers are made of a compound semiconductor containing phosphorous.

Assignees

• Fujitsu Ltd

Inventors

• Matsumoto Takeshi

Classifications

• H10P14/3444

  P-type · CPC title

• H10P14/3442

  N-type · CPC title

• H10P14/3421

  Arsenides · CPC title

• H10P14/3256

  Microstructure · CPC title

• H10P14/3252

  Alternating layers, e.g. superlattice · CPC title