US 7,627,009 B2 · Light-emitting device on n-type InP substrate heavily doped with sulfur

Abstract

The present invention provides a structure of a light-emitting device which prevents the inter diffusion of impurities from the high-doped n-type InP substrate to a p-type current blocking layer. The substrate of the invention is highly doped with sulfur (S) to obtain high quality surface whose etch pit density (EPD) is less than 100 cm−2. The device includes such substrate, an optical guiding portion with an active layer, and a current blocking portion provided so as to bury the guiding portion. This current blocking portion includes, from the side of the substrate, a p-type layer, an n-type layer and another p-type layer. The device of the invention provides an n-type layer that is moderately doped with silicon between the n-type substrate and the p-type current blocking layer to prevent the inter diffusion of impurities from the substrate to the p-type layer.

Claims10

Dependent claims

A light-emitting device, comprising:

an n-type InP substrate doped with sulfur and having an etch pit density less than 100 cm−2 at a primary surface thereof;
an optical guiding portion provided on the primary surface of the InP substrate, the optical guiding portion forming a mesa structure included with an active layer therein;
a current blocking portion provided in both sides of the optical guiding portion so as to bury the mesa structure of the optical guiding portion, the current blocking portion including a first p-type semiconductor layer made of InP based material, an n-type semiconductor layer made of InP based material, and a second p-type semiconductor layer made of InP based material;
and
an n-type layer doped with silicon (Si) and provided between the active layer and the n-type InP substrate, and between the first p-type semiconductor layer of the current blocking portion and the n-type InP substrate.

2 more elements

Dependencies are inferred from the claim text.

Light-emitting device on n-type InP substrate heavily doped with sulfur

Life of this patent

Light-emitting device on n-type InP substrate heavily doped with sulfur

Life of this patent

Abstract

Claims10