Patent ID: 8669585

Claim:
An apparatus comprising: a substrate of silicon; a buffer layer adjacent to the substrate; an N-type layer adjacent to the buffer layer, wherein the N-type layer includes a first sublayer that has a first silicon dopant concentration; a strain release layer with a first portion and a second portion, wherein the first portion is adjacent to the first sublayer of the N-type layer, and wherein the strain release layer has a second silicon dopant concentration; and a multiple quantum well active layer with a sublayer, wherein the sublayer of the multiple quantum well active layer is adjacent to the second portion of the strain release layer, wherein the sublayer of the multiple quantum well active layer has a third silicon dopant concentration, wherein both the first silicon dopant concentration and the third silicon dopant concentration are higher than the second silicon dopant concentration, wherein the N-type layer further includes a second sublayer that has a fourth silicon dopant concentration and a third sublayer that is formed between the buffer layer and the second sublayer and has a fifth silicon dopant concentration, wherein the second sublayer is formed between the first sublayer and the third sublayer, and the fourth silicon dopant concentration is lower than the first silicon dopant concentration and the fifth silicon dopant concentration.