SEMICONDUCTOR DEVICE

摘要

The characteristics of a semiconductor laser are improved. In a semiconductor laser having an n type cladding layer, an active layer, and a p type cladding layer, a current block layer is provided. For example, the current block layer is arranged partially between the p type cladding layer and the active layer, and in the overlapping region of the p type cladding layer and the active layer. Thus, in a current narrowing region of the overlapping region of the p type cladding layer and the active layer, the current block layer is arranged, thereby to suppress the current injected into a part of the active layer. This results in the formation of a saturable absorbing region, which causes a difference in intensity of the optical output of the semiconductor laser. This can implement self-pulsation.

主权项

1. A semiconductor device, comprising:
a first nitride semiconductor layer; a second nitride semiconductor layer arranged over the first nitride semiconductor layer; a third nitride semiconductor layer arranged over the second nitride semiconductor layer, and in a part of a formation region of the second nitride semiconductor layer; and a fourth nitride semiconductor layer arranged between the third nitride semiconductor layer and the second nitride semiconductor layer, and partially in an overlapping region of the third nitride semiconductor layer and the second nitride semiconductor layer, wherein the first nitride semiconductor layer is larger in band gap than the second nitride semiconductor layer, and is of a first conductivity type, wherein the third nitride semiconductor layer is larger in band gap than the second nitride semiconductor layer, and is of a second conductivity type which is the opposite conductivity type to the first conductivity type, and wherein the fourth nitride semiconductor layer is larger in band gap than the third nitride semiconductor layer.