SEMICONDUCTOR DEVICE

摘要

The semiconductor device has a barrier layer formed on a channel layer, an n type diffusion preventing layer formed on the barrier layer and containing aluminum, and a source electrode and a drain electrode formed on the diffusion preventing layer. The semiconductor device further has a p type cap layer formed on the diffusion preventing layer sandwiched between the source electrode and the drain electrode and a gate electrode formed on the cap layer. The diffusion preventing layer has an aluminum composition ratio greater than the aluminum composition ratio of the barrier layer.

主权项

1. A semiconductor device, comprising:
a substrate; a first nitride semiconductor layer formed over the substrate; a second nitride semiconductor layer formed over the first nitride semiconductor layer; a third nitride semiconductor layer formed over the second nitride semiconductor layer; a source electrode and a drain electrode for a field effect transistor formed over the third nitride semiconductor layer while being separated from each other; a fourth nitride semiconductor layer formed over the third nitride semiconductor layer sandwiched between the source electrode and the drain electrode while being separated from each of the source electrode and the drain electrode; and a gate electrode for the field effect transistor formed over the fourth nitride semiconductor layer, wherein the band gap of the second nitride semiconductor layer is greater than the band gap of the first nitride semiconductor layer, wherein the third nitride semiconductor layer contains aluminum and is an n type semiconductor layer, wherein the fourth nitride semiconductor layer is a p type semiconductor layer, and wherein the second nitride semiconductor layer contains aluminum at a composition ratio smaller than the aluminum composition ratio of the third nitride semiconductor layer or contains no aluminum.