Patent ID: 7148518
Filing Date: 2006-12-12
Classification: H01L

Abstract:
1. A group-III nitride semiconductor stack, comprising: a first group-III nitride layer; a graded low-temperature deposited layer formed on the group-III nitride layer and made of nitride in which group-III element composition is continuously changed; and a second group-III nitride layer formed on the graded low-temperature deposited layer, wherein the graded low-temperature deposited layer is continuous with the first and second group-III nitride layers in terms of composition and represented by a compositional formula AlxGa1−xN in which a composition ratio x increases from 0, becomes a maximum in the graded low-temperature deposited layer, decreases again, and becomes 0 at an uppermost portion of the graded low-temperature deposited layer along a direction of growth of films on the first group-III nitride layer.