Patent ID: 7550368

Claim:
A method of manufacturing a group-III nitride semiconductor stack, comprising: forming a first group-III nitride layer; forming a graded low-temperature deposited layer in which group-III element composition is continuously changed, on the first group-III nitride layer by continuously changing growth temperatures without growth interruption; and forming a second group-III nitride layer on the graded low-temperature deposited layer without growth interruption, 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 Al x Ga 1-x N 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.