摘要 |
A buffer layer structure for the GaN-based semiconductor devices is provided. The buffer layer proposed by the present invention comprises internally at least two sub-layers: a first intermediate layer and a second intermediate layer. Initially, the first intermediate layer is developed on the substrate under a low temperature using silicon-nitride (Si<SUB>x</SUB>N<SUB>y</SUB>, x,y>=0). The first intermediate layer is actually a mask having multiple randomly distributed Si<SUB>x</SUB>N<SUB>y </SUB>clusters. Then, a second intermediate layer is developed under a low temperature using aluminum-indium-gallium-nitride (Al<SUB>w</SUB>In<SUB>z</SUB>Ga<SUB>1-w-z</SUB>N, 0<=w,z<1, w+z<=1). The second intermediate layer does not grow directly on top of the first intermediate layer. Instead, the second intermediate layer first grows from the surface of the substrate not covered by the first intermediate layer's mask and, then, overflows to cover the top of the first intermediate layer. The buffer layer according to the present invention effectively reduces the defect density of the GaN-based semiconductor devices.
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