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There is disclosed a semiconductor device formed on a sapphire substrate, for example, a blue LED of a double-hetero structure having a laminated structure which comprises a first cladding layer made of a first conductivity type gallium nitride based semiconductor, an active layer made of a gallium

There is disclosed a semiconductor device formed on a sapphire substrate, for example, a blue LED of a double-hetero structure having a laminated structure which comprises a first cladding layer made of a first conductivity type gallium nitride based semiconductor, an active layer made of a gallium nitride based semiconductor into which impurity is not doped intentionally, and a second cladding layer made of a second conductivity type gallium nitride based semiconductor which being opposite to the first conductivity type on a sapphire substrate. A surface of the sapphire substrate is polished to have optical transmissivity of more than 60%.

대표청구항 ▼

[ What is claimed is:] [1.] A semiconductor device having a layered structure comprising:(a) a sapphire substrate having an upper surface and a lower surface, the lower surface being disposed at a bottom of the layered structure;(b) a first conductivity type semiconductor single crystal layer formed

[ What is claimed is:] [1.] A semiconductor device having a layered structure comprising:(a) a sapphire substrate having an upper surface and a lower surface, the lower surface being disposed at a bottom of the layered structure;(b) a first conductivity type semiconductor single crystal layer formed on the upper surface of said sapphire substrate; and(c) a second conductivity type semiconductor region provided on said first conductivity type semiconductor single crystal layer;wherein a surface roughness of the lower surface of said sapphire substrate corresponds to an unevenness of less than 10 nm as measured by a Probe method, and a thickness of the sapphire substrate is more than 260 .mu.m.