摘要 |
The present invention provides an epitaxially grown compound semiconductor film having a low density of crystal defects which are generated during the course of crystal growth of a compound semiconductor. The present invention also provides a compound semiconductor multi-layer structure including an n-type InP substrate, an n-type InP buffer layer, an undoped InGaAs light-absorbing layer, and an n-type InP cap layer, the layers being successively grown on the substrate through MOCVD. In the InGaAs layer, the compositional ratio of In/Ga is cyclically varied in a thickness direction (cyclic intervals: 80 nm) so as to fall within a range of ±2% with respect to a predetermined compositional ratio that establishes lattice matching between InGaAs and InP; specifically, within a range between 0.54/0.46 (i.e., In0.54Ga0.46As) and 0.52/0.48 (i.e., In0.52Ga0.48As)
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