PURPOSE: To obtain a stable ohmic contact by forming a double structure of an In1-xGaxAsyP1-y film and an In1-x'Gax'AsyP1-y'(x>x'+0.05) when forming the surface layer to become the primary layer of the electrode on an InGaAsP layer.
CONSTITUTION: An InGaAsP active layer 2, a P type InP clad layer 3, and an InGaAsP surface layer 4 are laminated and grown on an InP substrate 1, and an electrode metal layer which mainly contains Au is covered on the layer 4. In this structure, the layer 4 is not a single layer of InGaAsP, but is a laminate of the first surface InGaAsP layer 41 and the second surface InGaAsP layer 42. In other words, the layer 41 contacted with the electrode metal layer is formed of In1-xGaxAsyP1-y' and the layer 42 disposed at the lower side is formed of In1-x'Gax'Asy'P1-y'(x>x'+0.05). Thus, even if the reaction of Au in the electrode metal layer occurs in the layer 41, the surface of the layer 42 is stable, and the I-V characteristic does not decrease due to the heat treatment.
MORI TAKAO
KASHIWADA YASUTOSHI
HIRAO MOTONAO
FUJISAKI YOSHIHISA
IMAI KUNINORI
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