| 摘要 |
PROBLEM TO BE SOLVED: To form a surface protection film of an InP/InGaAs hetero junction bipolar transistor with good reproducibility, by using a lamination film consisting of an InP layer and an InGaAsP layer as a surface protection film. SOLUTION: A lamination film consisting of an InP layer 4 and an InGaAsP layer 5 is used as a surface protection film and a guard ring for an InP/InGaAs hetero junction bipolar transistor(HBT). As a result, it is possible to eliminate the need for etching the InP layer 4 to remain thin and to form a surface protection film of a uniform thickness without increasing manufacturing processes. If the InGaAsP layer 5 is provided between the InP layer 4 which becomes an emitter layer and an InGaAs emitter cap layer 7, the InGaAsP layer 5 becomes an etching stopper layer, and it is possible to obtain small energy discontinuous levelΔEc at a conduction band side formed in InP/InGaAs interface and to reduce a resistance of InP/GaAs interface.
|
