PURPOSE: To reduce an oscillation threshold current by forming a double hetero structure which includes an active layer having an oblique part, thereby reducing a leakage current which does not contribute to an oscillation by flowing the current in parallel with the surface of a substrate.
CONSTITUTION: A double hetero structure which includes an active layer is formed on a wafer having an N type GaAs layer 2 on an insulating GaAs substrate 1. When an N type Ga1-xAlxAs layer 4 grown at the maximum temperature of 790°C, cooling velocity of 0.4°C/min, and saturation degree of 1°C, the thickness in the sidewise direction becomes approx. 7 times of the thickness of the flat part. After an active layer 5 is then grown, a P type Ga1-xAlxAs clad layer 6 and an N type GaAs layer 7 are continuously grown. Then, a P type impurity Zn is diffused in striped shape from the surface of the grown layer, so that part of diffused front 8 reaches the inclined part of the layer 6. Then, an ohmic electrode 9 is formed at the P side. Then, the respective grown layers on the N type GaAs grown layer 2 and the P side electrode 9 are removed by etching for forming an N type side ohmic electrode, and an N type ohmic electrode 10 is formed.
WADA MASARU
SHIMIZU YUUICHI
ITOU KUNIO
