| 摘要 |
PURPOSE:To make the formation of an electrode on the top of a circular mesa easy by coating a resist and vapor-phase-etching after forming an insulating film on the circular mesa formed at the center of a concentric circle ring groove formed on a semiconductor layer. CONSTITUTION:An n-type InP 2, an undope active layer 3, a p-type InP 4 and a p-type InGaAsP 5 are formed in sequence on an n-type InP substrate 1 by crystal growth. An SiO2 film 6 is formed on the p-type InGaAsP 5 by CVD and the SiO2 film 6 only inside a circle the diameter of which is approx. 80mum is removed with a photo resist. Then, a resist 13 is coated on all the surface and the resist 13 only within as ring wherein the inner diameter of a concentric circle is 20mum and the outer diameter of the concentric circle is 80mum is removed. Then, semiconductor layer 1-5 are etched and a concentric circle ring groove 7 is formed. After an SiO2 film 8 is formed on all the surface, a resist 14 is coated and the resist 14 on the top of a circular mesa 12 is removed. Then, the SiO2 film 8 on the top of the circlar mesa 12 is removed by ion etching using a CF4 gas and the resist 14 is removed by washing. |
