| 摘要 |
PURPOSE:To flow all injected currents through an active layer, and to obtain an optical semiconductor device having high reliability and long life by laminating a semiconductor layer containing the active layer on a semiconductor substrate, growing the semiconductor layer in an epitaxial manner in a liquid phase, mesa- etching the grown layer and previously coating the interface of the grown layer with an insulating protective film. CONSTITUTION:An N type InP light guide layer 15, an N type or P type InGaAsP active layer 16, a P type InP light guide layer 17, and a P type InGaAsP cap layer 18 are laminated on an N type InP substrate 14, and grown in an epitaxial manner in a liquid phase. A striped protective film 19 consisting a of SiO2 or Al2O3 or the like in predetermined size is formed on the layer 18, and laminate is mesa-etched until etching intrudes to the layer 15 by using 1% bromine methanol while employing the protective film as a mask. The film 19 is removed, the whole exposed surface is coated with a protective film 20 composed of SiO2, Al2O3 or the like extending over the upper section of the layer 15 from a mesa section, and the upper section of the layer 18 is removed and a P<+> type diffusion region 21 for ohmic contact intruding into the layer 17 is formed in the removed section. |
