| 摘要 |
PURPOSE:To prevent the deterioration of an active layer due to heat treatment during manufacturing process, by forming a burried layer before the formation of a groove and the growth of the active layer. CONSTITUTION:The (110) plane of an N type InP substrate 21 is provided with corrugations 22 for diffraction grating having a pitch of 3,970Angstrom and a depth of 1,000Angstrom , by means of interference exposure and chemical etching. An N type InGaAsP film 23 is formed thereon to a thickness of about 0.1mum. An SiO2 mask is applied thereon and the film 23 is etched with a mixed solution of H2SO4 + H2O2 + H2O to form a stripe 24. An N type InP 25 film and P type InP film 26 are deposited by the liquid-phase growth, and are provided with a mask of SiO2. These are then etched with a mixed solution of HCl + H3PO4 to form a groove 27, while this solution does not etch the InGaAsP 24. Subsequently, an InGaAsP film 28, an InGaAsP film 29 as a light-emitting section, a P type InP film 30 and a P type InGaAsP film 31 are deposited in that order by the liquid-phase growth. Electrodes of Ti/Pt/Au and of Au/Sn are attached to the P- and N-sides, respectively. This laser has excellent threshold characteristics and temperature characteristics, showing little deterioration even if it is matured and a temperature of 50 deg.C with current of 50mW. |
