SEMICONDUCTOR LASER DEVICE

PURPOSE:To allow the obtainment of stable oscillation mode and good operating characteristic without the use of protecting masks of Si3N4, etc., by forming a band shaped stepwise difference on the semiconductor substrate to provide a specific plurality of semiconductor layers respectively thereon. CONSTITUTION:After p type impurity Zn etc. is high density diffused on a GaAs substrate 1 to provide carrier density 10 cm or more, a partial region on the diffused surface is etching removed to a band to form the p diffused region 13 and stepwise difference 15. An N type AlGaAs layer 2 is grown thereon to have thickness difference on the both ends of the stepwise difference 15 and cover the p diffused region 13 and stepwise difference 15 next to grow an N type GaAs active layer 3, N type AlGaAs layer 4 and contact layer 5. Next, Zn of the p diffused region 13 is driven by heat treatment to form the P type region 14 surrounded by the dot line in figure. Further, an etching groove 9 is formed on a part of the contact layer 5 with P side . N side electrodes 10, 11 and a metallic layer 12 for die bond to obtain a semiconductor laser device.