JPS6482686A - Semiconductor laser - Google Patents

Abstract

PURPOSE:To reduce astigmatism and to improve condensing characteristic of a laser beam by forming a refractive index waveguide structure without optical absorption effect. CONSTITUTION:In a first MOCVD crystal growing step, an N-type Al0.4Ga0.6As layer 2, an Al0.05Ga0.95As layer 3 to become a light emitting region, a P-type Al0.4Ga0.6As layer 4, a P-type Al0.3Ga0.7As layer 10, a P-type Al0.5Ga0.5As layer 11 and a P-type GaAs layer 7 are sequentially formed on an N-type GaAs substrate 1. Then, in a normally frequently using step, a mesalike crystal laminate is formed. Thereafter, in a second MOCVD crystal growing step, gas etching is conducted immediately before a crystal growth to surround the mesa section, chemically etched surface is clarified, the layer 10 remaining except the mesa region is removed, an N-type Al0.5Ga0.5As layer 13 and an N-type GaAs layer 5 are sequentially formed to surround the mesa section. Eventually, after an SiO2 film 12 is removed, a P-type ohmic electrode 8 and an N-type ohmic electrode 9 are formed. Thus, a refractive index waveguide mechanism is formed without optical absorption effect, thereby obtaining an optical beam having less astigmatism and excellent condensing characteristic.