TRANSVERSE BURIED TYPE SURFACE EMITTING LASER

摘要

PURPOSE:To improve the carrier entrapping efficiency so as to obtain a laser beam of a small diameter through a low threshold current by a method wherein a clad layer and a carrier injecting region of semiconductor with a broad forbidden band. CONSTITUTION:An lower reflecting layer consisting of 60 pairs of Al0.3Ga0.7As/ GaAs thin films, a GaAs active layer a half wavelength in thickness, an upper reflecting layer consisting of 20 pairs of the same thin films as those of the lower reflecting layer are formed on a substrate 5 and subjected to selective etching so as to leave an island-shaped form 2X8mum in size unremoved for the formation of a vertical optical resonator 1. An n-Al0.4Ga0.6As layer and an n<+>-GaAs cap layers 2 and 3 are formed on. the periphery of the resonator 1 through selective liquid growth. A window 14 is provided to an SiNX film 13 and Zn is diffused so as to form a p-type small carrier injecting layer 4. The injecting layer 4 has a such a structure as small number of carriers are laterally injected and prevented from diffusing laterally, so that an oscillating threshold value can be decreased and also a beam can be reduced in diameter.