Index guided semiconductor laser diode with reduced shunt leakage

Abstract

An index-guided semiconductor laser diode made by impurity-induced layer disordering (IILD) of AlInP, GaInP and AlGaInP heterostructures. Several techniques for reducing parasitic leakage current via the n-type IILD regions, are described. These include removing the upper portions of the material outside the laser stripe, which can be accomplished by wet or dry etching of the material in a self-aligned manner. As an alternative, after formation of the waveguide, appropriately doped layers are grown over the disordered and as-grown regions of the structure to contact the active waveguide and simultaneously block parasitic shunt current from the disordered regions. Another method provides shallow inset insulating regions to replace the n-type disordered regions at the vicinity of a cap layer used to reduce a current barrier.