WAFER-SCALE PROCESSING OF INGAASP INP LASERS

Chemically assisted ion beam etching (CAIBE) and electron cyclotron re sonance (ECR) plasma deposition have been used to etch and coat 1.3 mu m InGaAsP/InP heterostructure lasers in full wafer form. Ar/Cl2 CAIBE, using an ECR dual grid ion source, was used to etch 4 mum deep vertic al (90-degrees +/- 0.50), smooth facets at rates up to 1.3 mum/min. An integrated back facet monitor was simultaneously fabricated in the sa me heterostructure. High-reflectivity Si/SiO2 optical coatings were de posited on the etched facets by low-temperature (< 120-degrees-C) ECR plasma deposition and selectively patterned by liftoff. Full wafer tes ting of the processed devices showed good uniformity (+/- 3%) with las er threshold currents of 25 mA and a slope efficiency of 0.23 W/A at 2 5-degrees-C and 0.11 W/A at 85-degrees-C. Back facet monitor efficienc y was 0.4 A/W over the whole temperature range.