Facet Passivation of GaAs Based LDs by N2 Plasma Pretreatment and RF Sputtered AlxNy Film Coating

RF sputtered Al_xN_y thin film is deposited on the cavity surface of LD (laser diode) by N₂ plasma pretreatment. Firstly optimize the preparation process of Al_xN_y film, and test the chemical ratio, reflectivity and optical absorption of the optimized Al_xN_y film by EDX, spectrophotometer and surface thermal lens technology respectively, which verify the feasibility of Al_xN_y used for facet coating film in LD process; then optimize the N₂ plasma cleaning process, and use PL to find out that sputtered Al_xN_y passivation film by N₂ plasma pretreatment can increase the GaAs surface photoluminescence efficiency by 119%. Finally, a 10 nm thick Al_xN_y passivation film is coated on cavity surface of LD with optimized N₂ plasma pretreatment, which leads to a higher reliability than the traditional LD.