MICROWAVE PLASMA-ASSISTED LCVD GROWTH AND CHARACTERIZATION OF GAN

Gallium nitride films have been grown by microwave plasma assisted las er induced chemical vapor deposition at about 550 degrees C. Trimethyl gallium and ammonia served as group III and group V sources, respectiv ely. Ammonia was introduced into the reaction chamber by two separate lines. In one of the lines, ammonia first passed through a microwave c avity where it could be ionized into a plasma, before being delivered to the chamber. An ArF excimer laser (193 nm) was used to photodissoci ate the ammonia and trimethylgallium introduced through the other line . The room temperature electron concentration and Hall mobility of the films were measured to be in the range 10(15)-10(16) cm(-3) and up to 200 cm(2)/Vs, respectively. Strong room temperature near-band photolu minescence detected from the films indicated their good optical qualit y. The photoconductive decay of photocarriers was also investigated.