Formation of gallium nitride (GaN) transition layer by plasma immersion ion implantation and rapid thermal annealing

Recent advances in the preparation of gallium nitride (GaN) and related compounds have made possible the production of blue semiconductor laser. Conventional preparation involves growing GaN thin films on lattice-mismatching sapphire using metal-organic chemical vapor deposition (MOCVD). In this article, we describe an alternative method to produce a lattice-matching strained layer in GaAs for subsequent GaN growth by plasma immersion ion implantation (PIII) followed by rapid thermal annealing. Our novel approach uses broad ion impact energy distribution and multiple implant voltages to form a spread-out nitrogen depth profile and an amorphous surface layer. This approach circumvents the retained dose and low nitrogen content problems associated with ion beam implantation at fix energy. Based on our Raman study, the resulting structure after PIII and rapid thermal annealing is strained and contains some GaN possibly in crystal form.