Etch characteristics of GaN and BN materials in chlorine-based plasmas

Reactive ion etching (RIE) was performed on GaN and BN thin films using chl orine-based plasmas. The optimum chemistry was found to be BCl3/Cl-2/N-2/Ar and Cl-2/Ar at 30 and 40 mtorr for GaN and BN etching, respectively. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) ana lysis of the GaN and BN etched surfaces show a decrease in the surface nitr ogen atomic composition and an increase in chlorine impurity incorporation with increasing self-de bias. A photo-assisted RIE (PA-PIE) process using a n IR filtered Xe lamp beam was then used and resulted in improved etch rate s and surface composition. Optical emission spectroscopy (OES) measurements have also shown photoenhancement of the etch process.