Reactive MBE Growth of GaN and GaN∶:H on GaN/SiC Substrates

Reactive N and H, created using rf plasma sources, were used to grow undoped GaN along with p-type GaN:Mg and p-type GaN:Mg:H thin films. By comparing the optical emission spectra from several rf sources with observed GaN grow rates, we deduce that nitrogen atoms and I stpositive series nitrogen molecules (3.95 eV binding energy) are the reactive species responsible for GaN film growth. A Mg ground state acceptor binding energy of about 224 meV was determined from low temperature photoluminescence (PL) experiments for both p-type GaN:Mg and p-type GaN:Mg:H films.