B. Molnar et al., THE INFLUENCE OF CH4 H-2/AR PLASMA-ETCHING ON THE CONDUCTIVITY OF N-TYPE GALLIUM NITRIDE/, Journal of applied physics, 78(10), 1995, pp. 6132-6134
The influence of plasma etching on the electrical properties of n-type
gallium nitride (GaN) thin films has been investigated. Electron-cycl
otron-resonance microwave plasma reactive ion etching in CH4/H-2/Ar, i
n CH4/H-2, and in H-2 results in an increase in the GaN layer's sheet
carrier concentration and a decrease in the effective Hall mobility. N
either wet chemical etching nor etching in Cl-2 or BCl3 plasmas introd
uces similar changes. Therefore, the observed damage is considered to
be related to the CH4/H-2/Ar plasma chemistry. in particular, it sugge
sts hydrogen influence on the defect generation. Subsequent annealing
of the affected GaN layers at 800 degrees C removes the plasma damage.