RELATIONSHIP OF BACKGROUND CARRIER CONCENTRATION AND DEFECTS IN GAN GROWN BY METALORGANIC VAPOR-PHASE EPITAXY

Experimental results show that the background carrier concentrations i n GaN films grown bq metalorganic vapor phase epitaxy are related to d efects. A thermal equilibrium method was used to calculate the backgro und carrier concentration related to intrinsic defects in an ideal GaN crystal, The results show that the N vacancy concentration does not e xceed 2x10(17) cm(-3) in GaN grown at temperatures ranging from 800 to 1500 K. It can be concluded that the N vacancy is one of the major so urces of carriers when the carrier concentration n<2x10(17) cm(-3), bu t the main sources should be other defects when n>2x10(17) cm(-3); thi s conclusion may lead to ways for further improving the quality of GaN films. (C) 1997 American Institute of Physics.