N incorporation in GaNxP1-x and InNxP1-x using a RF N plasma source

We report a study of N incorporation behavior into GaP and InP as a function of growth conditions. With increasing N-2 how-rate fraction (N-2 flow rate over total group-V gas flow rate), the N composition increases up to a point but then saturates. This might be due to the small solubility of N in these materials or the leveling off of the active N species at higher N-2 flow rate. At a fixed N-2 flow-rate fraction, the higher the growth temperature T-s is, the less N can be incorporated, which results from the lowering of the sticking coefficient of nitrogen at higher T-s. Although the general trend of the growth condition dependence is the same for N incorporation in InP and GaP, the amount of N that can be incorporated is quite different. With GaP, N as high as 16% can be obtained, while with InP, only less than 1% can be incorporated. This is considered to be due to the very high equilibrium vapor pressure of N-2 over InN compared to that over GaN.