Heavily-doped polycrystalline material which had been grown by molecular beam epitaxy and metalorganic chemical vapor deposition was studied by using secondary ion mass spectrometry and Hall measurements. It was found that C diffusion was negligible, even during post-growth annealing at 800C. However, annealing increased the resistivity of C-doped GaAs, and this was suggested to be due to a change in the occupation site preference of C atoms from As sites.

Comparison of Be and C Diffusion in Heavily Doped Polycrystalline GaAs. K.Mochizuki, T.Nakamura: Applied Physics Letters, 1994, 65[16], 2066-8