NITRIDATION AND CVD REACTIONS WITH HYDRAZINE

The low-temperature nitridation of gallium arsenide, silicon and trans ition metals was investigated using hydrazine. Gallium nitride films w ere grown on gallium arsenide (GaAs) by direct reaction of the semicon ductor surface layers with hydrazine at 200 - 400 degrees C. Auger ele ctron spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses show that the films are primarily gallium nitride with a small oxide impurity Thin nitride films (similar to 15 Angstrom) were grown on sil icon by reaction with hydrazine at 300-500 degrees C. Ellipsometry res ults suggest that the film growth goes through different phases follow ing linear, parabolic and logarithmic functions with time. XPS analysi s shows that the nitride films could be formed at much lower temperatu res than possible with ammonia (300 vs.,600 degrees C). The formation of numerous transition metal nitrides (Go, Cr, Fe, Mo, Si, Ta, Ti, V, and W) by reaction with hydrazine at 400 degrees C is demonstrated, as well as the chemical vapor deposition of boron nitride films from dib orane and hydrazine reactants. The temperature at the mixing point was critical in determining the final composition of the film. A 1-D tran sport model suggests that the reaction rate at 400 degrees C was kinet ically limited The results also agree qualitatively with thermodynamic equilibrium calculations.