Gallium Nitride

Halide/Hydride vapor phase epitaxy

Gallium Monochloride precursor

In typical HVPE process for GaN deposition gallium monochloride GaCl and ammonia NH3 are used as precursors of gallium and nitrogen:


The reaction is exothermic, and the reaction driving force decreases with increasing temperature:

Typical deposition temperature for epitaxial growth is 800-1100°C. At lower temperatures the deposition rate decreases due to reaction kinetic limitation, at higher temperatures the deposition rate decreases as a result of a decrease in supersaturation:

GaN HVPE deposition rate temperature dependence
GaN HVPE deposition rate temperature dependence

Gallium trichloride precursor

GaN deposition by  reaction of gallium trichloride GaCl3 and ammonia

GaCl3 + NH3 = GaN + 3HCl

is endothermic and the reaction driving force increases with increasing temperature, that makes possible to deposit GaN at temperatures 1300-1400°C:


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