New Chemical Routes to Metal Nitrides

Abstract

ABSTRACTAfter a brief introduction on how the differing properties of H2O and NH3may effect the strategies used to synthesize metal nitrides, an overview of our use of azides to produce aluminum nitride thin films will be presented. The effect of changing the nitrogen source to one which contains at least one N - C bond is to increase dramatically the carbon content of the films. Replacing the alkyl groups attached to the aluminum with hydride ligands removes the final carbon source and forms what appears to be a promising new class of precursors. This is demonstrated by the study of the reaction of Me3NGaH3with NH3to produce the novel trimer, [H2GaNH2]3. This fully characterized molecule converts at 150°C into gallium nitride. Surprisingly, it yields GaN having the sphalerite structure instead of the known wurtzite phase. A discussion of the reasons for this unusual route to a new crystalline phase of GaN is included.