ORGANOMETALLIC PRECURSORS FOR THE FORMATION OF GALLIUM NITRIDE BY METAL ORGANIC-CHEMICAL VAPOR-DEPOSITION - THERMAL-DECOMPOSITION OF TRINEOPENTYL GALLIUM AND OF ITS ADDUCTS WITH AMMONIA, DIMETHYLAMINE AND T-BUTYLAMINE

In the absence of air Np3Ga(Np = (CH3)3CCH2-) decomposes thermally at 310-340-degrees-C to yield isobutene and neopentane as the principal gaseous products together with a film of a material of metallic appearance. NP3Ga reacts readily with NH3, Me2NH and (t)BuNH2 to form 1:1 adducts NP3Ga . NH3 (1), Np3Ga . NMe2H (II) and Np3Ga . NtBuH2 (III). Adducts I and II decompose initially at 130-140-degrees-C to give neopentane and a solid containing gallium-nitrogen; on prolonged heating at this temperature all the N-containing groups are lost by Ga-N bond rupture. For III complete dissociation occurs at the relatively low temperature of 100-degrees-C. Thus none of these adducts would appear to be suitable precursors for the formation of GaN by metal organic chemical vapour deposition (MOCVD).