Abstract: A method of forming a (gallium, aluminum, indium) nitride base layer on a substrate for subsequent fabrication, e.g., by MOCVD or MBE, of a microelectronic device structure thereon. Vapor-phase (Ga, Al, In) chloride is reacted with a vapor-phase nitrogenous compound in the presence of the substrate, to form (Ga, Al, In) nitride. The (Ga, Al, In) nitride base layer is grown on the substrate by HVPE, to yield a microelectronic device base comprising a substrate with the (Ga, Al, In) nitride base layer thereon. The product of such HVPE process comprises a device quality, single crystal crack-free base layer of (Ga, Al, In) N on the substrate, in which the thickness of the base layer may, for example, be on the order of 2 microns and greater and the defect density of the base layer may, for example, be on the order of 1E8 cm.sup.-2 or lower. Microelectronic devices thereby may be formed on the base layer, over a substrate of a foreign (poor lattice match) material, such as sapphire.

Abstract: An MOCVD precursor composition useful for MOCVD formation of a non-linear optically active metal borate thin film, comprising: (I) an organometallic source reagent for a metal reactively forming a non-linear optically active metal borate, and (II) an organoborate compound of the formula: B(OR).sub.3, wherein each R is independently selected from H, alkyl, aryl, alkaryl, arylalkyl, alkenyl, fluoroalkyl, fluoroaryl, fluoroaralkyl, fluoroalkaryl, trialkylsilyl, and C.sub.5 -C.sub.8 carbocylic groups, as the aforementioned borate source reagent. Such composition may be employed for forming a non-linear optically active metal borate thin film on a substrate, via depositing by CVD on said substrate a metal from the organometallic source reagent and a borate from the organoborate compound, to react the metal with the borate and yield the non-linear optically active metal borate on the substrate.