MOLECULAR DESIGN OF SINGLE-SOURCE PRECURSORS FOR 3-6 SEMICONDUCTOR-FILMS - CONTROL OF PHASE AND STOICHIOMETRY IN INXSEY FILMS DEPOSITED BY A SPRAY MOCVD PROCESS USING SINGLE-SOURCE REAGENTS

Thin films of the 3-6 semiconductors InSe and In2Se3 have been prepared by a spray MOCVD process using Me2InSePh and In(SePh)3, respectively, as single-source precursors. The new compound, Me2InSePh, was prepared by a redistribution reaction between InMe3 ana In(SePh)3 (2:1 molar ratio in toluene) and In(SePh), was prepared by an oxidative addiction reaction of diphenyl diselenide (Ph2Se2) and indium powder in refluxing toluene. The fabrication of the films was carried out by ultrasonically nebulizing a toluene solution of the precursor and transporting the mist, in an argon carrier gas, into a heated reactor zone containing the substrate. With a GaAs(100) substrate at 408-477-degrees-C the InSe films were primarily the known hexagonal phase with a low level of a new zinc blende-like cubic phase. When the substrate temperature was lowered to 309-365-degrees-C, films of the the new cubic phase (a = 5.72 angstrom) were obtained. Solid-state pyrolysis of the In(SePh)3 precursor, under an argon atmosphere, gives In2Se3, SePh2, and Se2Ph2. Highly (00l) oriented thin films of hexagonal In2Se3 have been prepared on a GaAs(100) substrate at temperatures between 470 and 530-degrees-C. The films were characterized by X-ray diffraction and scanning electron microscopy.