Crystalline Tetrahedral Phases Al1-xBxPSi3 and Al1-xBxAsT3 (T = Si, Ge) Via Reactions of Al(BH4)3 and M(TH3)3 (M = P, As)

Abstract

Crystalline (III-V)1-y(IV2)y hybrid semiconductors Al1-xBxPSi3 and Al1-xBxAsSi3 have been grown on Si(001) substrates via reactions of Al(BH4)3 and M(SiH3)3 (M = P, As). These films are characterized for structure, composition, and phase morphology The materials form by interlinking III-V-IV3 tetrahedral units that construct a cubic lattice with average diamond-like symmetry containing isolated III-V pairs. This synthetic approach was extended to alloy systems in which the III-V pairs are imbedded in a Ge-matrix using As(GeH3)3. These materials are grown on Ge/Si(001) platforms and a comparative study of two growth methods is presented. One describes a low pressure CVD route via reactions of Al(BH4)3 and As(GeH3)3, and the other is a gas-source MBE technique combining Al atoms from an effusion cell with the germyl-arsene precursor. Both sets of films are studied using aberration-corrected STEM. Globally the results show that Al(BH4)3 acts as a carbon-free source of Al compatible with CVD protocols.