SURFACE REACTIVITY OF ALKYLGOLD(I) COMPLEXES - SUBSTRATE-SELECTIVE CHEMICAL-VAPOR-DEPOSITION OF GOLD FROM RAUP(CH3)3 (R=CH2CH(3), CH3) AT REMARKABLY LOW-TEMPERATURES

The reactivity of CH3CH2AuP(CH3)(3) and CH3AuP(CH3)(3) is investigated on silicon, chromium, copper, PMDAODA polyimide, and silicon dioxide surfaces at temperatures ranging from 25 to 400 degrees C in an ultrah igh-vacuum chamber. By exploitation of the advantages of kinetically c ontrolled reaction conditions and atomically clean surfaces, high-puri ty gold films are deposited at temperatures as low as room temperature . The surface reaction generating elemental gold is subject to an unus ual level of control. Excursions to only moderately higher temperature serve to tune the process from one which is completely selective for metal and semiconductor surfaces to one which provides blanket deposit ion. Enhanced selectivity, allowing the discrimination between differe nt metal substrates (e.g. Cr versus Cu or Au) is achieved by prior exp osure of the substrate surface to inhibition agents such as P(CH3)3 an d BF3, The inhibition by BF3 is essentially complete for deposition on Cr at 25 degrees C but is reversed by relatively mild heating of the substrate to 350 degrees C.