LASER PHOTOCHEMICAL DEPOSITION OF GOLD FROM TRIALKYLPHOSPHINE ALKYLGOLD(I) COMPLEXES

The deposition of gold bearing tracks, by the argon ion laser photolys is at 257 nm of R'Au-I-PR(3), R,R' = C2H5, CH3, is reported. Deposits were obtained on optically polished fused quartz and (100) n-type sing le crystal silicon with a thermally grown oxide layer (3000 Angstrom). Tracks were deposited at a range of scan speeds from O to 200 mu m s( -1) and characterized by scanning electron microscopy (SEM), laser ion ization mass analysis (LIMA), and scanning profilometry. Electrical re sistivities as low as 4.51 mu Omega cm, within a factor of 3 of the va lue for bulk gold (2.44 mu Omega cm), were measured for tracks deposit ed at 40 mW and a scanning speed of 7.5 mu m S-1 However, the electric al conductivity of the deposits is highly sensitive to the structure o f the organogold precursor. Mass spectral data obtained by LIMA indica te that the incorporation of the precursor and/or various photolysis b yproducts into the deposit is related to the volatility of the ligand. Contamination is observed in tracks deposited from compounds containi ng the heavier ligand. Also, the electrical resistivities are correspo ndingly higher. Although isothermal annealing above 100 degrees C remo ves fragments containing the ligand, the resulting electrical conducti vities are not improved.