ELECTROLESS NI-P DEPOSITION ON SILICON WITH PD ACTIVATION

The electroless Ni-P deposition on silicon with Pd activation was investigated by Rutherford backscattering spectrometry (RBS) and electron microscopy. An "RBS double-layer" structure SiPdNiP/NiP with different composition was simulated to evaluate the composition profiles of the films produced by electroless NiP deposition with Pd activation. During deposition on Si with Pd activation, the initially formed NiP alloy was found to contain approximately two times more P than that formed after long deposition times. To explain the distribution of P in NiP alloy suggested that the catalytic properties of the surface change during the deposition process. The thickness of the SiPdNiP layer also changes during NiP deposition. It was observed that the maximum thickness of SiPdNiP layer ranges from 2400 to 2500 angstrom. Contact hole to silicon device with a 0.5-mu-m depth p-n junctions and a 1.5-mu-m nominal sizes were filled by NiP after Pd activation. The contact resistivity on n-type silicon (R(s) = 40 +/- 10-OMEGA/square and N = 3 . 10(19) CM-3) was in the 10(-8) OMEGA . cm2 range after a 450-degrees-C nitrogen annealing cycle for 30 min.