Silicide formation by thermal annealing of Ni and Pd on hydrogenated amorphous silicon films

Abstract

Silicide formation with the near-noble metals Ni and Pd on hydrogenated amorphous silicon substrates was studied with Rutherford backscattering spectrometry and forward recoil spectrometry. Upon annealing, Ni2Si (or Pd2Si) grows with the square root of time, and the activation energy is identical to that of the corresponding metal on single-crystal silicon substrates. The growth is slightly faster for hydrogenated amorphous silicon, which is attributed to the amorphous structure. During silicide formation, the hydrogen is released from silicides and presumably outdiffuses into a vacuum without interfacial accumulation. Thus, barrier formation does not occur, and the presence of hydrogen in the substrates has no effect on silicide growth.