Epitaxial Nickel Disilicide Formation by Electron Beam Annealing

A multiply-scanned electron beam was used to form nickel silicides from thin nickel films on unimplanted and arsenic implanted silicon (100) substrates. Films of thickness 300, 660 and 1000A were annealed using a power density of 7.9Wcm−2 and irradiation times of 5 to 150 secs. Rutherford backscattering and channelling techniques were used to determine the stoichiometry, thickness and epitaxial quality of the annealed films. The thinnest gave a Xmin of ∼ 18% and the thickest a Xmin of ∼ 40%. Resistivities were measured by the four-probe technique. Chemical composition was determined by X-ray and glancing angle electron diffraction (RHEED). Transmission electron microscopy (TEM) was used to estimate grain size of the disilicide phase and scanning electron microscopy (SEM) to study surface textures. The effect of arsenic implantation on growth rate, epitaxial quality and surface texture is demonstrated.