Electrical and structural properties of pulse laser-annealed polycrystalline silicon films

Doped epitaxial films of Si on single-crystal high-resistivity Si substrates have been prepared using ion implantation and Q-switched ruby laser annealing of LPCVD polycrystalline Si layers. Films, doped with B or As in the range 1017to 5 × 1020cm-3were studied by the measurement of their resistivities, Hall mobilities, and doping density profiles. The good film quality achieved permitted the fabrication of p-channel MOS transistors which, through measurements of threshold voltage and transconductance, yielded additional data on the surface mobility and the integrity of the Si-SiO2interface. The electrical properties of the films compared favorably with those of similarly doped single-crystal material, and transmission electron microscopy was used to confirm the good structural quality of the epitaxial growth.