INFLUENCE OF GRAIN-BOUNDARY SCATTERING IN THE INFRARED RESPONSE OF SILICIDE SCHOTTKY-BARRIER DIODES

The infrared response of polycrystalline and epitaxial CoSi2/Si Schott ky diodes has been studied as a function of the silicide thickness. Al though both types of diodes present very similar barrier height, it is observed that, for thick silicide films, the quantum efficiency of th e polycrystalline diodes is two times higher than for the epitaxial di odes. This behavior is attributed to grain boundary scattering of the excited carriers. Nevertheless, this effect is not so strong for thin silicide films because the thickness of the film is much smaller than the grain diameter, and the dominant effect in the quantum efficiency is the scattering at the silicide interfaces and not at the grain boun daries. (C) 1996 American Institute of Physics.