We report the PtSi film thickness dependence on the electrical barrier height and quantum efficiency of PtSi Schottky barrier detector (SBD). The thickness of the PtSi film was varied from 20 to 120 Angstrom. The electrical barrier height of the SBD is about 0.186+/-0.002 eV. It was observed that the grain size and the film thickness have negligible effect on the electrical barrier height. However, the quantum efficiency of the SBDs is strongly dependent on the film thickness. When the PtSi thickness is about 80 Angstrom, the quantum efficiency exhibits its peak value exceeding 1%. The positive quantum efficiency dependence on the film thickness is referred to the enhancement of elastic phonon scattering and the absorption dependence on the film thickness. When the film thickness is thicker than 80 Angstrom, the decrease of the quantum efficiency is deduced from the inelastic scattering, like hole/hole scattering, imperfection scattering and impurity scattering during the hot hole transporting to the PtSi/Si interface. (C) 2002 Elsevier Science B.V. All rights reserved.