Microstructure effects on quantum efficiency in PtSi/p-Si(100) Schottky barrier detector

Abstract

The microstructure effects on the performance of the PtSi Schottky barrier detector (SBD) have been investigated in detail. The growth temperatures were ranged from 350 to 550°C. The thickness of the PtSi film measured by high resolution transmission electron microscopy (HRTEM) is around 4 nm. The electron diffraction pattern shows an intermingling of both ( 1 1 ̄ 0 ) and ( 1 2 ̄ 1 ) orientations when the PtSi film is formed at 350°C. However, the diffraction patterns show only ( 1 2 ̄ 1 ) orientation when the PtSi films are formed above 450°C. It was found that the electrical barrier height of the Schottky barrier detector formed at 350°C is about 0.02 eV higher than that formed above 450°C. The microstructure of the PtSi film does not change even though the formation temperature is further increased to 550°C. Nevertheless, the higher the formation temperature, the larger is the grain size. It was also observed that the grain size does not change the electrical barrier height. However, the quantum efficiency of the detector is much higher if the grain size is larger. The results indicate that the quantum efficiency of the detector can be improved if the PtSi film has ( 1 2 ̄ 1 ) orientation and larger grain size.