The effects of the microstructure and the electrical and optical properties on the formation at highly efficient infrared PtSi Schottky barrier detectors (SBD) have been studied in detail. Two- to twelve-nanometer-thick PtSi films were grown by evaporation at temperature ranging from 350 to 550 °C. The electron diffraction patterns indicate the existence of both the (11̄0) and (12̄1) orientations when PtSi films formed at 350 °C. However, the diffraction patterns show only the (12̄1) orientation when the PtSi films are formed at 450 °C or above. The electrical barrier height of the Schottky barrier detector that formed at 350 °C was about 20 meV higher than that formed at 450 °C or above. The grain size and the film thickness had a negligible effect on the electrical barrier height. However, the optical performance was strongly dependent on the film thickness and the growth conditions. The 350 °C PtSi film showed increased quantum efficiency as the film thickness decreased. The optimal thickness that provided the highest responsivity was 2 nm. On the other hand, the optimal thickness shifted to 8 nm for PtSi film formed at 450 °C or above. These results indicate that the quantum efficiency of a detector can be improved if the PtSi film has an orientation at (12̄1), a larger grain size, and an optimal film thickness.
- Electron diffraction
- PtSi Schottky barrier detector (SBD)
- Transmission electron microscopy (TEM)