An MOS-Type Two-Dimensional PSD Using the AC Photovoltage Phase

A simulation and experiments have been conducted to develop a two-dimensional position-sensitive detector (PSD) from the previously presented MOS-type PSD. The ac photovoltage phase is used as a positional signal for this MOS-type PSD which requires no reverse-bias voltage, being similar to the Wallmark-type or floating-junction PSD. The simulation has been made using a RC network which equivalently represents the PSD; it has been shown that our PSD is useful for two-dimensional photosensing, admitting a light spot even of nonuniform intensity incident on its face. Experiments have demonstrated that the MOS-type two-dimensional PSD of Al-SiO2-Si has good linearity and electrically adjustable sensitivity. A resolution of 1 µm also has been demonstrated for the present PSD equipped with a simple phase-measuring system.