Design and performance of the mesh-type high-speed silicon optical position-sensitive devices

A high speed optical position-sensitive device (PSD) which was fabricated using a certain structure of the mesh-type resistive layer for reducing the junction capacitance is discussed. Its performance is compared with the conventional type of PSD (CPSD) fabricated by the same technology. The mesh-type high speed PSD (MEPSD) is based on an ion-implanted Si p-i-n structure and has an area of 14*14 mm/sup 2/ with 30- mu m strip-width and 125- mu m pitch. The temporal response of the MEPSD is found to be improved by a factor of 1.83 times compared to the CPSD. A photosensitivity comparable to that of the CPSD is obtained. Its position linearity for detection is also comparable with that of the CPSD. The performance of the laboratory demonstration devices illustrates the feasibility of the concept for high-speed PSD.<
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