A μp-controlled flying-spot scanner with an intelligent A/D-converter unit

A flying-spot scanning technique is useful for the measurement and mapping of inhomogeneities in semiconductor parameters such as minority carrier lifetime, resistivity, and surface-recombination velocity. This paper describes a system based on a 16-bit microprocessor and an intelligent 12-bit A/D-acquisition unit for automatic control and data processing of the measurement. The processor controls the scanning equipment while the intelligent A/D unit supervises the measurement by means of a single-chip microcomputer analyzing feedback signals from the scanner. Therefore, real-time data processing is achieved which significantly enhances the applicability of the flying-spot scanning technique.