CHARACTERIZATION OF DYNAMIC BEHAVIOR OF METAL-SEMICONDUCTOR-METAL PHOTODETECTORS BY CORRELATION TECHNIQUE

The frequency response, linearity, and sensitivity of metal-semiconduc tor-metal (MSM) photodetectors are investigated. A new measurement tec hnique is presented for examination of the dominant effects on current transport. The technique is based on optical excitation of a device b y subsequent pulses of varying delay and on correlation of the pulse r esponses. In combination with time domain measurements an efficient te chnique for material and device optimization is attained. Characteriza tion of the MSM-photodetectors results in a short risetime (800 fs) an d pulse width (9 ps) and excellent linearity using n-type epitaxiallay ers. In contrast to semiinsulating layers no pulse tails are observed.