Quasi-two-dimensional simulation of an ion-implanted GaAs MESFET photodetector
✍ Scribed by M. Madheswaran; V. Rajamani; P. Chakrabarti
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 216 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0895-2477
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✦ Synopsis
A quasi-two-dimensional numerical model of an optically ( ) gated GaAs metal semiconductor field-effect transistor MESFET has been de¨eloped for the characterization of the de¨ice as a photodetector. The model considers the channel to be nonuniformly doped. The model in¨ol¨es the solution of a 1-D Poisson's equation, and takes into account the field-dependent mobility of the carriers in the channel for computation of the current. It has been found that, in a short-channel MESFET photodetector, the drain current saturation is caused by the ¨elocity saturation of the carriers rather than pinch off. The photocurrent gain, responsi¨ity, and the input RC time constant of an ion-implanted GaAs MESFET ha¨ing a semitransparent metal gate ha¨e been estimated numerically on the basis of the model. The de¨ice has a high photocurrent gain, a high responsi¨ity, and a low-input RC time constant at an operating wa¨elength of 0.85 m.