Characterization of GaAs MESFET gate capacitances
An accurate and simple technique to characterize gate capacitances of small-geometry gallium-arsenide (GaAs) MESFETs is presented. The gate capacitive current is converted into voltage and detected by a lock-in amplifier. Subfemtofarad accuracy is achieved. A set of MESFETs with minimum channel length of 0.8 mu m and various channel widths has been accurately characterized. The gate-to-drain and gate-to-source capacitances show strong bias dependences. >