PROPERTIES OF METAL-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS FABRICATEDON CARBON-DOPED SEMIINSULATING GAAS CRYSTAL GROWN BY LIQUID ENCAPSULATED CZOCHRALSKI METHOD

Metal-semiconductor field-effect transistors (MESFETs) whose active la yers were made by ion-implantation were fabricated on a new type of se mi-insulating liquid-encapsulated Czochralski (LEC)-grown crystal dope d with carbon. The short-channel effect was suppressed and transconduc tance (gm), drain conductance and breakdown voltage were improved by c arbon doping. These improvements were deduced as being due to a reduct ion in leakage under the channel. No change in the frequency dependenc e of the gm was recognized. Thus, the doped carbon did not generate an y observable traps by which the properties of MESFET were degraded.