Metal-insulator-semiconductor capacitor formed on silicon carbide

Claim 1

A variable capacitance metal-insulator-semiconductor capacitor with reduced series resistance and lesser leakage current, suitable for operation at high temperatures and high radiation densities, and comprising: a substantially variable capacitance doped semiconductor portion formed of silicon carbide having substantially uniform high resistivity for substantially varying the capacitance thereof when said doped semiconductor portion is depleted of carriers; a substantially constant capacitance portion of insulator material upon one surface of said silicon carbide semiconductor portion; a metal portion upon said substantially constant capacitance insulator portion for defining an active region of said silicon carbide semiconductor portion, and for variably depleting said active region of carriers when a bias is applied to said metal portion; and an ohmic contact upon said one surface of said silicon carbide semiconductor portion so that a bias applied to said metal portion variably depletes said silicon carbide semiconductor portion of carriers, substantially varies the capacitance of said silicon carbide semiconductor portion, and correspondingly substantially varies the total capacitance of said capacitor.