Electron Beam Activated Diamond Devices

Abstract

ABSTRACTDiamond's unique properties are ideally suited for high power and high frequency electronic applications. Natural type Ila diamond wafers of various thicknesses and active areas were used to construct several electron beam activated diamond devices. Average voltage gradients in the diamond target on the order of a mega-volt per centimeter were obtained. Possibilities of improving the attainable average voltage gradient are discussed. Electron activation avoids the necessity of semiconducting doping of the active diamond devices. The electron bombardment on diamonds yields a current-voltage characteristics very similar to that of a bipolar transistor. In the experiments discussed here, the diamond conduction to bombarding current gain ranged from 1,000 to 3,000 depending upon the diamond thickness and the bombarding electron energy. The bombarded diamond on-state resistance is consistent with a simple carrier drift and space charge model. Maximum conduction current density achieved in diamond is 19kA/cm2. High power switching of greater than 25kW with less than 100ns risetime is demonstrated. An electron beam bombarded millimeter wave diamond device has generated more than one watt of power.