Abstract: A semiconducting diode utilizing the transit time of electrical charge carriers in a semiconductor medium, having an input structure formed by a matrix of micropoints, said matrix consisting of a plurality of microscopic contacts separated by an insulating layer. The diameter of each contact is of the order of 0.5 to 5 micrometers, the distance between the closest contacts being of the order of 0.5 to 15 micrometers. The contacts are made of metal or of an alloy of low resistivity or of a semiconductor material generally doped more heavily than the layer of the semiconductor lying under the microscopic contact. The result of such a structure is an increase in efficiency attributable to the reduction in avalanche voltage or to a better injection by tunnel effect.

Abstract: A method for virtually eliminating contact resistances in particular at very high frequency, for instance in the case of source and drain contacts of a field effect transistor. The method consists in creating a matrix of depressions or "dishes", for example 1 to 6 microns in diameter, separated by intervals of some few microns. In a first step, windows are opened in an insulating layer by an etching operation. In a second step, by ion machining, angular profiles are carved in the bottom of the dishes for promoting tunnel effect. In a last step a metal layer is deposited and enshrouds the matrix.

Abstract: A junction-type field-effect structure has an active layer covered at least in part by a dielectric layer. A metal base is applied to the dielectric layer.

Abstract: In a Gunn effect device the cathode contact is formed by an assembly of zones through which is effected the injection of current adjoining an assembly of zones which on the contrary are capable of blocking this injection. A layer of dielectric material possibly insulates these two types of zones. A metallic control electrode assures the arrival of the current. The respective dimensions of these zones are determined in such manner that, in operation, the injected current is channeled between parts of the device made dielectric by the creation of space charges.