Abstract: A unipolar semiconductor device having a drift layer (3) doped according to a first conductivity type forming a conducting path and regions (7, 8) doped according to a second conductivity type and arranged next to the drift layer, has the drift layer and the regions of a semiconductor material having an ionization energy Ei of dopants of the second conductivity type therein exceeding 0.5 eV and/or a solubility of the dopants of the second conductivity type therein being less than 1018 cm?3.

Abstract: A lateral field effect transistor for high switching frequencies having a source region layer (4) and a drain region layer (5) laterally spaced and of highly doped first conductivity type, a first-conductivity-type channel layer (6) of lower doping concentration extending laterally and interconnecting the source region layer (4) and the drain region layer (5). The transistor has a gate electrode (7) arranged to control the properties of the channel layer (6), and a second-conductivity-type base layer (8) arranged under the channel layer (6) at least partially overlapping the gate electrode (7) and at a lateral distance to the drain region layer (5), the highly doped second-conductivity-type base layer (8) being shorted to the source region layer (4).

Abstract: A semiconductor device comprises a first layer (1) of a wide band gap semiconductor material doped according to a first conductivity type and a second layer (3) on top thereof designed to form a junction blocking current in the reverse biased state of the device at the interface to said first layer. The device comprises extension means for extending a termination of the junction laterally with respect to the lateral border (6) of the second layer. This extension means comprises a plurality of rings (16-21) in juxtaposition laterally surrounding said junction (15) and being arranged as seen in the lateral direction away from said junction alternatively a ring (16-18) of a semiconductor material of a second conductivity type opposite to that of said first layer and a ring (19-21) of a semi-insulating material.

Abstract: A semiconductor device of unipolar type has Schottky-contacts (6) laterally separated by regions in the form of additional layers (7, 7?) of semiconductor material on top of a drift layer (3). Said additional layers being doped according to a conductivity type being opposite to the one of the drift layer. At least one (7?) of the additional layers has a substantially larger lateral extension and thereby larger area of the interface to the drift layer than adjacent such layers (7) for facilitating the building-up of a sufficient voltage between that layer and the drift layer for injecting minority charge carriers into the drift layer upon surge for surge protection.

Abstract: Method for producing a field effect transistor having a source region (9), a drain region and a channel layer (11) interconnecting the source and drain regions, and including the step of providing a sacrificial layer (4) on part of a semiconductor material (1) whose edge is used to define the edge of an implant, such as the source region (9), in the semiconductor material (1), where the edge (4c) of the sacrificial layer (4) is subsequently used to define the edge of a gate (16).

Abstract: A unipolar semiconductor device having a drift layer (3) doped according to a first conductivity type forming a conducting path and regions (7, 8) doped according to a second conductivity type and arranged next to the drift layer, has the drift layer and the regions of a semiconductor material having an ionization energy Ei of dopants of the second conductivity type therein exceeding 0.5 eV and/or a solubility of the dopants of the second conductivity type therein being less than 1018 cm?3.