Abstract: A current-limit circuit comprising a control transistor coupled to a power transistor in a current mirror configuration. A switch transistor is operatively coupled between the output of the power transistor and the control transistor to selectively activate the control transistor in response to an over current condition detected by a defect transistor. Current drawn through the power transistor in the over current condition is limited by the control transistor which is powered from the gate of the power transistor. The power and detect transistors are integrated on a semi-conductor substrate of a first conductivity type defining first and second surfaces. An array of adjacent transistor body regions of a second conductivity type provided adjacent said first surface with gate electrodes extending between adjacent body regions and insulated therefrom by a gate insulator layer. Transistor source regions of said first conductivity type are provided in said body regions adjacent said gate electrodes.

Abstract: A semiconductor device (e.g. MOSFET or IGBT) comprises active and termination regions (1,2) formed in a semiconductor substrate (4). The substrate (4) has an upper surface and a termination including a trench (12) extending into the substrate (4) from the upper surface within the termination region (1). Termination trench (12) is at least partly filled with an insulating material (13) which extends from the termination trench (12) to overlie adjacent regions of the device above the surface. A channel stop region (11) extends laterally from a side wall of the termination trench (12) into the substrate (4).

Abstract: An insulated gate bipolar transistor having a collector electrode 3, an emitter region 6 and a base region 4 formed between the collector electrode and the emitter region, further including a channel stop region 17 spaced from the emitter region and electrically connected to the collector electrode. The base region 4 includes a first region 4c between the emitter region and the channel stop region and a second region between the first region and the collector electrode, the first region having a higher minority-carrier-lifetime than the second region, whereby the first region provides a conductivity modulated conduction path between the emitter region and the channel stop region when the insulated gate bipolar transistor is reverse biased.

Abstract: A method for implanting ions into a surface of a semiconductor structure covered by a layer of insulating material, for example into a trench wall covered by a layer of oxide. A beam of ions is directed at a glancing angle to the layer of insulating material such that a substantial proportion of ions which are implanted into the semiconductor structure surface are scattered from the beam by the layer of insulating material. It is possible therefore to implant ions into a trench wall without requiring a beam source arranged to deliver a beam at a large angle to the trench wall surface.