Optically controlled silicon carbide and related wide-bandgap transistors and thyristors
AssigneePower Integrations, Inc.
InventorMichael S. Mazzola
Life of this patent
Estimating the term…
Abstract
An optically active material is used to create power devices and circuits having significant performance advantages over conventional methods for affecting optical control of power electronics devices and circuits. A silicon-carbide optically active material is formed by compensating shallow donors with the boron related D-center. The resulting material can be n-type or p-type but it is distinguished from other materials by the ability to induce persistent photoconductivity in it when illuminated by electromagnetic radiation with a photon energy in excess of the threshold energy required to photoexcite electrons from the D-center to allowed states close to the conduction band edge, which varies from polytype to polytype.
Claims24
1-26. (canceled)
A device comprising:
- an optically active switch that comprises
- a substrate,
- an optically active, semi-insulating silicon carbide layer above the substrate, the silicon carbide layer having boron-related D-center defects formed therein, wherein the silicon carbide layer is optically active in that the silicon carbide layer switches into conduction in response to sub-bandgap wavelength illumination, the switching of the silicon carbide layer into conduction in response to the sub-bandgap wavelength illumination closing the optically active switch, and
- an optically transmissive layer configured to allow the sub-bandgap wavelength illumination to illuminate the silicon carbide layer.
A device comprising:
- a controller to drive a one or more sources of electromagnetic radiation of a longer wavelength and electromagnetic radiation of shorter wavelength;
- a half-bridge power circuit comprising a high side transistor switch that comprises an optically active silicon carbide layer, wherein the silicon carbide layer is optically active in that the silicon carbide layer switches from an equilibrium state to a non-equilibrium state in response to the shorter wavelength electromagnetic radiation and from the non-equilibrium state to the equilibrium state in response to the longer wavelength electromagnetic radiation,
- wherein timing of the illumination of the high side transistor switch by the longer wavelength electromagnetic radiation and the shorter wavelength electromagnetic radiation is determined by the controller.
A vertical trench bipolar junction transistor comprising:
- a collector contact;
- a collector formed of semiconductor material and electrically connected to the collector contact;
- an optically active silicon carbide region above the collector;
- an emitter formed of semiconductor material and above the optically active silicon carbide portion;
- an emitter contact electrically connected to the emitter,
- wherein the silicon carbide region is optically active in that the silicon carbide region increases in conductivity in response to illumination thereby acting as a base and allowing current to flow between the collector and the emitter of the vertical trench bipolar junction transistor, and
- a trench extending through the emitter, the trench disposed to permit illumination originating from above the emitter contact to reach the silicon carbide region.
Dependencies are inferred from the claim text.