Cree Research Inc.

General Instrument Corporation

C3 Corporation

Douglas G Waltz

John Adam Edmond

Charles Eric Hunter

Calvin H Carter, Jr

Muni M Mitchell

Mohammad Sedigh

Roman Hamerski

Douglas A Asbury

Diamond gemstones and gemstones formed of crystals of silicon carbide are distinguished from each other by introducing a band of ultraviolet light into a target gemstone and measuring the transmissivity of that band of light by the gemstone. A diamond will transmit light within a certain band of the ultraviolet spectrum, while a silicon carbide gemstone will block light within this band. Several instruments for carrying out this procedure are described, including an instrument that utilizes a fiberoptic strand to convey ultraviolet light that has passed through the gemstone to a solid state photodetector.

Optical testing system for distinguishing a silicon carbide gemstone

A method of testing a semiconductor device, having the steps of pulsing the semiconductor device with a predetermined level of current for a duration of time so as to cause inadequate parts to degrade and to cause adequate parts to stabilize, and measuring predetermined electrical or optical performance characteristics for the semiconductor device after the current pulse. A system for testing a semiconductor device on a wafer is also provided having a contact probe for applying current pulses to the semiconductor device on the wafer, measuring means electrically connected to the probe for measuring predetermined electrical or optical performance characteristics of the semiconductor device on the wafer, and optical detection means electrically connected to the measuring means for detecting radiation emitted from the semiconductor device on the wafer.

System and method for accelerated degradation testing of semiconductor

The invention is a packaged diode suitable for operation at temperatures above 200.degree. C. and during temperature excursions between -65.degree. C. and at least 350.degree. C. The invention comprises a diode having respective p-n portions with a p-n junction therebetween, and formed of a semiconductor material that is stable and will exhibit satisfactory diode characteristics at such temperatures. Ohmic contacts are made to the opposite sides of the junction diode and to the respective p and n portions of the diode. An electrode adjacent each of the ohmic contacts is formed of an electrically conductive material that has a coefficient of thermal expansion similar to the coefficient of thermal expansion of the semiconductor material for providing structural support to the junction diode and electrical contact therewith. A lead contacts each of the electrodes opposite each electrode's contact with the diode. Each lead is formed of an electrically conductive material and is joined to the respective electrode by an alloy that likewise remains physically and electrically stable at temperatures greater than 200.degree. C. and during repetitive operating cycles over temperature excursions between about -65.degree. C. and 350.degree. C. A packaging material surrounds the junction diode and portions of the electrode to hermetically seal it.

Packaged diode for high temperature operation

Growing community of inventors

Durham, NC, United States of America

Douglas G Waltz