CREE, INC. has acquired a portfolio of patents and patent applications related to semi-insulating siliconcarbide (SiC) material and power device technology from German car corporation Daimler AG. The portfolio consists of approximately 20 patent families including issued patents in the US, Germany, Japan, and China. Financial terms were not disclosed.

U.S. Patent No. 5,856,231 ('231) titled "Process for Producing High- Resistance Silicon Carbide" is an important piece of the portfolio. It relates to the manufacturing of semiinsulating SiC using vanadium doping. The vanadium doping process is used to make silicon carbide chips for higher-end radio-frequency (RF) applications.

"We had licensed this impressive group of patents for many years and the full acquisition is a valuable addition to our already extensive intellectual- property position," says Dr. Cengiz Balkas, Cree Vice President and General Manager, Power and RF. Dr. Vijay Balakrishna, Cree Product Line Manager, Materials, adds, "Cree is already the leader in highpurity semi-insulating SiC and acquiring the '231 patent further bolsters our IP position, especially in semi-insulating SiC achieved through vanadium doping."

According to Cree's Michelle Murray, "Silicon carbide is typically an electrically conductive material when it is grown. Adding vanadium allows one to easily convert the SiC from a conductor to an insulator. Semi-insulating SiC is preferred for high-power RF transistor applications, such as cellular communications or military radio broadcast Adding (doping) Vanadium to SiC is an effective method to produce semi-insulating SiC for high-power RF/microwave transistors."

Cree is an innovator of lightingclass light-emitting diodes (LEDs), LED lighting, and semiconductor solutions for wireless and power applications. Cree's product families include LED fixtures and bulbs, blue and green LED chips, high-brightness LEDs, lighting-class power LEDs, powerswitching devices, and RF/wireless devices. Cree also offers solutions in applications like general illumination, backlighting, electronic signs and signals, variable-speed motors, and wireless communications.