Ohmic and Schottky contacts for SiC devices

Low resistivity (< 1.10-5 Ω.cm-2) Ohmic and Schottky contacts based on Ni, Ni/Si, Al, Al/Si, Ti, AlSiTi, Pd, Pd/Ti, Pd/Si have been formed to n- and p-type SiC using sputtering, e-beam evaporation and thermal deposition. Technology for production of reproducible and reliable contacts to MESFET, MOSFET, IMPATT and power diodes, operating at temperatures up to 600ºC has been developed.

Packaging and packages for high temperature devices

The packages with high thermal conductivity were designed on Cu-Mo base plate. Eutectic Au / 6%Si and Au / 12%Ge alloys as the highest temperature solder for SiC chips are used. High power (up to 100 W), high frequency (10 GHz) and high temperature (300ºC) packages for SiC MESFET and MOSFET devices were designed.

Thermoelectric cooling – heating systems

Thermoelectric cooling-heating aggregates (TCHA) designed on the base of Peltier modules are used to cool and/or heat air in enclosures under ambient temperature from minus 20 to 40C with power supply 12 or 24 V DC and 220 V, 50 Hz AC. TCHA with different power generation (30, 45 and 60 W) are being produced. An isothermal container (thermostabilizer) for storage and transportation of blood, blood components and other medical goods have been are designed and produced based on TCHA. It provides and maintains temperatures from 1 to 8С in its enclosure at an ambient temperature from minus 20 to 40С at power supply from 11 to 33 V DC and 220 V, 50 Hz AC. After a power cut off the holdover time is 10 hours (at an ambient temperature of 32С). The container has a capacity 45 l and 50 W average power consumption. It has been awarded a Gold Medal at the 55th International Technical Fair in Plovdiv in 1999 and a Diploma at the IV International Exhibition of Military Equipment – “Hemus’2000” – Plovdiv. A household refrigerator (minibar) with volume 30 and 50 l and power supply of 12 or 24 V DC and 220 V, 50 Hz AC is produced on regular basis. The storage temperature is adjustable in the range 3 to 12С. The refrigerator has been awarded a Silver Diploma at the 23 International Fair in Scopje, Macedonia. A bench-top cooler for rapid cooling in dental and medical applications with cooling plate temperature - minimum 27С under ambient temperature and power supply 220 V was designed. Heat Pipes for transferring heat from thermoelectric modules and other electronic equipment аre being developed.

Photoconductive cells

Photoconductive cells with dark resistance over 1.107 Ω, resistance at illumination 200 lx lower than 5.103 Ω and peak response wavelength 640 – 680 nm are produced.

Bulk microwave sensors for human presence

Bulk microwave sensors for security applications and power saving light systems with supply voltage 12 V, current consumption 30 mA and effective radius of operation up to 5 m are produced.

Photoprobes

Photoprobes for embedding in control panels of automated oil torches with power supply 220 V / 50 Hz, threshold level actuation of 60 lx and load current 10 mA are in production. In combination with the other torch components they maintain constant fuel flow, and interrupt the flow, when the flame is extinguished.