Siliciumkarbid

Siliciumkarbid, også kaldt karborundum, carborundum, har den kemiske forkortelse SiC, som består af silicium og carbon.

Et stykke siliciumkarbid

Det er et industrielt fremstillet materiale, som anvendes til slibeprodukter og som tilsætningsstof. Materialet er noget af det hårdeste, som findes, med værdien 9,5 på Mohs hårdhedsskala; kun diamanter er hårdere med en Mohsværdi på 10.

Siliciumkarbid er i ren form farveløs, isolerende, ildfast og har halvlederegenskaber. Det har en række brugsområder som slibemiddel, inden for keramik- og støberivirksomhed.

Siliciumkarbid indgår i rumfærgens varmeskjold, og visse skivebremser er opbygget af materialet. I nyere tid er man begyndt at lave dioder (SiC-Schottky-diode) og transistorer af halvlederlegeringen. ^{[1] [2] [3]}

Kilder/referencer

1. 25 August, 2004, BBC News: Door open for silicon replacement Citat: "...Previous research has already shown that even at red-hot temperatures as high as 650C (1,202F), silicon carbide devices can function unperturbed and without the need for cooling....One exciting application for silicon carbide could be in deep-space missions, where nuclear power would be needed for the craft. Radiation-hardened silicon carbide devices would reduce the shielding needed to protect reactor control electronics..."
2. 2001, purdue.edu: Lateral power MOSFETs in silicon carbide Citat: "...silicon carbide is considered to be the material of choice for power switching electronics in the future...we present the first lateral power devices on a semi-insulating vanadium doped substrate of silicon carbide. The first generation of lateral DMOSFETs in 4H-SiC yielded a blocking voltage of 2.6 kV..."
3. Oct 28, 2011, powerelectronics.com: SiC “Super” Junction Transistors Deliver High Temp Performance Arkiveret 23. december 2011 hos Wayback Machine Citat: "...GeneSiC’s SiC-based 1200 V/220 mΩ Super Junction Transistors (SJTs) feature high temperature (> 300 °C) operation capability, ultra-fast switching transitions (< 15 ns)...The leakage current in the SJT at VDS = 1200 V is below 5 µA up to temperatures as high as 225 °C. Leakage currents of < 100 µA were measured even at 325 °C..."