I dagens verden er Halvleder blevet et emne med stigende interesse og debat. Med så mange forskellige meninger, forskning og perspektiver er det svært at komme til en endelig konklusion om denne sag. Det er dog ubestrideligt, at Halvleder vækker lidenskaber og udfordrer folks mentaliteter. Uanset om det ses fra et videnskabeligt, socialt, politisk eller økonomisk perspektiv, fortsætter Halvleder med at skabe kontroverser og påvirke livet for millioner af mennesker rundt om i verden. I denne artikel vil vi udforske de forskellige facetter af Halvleder og forsøge at kaste lidt lys over dette meget komplekse emne.
Halvledere er materialer, der har en elektrisk ledningsevne, der ligger mellem de ledende materialer og de isolerende. Der er ikke nogen skarp definition af, hvad en halvleder er, men det er typisk materialer med en resistivitet, der ligger i området fra ca. 10-5 til ca. 107 Ω · m.
Der er følgende kendetegn ved et rent halvledermateriale:
Der er ingen frie valenselektroner i halvlederkrystalgitteret. Derfor den "dårlige" elektriske ledningsevne, som bliver bedre med stigende temperatur.
Halvlederformer
Den hyppigst anvendte halvlederform er krystallinsk og produceres i en halvlederstang, som efterfølgende skæres i halvlederskiver (eng. wafer). Halvlederskiven kan fx også få navn efter halvlederen fx siliciumskive (eng. siliciumwafer).
firstprincipals.com: MESFET TechnologyArkiveret 18. oktober 2003 hos Wayback Machine Citat: "...The technology is covered by U.S. Patent 6,150,680, along with four associated foreign applications. Using a unique design approach, along with variations in processing, improvements at higher voltage and power can be achieved using III–V compounds such as GaAs, InP, and potentially GaN and SiC...."
Webarchive backup: Infineon Technologies Produces Worlds first Power Semiconductors in Silicon Carbide Citat: "...Due to its unique characteristics, the silicon carbide (SiC) material has high blocking voltage capability (up to 3500V) resulting in a higher schottky barrier, ten times higher electrical breakdown field strength, and a thermal conductivity comparable with that of copper..."
Webarchive backup: Januar 2002, Silicon carbide moves further towards commercialization Citat: "...A 3 x 4.1 mm^2 1800 V SiC JFET die was presented with a current-carrying capability of 15 A at an on-state voltage of just 2 V. ...Of the bipolar devices reported at the conference, the most impressive results came from Cree, which announced 10 kV, 200 A pulsed power performance from a 3 x 3 mm 4H-SiC pin diode. ..."
The Road to the Transistor, By Jed Margolin Citat: "...The copper oxide rectifier was invented in 1927 by L.O. Grondahl and P.H. Geiger...The selenium rectifier was invented in 1933 by C.E. Fitts..."
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..."
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..."