TY - GEN
T1 - Carrier lifetime studies of semi-insulating silicon carbide for photoconductive switch applications
AU - Hettler, C.
AU - James, C.
AU - Dickens, J.
AU - Neuber, A.
PY - 2010
Y1 - 2010
N2 - A contactless microwave photoconductivity decay (MPCD) method has been used to measure recombination lifetime and relative conductivity of semi-insulating (SI) silicon carbide (SiC) wafers. A pulsed laser, tunable from 210 nm to 2 m, has been used to probe above and below band gap photoconductive responses of four SI SiC wafers. The carrier lifetimes were calculated by comparing the reflected microwave signal to the photo response of a fast (<300 ps) photodiode. Three vanadium-doped 6H-SiC wafers, with bulk resistivities ranging from 105 Ω-cm to 1011 Ω-cm, and one high-purity semi-insulating (HPSI) 4H-SiC wafer (>109 Ω-cm) were studied. The photoconductive response of each wafer set is presented. The HPSI wafer demonstrated longer carrier lifetime and improved above band gap photoconductivity compared to the vanadium-doped wafers. The difference in carrier lifetimes are attributed to higher densities of recombination centers (vanadium acceptors) in the 6H-SiC substrates.
AB - A contactless microwave photoconductivity decay (MPCD) method has been used to measure recombination lifetime and relative conductivity of semi-insulating (SI) silicon carbide (SiC) wafers. A pulsed laser, tunable from 210 nm to 2 m, has been used to probe above and below band gap photoconductive responses of four SI SiC wafers. The carrier lifetimes were calculated by comparing the reflected microwave signal to the photo response of a fast (<300 ps) photodiode. Three vanadium-doped 6H-SiC wafers, with bulk resistivities ranging from 105 Ω-cm to 1011 Ω-cm, and one high-purity semi-insulating (HPSI) 4H-SiC wafer (>109 Ω-cm) were studied. The photoconductive response of each wafer set is presented. The HPSI wafer demonstrated longer carrier lifetime and improved above band gap photoconductivity compared to the vanadium-doped wafers. The difference in carrier lifetimes are attributed to higher densities of recombination centers (vanadium acceptors) in the 6H-SiC substrates.
KW - carrier lifetime
KW - photoconductive switching
KW - recombination lifetime
KW - semi-insulating
KW - silicon carbide
UR - http://www.scopus.com/inward/record.url?scp=80051779579&partnerID=8YFLogxK
U2 - 10.1109/IPMHVC.2010.5958289
DO - 10.1109/IPMHVC.2010.5958289
M3 - Conference contribution
AN - SCOPUS:80051779579
SN - 9781424471294
T3 - Proceedings of the 2010 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2010
SP - 34
EP - 37
BT - Proceedings of the 2010 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2010
T2 - 2010 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2010
Y2 - 23 May 2010 through 27 May 2010
ER -