TY - GEN
T1 - Hybrid physical-chemical vapor transport growth of SiC bulk crystals
AU - Fanton, M. A.
AU - Li, Q.
AU - Polyakov, A. Y.
AU - Cavalero, R. L.
AU - Ray, R. G.
AU - Weiland, B. E.
AU - Skowronski, M.
PY - 2006
Y1 - 2006
N2 - The effects of H2 addition to the growth ambient during physical vapor transport (PVT) growth of 6H and 4H SiC were investigated using SIMS, DLTS and Hall effect measurements. Using this hybrid physical-chemical vapor transport (HPVT) approach, boules were grown using Ar-H2 and He-H2 mixtures with H2 concentrations up to 50 at%. Thermodynamic modeling suggests that addition of H2 improves the carbon transport in HPVT compared to standard PVT. This should lead to a substantial decrease in the concentration of residual N donors and the concentration of electron traps. This is confirmed by the experimental results. As expected, the source transport rate increased as H2 was added to the growth environment due to increased C transport. The background nitrogen concentration and the free electron density decreased significantly with increasing H2 concentration. The formation of electron traps (activation energies of 0.4 eV, 0.6-0.65 eV, 0.7 eV, 0.9 eV and 1 eV) was also strongly suppressed. These changes were observed for H2 concentrations as low as 4 at%. The decreased N concentration improves the ability to produce high resistivity SiC material, and for H2 concentrations as high as 10-25%, the very first wafers cut from the seed end of the boules have a resistivity exceeding 106 Ωcm.
AB - The effects of H2 addition to the growth ambient during physical vapor transport (PVT) growth of 6H and 4H SiC were investigated using SIMS, DLTS and Hall effect measurements. Using this hybrid physical-chemical vapor transport (HPVT) approach, boules were grown using Ar-H2 and He-H2 mixtures with H2 concentrations up to 50 at%. Thermodynamic modeling suggests that addition of H2 improves the carbon transport in HPVT compared to standard PVT. This should lead to a substantial decrease in the concentration of residual N donors and the concentration of electron traps. This is confirmed by the experimental results. As expected, the source transport rate increased as H2 was added to the growth environment due to increased C transport. The background nitrogen concentration and the free electron density decreased significantly with increasing H2 concentration. The formation of electron traps (activation energies of 0.4 eV, 0.6-0.65 eV, 0.7 eV, 0.9 eV and 1 eV) was also strongly suppressed. These changes were observed for H2 concentrations as low as 4 at%. The decreased N concentration improves the ability to produce high resistivity SiC material, and for H2 concentrations as high as 10-25%, the very first wafers cut from the seed end of the boules have a resistivity exceeding 106 Ωcm.
UR - https://www.scopus.com/pages/publications/37849021567
UR - https://www.scopus.com/pages/publications/37849021567#tab=citedBy
U2 - 10.4028/0-87849-425-1.103
DO - 10.4028/0-87849-425-1.103
M3 - Conference contribution
AN - SCOPUS:37849021567
SN - 9780878494255
T3 - Materials Science Forum
SP - 103
EP - 106
BT - Silicon Carbide and Related Materials 2005, - Proceedings of the International Conference on Silicon Carbide and Related Materials 2005
PB - Trans Tech Publications Ltd
T2 - International Conference on Silicon Carbide and Related Materials 2005, (ICSCRM 2005)
Y2 - 18 September 2005 through 23 September 2005
ER -