ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Low-resistivity (〈0.1 Ω cm), p-type SiC layers of about 500 nm width and targeted acceptor concentrations of 1.5×1020 cm−3 and 5.0×1020 cm−3 were produced by the combination of high-dose (1.0 and 3.3×1016 cm−2), multienergy (50–450 keV) Al+ ion implantation of 6H-SiC at −130 °C, ion-beam-induced crystallization with 500 keV, 5×1015 Si+ cm−2 at 500 °C and subsequent furnace annealing at 1500 °C for 10 min. The implanted SiC layers have a nanocrystalline structure consisting of randomly oriented grains of mainly 3C-SiC. The electrical properties of the doped, nanocrystalline layers were investigated by sheet resistance and Hall measurements in dependence on temperature and compared with results from single-crystalline reference samples. In comparison with the standard doping process, the hole concentration at 50 °C is enhanced by more than one order of magnitude from 9.0×1017 cm−3 to 1.6×1019 cm−3 in the case of 1.5×1020 Al cm−3 and from 6.1×1018 cm−3 to 8.0×1019 cm−3 in the case of 5.0×1020 Al cm−3, respectively. It can be speculated that the loss of active Al acceptors by precipitation is reduced in the nanocrystalline layers and, therefore, the critical concentration for the formation of an impurity band can be achieved. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1490145
