Effects of C or Si co-implantation on the electrical activation of B atoms implanted in 4H–SiC

Abstract

The influence of co-implantation of C or Si ions on the electrical activation of B acceptors in 4H–SiC was studied by using Hall effect and photoluminescence (PL) investigations. The free hole concentration in B-implanted layers is found to increase due to co-implantation of C and to decrease owing to Si co-implantation. Hot co-implantation of C at 800 °C gives rise to a further increase of the free hole concentration. It is found that the intensity of the PL peak at a wavelength 383.9 nm, which arises from shallow B acceptors [Sridhara et al., Mater. Sci. Forum 264–268, 461 (1998)], is enhanced by the coimplantation of C. These results demonstrate that the electrical properties of B-implanted p-type layers are improved by C co-implantation. The mechanisms, which alter the electrical activation of implanted B atoms due to co-implantation of C or Si, are discussed.

Characterization of Defects Generated During Boron Diffusion in SiC

“…The nature of the 415nm and 427nm PL features inferred by examining the spectrum depth dependence is consistent with previous results [1][2][3][4][5][6][7][8][9]. Previous studies indicated that the sharp feature at 415 nm arises from donor-acceptor pair (DAP) recombination, involving traceimpurity-level nitrogen donor and the B acceptor atoms.…”

“…The as-implanted range of the lighter B atoms is greater, high temperature annealing produces greater dopant drive-in, and device reliability and performance is improved [1][2][3][4][5][6][7][8][9]. Thermal drive-in of implanted B offers several advantages over doping with other common p-type species in SiC.…”

Effects of hydrogen on the properties of SiC crystals grown by physical vapor transport: Thermodynamic considerations and experimental results

“…While the root cause of high resistivity in SiC is not well understood, purity of the material clearly plays a role. The main residual impurities in undoped SiC are nitrogen (shallow donors) [2] and boron (shallow acceptors) [3] commonly present in the high-10 15 cm À3 -low-10 16 cm À3 concentration [4]. High resistivity is achieved by balancing these shallow impurities by deeplevel defects.…”

Effect of boron on the resistivity of compensated 4H-SiC

“…8 The origin of the deep boron level has been suggested as a boron atom on a Si site next to a C vacancy, thus forming a complex. 9 The isolated carbon vacancy is suggested to act as a deep-donor-like level. Thus, it should be taken into account as a possible compensation center in p-type 4H-SiC.…”