Deep impurity levels and Ti solubilities were determined by means of deep-level transient spectroscopy. It was found that the Ti formed multi-levels; with an acceptor level of Ec - 0.09eV, a donor level of Ec - 0.27eV, and a double-donor level of Ev + 0.28eV. The solubilities, as a function of reciprocal temperature, were well-represented by straight lines with an associated activation energy of 3.8eV. The deep-level transient spectroscopy data indicated that the diffusivity (table 222) could be described by:
D(cm2/s) = 0.12 exp[-2.05(eV)/kT]
S.Kuge, H.Nakashima: Japanese Journal of Applied Physics, 1991, 30[11A], 2659-63
Table 221
Diffusion of Ti in Si
T (C) | D (cm2/s) |
950 | 5.2 x 10-10 |
1000 | 1.3 x 10-9 |
1050 | 2.2 x 10-9 |
1100 | 3.5 x 10-9 |
1150 | 7.3 x 10-9 |
1200 | 8.8 x 10-9 |