Satoshi Tobe

EQUILIBRIUM CONSTANT OF SEGREGATION-INDUCED FE GETTERED BY HEAVY BORON DOPING IN SI

The equilibrium constant of segregation-induced Fe gettering by heavy boron (B) doping in Si is obtained by experimental determination of the activation energy and the site density parameter of the gettering reaction. The activation energy is determined to be 0.68±0.03 eV by analyzing the temperature dependence of the equilibrium constant of the reaction. This result indicates that the Fe gettering is strongly related to formation of the Fe–B complex whose binding energy is very close to the value determined for the activation energy. Furthermore, the gettering site density is found to be proportional to the doped B concentration in the substrate crystal. It is understood from the activation energy value that the Fe gettering ability of each reaction site for heavy B doping is less than that for thin polycrystalline Si film on the back surface of a substrate. The well known high overall gettering capability of the heavily B-doped substrate is not simply due to the activation energy effect it is predominan...