Furnace-annealing behavior of B-doped poly-SiGe on insulating films has been investigated. With increasing Ge fraction, thermal stability of electrically active B atoms at a supersaturated concentration was significantly improved, for example, the stability at 800℃ for poly-Si_<0.6>Ge_<0.4> films was nine times as high as that for poly-Si films. The deactivation process consists of the fast and slow processes. The fast process was due to sweeping out of B atoms from substitutional to interstitial sites, enhanced by a local strain induced by the difference in atomic radii between Si and B atoms, and the slow process was due to trapping of B at grain boundaries during grain growth by annealing. The improved thermal stability of B atoms is due to the local strain compensation by Ge doping.
|Number of pages||4|
|Journal||Research Reports on Information Science and Electrical Engineering of Kyushu University|
|Publication status||Published - Sep 2003|