Electrical properties of B-ion-implanted Si layer preamorphized by Ge ions

B+-implanted Si layers preamorphized with 100-keV Ge+ implantation have been evaluated using Rutherford backscattering spectrometry and the van der Pauw technique. We suggest that the lower structural recovery, 98% of Si occupies substitutional sites, arises from the difference in tetrahedral covalent radii among Si, Ge, and B atoms. Electrical properties of dual Ge+/B+-implanted layers are discussed by a two-carrier model consisting of both electron and hole. The conversion temperature from the p- to the n-type varies from ∼15 to ∼ 125 °C with increasing electrical activation of the boron acceptor. The activation saturates at annealing temperatures above 800 °C. This restriction is due to the presence of the level and/or the defect induced in the preamorphization process.