Ion-beam-induced epitaxy in B-implanted silicon preamorphized with Ge ions

The ion-beam-induced epitaxial crystallization (IBIEC) of B⁺-implanted Si(100) layers, which are preamorphized by Ge⁺ ion implantation, has been studied by a 400 keV Ar⁺-ion irradiation at temperature ranges from 300 to 475°C. A minimum Rutherford backscattering yield of the regrowth layer is improved to 7.8% for an Ar⁺ ion dose of 1.3×10¹⁶/cm² at a substrate temperature of 400°C. The activation energy for IBIEC is estimated to be 0.22 eV. A peak of the depth B profile evaluated by secondary ion mass spectroscopy is shifted to about 35 nm toward the surface after Ar⁺ ion irradiation. However, the electrical activation of the implanted B atoms is restricted within about 10%. It is also demonstrated that the lateral crystallinity of the amorphous layer can be recovered selectively by the IBIEC technique.