Copper passivation of boron in Si1−xGex alloys and boron reactivation kinetics

✍ Scribed by M. Barthula; M.O. Aboelfotoh; F. Meyer

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 102 KB
• Volume: 55
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/s0167-9317(00)00463-9

✦ Synopsis

Copper passivation of boron in SiGe layers has been investigated by the use of Schottky barrier structures prepared by the deposition of copper on boron-doped SiGe alloys at room temperature. The boron passivation occurs at room temperature after Cu deposition and diffusion in the alloy. The Cu diffusivity is enhanced by dislocations and retarded by increasing the Ge content and (or) the compressive strain. The mechanisms for passivation seem similar to those evidenced for pure silicon: 1 the fast-diffusing interstitial Cu passivates the boron acceptors by forming neutral B-Cu complexes. The reactivation of boron is partially obtained after annealing at 2008C while the Cu Si Ge phase is formed. The reaction kinetics are first 3 12x x

order with an activation energy of 0.76 eV.