Title :
Realization of ultra-shallow junction: suppressed boron diffusion and activation by optimized fluorine co-implantation
Author :
Shano, T. ; Kim, R. ; Hirose, T. ; Furuta, Y. ; Tsuji, H. ; Furuhashi, M. ; Taniguchi, K.
Author_Institution :
Dept. of Electron. & Inf. Syst., Osaka Univ., Japan
Abstract :
The effects of F on B diffusion and activation have been studied by implanting various doses of F/sup +/ followed by Si/sup +/ preamorphization and B/sup +/ implant. In B tail region, the activation of B is suppressed with increasing F concentration, and B diffusion is also suppressed when F concentration exceeds a critical level, 1/spl times/10/sup 18/ cm/sup -3/, which was confirmed from the experiments using BDSL (Boron delta doped superlattice) implanted with F/sup +/. The fact that F atoms remain in silicon after annealing at 820/spl deg/C has been investigated. The experiments of a subamorphous threshold Si/sup +/ dose at high energy reveal that F atoms remain at excess vacancy region extending from the surface to about 0.8 R/sub p/ of the implanted Si profile.
Keywords :
annealing; boron; doping profiles; elemental semiconductors; fluorine; semiconductor doping; silicon; surface diffusion; 820 C; 820 degrees C; B diffusion; B implant; B tail region; BDSL; F atoms; F concentration; F diffusion; Si preamorphization; Si:B; Si:F; Si:F,B; annealing; subamorphous threshold Si/sup +/; Amorphous materials; Annealing; Atomic layer deposition; Boron; Implants; Information systems; MOSFET circuits; Silicon; Superlattices; Tail;
Conference_Titel :
Electron Devices Meeting, 2001. IEDM '01. Technical Digest. International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-7050-3
DOI :
10.1109/IEDM.2001.979640
