Defect engineering for ultra-shallow junctions using surfaces

E. G. Seebauer, C. T.M. Kwok, R. Vaidyanathan, Y. V. Kondratenko, S. H. Yeong, M. P. Srinivasan, Benjamin Colombeau, Lap Chan

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Formation of extremely shallow pn junctions with very low electrical resistance is a major stumbling block to the continued down scaling of microelectronic devices. Recent work in our laboratory has shown that the behavior of defects within silicon (and therefore dopants) can be changed significantly by controlling the chemical state of the surface. Certain chemical treatments of the surface induce it to act as an active "sink" for point defects that removes diffusing Si interstitials selectively over impurity interstitials, leading to less dopant diffusion and better electrical activation. The present work demonstrates such effects experimentally for dopants such as boron and arsenic in both crystalline and Ge pre-amorphized silicon wafers. Surface-based defect engineering was studied by annealing implanted Si according to various protocols with varying degrees of surface activity toward point defects. After implantation, specimens were heated to stimulate diffusive spreading of the implanted profile, with SIMS employed after annealing to monitor the spreading. SIMS measurements showed that the active surface caused less diffusion for boron and arsenic in crystalline silicon (c-Si). However, the boron dose loss in the case of the active surface was significantly higher than for the native oxide surface. This caused higher sheet resistance for the clean surface. Yet the percentage of activated boron was also higher for the clean surface. Thus, the atomically clean surface reduced transient enhanced diffusion and improved the percentage of dopant activation despite higher sheet resistance. Similar trends were observed in Ge preamorphized silicon. Additionally, the active surface dramatically reduced the number of end-of-range defects observed by electron microscopy.

Original languageEnglish (US)
Title of host publicationIon Implantation Technology 2008 - 17th International Conference on Ion Implantation Technology, IIT 2008
EditorsEdmund G. Seebauer, Amitabh Jain, Yevgeniy V. Kondratenko, Susan B. Felch
PublisherAmerican Institute of Physics Inc.
Number of pages4
ISBN (Electronic)9780735405974
StatePublished - Jan 1 2008
Event17th International Conference on Ion Implantation Technology, IIT 2008 - Monterey, United States
Duration: Jun 8 2008Jun 13 2008

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


Other17th International Conference on Ion Implantation Technology, IIT 2008
CountryUnited States


  • Arsenic diffusion in silicon
  • Boron diffusion in silicon
  • Clean surface
  • Diffusion modeling
  • Dopant behavior during annealing
  • Ge pre-amorphized silicon

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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    Seebauer, E. G., Kwok, C. T. M., Vaidyanathan, R., Kondratenko, Y. V., Yeong, S. H., Srinivasan, M. P., Colombeau, B., & Chan, L. (2008). Defect engineering for ultra-shallow junctions using surfaces. In E. G. Seebauer, A. Jain, Y. V. Kondratenko, & S. B. Felch (Eds.), Ion Implantation Technology 2008 - 17th International Conference on Ion Implantation Technology, IIT 2008 (pp. 34-37). (AIP Conference Proceedings; Vol. 1066). American Institute of Physics Inc..