Applied Physics A

, Volume 114, Issue 4, pp 1009–1016

Improving dopant incorporation during femtosecond-laser doping of Si with a Se thin-film dopant precursor

Authors

    • Department of Materials Science and EngineeringMassachusetts Institute of Technology
  • Meng-Ju Sher
    • Department of PhysicsHarvard University
  • Benjamin Franta
    • School of Engineering and Applied SciencesHarvard University
  • Yu-Ting Lin
    • School of Engineering and Applied SciencesHarvard University
  • Eric Mazur
    • Department of PhysicsHarvard University
    • School of Engineering and Applied SciencesHarvard University
  • Silvija Gradečak
    • Department of Materials Science and EngineeringMassachusetts Institute of Technology
Article

DOI: 10.1007/s00339-013-7673-8

Cite this article as:
Smith, M.J., Sher, M., Franta, B. et al. Appl. Phys. A (2014) 114: 1009. doi:10.1007/s00339-013-7673-8

Abstract

We study the dopant incorporation processes during thin-film fs-laser doping of Si and tailor the dopant distribution through optimization of the fs-laser irradiation conditions. Scanning electron microscopy, transmission electron microscopy, and profilometry are used to study the interrelated dopant incorporation and surface texturing mechanisms during fs-laser irradiation of Si coated with a Se thin-film dopant precursor. We show that the crystallization of Se-doped Si and micrometer-scale surface texturing are closely coupled and produce a doped surface that is not conducive to device fabrication. Next, we use this understanding of the dopant incorporation process to decouple dopant crystallization from surface texturing by tailoring the irradiation conditions. A low-fluence regime is identified in which a continuous surface layer of doped crystalline material forms in parallel with laser-induced periodic surface structures over many laser pulses. This investigation demonstrates the ability to tailor the dopant distribution through a systematic investigation of the relationship between fs-laser irradiation conditions, microstructure, and dopant distribution.

Supplementary material

339_2013_7673_MOESM1_ESM.pdf (117 kb)
(PDF 117 kB)

Copyright information

© Springer-Verlag Berlin Heidelberg 2013