Surface morphologies of excimer-laser annealed BF2+ implanted Si diodes

A. Burtsev*, H. Schut, L. K. Nanver, A. Van Veen, J. Slabbekoorn, T. L.M. Scholtes

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)

Abstract

Laser-induced surface roughness and damage formation in ultra-shallow n+-p and p+-n junctions, formed by low energy (5 keV) As+ and BF2+ implantations in Si, respectively, with a dose of 1 × 1015 cm-2 have been investigated by atomic force microscopy (AFM) and Positron Annihilation Doppler Broadening (PADB) technique. The Si surface roughness is found to increase with laser energy density, and reaches a value of 3.5 rm after excimer-laser annealing (ELA) at 1100 mJ/cm2. However, anomalous behavior is witnessed for BF2+-implanted Si sample at 800 mJ/cm 2, at which energy very high surface protrusions up to 9nm high are observed. By PADB this behavior is correlated to extensive deep microcavity formation in the Si whereby the volatile F2 fraction can accumulate and evaporate/out-diffuse, leading to Si surface roughening. The consequences for the diode characteristics and contact resistivity are examined.

Original languageEnglish
Pages (from-to)109-113
Number of pages5
JournalMaterials Science and Engineering B: Solid-State Materials for Advanced Technology
Volume114-115
Issue numberSPEC. ISS.
DOIs
Publication statusPublished - 30 Dec 2004
Externally publishedYes

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Keywords

  • Excimer-laser annealing
  • Laser-induced surface roughness
  • Low-energy implantation
  • Positron annihilation Doppler broadening technique
  • Silicon diodes
  • Ultra-shallow junctions

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