AIP Advances (Jun 2012)

In-line Si1-xGex epitaxial process monitoring and diagnostics using multiwavelength high resolution micro-Raman spectroscopy

  • Chun-Wei Chang,
  • Min-Hao Hong,
  • Wei-Fan Lee,
  • Kuan-Ching Lee,
  • Shen-Min Yang,
  • Ming-Shan Tsai,
  • Yen Chuang,
  • Yu-Ta Fan,
  • Noriyuki Hasuike,
  • Hiroshi Harima,
  • Takeshi Ueda,
  • Toshikazu Ishigaki,
  • Kitaek Kang,
  • Woo Sik Yoo

DOI
https://doi.org/10.1063/1.4711043
Journal volume & issue
Vol. 2, no. 2
pp. 022117 – 022117-11

Abstract

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Multiwavelength, high resolution micro-Raman spectroscopy was applied to in-line process monitoring and diagnostics of undoped and B-doped Si1-xGex epitaxy on Si(100) device wafers. This noncontact technique was used to monitor the Ge content, B concentration and thickness of single and double Si1-xGex epitaxial layers. Epitaxial process problems were diagnosed nondestructively. Raman peak positions and full-width-at-half-maximum of the Si-Si peak(s) from the Si1-xGex epitaxial layer(s) and Si substrates, in the wavenumber range of 475 ∼ 535 cm-1, were monitored under ultraviolet and visible excitation wavelengths. The Ge content, B concentration and Si1-xGex epitaxial film structures were verified by secondary ion mass spectroscopy (SIMS) depth profiling results. In-line monitoring of Si-Si and Si Raman peaks is very effective in noncontact material property characterization, epitaxial process optimization, and quality control applications.