Advanced Optical Techniques for the Determination of Composition and Thickness of Strained SiGe Alloys for a Manufacturing Environment
C A. King, H Pois, S Zangooie, R M. Young, Joseph Woicik, J A. Gupta
We report the construction and testing of a model for the measurement of graded SiGe bipolar transistor structures after epitaxial growth. Using a commercially available system with spectroscopic ellipsometry as well as other optical measurement technologies, we have established excellent repeatability and accuracy results with a non-invasive measurement. We found the repeatability for all layers in the actual device stack to be better than 0.5 nm during a load/unload experiment consisting of 30 cycles. In addition, comparison of the optically measured Ge profile with SIMS showed excellent agreement. These results demonstrate that optical measurements are possible for monitoring the epitaxial growth production process for high performance graded SiGe bipolar transistors.
Applied Physics Letters
epitaxial growth, secondary ion mass spectrometry (SIMS), SiGe bipolar
, Pois, H.
, Zangooie, S.
, Young, R.
, Woicik, J.
and Gupta, J.
Advanced Optical Techniques for the Determination of Composition and Thickness of Strained SiGe Alloys for a Manufacturing Environment, Applied Physics Letters
(Accessed September 22, 2023)