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Fundamental challenges and potential solutions for THz SiGeC heterojunction bipolar transistors


Investigation of potential roadblocks for achieving the ultimate performance potential of SiGeC HBT technology

IHP's Contribution

  • Vertical structure by (i) realization of highly conductive layers with extremely shallow vertical doping profiles and extremely steep gradients under the constraints of maximizing the safe operating area by maximizing the breakdown voltage and minimizing the collector current density at peak fT and fmax. and (ii) Optimization of the Ge profile composition and impact on the ultimate high-frequency performance
  • Lateral structure by (i) exploring the trade-off between various architectures with respect to high-frequency performance and self-heating and (ii) possible measures for dealing with the high current densities which are expected to exceed the limits of presently used metallization materials
  • TCAD and HBT modeling by (i) calibration of physical TCAD simulation models for advanced vertical profiles in order to enable more accurate predictions (e.g. for process development) and evaluation of the performance limit, (ii) exploration of the impact of process tolerances in extremely scaled structures, and (iii) evaluation of the suitability of an existing SiGeC HBT compact model and its underlying formulations.


The project is funded by the DFG under the N° HE 6846/1-1

Project Partners


Selected Publications

J. Korn, H. Rücker, B. Heinemann, A. Pawlak, G. Wedel, M. Schröter, “Experimental and Theoretical Study of fT for SiGe HBTs with a Scaled Vertical Doping Profile,” in Proceedings BCTM, IEEE, pp. 117-120, 2015.

The building and the infrastructure of the IHP were funded by the European Regional Development Fund of the European Union, funds of the Federal Government and also funds of the Federal State of Brandenburg.