Colombo Bolognesi

ETH-Zurich
  • Gate Recess Etch Sensitivity of Thick and Highly-Doped GaInAs Cap Layer in InP HEMT Fabrication

    Colombo Bolognesi, ETH-Zurich
    Daxin Han, ETH-Zürich
    Diego Calvo Ruiz, ETH-Zürich
    Tamara Saranovac, ETH-Zurich
    Olivier Ostinelli, ETH-Zurich

    The use of highly-doped thick cap layers is a common strategy to enhance the performance of GaInAs/AlInAs/InP High Electron Mobility Transistors (HEMTs) by reducing the Ohmic contact resistance (RC). However, because of the high doping level, cap layers become very sensitive to processing steps performed before and during gate recess etching. In this paper, the sensitivity of gate recess etching on a 20 nm highly-doped GaInAs cap layer (doped 7.3 × 1019 cm-3) is studied with respect to Ohmic contact type (annealed/non-annealed), chip size, gate finger length, and etchant choice. The use of very high cap doping levels exacerbates device and process scaling challenges. For example, the recess finger length dependence complicates multi-project wafer runs which would simultaneously include narrow finger HEMTs used in digital ICs and longer finger HEMTs used in microwave analog circuits.

    Download Paper
  • 5.1 Pt Gate Sink-In Process Details Impact on InP HEMT DC and RF Performance

    Tamara Saranovac, ETH-Zurich
    Olivier Ostinelli, ETH-Zurich
    Colombo Bolognesi, ETH-Zurich
    Download Paper
  • 10.1 Comparison of Charge Dissipation Layers and Dose Sensitivity of PMMA Electron Beam Lithography on Transparent Insulating Substrates such as GaN

    Anna Hambitzer, ETH-Zurich
    A. Olziersky, IBM-Research Zurich
    Tamara Saranovac, ETH-Zurich
    Colombo Bolognesi, ETH-Zurich
    Download Paper
  • 20.11 Comparison of Ion-Milling and Ion-Sputtering to Remove Edge Roughness of EBL Defined Emitter Metallization in InP/GaAsSb DHBTs

    Wei Quan, ETH-Zurich
    Ralf Flueckiger, ETH-Zurich
    Maria Alexandrova, ETH-Zurich
    Colombo Bolognesi, ETH-Zurich
    Download Paper