ABSTRACT
In this study, we propose new GaAs MOS varactors, fabricated using a low-cost GaAs oxidation technology utilizing the collector layers of GaAs based HBTs for the first time to our knowledge. GaAs MOS varactors showed much-improved capacitance ratios compared to those of the conventional pn varactors because of the broader range in the capacitance-voltage characteristics of the MOS structure. 2
2. Device Structure and Fabrication Figure 1 shows a schematic cross-sectional view of the proposed new GaAs MOS varactor in comparison with the base-collector pn varactor.
