Electron Tunneling and Field-Effect Devices in mm-Wave Circuits

Short high-frequency electromagnetic pulses, also referred to as wavelets, are considered for use in various short-range impulse based ultra-wideband applications, such as communication, imaging, radar, spectroscopy, and localization. This thesis investigates field-effect and tunneling based semiconductor devices and their operation in millimeter-wave (mm-wave) impulse transceivers. The main research contribution of this work is the demonstration of a novel high performance InGaAs MOSFET and its integration in a wavelet generator. The first topic of this thesis is the design and fabrication of a gated tunnel diode (GTD) device. The main feature of the GTD is the ability to switch it between positive differential output conductance (PDC) and negative differential output conductance (NDC). This makes it a versatile element, which can be used to improve circuit functionality. The second topic is the design and fabrication of an epitaxially regrown InGaAs MOSFET. The device architecture was developed with the aim of minimizing the on-resistance (Ron) to increase the on-state current and extrinsic transconductance (gm,ext.). A 55-nm-gate length MOSFET yields gm,ext.=1.9 mS/μm at VGS=0.5 V and VDS=1 V, Ron=199 Ωμm, an extrapolated fmax of 292 GHz, and ft of 244 GHz. The device performance is analyzed by constructing a small-signal model, which includes the influence of impact ionization, band-to-band tunneling, and the wideband frequency response of gate oxide border traps. Vertical gate-all-around nanowire MOSFETs integrated on a Si platform are also investigated and exhibit gm,ext.=0.155 mS/μm, fmax=9.3 GHz, and ft=14.3 GHz. The regrown MOSFET is furthermore combined with an RTD to form a switchable NDC component, which is integrated in parallel to an inductive coplanar waveguide to form an oscillator circuit. By switching the output of the RTD-MOSFET between NDC and PDC it is possible to kick-start and rapidly quench the oscillator to produce mm-wave wavelets. The wavelet generator delivers coherent 41-ps-short wavelets with a peak output power of 7 dBm at a rate of 15 Gpulses/s. The wavelets are generated at an energy consumption of 1.9 pJ/pulse