Abstract: Disclosed are structures and methods related to metallization of a doped gallium arsenide (GaAs) layer. In some embodiments, such metallization can include a tantalum nitride (TaN) layer formed on the doped GaAs layer, and a metal layer formed on the TaN layer. Such a combination can yield a Schottky diode having a low turn-on voltage, with the metal layer acting as an anode and an electrical contact connected to the doped GaAs layer acting as a cathode. Such a Schottky diode can be utilized in applications such as radio-frequency (RF) power detection, reference-voltage generation using a clamp diode, and photoelectric conversion. In some embodiments, the low turn-on Schottky diode can be fabricated utilizing heterojunction bipolar transistor (HBT) processes.