Гетеробарьерные варакторы с неоднородно легированными модулирующими слоями
Optimal capacitance-voltage characteristic is critical for heterobarrier varactor diode (HBV) performance in terms of multiplication efficiency in mm- and sub-mm wave ranges. Numerical model of capacitance-voltage characteristics and leakage current for HBV with arbitrary heterostructure composition and doping profile was verified on published data and original experimental results. Designed HBV heterostructure with three undoped InAlAs/AlAs/InAlAs barriers surrounded with non-uniformly doped n-InGaAs modulation layers was grown by molecular-beam epitaxy on InP substrate and test HBV diodes have been fabricated. Test HBV diodes demonstrate capacitance-voltage characteristics with cosine shape at bias voltage up to two volts, increased capacitance ratio and low leakage current values.