CAPACITANCE ENGINEERING FOR INP-BASED HETEROSTRUCTURE BARRIER VARACTOR

We investigate new schemes of M-based heterostructure barrier varactor s with the aim of enhancing the capacitance nonlinearity of the device s. Starting from a generic steplike InGaAs/LnAlAs/AlAs single barrier heterostructure, planar-doped and buried InAs quantum-well barrier het erostructures were successfully fabricated. It is shown that both solu tions lead to more efficient screening of electric held near equilibri um and hence to improvement in the capacitance-voltage ratios with val ues as high as similar to 7:1. Under bias, the capacitance modulation is governed by an escaping mechanism in contrast to the conventional d epletion operation mode observed for conventional varactors.