Si field-effect transistor with doping dipole in buffer layer

Abstract

An Si field-effect transistor with a doping dipole layer obtained by delta-n (δn) layer and delta-p (δp) layers in the buffer layer is proposed and fabricated. The dipole creates a large barrier between the channel and the buffer layer, and consequently more holes are confined in the upper undoped region (the channel layer) rather than around the δp layer by the influence of the transverse electric field coming from the δn barrier layer. This simple homoepitaxial grown Si structure exhibits an excellent property, i.e., not only high hole mobility (1350 cm2 V−1 s−1) but also enhanced extrinsic transconductance (50 mS/mm), which is expected to provide an additional degree of freedom for Si-based device applications.