ELECTRON-MOBILITY ENHANCEMENT IN SI USING DOUBLY DELTA-DOPED LAYERS

Large enhancements in the electron mobility are reported for structure s containing a pair of closely spaced Sb delta-doped layers in Si. The room-temperature mobility is enhanced by a factor of 2 compared to co rresponding uniformly doped layers of singly delta-doped structures. E ven higher mobilities were obtained by using a Schottky gate on top an d applying a voltage to adjust the potential well. With an effective g ate voltage of approximately -0.3 V the mobility was 1200 cm2 V-1 s-1 at room temperature, which is an enhancement by a factor of 10 relativ e to the layer with equivalent bulk doping concentration. The high mob ility is attributed to wave functions with nodes at the delta-doped la yers.