ELECTRON CONFINEMENT POTENTIAL IN ETCHED SI SIGE QUANTUM DOTS/

We present an analysis of the confinement potential in etched Si/SiGe dot arrays fabricated from a high electron mobility Si/SiGe heterojunc tion The fi ee electrons in the dots are investigated by far-infrared magnetospectroscopy. The analysis of the resonances associated with th e plasmon modes provides a determination of the confining potential, t he electron population in the dots, the negative surface charge on the etched sidewalls, and the lateral depletion length. The confinement p otentials calculated by a simple electrostatic model without any adjus table parameters are found to be in very good agreement with the exper imental data.