Position and number control of donor-QD potential by pattern-doping in SOI-FET channels

We study the statistical way to control the position and number of lowest-energy donor-induced quantum dots (QDs) formed in the channels of SOI-FETs, even using the conventional random doping process. By Kelvin probe force microscopy (KPFM) and simulations, we find that selective-patterned-doping works effectively to form a unique QD nearby the central position of the pattern, associated with bell-shaped potential background due to positive donors. It should be noted, however, that the controllability of position and number is gradually lost with increasing screening by coverage of free electrons.