Determination of the eigenstates and wavefunctions of a single gated As donor

Current semiconductor devices have been scaled to such dimensions that we need take atomistic approach to understand their operation for nano-electronics. From a bottoms-up perspective, the smallest functional element within a nanodevice would be a single (dopant) atom itself. Control and understanding over the eigenenergies and wavefunctions of a single dopant could prove a key ingredient for device technology beyond-CMOS. Here, we will discuss the eigenlevels of a single As donor in a three terminal configuration. The donor is incorporated in the channel of prototype transistors called FinFETs. The measured eigenlevels are shown to consist of levels associated with the donors Coulomb potential, levels associated with a triangular well at the gate interface and hybridized combinations of the two. The theoretical framework in which we describe this system (NEMO-3D) is based on a tight-binding approximation.