Laterally resolved doping by focused ion beam implantation

Maskless focussed ion beam implantation is proposed as an attractive option for the fabrication of electronic devices in the sub 100 nm range. As a step towards this goal we have demonstrated laterally resolved p- and n-type doping in GaAs by implantation of Be/sup +/ and Si/sup +/, respectively. By Si/sup +/-implantation into an Al/sub x/Ga/sub 1-x/As/GaAs-heterostructure it was possible to create a laterally structured two dimensional electron gas.