In-plane-gate transistors on nonepitaxial silicon directly written by focused-ion-beam implantation

It is demonstrated that focused-ion-beam written in-plane-gate transistors, working at room temperature can be realized on (100) silicon-on-insulator wafers, separated by implanted oxygen, without the need for epitaxial growth processes. Typical channel widths are in the sub-mu m range. Their electrical features at room temperature are characterized by transport and Hall measurements. The channel current is measured as a function of the geometrical channel width and the implanted dose. Activation of the implanted gallium by rapid thermal annealing changes the character of the insulating lines from Ohmic barriers to npn-junctions. Consequently the leakage current across the barriers decreases significantly, the direct current output characteristics of the transistors are improved with higher implantation doses and smaller geometrical channel widths are achievable. (C) 1996 American Institute of Physics.