A new fabrication method of small-dimension devices—Multiple-wall self-aligned devices

The fabrication procedure and device characteristics of the multiple-wall self-aligned devices are described. Two neighboring resist walls are photolithographed on a silicon wafer to protect the intervening region between the walls from diagonal incident ion beams. By using this shadowing effect in ion-beam etching and the ion implantation, only one photomask or one electron-beam exposure is required to fabricate the major components of MOSFET´s or bipolar transistors. The results of performance testing of MOS and bipolar transistors fabricated with this process are presented.