ATOMICALLY SHARP SILICON AND METAL FIELD EMITTERS

A number of new technologies require the use of sharp tips to serve as electron emitters in vacuum microelectronics devices or as mechanical, electrical, or magnetic microsensors or probes. For applications involving tunneling over short (1.0-nm) distances, a single atom on a macroscopically blunt tip is satisfactory, but for applications requiring high (nm) lateral resolution or field emission over large distances, the half-angle of the tip needs to be small as well. A method is described for forming atomically sharp silicon tips of less than 10-15-degrees half-angle by utilizing a known oxidation inhibition at regions of high curvature; equally sharp silicon wedges are now made in a similar fashion. The sharp silicon tips serve as the starting point for forming sharp tips of W, beta-W, and gold. Field emission data from silicon emitters are compared with Fowler-Nordheim modeling, and emission as a function of emitter-anode distance is described.