Formation of Single Crystal Si-Nanowire by Electric Field Self-Redistribution Effect in Anodic Oxidation for Multilayer Array Application

Single crystal silicon nanowire was formed successfully by electric field self-redistribution effect in anodic oxidation (ANO) with room temperature process. By using the ANO process with large electric field and long oxidation time, nanowires with a diameter of 9 nm can be achieved in this study. The silicon nanowire with tunable diameter in double layer array was automatically formed due to the self-ending oxidation blocking caused by the self-redistribution nature of electric field. The E-beam lithography with different photoresist widths from 60 to 90 nm was designed for observing the formation of nanowire. It can be observed that the convex profile of silicon shows larger electric field than concave profile in the ANO process and therefore induces thicker oxide. The single crystal Si-nanowire array by the ANO process is potential for the complementary metal-oxide-semiconductor devices application in the next generation.