Novel Fabrication Method of a Round Microtip Based on Aluminum Spike Phenomenon

Abstract

In this paper, we present a new method of fabricating microtips based on the aluminum spike phenomenon. Silicon dissolves in aluminum at high temperatures above 400 °C, and normally this is an undesirable effect in integrated circuit (IC) processing. However, in this study, this phenomenon is exploited, with which a round tip is fabricated by a simple process involving the annealing of aluminum at 800 °C; a major advantage of the method is that the apex of the fabricated tip is round. The penetration depth of aluminum increases with annealing time, and the height of the fabricated tip can be controlled by adjusting annealing time. The height and width of the tip, annealed for 25 min using (100) silicon wafer, are 40 and 80 µm, respectively.