A new approach for CMOS-compatible fabrication of cantilever/tip systems for probe-storage applications

In this work an original approach for the fabrication of the mechanical part of the Millipede, a MEMS-based scanning-probe data storage system, is reported. It allows the integration of both mechanical and electronic parts on the same wafer, by using CMOS-compatible processes. The proposed approach is based on the selective etching of p-type silicon, used as a sacrificial layer, with respect to n-type silicon, which is exploited as structural material (selective p-to-n electropolishing). Experimental results on chips fabricated by using the BCD6 process of STMicroelectronics demonstrate the feasibility of using this approach for the fabrication of freestanding n-type silicon cantilevers by selective etching of the p-type substrates.