New wafer-scale MEMS fabrication of 3D silicon/metal cantilever array sensor

This paper presents a new wafer-scale micromachining technology of three-dimensional (3D) cantilever array for sensor application. The 3D cantilever consists of a vertically Si/metal laminated structure and works in the in-the-plane mode so that it has the advantage of easy-to-package, non-stiction and compact. Prototype of 5-pair 3D cantilever array was successfully fabricated in 4-inch wafer scale. However, its fabrication is involved of micromachining technology of metal film on high aspect ratio structures. 4-inch wafer-scale wet-etching technology of electroless-plated Ni-8%P alloy film (~1.5 μm-thick) was for the first time successfully established on a high topographic surface with the minimum feature size of about 20 μm.