Ultrathin Silicon Chips of Arbitrary Shape by Etching Before Grinding

Abstract

A complementary-metal-oxide-semiconductor-compatible fabrication technique for ultrathin silicon chips of arbitrary shape is reported. It combines deep reactive ion etching and wafer grinding to define the in-plane geometry and thickness of the chips, respectively. Neural probes with shaft lengths up to 12 mm and thicknesses down to 25 μm were fabricated.