High-value MOS capacitor arrays in ultradeep trenches in silicon

Abstract

A fully Si-compatible process has been developed to manufacture 6-inch silicon (100) wafers with patterns of trenches, several hundreds of μm deep with a pitch of a few μm. The hundred-fold enlarged silicon surface is used as a substrate for MOS (Metal-Oxide-Semiconductor) capacitor arrays with a capacitance of 1 nF to 1 μF. The specific capacitance was as high as 100 nF/mm2.