Three-dimensional silicon-integrated capacitor with unprecedented areal capacitance for on-chip energy storage

Here, we leverage the unique atomic layer deposition of conductive (TiN) and dielectric (Al2O3 and HfAlOx) nanocoatings (20 and 40 nm) into trenches etched in silicon with ultra-high aspect-ratio (up to 100) to integrate 3D microcapacitors with areal capacitance up to 1 mu F/mm(2). This sets the new record for silicon capacitors, both integrated and discrete, and paves the way to on-chip energy storage. The 3D microcapacitors feature excellent power and energy densities, namely, 566 W/cm(2) and 1.7 mu Wh/cm(2), respectively, which exceed those of most DCs and SCs. Further, the 3D microcapacitors show excellent stability with voltage (up to 16 V) and temperature (up to 100 degrees C), over 100 h of continuous operation.