Magnetic Field-Assisted Self-Wound 3-D Nanomembrane Capacitors Bridge the Gap Between MLCC and Trench Capacitor Technologies

摘要

This letter reports the transformation of large-area planar metal-insulator-metal (MIM) nanomembrane capacitors into compact tubular 3-D architectures. By combining the powerful approach of straininduced nanomembrane self-assembly with an external magnetic field, a stable winding process over a large distance in the range of centimeters is demonstrated. A wet release platform based on encapsulated methyl cellulose allows to release the planar structures with rates of several 100 mu m/s from their substrate. Footprint shrinkage factors up to 230 are shown by assembling 24-mm long planar structures into 3-D architectures having 82-mu m diameter and similar to 120 windings. The fabricated capacitors feature a capacitance per footprint up to 1.3 mu F/mm(2) for a 15-nm Al2O3 dielectric with less than 100-nA/mu F leakage at 6 V and improved frequency characteristics. This technology is a promising candidate for bridging the gap between discrete multilayer ceramic capacitor (MLCC) and ON-chip trench capacitor technologies.