Monolithic Heterogeneous Integration of 3D Radio Frequency L−C Elements by Self‐Rolled‐Up Membrane Nanotechnology.

This work reports a three‐dimensional (3D) radio frequency L−C filter network enabled by a CMOS‐compatible two‐dimensional (2D) fabrication approach, which combines inductive (L) and capacitive (C) self‐rolled‐up membrane (S‐RuM) components monolithically into a single L−C network structure, thereby greatly reducing the on‐chip area footprint. The individual L−C elements are fabricated in‐plane using standard semiconductor processing techniques, and subsequently triggered by the built‐in stress to self‐assemble and roll into cylindrical air‐core architectures. By designing the planar structure geometry and constituent layer properties to achieve a specific number of turns with a desired inner diameter when the device is rolled up, the electrical characteristics can be engineered. The network layouts of the L and C components are also reconfigurable by selecting appropriate input, output, and ground contact routing topographies. The devices demonstrated here operate over the range of ≈1−10 GHz. Their area and volume footprints are ≈0.09 mm2 and ≈0.01 mm3, respectively, which are ≈10× smaller than most of the comparable conventional filter designs. These S‐RuM‐enabled 3D microtubular L−C filter networks represent significant advancement for miniaturization and integration of passive electronic components for applications in mobile connectivity and other frequency range. [ABSTRACT FROM AUTHOR]