Thin-film multilayer Parylene interposer for high-density 3D packaging with embedded capacitors

A novel all-Parylene based multilayer organic interposer for high-density 3D packaging is presented. The multilayer interposer consists of both a thick 50µm Parylene substrate layer as well as thin layers, down to ∼50 nm, which are formed by successive conformal thin-film deposition. The processing of the layers utilizes standard thin film techniques such as photolithography, dielectric/metal deposition, and dry/wet etching. This allow excellent control over feature dimension both vertically (<0.1 µm) and horizontally (< 10 µm). On a multilayer design platform, high-density (∼ 450 pF/mm²) metal-insulator-metal capacitors are implemented with an ultra-thin (47 nm) deposition of Parylene-N as a capacitor dielectric. Capacitances and breakdown voltages are characterized over fabricated capacitors of various sizes. To demonstrate the Parylene stack-up is designed and implemented. For directly transmitted RF power, the rectifier generates 6.35 Volts of DC voltage. This shows the embedding of both the RF capacitors as well as the high valued storage capacitors is successful and applicable to RF power delivery.