Integrated Stacked Parallel Plate Shunt Capacitor for Millimeter-Wave Systems in Low-Cost Highly Integrated CMOS Technologies

• Published in: IEEE solid-state circuits letters Vol. 5; pp. 114 - 117
• Main Authors: El-Chaar, Mohamad, Podevin, Florence, Bourdel, Sylvain, de Souza, Antonio A. L., Arnould, Jean-Daniel
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analog circuits; Broadband; Capacitance; capacitor; Capacitors; Circuit design; CMOS; decoupling; Engineering Sciences; Frequency measurement; Frequency ranges; integrated; Integrated circuits; Low cost; Metals; Micro and nanotechnologies; Microelectronics; millimeter wave; Millimeter waves; on-chip; on-wafer measurement; parallel plate; Parallel plates; passive; quality factor; Resistance; Shunt capacitors; Topology; wideband; CMOS; quality-factor; wideband; decoupling; broadband; parallel plate; on-wafer measurement; on-chip; millimeter-wave; passive; integrated; capacitor
• ISSN: 2573-9603; 2573-9603
• DOI: 10.1109/LSSC.2022.3172992

This letter presents a stacked parallel plate (SPP) shunt capacitor (SC) that benefits from metal stack increment with process nodes advancement. It demonstrated high quality (<inline-formula> <tex-math notation="LaTeX">Q </tex-math></inline-formula>) factor and high self-resonance frequency (SRF), promoting the design of analog integrated circuits (ICs) in low-cost highly integrated CMOS technologies at the millimeter-wave (mm-wave) frequency range. As a proof-of-concept, an analytical-equation-based design method is also proposed and three ac-grounded capacitors: 300; 600; and 900-fF, are implemented in STMicroelectronics (STM) 55-nm process. Characterization is performed up to 100 GHz. An effective capacitance density of 0.8 <inline-formula> <tex-math notation="LaTeX">{\mathbf {fF}}/\mu \mathbf {m}^{\mathbf {2}} </tex-math></inline-formula> is obtained. Measurements show <inline-formula> <tex-math notation="LaTeX">Q </tex-math></inline-formula>-values reaching up to 14.7 at 100 GHz and equivalent input series resistances with flat wideband behavior reaching at most an average of 0.55 <inline-formula> <tex-math notation="LaTeX">\Omega </tex-math></inline-formula>. SRFs of 140 GHz for the 900-fF SPP-SC up to 368 GHz for the 300-fF SPP-SC are also determined from measurements: the highest SRFs for such large capacitances to the authors' knowledge.