High-Resistivity Trap-Rich Silicon Substrate Advantages for Large Integrated MIM Capacitors

Metal-insulator-metal (MIM) capacitors are critical passive components in integrated circuits (ICs) and are widely used in analog, mixed-signal, and radio frequency (RF) applications. This study investigates the advantages of high-resistivity (HR) silicon substrate incorporating a trap-rich (TR) layer (HR-Si+TR) on the performance of large MIM capacitors, compared with conventional silicon substrate, through experimental measurements and electromagnetic simulations. A lumped-element <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $</tex-math> </inline-formula>-model is validated to extract and interpret key performance metrics of the MIM structures, accounting for dielectric leakage, substrate coupling, and resistive losses. A substantial improvement in the quality factor is observed, reaching 65 at 170 MHz compared to 13.5 for the standard Std-Si reference at the same frequency, alongside a slight increase in the resonance frequency. This enhancement originates from the HR-Si+TR substrate transition to dielectric-like behavior at frequencies below the operational RF range, which substantially reduces substrate losses and parasitic coupling. Consequently, minimized parasitic capacitances (ground coupling and fringing effects) allow for a higher quality factor and resonant frequency.