A 90 nm CMOS MS/RF based foundry SOC technology comprising superb 185 GHz f/sub T/ RFMOS and versatile, high-Q passive components for cost/performance optimization

Abstract

A versatile mixed-signal and RF (MS/RF) technology based on a foundry 90 nm CMOS process was demonstrated with excellent MOS transistor f/sub T/ at 160-185 GHz. Passive elements of various process schemes were fabricated for cost/performance evaluation. To realize low-cost system-on-chip (SOC), passive elements like 0.9 /spl mu/m Cu inductors and metal-stacked capacitors (MOM) were implemented using a standard logic back-end process. For high performance MS/RF solutions, inductors with 3 /spl mu/m Cu and ultra thick 6 /spl mu/m Cu top metal were fabricated to achieve high quality factors, Q>15 at 1 GHz and peak Q>20. Precision metal-sandwiched capacitors (MIM) with unit capacitances of 1.0, 1.5 and 2.0 fF//spl mu/m/sup 2/ were characterized and compared. Comparable or better matching was observed for MIM with higher unit capacitance, implying the possibility for chip size reduction. Specifically, the advantage of better MIM matching was demonstrated for the first time on the data resolution improvement of an A-to-D converter.