High density metal insulator metal capacitors using PECVD nitride for mixed signal and RF circuits

Abstract

High density metal-insulator-metal capacitors with capacitance densities of 1.0 to 2.0 fF//spl mu/m/sup 2/ using PECVD nitride dielectric have been integrated for the first time into the backend metallization layers of a 0.25 /spl mu/m CMOS process flow. Capacitor breakdown voltage, linearity and reliability meet mixed-signal circuit requirements with less than 0.1% 3-sigma percentage matching for a 0.225 pF capacitor. Less than 0.6 defects/cm/sup 2/ has been achieved for 2.0 fF//spl mu/m/sup 2/ capacitance density. Q>80 at 2 GHz was measured, indicating its usefulness in RF applications.