A 3.3 fF/μm2 40 V BST MIM capacitor suitable for above MMIC integration

A high performance metal-insulator-metal (MIM) capacitor with Ba(1-x)SrxTiO3 (BST) films deposited at 200°C is presented for the first time. Through a detailed analysis of the relationship between BST crystallographic structures and its electrical characteristics, a triple-layered BST structure was found to be effective in suppressing leakage current and hence increasing breakdown voltage while maintaining a high capacitance density. By using the triple-layered BST structure, an excellent MIM capacitor with a capacitance density of 3.3 fF/μm2, a breakdown voltage of 40 V and an insertion loss below 0.05 dB has been successfully obtained. This MIM capacitor can be easily integrated into conventional microwave monolithic integrated circuits (MMICs)