Integrated circuit capacitor in a silicon-on-insulator integrated circuit

摘要

An integrated circuit capacitor includes a silicon-on-insulator (SOI) substrate and a doped epitaxial layer of a first conductivity type formed on the SOI substrate. The doped epitaxial layer is used as a first plate of the integrated circuit capacitor. A gate oxide layer is formed on the doped epitaxial layer and is used as a dielectric layer of the integrated circuit capacitor. A polysilicon gate is formed on the gate oxide layer and is used as a second plate of the integrated circuit capacitor. A method of forming an integrated circuit capacitor includes: establishing a silicon-on-insulator (SOI) substrate having an insulating layer formed on a substrate; forming a buried layer on the insulating layer; forming an epitaxial layer of a first conductivity type on the buried layer; forming a local oxidation silicon layer on the epitaxial layer that surrounds a first selected surface area of the epitaxial layer; implanting a collector into the epitaxial layer in the first selected surface area of the epitaxial layer; forming a gate oxide layer on the collector; and forming a polysilicon gate on the gate oxide layer and a first portion of the local oxidation silicon layer.