Method for in-situ removal of side walls in MOM capacitor formation

A method for fabricating an MOM capacitor (10) includes forming a first conductive layer (18) on an insulating support (12, 14), depositing a dielectric film (20) on the conductive layer, and patterning the dielectric film to define the capacitor feature. The dielectric film may comprise a stack of oxide and nitride layers (22, 24, 26). The dielectric is etched anisotropically with a fluorocarbon plasma to remove unwanted dielectric material (38) around the capacitor feature. Sidewalls (40), built up during the anisotropic etch as a result of sputtering the first conductive layer during the necessary overetch, are removed in a low power, higher pressure etch with an SF6 plasma, which is substantially isotropic in character. The process allows a sidewall-free capacitor to be formed in a single reactor without the need for solvent cleaning to remove the sidewall material.