Improvement of mim capacitor early breakdown by metal deposition process optimization and ar sputter etch implementation

Bottom metal with short stable time, higher back-side Ar flow, and multiple deposit steps can greatly reduce the surface roughness and prevent local thinning of the insulator. Moreover, when applying a sputter etch prior to top metal deposition, a more smooth surface of dielectric films are achieved and a significant improvement of capacitance uniformity. A soft Ar sputter etch at low DC bias prior to the top metal deposition improves the dielectric film quality in metal-insulator-metal capacitors. A significant reduction of early breakdown is achieved by implementing a soft sputter etching. We propose that by Ar sputter etch prior to the top metal deposition, not only removes the top of insulator film but also eliminating some particle, metal precipitates and contamination. After process optimization, we successfully obtain good MIM capacitors with uniform breakdown electric fields and capacitance which could be applicable for mass production.