METHODS FOR ADJUSTING CRITICAL DIMENSION UNIFORMITY IN AN ETCH PROCESS WITH A HIGHLY CONCENTRATED UNSATURATED HYDROCARBON GAS

• Main Authors: LEE CHANGHUN, DING GUOWEN, SU TEH-TIEN
• Format: Patent
• Language: English
• Published: 07.01.2010
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Methods for etching a metal material layer disposed on a substrate to form features with desired profile and uniform critical dimension (CD) of the features across the substrate. In one embodiment, a method for etching a material layer disposed on a substrate includes providing a substrate having a metal layer disposed on a substrate into an etch reactor, flowing a gas mixture containing at least a halogen containing gas and a passivation gas into the reactor, the passivation gas including a nitrogen containing gas and an unsaturated hydrocarbon gas, wherein the nitrogen gas and the unsaturated hydrocarbon gas and etching the metal layer using a plasma formed from the gas mixture. The CD uniformity could be conveniently, efficiently tuned by the gas ratio, if the concentration of the unsaturated hydrocarbon gas is high enough that the molecular ratio of the unsaturated hydrocarbon gas in the diluent gas times the reactor pressure in milliTorr is greater than 1.25.