METHOD FOR ETCHING PT LAYER IN SEMICONDUCTOR FARBRICATION

摘要

PURPOSE: A method for etching a platinum film of a semiconductor device is provided to improve an etch slope on a side wall of the platinum film by over-etching the platinum film using an adhesive layer including a Ti on an upper part of the platinum film as an etch mask, by heating a semiconductor substrate where the platinum film is formed. CONSTITUTION: A bottom film is formed on a semiconductor substrate(100). The bottom film is formed by stacking an inter layer dielectric(102) and forming a contact hole by patterning the inter layer dielectric and then by filling the contact hole with a polysilicon plug(104). Then, the semiconductor substrate is planarized by an etch back or a CMP or a planarization process. And, a barrier layer(106) is formed with a TiN or a material containing TiN. Then, a platinum layer(108) is formed on the barrier layer by a CVD or a sputtering method. An adhesive layer is formed with a Ti film to increase the adhesion between the platinum film and a mask layer. Then, the platinum film is etched until the barrier layer is revealed using the mask pattern and an adhesion mask pattern as an etch mask. And, a platinum film(108A) having an improved etch slope is formed by over-etching the platinum film. Then, after performing the over-etching, the adhesion mask pattern on the platinum film and the barrier layer below the platinum are patterned using an Ar/Cl2 etch gas.