METHOD FOR FORMING CONTACT HOLES OF SEMICONDUCTOR DEVICES

摘要

PURPOSE: A contact hole formation method is provided to simultaneously form a self-align contact and a butting contact without stopping and residues by using improved etchants. CONSTITUTION: An etch stopping layer(20) and an interlayer insulator(22) are sequentially deposited on a semiconductor substrate(10) having a transistor. Then, two-step etching processes are performed to form a contact hole. The two-step etching comprises firstly etching the interlayer insulator(22) and the etch stopping layer(20) using an etchant contained C2F6, CH3F, and O2, thereby preventing a stopping phenomenon and a residue generation due to O2, and secondly etching using C4F6, CH3F, CO and Ar as an etchant, thereby simultaneously forming the contact hole for butting contact and self-align contact.