METHOD OF FORMING CONTACT HOLE

摘要

PROBLEM TO BE SOLVED: To provide a method of forming contact holes of a high aspect ratio without roughening an insulating film around the periphery thereof. SOLUTION: An antireflection film 4 and a resist film 5 are formed on an insulating film 3 formed on a semiconductor substrate 1. By using a pattern of the resist film for a mask, the insulating film 3 is etched by an etching gas of fluorocarbon family to open contact holes. Then the antireflection film 4 and the resist film 5 are removed by using an oxygen plasma, and further a treatment is made by the oxygen plasma applying a bias to the substrate 1. By this treatment, the etching gas component 6 of fluorocarbon family penetrated between the insulating film 3 and the antireflection film 4 of low adhesion is removed, and roughening of the insulating film 3 around periphery of the contacts by the cleaning process using sulfuric acid or the like is prevented.