HARD MASK FILMS WITH GRADED VERTICAL CONCENTRATION FORMED USING REACTIVE SPUTTERING IN A RADIO FREQUENCY DEPOSITION CHAMBER

摘要

A method of forming a semiconductor structure includes, in a radio frequency (RF) deposition chamber, depositing a titanium film using physical vapor deposition and forming a graded hard mask film by reactive sputtering the titanium film with nitrogen in the RF deposition chamber. The graded hard mask film is a titanium nitride film with a graded vertical concentration of nitrogen. The method may further include, during deposition of the titanium film and during formation of the graded hard mask film, modulating one or more parameters of the RF deposition chamber, such as modulating an auto capacitance tuner (ACT) current, modulating the RF power, and modulating the pressure of the RF deposition chamber.