Method for reducing stress on collimator titanium nitride layer

摘要

A method for reducing the stress on a titanium nitride layer formed by collimator sputtering. On a semiconductor substrate, an insulated oxide layer is formed. A trench is formed in the insulated oxide layer. On the trench, a first titanium nitride layer is formed conformally by using physical or chemical vapor deposition as a buffer layer. A second titanium nitride layer is formed by collimator sputtering on the first titanium layer. The orientation of lattice arrangement of the second titanium nitride layers is changed from <100>-orientation to <111>-orientation, and therefore, the stress is reduced.