The etch properties of physical vapor deposited TaN used as a metal gate electrode have been found to be dependent on its crystalline microstructure. As found by X-ray diffraction, the initially amorphous TaN crystallizes at temperatures above 500 degrees C. The crystallization results in lower resistivity (decreased by 13%), and lower etch rate in BCl3 plasma (decreased by 24%). The different crystalline microstructure can manifest itself in different etch results when the same etch process is applied for gate stacks that contain the same TaN but were subjected to different thermal budget. (c) 2006 The Electrochemical Society.