Effect of oxide and W-CMP on the material properties and electromigration behaviour of layered aluminum metallisations
It has been found that chemical mechanical polishing increases the electromigration resistance of a Ti/AlCu/Ti/TiN metal stack. (111) X-ray diffraction polefigures indicate an increased (111) texture of AlCu deposited on a substrate that received at least one CMP step. This improved (111) texture can be attributed to a decreased roughness of the underlying oxide when chemical mechanical polishing is used.
w-cmp electromigration aluminum metallisation texture oxide cmp reliability