Copper Barriers Hold Up Under Stress

摘要

The technology behind the traditional tantalum-based barrier and copper seed is being successfully applied to future generations using various ionized physical vapor deposition (PVD) schemes. How far PVD technology can be extended is unknown, although it seems clear that it will satisfy the requirements of the 32 nm generation. "The issue is real estate management. How do you make the deposited films thin enough and conformal enough, while leaving an opening at the end for the electroplating? At the 22 nm node, even with only 1-2 nm of barrier on each side, with the copper seed overhang, the technology will have to be improved to fill a 40 nm trench," said Makarem Hussein, senior principal engineer of components research at Intel Corp. (Hillsboro, Ore.).