Multistep method of depositing metal seed layers

摘要

Metal seed layers are deposited on a semiconductor substrate having recessed features by a method that involves at least three operations. In this method, a first layer of metal is deposited onto the substrate to cover at least the bottom portions of the recessed features. The first layer of metal is subsequently redistributed to improve sidewall coverage of the recessed features. Next, a second layer of metal is deposited on at least the field region of the substrate and on the bottom portions of the recessed features. The method can be implemented using a PVD apparatus that allows deposition and resputtering operations. This sequence of operations can afford seed layers with improved step coverage. It also leads to decreased formation of voids in interconnects, and to improved resistance characteristics of formed IC devices.