Patent ID: 8298936

Claim:
An apparatus for depositing a metal seed layer on a semiconductor wafer having recessed features and a field region, comprising: (a) a physical vapor deposition (PVD) process chamber having a target for sputtering a metal onto the semiconductor wafer; (b) a wafer support in the PVD process chamber for holding the wafer in position during deposition of the metal; and (c) a controller comprising program instructions for (i) sputtering the metal from the target in the PVD process chamber onto the semiconductor wafer under conditions that coat at least the bottom portions of the recessed features and the field region thereby forming a first layer of metal wherein the first layer forms a thick layer on the bottom portions of the recessed features and on the field region, while forming a substantially thinner layer on the sidewall portions of the recessed features, and while forming substantially no overhangs at the openings of the recessed features; (ii) subsequently resputtering the first layer of metal to redistribute the metal from the bottom portions of the recessed features to the sidewalls of recessed features, wherein said resputtering removes more than 50% of the first layer of metal thickness from the bottom portions of at least some of the recessed features; and (iii) subsequently sputtering the metal from the target in the PVD process chamber onto the semiconductor wafer to form a second layer of metal and to coat inadequately coated regions of the wafer substrate, wherein the program instructions are configured to provide a continuous seed layer having a thickness suitable for subsequent electroplating thereon.