Patent ID: 7682966

Claim:
A method of depositing a metal seed layer on a wafer substrate having recessed features and a field region, the method comprising: (a) depositing a first layer of metal onto the wafer substrate by sputtering a metal using ionized physical vapor deposition (iPVD), wherein the deposited 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; (b) subsequently etching the first metal layer from the bottom portions of the recessed features while redistributing the first metal layer to the sidewall portions of the recessed features to increase the thickness of the first metal layer on the sidewall portions of the recessed features, wherein said etching removes more than 50% of the first layer of metal from the bottom portions of at least some of the recessed features; and (c) after redistributing the deposited metal, depositing a second layer of metal by sputtering a metal using ionized physical vapor deposition (iPVD) to coat inadequately coated regions on the wafer substrate, wherein the method provides a continuous metal seed layer having a thickness suitable for subsequent electroplating thereon.