Collimated magnetron sputter deposition

Abstract
A technique to deposit films compatible with lift‐off patterning techniques and hole filling has been developed for large magnetron sputter deposition systems. This technique allows the patterned sputter deposition of Cu films, as well as other relevant metal or alloy systems, using conventional lift‐off lithography techniques. To overcome the gas scattering effects which are prevalent in the normal range of magnetron operation and which would prohibit lift‐off of a photoresist mask by coating the sides of the mask, a hollow cathode electron source has been implemented near the magnetron cathode which allows operation (i.e., sputtering) of the cathode at full power in the low 10−4 Torr range. At this pressure, the mean free path for the sputtered atoms greatly exceeds the typical cathode‐to‐sample throw distance of 5–7 cm. To overcome the broadness of the sputtering target and the cosine‐like distribution of the emitted, sputtered atoms, an array of collimating tubes is placed just above the sample to res...