MULTIPLE TIER COLLIMATOR SYSTEM FOR ENHANCED STEP COVERAGE AND UNIFORMITY

摘要

A collimator system for use in PVD sputtering of semiconductor wafers having multiple tiers provided between a target and wafer substrate. The collimator system prevents target atoms from contacting the wafer at substantially oblique angles, thereby providing good step coverage uniformity over the surface of the wafer. Additionally, the presence of more than one tier prevents localized build-up of target atoms that occurs in conventional single tier collimators, thereby providing good flat coverage uniformity over the surface of the wafer.