Precision leveling of semiconductor wafer avoiding damage to connections includes plasma deposition of dielectric, then controlled polishing

摘要

Gaps between metal connecting lines (10) are filled with an intermetallic dielectric (12) on the wafer using a high density plasma deposition process to cover the lines, intervening spaces and the surface of a dielectric layer (11) between the lines. The over-filled surface is brought into contact with a polishing disc with fixed polishing agent. The two are moved relatively reaching a polishing rate sufficient to achieve a predetermined end point with a uniformly planar surface on the wafer. This comes sufficiently close to the connecting lines but is kept away enough to prevent damage to them.