55 Nm Logic Circuit Passivation Film Etching Technology Was Studied

Al passivation layerwindow open is the laststep of the whole process flow in semiconductormanufacturing. Al Passivation layerwindow etch opensexposes the aluminumpad for the followed encapsulation work. The passivation layer contains outside Si-N and Si-O materials as well as the inside TiN and Al. Usually, C-F gas is used for main etch. The C-F reactswith TiN and produces the solid TiN4. TiN4is hard to remove by pumping, so the polymer will deposit on chamber inside or wafer surface. The polymer depositionwill negativelyimpact the process flow. As the chip design is more and more complicated and the CD control is more and more strict, we must control the polymer deposition.55nm semiconductormanufacturingtechnology is advanced in the world. This thesis aims to study the TiN etch process which mainly impactson the passivation layer etch, improving the passivation layer etch effects.In this thesis to improve the etch effects two ideas are proposed. One is to reduce the polymer productionduring TiN etch. The other one is to enhance the polymer removalcapability. Enhancing TiN etch rate and improving the uniformitywill reduce the etch time. So the polymer production will be less. Reducing polymer has many methods. If chemicalinteraction is hard to remove the polymer, we can use plasma bombardment todestroy the polymer structure. Then the polymer will be easy to take chemicalinteraction or to be removed after plasma bombardment.