Advanced excursion control and diagnostics for CMP process monitoring

摘要

This CMP processes are generally well known and established critical steps in semiconductor manufacturing, but must be very closely monitored and controlled to maintain process uniformity and minimize process induced defects. CMP processes are generally monitored using a combination of blanket test wafers, short loop patterned wafers and product wafers, along with a variety of in-situ controls. This paper talks about the techniques demonstrated for defect excursion monitoring in CMP module using short loop test wafers and an advanced dark Field inspection tool. These techniques enable effective control and monitoring of the CMP tools used for manufacturing advanced semiconductor logic devices. We talk about three approaches that helped accomplish this objective: (i) Pattern wafer inspection at M1 Cu CMP level using Puma 9550 DF inspector (ii) use of In-line Defect Organizer (iDO) to effectively and automatically extract and classify scratches — the key defect of interest to the CMP process engineer; and (iii) use of quick recipe templates to diagnose and make required recipe changes for 32 nm and 22 nm devices using "Auto Derivative Recipe" feature on Puma 9550 to maximize engineering and tool efficiency