OPTIMIZATION OF A HYBRID FIXED ABRASIVE CMP PROCESS FOR HARP~(TM)-BASED STI PLANARIZATION

摘要

The performance of a hybrid fixed abrasive (FA) CMP process developed by Applied Materials for planarizing HDP-filled STI patterned wafers was evaluated using IMEC's 65 nm node STI structures with HARP~(TM) gap fill. While the original hybrid FA CMP process resulted in satisfactory polish planarity performance with low dishing, it did not fully meet the integration requirement of low silicon nitride loss in the polish stop layer. The conformal nature of HARP deposition was considered in the development of an improved hybrid fixed abrasive CMP process and in the layout of dummy fill features for an improved 65 nm STI mask. The new process provides superior planarization performance for HARP-filled STI structures at device nodes of 65 nm and below.