High density plasma enhanced chemical vapor deposition process in combination with chemical mechanical polishing process for preparation and planarization of intemetal dielectric layers

摘要

A wafer planarization process which utilizes combined high density plasma chemical vapor deposition (HDP-CVD) process and chemical mechanical polishing (CMP) process is disclosed. This process includes the steps of (a) forming a first HDP-CVD layer on the surface of a semiconductor wafer using a first HDP-CVD composition having a higher etching/depositing component ratio and thus a lower CMP removal rate; (b) forming a second HDP-CVD layer on the first HDP-CVD layer using the same HDP-CVD process but with a second HDP-CVD composition having a lower etching/depositing component ratio and thus a higher CMP removal rate; and (c) using a chemical mechanical process to remove at least a part of the second HDP-CVD layer using the first HDP-CVD layer as a stopper. A protective layer with the same etching/deposition components but a different ratio than the sacrificial layer can be deposited on the sacrificial layer to minimize the dishing effect during the initial stage of the chemical mechanical polishing process.