METHOD OF FLATTENING POLYMER LAYER

摘要

PURPOSE: A method of flattening polymer layer is provided to flat photoresist layer without reducing the thickness of a different material layer such as dielectric layer while manufacturing a semiconductor device. CONSTITUTION: A polymer layer which contains photoresist is flattened through a chemical mechanical polishing method. An abrasive composition used in this case is very selective to a dielectric layer, and especially its selection ratio to a silicon nitride layer is about 10:1, preferably at least about 1000:1. This composition is at least of pH 8 or so, preferably pH 11 to 13 or so. A typical abrasive composition can contain abrasive material such as silica or alumina basic solution. An oxidizing component resides as much as 2 wt.%, an abrasive composition can contain a strong base and requires no oxidizing agent or no abrasive material. A proper strong base contains a hydroxide such as a trimethyl ammonium hydroxide or sodium hydroxide.