Patent ID: 6410403
Filing Date: 2002-06-25
Classification: H01L

Abstract:
A method of planarizing an isolation region; comprising the steps of:a) forming a pad oxide layer, a first nitride layer, a sacrificial oxide layer and a second nitride layer over a substrate; b) forming a trench through said pad oxide layer, said first nitride layer, said sacrificial oxide layer and said second nitride layer and in said substrate; c) depositing an oxide layer filling said trench and over said second nitride layer; d) chemical-mechanical polishing said oxide layer and said second nitride layer down to a level so that said second nitride layer has a thickness of between about 50 and 200 Ã¥; e) removing said second nitride layer and said sacrificial oxide layer and a thickness of said oxide layer; f) chemical-mechanical polishing said oxide layer and said first nitride layer so that the top surface of said oxide layer is about level within 10 percent, with the top surface of said first nitride layer.