Etching composition hydrogen fluoride useful for selectively etching oxide layer and for manufacturing semiconductor device comprises ammonium fluoride, non-ionic polymer surfactant and water

摘要

An etching composition comprises (wt.%) hydrogen fluoride (0.1 - 8), ammonium fluoride (10 - 25), non-ionic polymer surfactant (0.0001 - 3) and water. Independent claims are included for the following: (1) preparation of the composition involving preparing a first mixture solution by mixing a non-ionic polymer surfactant and a hydrogen fluoride solution, preparing a second mixture solution by mixing water and the first mixture, and preparing the etching composition by mixing an ammonium fluoride solution and the second mixture solution; (2) an etching involving forming a nitride layer on a substrate, forming an oxide layer, patterning the oxide layer to form a contact hole exposing the nitride layer, forming a polysilicon layer pattern on the exposed nitride layer and an inner side wall portion of the contact hole, and removing the oxide layer using the etching composition; (3) manufacturing a semiconductor device involving forming an etch stop layer on a semiconductor substrate, forming a first oxide layer on the etch stop layer, forming a second oxide layer on the first oxide layer, partially removing the first and the second oxide layers to expose the contact region, forming a polysilicon layer pattern which contacts the contact region and removing the first and second oxide layers using the etching composition.