Patent ID: 8241982
Filing Date: 2012-08-14
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device, wherein an element separation film containing oxygen demarcates a field region and an active region, the semiconductor device having an electrode layer and a nitrogen-containing layer being in contact with the electrode layer in the active region, the method comprising: plasma nitriding to form a nitrogen-containing layer of a silicon nitride film on a surface of the electrode layer and a nitrogen-containing layer of a silicon oxynitride film on a surface of the element separation film respectively by applying a plasma of a processing gas including an argon gas and a nitrogen-containing gas to exposed surfaces of the electrode layer and the element separation film, the electrode layer comprising polysilicon as a main component and the element separation film comprising silicon oxide as a main component; and selectively etching to selectively remove the nitrogen-containing layer of the silicon oxynitride film formed on the surface of the element separation film while leaving the nitrogen-containing layer of the silicon nitride film formed on the surface of the electrode layer, wherein in said selectively etching, the nitrogen-containing layer of the silicon oxynitride film is selectively removed by wet etching using a dilute hydrofluoric acid solution having a concentration ranging from not less than 0.07% to not more than 1%.