Semiconductor device and method for manufacturing the same

摘要

An oxide film 26 is formed on a silicon substrate 10. The oxide film 26 is topped with wiring patterns 34. Top and side portions of the wiring patterns 34 are covered with nitride film top walls 36 and nitride film side walls 38. After an interlayer oxide film 40 is deposited, contact holes 42 are formed through self-alignment. Under the nitride film side walls 38, isotropic etching is carried out to retract side edge surfaces 32 of the oxide film 26 from the wall surface. Contacts 44 are then formed inside the contact holes 42 whose bottom diameter is expanded by the isotropic etching above.