METHOD FOR FORMING CONTACT PLUG FOR CHARGE STORAGE ELECTRODE IN SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing a semiconductor device is to prevent a punch through of a barrier nitride layer in forming a contact plug for a charge storage electrode. CONSTITUTION: A bit line(31) is formed on a lower layer(30). The bit line includes a nitride layer(32) and a nitride layer spacer(33). An interlayer dielectric(34) and the first sacrificial oxide layer(35) are formed on the entire structure. A contact hole for a charge storage electrode is formed by selectively etching the interlayer dielectric and the first sacrificial oxide layer. A polysilicon layer is deposited on the entire structure to form a contact plug for a charge storage electrode. A polysilicon plug is formed by etching back the polysilicon layer. A barrier nitride(37) is deposited on the entire structure to prevent a crack in a sequent step. The second sacrificial oxide layer(38) is deposited on the entire structure. After selectively etching the second sacrificial oxide layer, the exposed barrier nitride layer is removed.