SEMICONDUCTOR DEVICE AND METHOD OF FORMING CONTACT PLUG IN SEMICONDUCTOR DEVICE

摘要

A semiconductor device and a method for forming a contact plug thereof are provided to enhance integration and reliability by easily forming a bit line on a top of a contact plug formed into a high density in a narrow space. A first insulation layer(104) is formed on a top of a semiconductor substrate(100) including a junction region. A hard mask(106) is used in a contact hole etching process, and is formed on a top of the first insulation layer. A trench is formed by etching the first insulation layer and the hard mask corresponding to the junction region. A spacer film is formed on a top of a second hard mask including the trench. A spacer(110a) is formed on a side wall of the trench. A bottom width of the spacer is narrower than a top width of the spacer. A contact hole is formed by etching the first insulation layer exposed in a bottom of the trench. A material layer for a contact plug is formed on a top of the first hard mask including the contact hole. The contact hole is filled with the material layer for the contact plug. A contact plug(112a) is formed on the contact hole by performing a planarization process or an etch back process.