Dielectric capacitor film for dram cell and method of forming the same.

摘要

An ultra thin triple layer dielectric film for use as a storage capacitor in a Dynamic Random Access Memory (DRAM) cell and a method of forming the same is disclosed. The thin dielectric film has an equivalent thickness Teq of no greater than about 7 nanometers. The capacitor film is prepared by forming a layer of silicon oxynitride SixNyOz from either a thin film of silicon oxide SiO2 situated on a substrate to which a nitridation process is applied or from direct nitridation of silicon deposits or a silicon substrate. Upon the oxynitride layer there is deposited a thin nitride layer, the top portion of which is subsequently oxidized at a high temperature for a short time to convert the top portion of the nitride layer into a thin silicon dioxide layer. The resulting structure comprises a oxynitride/nitride/dioxide dielectric having a low Teq (no greater than about 7 nanometers), and high capacitance. The ultra thin triple layer dielectric film can be used as a storage capacitor in a trench embodiment as well as a planar or stacked configuration mounted on a substrate. <IMAGE>