METHOD FOR MANUFACTURING CAPACITOR USING ATOMIC LAYER DEPOSITION

摘要

PURPOSE: A method for manufacturing a capacitor using an ALD(Atomic Layer Deposition) is provided to improve electrical properties of a dielectric film by preventing a metallic Al2O3 layer and hydrogen between a lower electrode and the dielectric film. CONSTITUTION: A lower electrode(10) is formed on a semiconductor substrate. A dielectric film is deposited on the lower electrode. The dielectric film includes a chemical oxide(12) and an Al2O3 layer. The Al2O3 layer includes a seed layer(14) formed by using Al(CH3)3 as a source and an upper layer(16). An upper electrode(18) is formed on the dielectric film. The lower electrode is formed by depositing sequentially a doped polysilicon layer with a thickness of 50 to 300 angstrom and an undoped polysilicon layer with a thickness of 50 to 300 angstrom, and then doping PH3 under nitrogen gas atmosphere at the temperature of 500 to 700 °C. The chemical oxide with a thickness of 5 to 10 angstrom is formed by cleaning the lower electrode using HF+SC-1(NH4OH: H2O2: H2O). The seed layer and the upper layer of the Al2O3 layer are formed by using O3 gas and H2O gas as reaction gases, respectively.