Al-doped TiO2 films with ultralow leakage currents for next generation DRAM capacitors

Al-doped TiO2 thin films to be used in future DRAM capacitors with excellent leakage properties as well as high dielectric constants are fabricated. The next generation stack structured DRAM cell composed of a transistor and a capacitor is shown (see Figure). A large cell capacitance is required for successful operation of DRAMs irrespective of the feature size of the cell. Therefore, as scaling down of the DRAMs proceeds, a higher-k material such as Al-doped TiO2 has to be eventually implemented in the capacitor.