Title :
Thermally robust Ta2O5 capacitor for the 256-Mbit DRAM
Author :
Kwon, Kee-Won ; Kang, Chang-Seok ; Park, Soon Oh ; Kang, Ho-Kyu ; Ahn, Sung Tae
Author_Institution :
Semicond. R&D Centre, Samsung Electron. Co., Kyungki, South Korea
fDate :
6/1/1996 12:00:00 AM
Abstract :
The thermal degradation of the Ta2 O5 capacitor during BPSG reflow has been studied. The cause of deterioration of Ta2O5 with the TiN top electrode was found to be the oxidation of TiN. By placing a poly-Si layer between TiN and BPSG to suppress oxidation, the low leakage current level was maintained after BPSG reflow at 850°C. The Ta2O5 capacitor with the TiN/poly-Si top electrode was integrated into 256-Mbit DRAM cells and excellent leakage current characteristics were obtained
Keywords :
DRAM chips; capacitors; integrated circuit reliability; leakage currents; phosphosilicate glasses; silicon; tantalum compounds; titanium compounds; 256 Mbit; 850 degC; BPSG reflow; DRAM cells; Si-Ta2O5-TiN-B2O3-P2O5-SiO2; Si-Ta2O5-TiN-BPSG; leakage current level; polysilicon layer; thermal degradation; Annealing; Capacitors; Electrodes; Leakage current; Plasma measurements; Plasma temperature; Random access memory; Robustness; Thermal degradation; Tin;
Journal_Title :
Electron Devices, IEEE Transactions on
