電漿處理或快速熱回火於MOHOS電容器儲存層之研究

Abstract

In the TaN / SiO2 / HfO2 / SiO2 / Si structure, the HfO2 charge storage layer was treated by H2 or NH3 plasma treatment for three minutes. The power of the plasma treatment is 200 watt and the gas flow is 200 sccm. The results indicate the direction of C-V hysteresis curve is counterclock- wise and the voltage is 4.5V and 4V respectively. The defects resulting from hydrogen atoms can induce the fixed positive charges and result in charging or discharging on the HfO2 film. After N2 plasma treatment, the hysteresis phenomenon of the C-V hysteresis curve disappeared. The reason is that the defects in the HfO2 film could be passivated by nitrogen atoms. In the memory window, the electrons stored on the film could be discharged easily after H2 plasma treatment owing to the shallow electron traps. But, the electrons do not discharge easily after NH3 plasma treat- ment. The reason is the shallow electron traps could be passivated by nitrogen atoms. Experimental results indicate the memory window (2V ~ 3 V) could be obtained after H2 or NH3 plasma treatment after discharging for 1000 sec.