Improved electrical characteristics and reliability of amorphous InGaZnO metal–insulator–semiconductor capacitor with high κ HfOxNy gate dielectric

✍ Scribed by Xiao Zou; Guojia Fang; Longyan Yuan; Xingsheng Tong; Xingzhong Zhao

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 809 KB
• Volume: 50
• Category: Article
• ISSN: 0026-2714
• DOI: 10.1016/j.microrel.2010.04.002

✦ Synopsis

High j HfO x N y film was deposited on amorphous InGaZnO (a-IGZO) by radio-frequency reactive sputtering using an HfO 2 target in nitrogen plus argon ambience, the electrical characteristics and reliability of a-IGZO metal-insulator-semiconductor (MIS) capacitors were investigated. Experimental results indicate that the nitrogen incorporation into HfO 2 can produce a strong nitride interfacial barrier layer, thus lead to reducing the interface state density, suppressing the hysteresis voltage, and decreasing the gate-leakage current. Improved performance has been achieved for HfO x N y gate dielectric a-IGZO MIS capacitors, with a interface state density of 5.1 Â 10 11 eV À1 cm À2 , a gate-leakage current density of 3.9 Â 10 À5 A/cm 2 at V fb + 1 V, an equivalent permittivity of 24, and a hysteresis voltage of 105 mV. Moreover, the enhanced reliability of Al/HfO x N y /a-IGZO MIS capacitor is observed with a small degradation of electrical characteristics after a high field stressing at 10 MV/cm for 3600 s.