摘要
The effects of different NH3-plasma treatment procedures on interracial and electrical properties of Ge MOS capacitors with stacked gate dielectric of HtTiON/TaON were investigated. The NH3-plasma treatment was performed at different steps during fabrication of the stacked gate dielectric, i.e. before or after interlayer （TaON） deposition, or after deposition ofhigh-k dielectric （HfriON）. It was found that the excellent interface quality with an interface-state density of 4.79 × 101l eV-lcm-2 and low gate leakage current （3.43 ×10-5 A/cm2 at Vg = 1 V） could be achieved for the sample with NH3-plasma treatment directly on the Ge surface before TaON deposition. The involved mechanisms are attributed to the fact that the NH3-plasma can directly react with the Ge surface to form more Ge-N bonds, i.e. more GeOxNy, which effectively blocks the inter-diffusion of elements and suppresses the formation of unstable GeOx interfacial layer, and also passivates oxygen vacancies and dangling bonds near/at the interface due to more N incorporation and decomposed H atoms from the NH3-plasma.
The effects of different NH3-plasma treatment procedures on interracial and electrical properties of Ge MOS capacitors with stacked gate dielectric of HtTiON/TaON were investigated. The NH3-plasma treatment was performed at different steps during fabrication of the stacked gate dielectric, i.e. before or after interlayer （TaON） deposition, or after deposition ofhigh-k dielectric （HfriON）. It was found that the excellent interface quality with an interface-state density of 4.79 × 101l eV-lcm-2 and low gate leakage current （3.43 ×10-5 A/cm2 at Vg = 1 V） could be achieved for the sample with NH3-plasma treatment directly on the Ge surface before TaON deposition. The involved mechanisms are attributed to the fact that the NH3-plasma can directly react with the Ge surface to form more Ge-N bonds, i.e. more GeOxNy, which effectively blocks the inter-diffusion of elements and suppresses the formation of unstable GeOx interfacial layer, and also passivates oxygen vacancies and dangling bonds near/at the interface due to more N incorporation and decomposed H atoms from the NH3-plasma.
基金
supported by the National Natural Science Foundation of China(Nos.61176100,61274112)
