TaON界面层Hf基高κ栅介质Ge MOS电容特性研究

Electrical Properties of Hf-based High-κ Gate Dielectric Ge MOS Capacitor with TaON Interlayer

制备了含TaON界面层的Hf基氧化物和氮氧化物叠层高κ栅介质GeMOS电容。器件的测量结果表明,HfTaON/TaON叠层栅介质GeMOS电容表现出良好的界面特性、低的栅极漏电流密度、小的等效氧化物厚度(0.94nm)、高的介电常数(～24)和良好的可靠性。这些都归因于TaON界面层阻挡了O及金属原子向Ge衬底的扩散,抑制了不稳定的低κGeOx的生长,从而改善界面质量,增强器件性能。

Hf-based oxide and oxynitride high κ gate stack dielectrics with TaON interlayer were grown on Ge substrate to fabricate MOS capacitors. The measuring results of device performances indicate that the MOS capacitor with a gate stack of HfTaON and thin TaON interlayer exhibits good interface properties, low gate leakage, small equivalent oxide thickness （0. 94 nm）, high permittivity （- 24）, and enhanced device reliability. All these should be attributed to the blocking role of the TaON interlayer against penetration of O into the Ge substrate, which effectively improve interface quality and achieve superior device performances by suppressing the formarion of unstable low-κ GeOx.