Tsai Yi-He, Chou Chen-Han, Li Hui-Hsuan, Yeh Wen-Kuan, Lin Yu-Hsien, Ko Fu-Hsiang, Chien Chao-Hsin
Graduate Program for Nanotechnology Department of Materials Science and Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan.
Department of Electronics Engineering and the Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwan.
J Nanosci Nanotechnol. 2019 Aug 1;19(8):4529-4534. doi: 10.1166/jnn.2019.16494.
A high-quality HfGeO interfacial layer (IL) was formed in a HfO₂/Al₂O₃/HfO₂/GeO gate stack through thermal annealing. The diffusing of GeO into the HfO₂ layer led to the mixing of the GeO and HfO₂ layers, as identified through energy-dispersive X-ray Spectroscopy (EDX). X-ray photo-electron spectroscopy (XPS) data for HfGeO IL confirmed the formation of Ge-O-Hf bonds owing to the induced shift of the Ge3d spectra to lower binding energies. The electrical and reliability data indicated that the capacitor with HfGeO IL presented not only lower interface states density (Dit, approximately 7 × 10 eVcm) but also less Dit increment (approximately 3 × 10 eVcm) after stressing than did the capacitor without the HfGeO IL. Moreover, the Ge p-metal-oxide-semiconductor field-effect transistor HfGeO IL exhibited a high effective hole mobility (approximately 704 cm2/V s).
通过热退火在HfO₂/Al₂O₃/HfO₂/GeO栅堆叠中形成了高质量的HfGeO界面层（IL）。通过能量色散X射线光谱（EDX）确定，GeO扩散到HfO₂层中导致了GeO和HfO₂层的混合。HfGeO IL的X射线光电子能谱（XPS）数据证实，由于Ge3d光谱向更低结合能的诱导位移，形成了Ge-O-Hf键。电学和可靠性数据表明，与没有HfGeO IL的电容器相比，具有HfGeO IL的电容器不仅具有更低的界面态密度（Dit，约7×10 eVcm），而且在应力后Dit的增加也更少（约3×10 eVcm）。此外，Ge p型金属氧化物半导体场效应晶体管HfGeO IL表现出高的有效空穴迁移率（约704 cm2/V s）。
