Title :
Investigation of band structure at metal-gate/high-k interface of metal oxide semiconductor device with high-k and metal gate stack
Author :
Xiaolei Wang ; Wenwu Wang ; Kai Han ; Hong Yang ; Jing Zhang ; Xueli Ma ; Jinjuan Xiang ; Chao Zhao ; Dapeng Chen ; Tianchun Ye
Author_Institution :
Key Lab. of Microelectron. Devices & Integrated Technol., Inst. of Microelectron., Beijing, China
Abstract :
Band alignment of TiN/HfO2 interface of TiN/HfO2/SiO2/Si stack is investigated by x-ray photoelectron spectroscopy (XPS). The p-type Schottky barrier height (p-SBH) is found to increase with thicker HfO2 thickness. Since considering only the metal/dielectric interface cannot explain this phenomenon, band alignment of TiN/HfO2 interface of TiN/HfO2/SiO2/Si stack is demonstrated based on band alignment of entire gate stack. Dependence of p-SBH on HfO2 thickness is interpreted and contributed to fixed charges in gate stack, interfacial gap state charges at HfO2/SiO2 interface, and space charges in Si substrate. Electrical measurements of capacitor structures further support XPS results and corresponding explanation.
Keywords :
Schottky barriers; band structure; elemental semiconductors; hafnium compounds; high-k dielectric thin films; silicon compounds; titanium compounds; HfO2 thickness; Si substrate; TiN-HfO2; TiN-HfO2-SiO2-Si; X-ray photoelectron spectroscopy; XPS; band alignment; band structure; capacitor structure; electrical measurement; gate stack; interfacial gap state; metal oxide semiconductor device; metal-gate-high-k interface; p-SBH; p-type Schottky barrier height; space charges; Dielectrics; Hafnium compounds; High K dielectric materials; Logic gates; Silicon; Tin;
Conference_Titel :
Junction Technology (IWJT), 2012 12th International Workshop on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4673-1258-5
Electronic_ISBN :
978-1-4673-1256-1
DOI :
10.1109/IWJT.2012.6212837
