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

fYear

2012

fDate

14-15 May 2012

Firstpage

176

Lastpage

179

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;

fLanguage

English

Publisher

ieee

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

Type

conf

DOI

10.1109/IWJT.2012.6212837

Filename

6212837