Title :
Band alignment of high-k dielectric on SiO2/Si stack
Author :
Jinjuan Xiang ; Xiaolei Wang ; Tingting Li ; Chao Zhao ; Wenwu Wang ; Junfeng Li ; Dapeng Chen ; Tianchun Ye
Author_Institution :
Key Lab. of Microelectron. Devices & Integrated Technol., Inst. of Microelectron., Beijing, China
Abstract :
Band alignments of high-k dielectrics such as atomic layer deposition (ALD) grown HfO2 and Al2O3 with different thicknesses on SiO2/Si stack are investigated by X-ray photoelectron spectroscopy (XPS). The band offsets at HfO2/SiO2, Al2O3/SiO2 and SiO2/Si interfaces are found to vary with physical thickness of high-k dielectric. Concepts of gap states and charge neutrality level (CNL) are employed to discuss band lineup of high-k/SiO2/Si stack. The XPS observed results are successfully interpreted and attributed to lower CNLs of HfO2 and Al2O3 related to that of SiO2/Si stack, indicating feasibility of gap state based theory in investigating band alignment of oxide/semiconductor and oxide/oxide heterojunctions.
Keywords :
MIS devices; X-ray photoelectron spectra; aluminium compounds; atomic layer deposition; hafnium compounds; high-k dielectric thin films; semiconductor-insulator boundaries; silicon compounds; Al2O3-SiO2; HfO2-SiO2; SiO2-Si; X-ray photoelectron spectroscopy; atomic layer deposition; band alignment; gap state; high-k dielectric; oxide-oxide heterojunction; oxide-semiconductor heterojunction; Abstracts; Hafnium compounds; High K dielectric materials; Silicon; Thermodynamics;
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.2012.6212847
