Title :
Effects of rapid thermal annealing on the interface and oxide trap distributions in hafnium oxide films
Author :
Zhan, Nian ; Ng, K.L. ; Wong, Hei ; Poon, M.C. ; Kok, C.W.
Author_Institution :
Dept. of Electr. & Electron. Eng., Hong Kong Univ. of Sci. & Technol., China
Abstract :
The effects of rapid thermal annealing on the interface charge and oxide charge densities of sputtered hafnium oxide (HfO2) films were investigated systematically. We found that both interface and oxide charge densities are strongly governed by the post-deposition annealing (PDA) conditions but have different dependencies. The interface trap density can be reduced by more than one order of magnitude to a value close to that of the Si/SiO2 interface after proper (>600°C) annealing. This effect is due to the formation of SiO2 at the HfO2/Si interface. However, PDA has a negative impact on the oxide charge density. The PDA-induced oxide charge generation is attributed to the grain boundary interface states because of the crystallization of the HfO2 at temperature greater than 650°C.
Keywords :
MIS capacitors; MIS structures; aluminium; capacitors; crystallisation; dielectric materials; dielectric thin films; elemental semiconductors; grain boundaries; hafnium compounds; interface states; rapid thermal annealing; silicon; silicon compounds; sputtered coatings; Al-HfO2-Si; HfO2-Si interface; Si-SiO2 interface; SiO2-HfO2-Si; crystallization; grain boundary interface states; hafnium oxide films; interface charge density; interface trap; oxide charge; oxide charge density; oxide trap; post-deposition annealing oxide charge generation; rapid thermal annealing; sputtered coatings; Capacitance-voltage characteristics; Grain boundaries; Hafnium oxide; Interface states; Rapid thermal annealing; Semiconductor films; Senior members; Silicon; Sputtering; Temperature;
Conference_Titel :
Electron Devices and Solid-State Circuits, 2003 IEEE Conference on
Print_ISBN :
0-7803-7749-4
DOI :
10.1109/EDSSC.2003.1283566
