Title :
MOS characteristics of ultrathin CVD HfAlO gate dielectrics
Author :
Bae, S.H. ; Lee, C.-H. ; Clark, R. ; Kwong, D.L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Texas, Austin, TX, USA
Abstract :
Thermally stable, high-quality ultrathin (EOT=13 A) CVD HfAlO gate dielectrics with poly-Si gate electrode have been investigated for the first time. Results demonstrate that while in situ doping with Al significantly increases the crystallization temperature of HfO/sub 2/ up to 900/spl deg/C and improves its thermal stability, it also introduces negative fixed oxide charges due to Al accumulation at the HfAlO-Si interface, resulting in mobility degradation. The effects of Al concentration on crystallization temperature, fixed oxide charge density, and mobility degradation in HfAlO have been characterized and correlated.
Keywords :
CVD coatings; MOSFET; carrier mobility; crystallisation; dielectric thin films; hafnium compounds; semiconductor-insulator boundaries; thermal stability; 13 A; 900 degC; Al accumulation; Al concentration; CVD HfAlO gate dielectrics; HfAlO-Si; HfAlO-Si interface; HfO/sub 2/ crystallization temperature; HfO/sub 2/ thermal stability; MOS characteristics; fixed oxide charge density; high-quality gate dielectrics; in situ doping; mobility degradation; negative fixed oxide charges; poly-Si MOSFETs; poly-Si gate electrode; ultrathin gate dielectrics; Crystalline materials; Crystallization; Dielectric materials; Dielectric substrates; Electrodes; Grain boundaries; Hafnium oxide; Temperature; Thermal degradation; Thermal stability;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2003.816578
