Title :
Hafnium Titanate bilayer structure multimetal dielectric nMOSCAPs
Author :
Rhee, Se Jong ; Zhu, Feng ; Kim, Hyoung-Sub ; Choi, Chang Hwan ; Kang, Chang Yong ; Zhang, Manhong ; Tackhwi Lee ; Ok, Injo ; Krishnan, Siddarth A. ; Lee, Jack C.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Texas, Austin, TX, USA
fDate :
4/1/2006 12:00:00 AM
Abstract :
A novel approach of fabricating laminated TiO2/HfO2 bilayer multimetal oxide dielectric has been developed for high-performance CMOS applications. Ultrathin equivalent oxide thickness (∼8 Å) has been achieved with increased effective permittivity (k∼36). Hysteresis was significantly reduced using the bilayer dielectric. Top TiO2 layer was found to induce effective negative charge from the flatband voltage shift. Leakage current characteristic was slightly higher than control HfO2, and this is believed to be due to the lower band offset of TiO2. However, the interface state density of this bilayer structure was found to be similar to that of HfO2 MOSCAP because the bottom layer is HfO2. These results demonstrate the feasibility of new multimetal dielectric application for future CMOS technology.
Keywords :
CMOS integrated circuits; MOS capacitors; dielectric materials; hafnium compounds; interface states; leakage currents; permittivity; titanium compounds; CMOS technology; TiO2-HfO2; bilayer dielectric; flatband voltage shift; hafnium titanate bilayer structure; hysteresis reduction; interface state density; leakage current; multimetal dielectric nMOSCAP; multimetal oxide dielectric; ultrathin equivalent oxide thickness; CMOS technology; Dielectric devices; Dielectric materials; Dielectric substrates; Hafnium oxide; Hysteresis; Leakage current; Permittivity; Thermal stability; Titanium compounds; Bilayer; equivalent oxide thickness (EOT); fixed charge; flatband voltage; leakage current density;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2006.871187
