Hafnium Titanate bilayer structure multimetal dielectric nMOSCAPs

• Published in: IEEE electron device letters Vol. 27; no. 4; pp. 225 - 227
• Main Authors: Se Jong Rhee, Feng Zhu, Hyoung-Sub Kim, Chang Hwan Choi, Chang Yong Kang, Manhong Zhang, Tackhwi Lee, Ok, I., Krishnan, S.A., Lee, J.C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-04-2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Bilayer; CMOS; CMOS technology; Density; Design. Technologies. Operation analysis. Testing; Dielectric devices; Dielectric materials; Dielectric substrates; Dielectrics; Electronics; equivalent oxide thickness (EOT); Exact sciences and technology; fixed charge; flatband voltage; Hafnium; Hafnium oxide; Hysteresis; Integrated circuits; Laminates; Leakage current; leakage current density; Oxides; Permittivity; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Thermal stability; Titanium compounds; Titanium dioxide; Ultrathin films; Interface state; High performance; Density of states; Stratified material; HfO2; equivalent oxide thickness (EOT); Bilayer; flatband voltage; leakage current density; Flat band voltage; Complementary MOS technology; fixed charge; Leakage current; Band offset; Permittivity; Current density; Bilayers; TiO2
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2006.871187

A novel approach of fabricating laminated TiO/sub 2//HfO/sub 2/ bilayer multimetal oxide dielectric has been developed for high-performance CMOS applications. Ultrathin equivalent oxide thickness (/spl sim/8 /spl Aring/) has been achieved with increased effective permittivity (k/spl sim/36). Hysteresis was significantly reduced using the bilayer dielectric. Top TiO/sub 2/ layer was found to induce effective negative charge from the flatband voltage shift. Leakage current characteristic was slightly higher than control HfO/sub 2/, and this is believed to be due to the lower band offset of TiO/sub 2/. However, the interface state density of this bilayer structure was found to be similar to that of HfO/sub 2/ MOSCAP because the bottom layer is HfO/sub 2/. These results demonstrate the feasibility of new multimetal dielectric application for future CMOS technology.