Title :
Improved device performance and reliability in high κ HfTaTiO gate dielectric with TaN gate electrode
Author :
Lu, N. ; Li, H.J. ; Gardner, M. ; Kwong, D.L.
Author_Institution :
Microelectron. Res. Center, Univ. of Texas, Austin, TX, USA
Abstract :
The device performance and reliability of higher-κ HfTaTiO gate dielectrics have been investigated in this letter. HfTaTiO dielectrics have been reported to have a high-κ value of 56 and acceptable barrier height relative to Si (1.0 eV). Through process optimization, an ultrathin equivalent oxide thickness (EOT) (∼9 Å) has been achieved. HfTaTiO nMOSFET characteristics have been studied as well. The peak mobility of HfTaTiO is 50% higher than that of HfO2 and its high field mobility is comparable to that of HfSiON with an intentionally grown SiO2 interface, indicative of superior quality of the interface and bulk dielectric. In addition, HfTaTiO dielectric has a reduced stress-induced leakage current (SILC) and improved breakdown voltage compared to HfO2 dielectric.
Keywords :
MOSFET; dielectric thin films; electrodes; electron mobility; hafnium compounds; leakage currents; semiconductor device breakdown; semiconductor device reliability; silicon compounds; tantalum compounds; HfTaTiO; SiO2; TaN; breakdown voltage; charge trapping; electron mobility; gate electrode; high field mobility; high-k gate dielectrics; nMOSFET; process optimization; reliability; stress-induced leakage current; time zero dielectric breakdown; ultrathin equivalent oxide thickness; Crystallization; Dielectric breakdown; Dielectric devices; Electrodes; Electron mobility; Hafnium oxide; Leakage current; MOSFET circuits; Permittivity; Temperature; Charge trapping; MOSFET; electron mobility; equivalent oxide thickness (EOT); high; time zero dielectric breakdown (TZDB);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2005.857698
