Title :
Improvement in high-k (HfO/sub 2//SiO/sub 2/) reliability by incorporation of fluorine
Author :
Seo, Kang-ill ; Sreenivasan, Raghavasimhan ; Mclntyre, P.C. ; Saraswat, Krishna C.
Author_Institution :
Dept. of Mater. Sci. & Eng., Stanford Univ., CA
Abstract :
We demonstrate that negative bias temperature instability (NBTI) of high-k (HfO2/SiO2) gate stacks are significantly improved by incorporating fluorine and engineering its concentration profile. We find that F piles up at HfO2/SiO 2 interface and diffuses into the underlying SiO2/Si interface. The HfO2/SiO2 stack with F shows significantly less CV hysteresis, positive charge trapping and interface states generation compared to control samples without F under the same negative bias condition. F is believed to form stronger Hf-F and Si-F bonds compared to Hf-H and Si-H bonds which improve the reliability of HfO2/SiO2
Keywords :
doping profiles; fluorine; hafnium compounds; high-k dielectric thin films; interface states; reliability; silicon compounds; HfO2-SiO2; SiO2-Si; charge trapping; concentration profile; fluorine incorporation; high-k gate stacks; interface states generation; negative bias temperature instability; CMOS technology; Electron traps; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; Interface states; Niobium compounds; Stress; Temperature distribution; Titanium compounds;
Conference_Titel :
Electron Devices Meeting, 2005. IEDM Technical Digest. IEEE International
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-9268-X
DOI :
10.1109/IEDM.2005.1609367
