Title :
Threshold voltage (Vth) instability in HfO2 high-κ gate stacks with TiN metal gate: comparison between NH3 and O3 interface treatments
Author :
Wang, Xuguang ; Peterson, Jeff ; Majhi, Prashant ; Gardner, Mark I. ; Kwong, Dim-Lee
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Texas, Austin, TX, USA
Abstract :
The impacts of O3 or NH3 interface treatments on the long-term Vth instability in nMOSFET HfO2 high-κ gate stacks with TiN metal gate electrodes are compared. The NH3 interface treatment is found to be beneficial to suppress the Vth shift compared to the O3-treated samples. This is explained by an enhanced valence band electrons injection in O3-treated samples and is experimentally confirmed through a carrier separation measurement. The dynamic stress measurement also indicates that trapped charges are more easily detrapped in NH3-treated samples than O3-treated samples, improving significantly the Vth stability.
Keywords :
MOSFET; ammonia; charge injection; electron traps; hafnium compounds; interface phenomena; metal-insulator boundaries; oxygen; titanium compounds; HfO2-TiN; NH3 interface treatment; O3 interface treatment; TiN metal gate; carrier separation measurement; charge trapping; dynamic stress measurement; enhanced valence band electrons; high-k gate stacks; metal gate electrodes; nMOSFET; threshold voltage instability; valence band electrons injection; Electrodes; Electron traps; Hafnium oxide; Lead compounds; MOS devices; MOSFET circuits; Stability; Stress measurement; Threshold voltage; Tin; $V_rm th$ instability; Charge trapping; HfO$_2$; dynamic stress measurement; valance band electrons injection;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2004.836806
