Title :
Robust high-quality HfN-HfO2 gate stack for advanced MOS device applications
Author :
Yu, H.Y. ; Kang, J.F. ; Ren, C. ; Chen, J.D. ; Hou, Y.T. ; Shen, C. ; Li, M.-F. ; Chan, D.S.H. ; Bera, K.L. ; Tung, C.H. ; Kwong, D.-L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore, Singapore
Abstract :
In this letter, a thermally stable and high-quality HfN-HfO2 gate stack for advanced MOS applications is reported for the first time. Negligible changes in both equivalent oxide thickness (EOT) and work function of HfN-HfO2 gate stack are demonstrated even after 1000°C postmetal annealing (PMA), which is attributed to the superior oxygen diffusion barrier property of HfN as well as the thermal stability of the HfN-HfO2 interface. Therefore, even without surface nitridation prior to HfO2 deposition, the EOT of HfN-HfO2 gate stack can be successfully scaled down to less than 10 Å after 1000°C PMA with excellent leakage and long-term reliability.
Keywords :
MOS capacitors; annealing; dielectric thin films; diffusion barriers; hafnium compounds; leakage currents; nitridation; semiconductor device reliability; thermal stability; work function; 1000 C; HfN-HfO2; advanced MOS device; deposition; equivalent oxide thickness; gate stack; high-K gate dielectrics; leakage reliability; long-term reliability; metal gate electrode; oxygen diffusion barrier property; postmetal annealing; surface nitridation; thermal stability; work function; Annealing; Chemical vapor deposition; Dielectric substrates; Electrodes; Hafnium oxide; MOS devices; Microelectronics; Robustness; Scalability; Thermal stability;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2003.820649
