Title :
Improved short channel device characteristics with stress relieved pre-oxide (SRPO) and a novel tantalum carbon alloy metal gate/HfO2 stack
Author :
Tseng, H.-H. ; Capasso, C.C. ; Schaeffer, J.K. ; Hebert, E.A. ; Tobin, P.J. ; Gilmer, D.C. ; Triyoso, D. ; Ramon, M.E. ; Kalpat, S. ; Luckowski, E. ; Taylor, W.J. ; Jeon, Y. ; Adetutu, O. ; Hegde, R.I. ; Noble, R. ; Jahanbani, M. ; El Chemali, C. ; White,
Author_Institution :
Technol. Solution Organ., Freescale Semicond., Austin, TX, USA
Abstract :
Threshold voltage instability is a critical problem for high-K dielectric implementation. This problem is much more serious for short channel devices due to process induced gate edge damage. A novel stress relieved pre-oxide (SRPO) followed by ALD of HfO2 reduces the local charge density near the gate edge and short channel threshold voltage instability. Excellent cross wafer CETinv uniformity is achieved for the SRPO process. A new tantalum carbon alloy metal gate achieves a lower Vtsat than TaSiN gated devices due to a lower work function. Compared to HfO2/TaSiN devices using standard RCA pre-clean, HfO2/tantalum carbon alloy metal gate stack using the novel SRPO demonstrates a 3× smaller Vt shift for short channel devices and a 16% Ion/Ioff improvement.
Keywords :
dielectric devices; hafnium compounds; insulated gate field effect transistors; semiconductor device breakdown; tantalum compounds; HfO2-TaSiN; Ion/Ioff improvement; cross wafer CETinv uniformity; high-K dielectric; local charge density; process induced gate edge damage; short channel device characteristics; standard RCA pre-clean; stress relieved pre-oxide; tantalum carbon alloy metal gate; threshold voltage instability; threshold voltage saturation; threshold voltage shift; work function; Annealing; CMOS process; Dielectric substrates; Fabrication; Hafnium oxide; High-K gate dielectrics; Silicon; Temperature; Thermal stresses; Threshold voltage;
Conference_Titel :
Electron Devices Meeting, 2004. IEDM Technical Digest. IEEE International
Print_ISBN :
0-7803-8684-1
DOI :
10.1109/IEDM.2004.1419303
