TY - JOUR
T1 - Hafnium or zirconium high-k fab cross-contamination issues
AU - Vermeire, Bert
AU - Pandit, Viraj S.
AU - Parks, Harold G.
AU - Raghavan, Srini
AU - Ramkumar, Krishnaswami
AU - Jeon, Joong
N1 - Funding Information:
Manuscript received November 1, 2002; revised April 5, 2004. This work was supported in part by the Center For Microcontamination, by the NSF/IUCRC located at the University of Arizona, Tucson, and by International SEMATECH. B. Vermeire was with the Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ 85721-0104 USA. He is now with the Ridgetop Group, Tucson, AZ 85704 USA. V. S. Pandit and H. G. Parks are with the Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ 85721-0104 USA (e-mail: [email protected]; [email protected]). S. Raghavan is with the Department of Materials Science and Engineering, University of Arizona, Tucson, AZ 85721 (e-mail: [email protected]). K. Ramkumar is with Cypress Semiconductor, San Jose, CA USA 95134 (e-mail: [email protected]). J. Jeon is with Advanced Micro Devices, Sunnyvale, CA 94088 USA (e-mail: [email protected]). Digital Object Identifier 10.1109/TSM.2004.835726 Fig. 1. Hf deposition on hydrophobic (squares) or hydrophilic (circles) wafers. Wafers were immersed for 10 min in a 0.01-M ionic strength solution with either 1 ppm of Hf (solid symbols) or 100 ppb of Hf (open symbols).
PY - 2004/11
Y1 - 2004/11
N2 - Hf and Zr contamination during immersion in process solutions is most likely to occur in neutral and caustic solutions. Both Hf and Zr contamination are introduced onto the wafer surface if they are present in an ammonium hydroxide peroxide mixture solution (which is caustic), but such contamination is removed using existing acid cleans. Large amounts of wafer-to-wafer cross contamination occurs in plasma etch tools. Particles can cause cross contamination in a thermal reactor during high-temperature anneals of high-k dielectric layers. Residual surface cross contamination does not diffuse into the wafers during thermal processing. If contamination remains on a wafer, gate oxide integrity degradation is only observed at high concentrations. Near surface minority carrier lifetime is also affected, but bulk lifetime is not.
AB - Hf and Zr contamination during immersion in process solutions is most likely to occur in neutral and caustic solutions. Both Hf and Zr contamination are introduced onto the wafer surface if they are present in an ammonium hydroxide peroxide mixture solution (which is caustic), but such contamination is removed using existing acid cleans. Large amounts of wafer-to-wafer cross contamination occurs in plasma etch tools. Particles can cause cross contamination in a thermal reactor during high-temperature anneals of high-k dielectric layers. Residual surface cross contamination does not diffuse into the wafers during thermal processing. If contamination remains on a wafer, gate oxide integrity degradation is only observed at high concentrations. Near surface minority carrier lifetime is also affected, but bulk lifetime is not.
KW - Cleaning
KW - Cross contamination
KW - Hafnium dioxide (HfO)
KW - High-k dielectric
KW - Zirconium dioxide (ZrO)
UR - https://www.scopus.com/pages/publications/9144272781
UR - https://www.scopus.com/pages/publications/9144272781#tab=citedBy
U2 - 10.1109/TSM.2004.835726
DO - 10.1109/TSM.2004.835726
M3 - Article
AN - SCOPUS:9144272781
SN - 0894-6507
VL - 17
SP - 582
EP - 589
JO - IEEE Transactions on Semiconductor Manufacturing
JF - IEEE Transactions on Semiconductor Manufacturing
IS - 4
ER -