AVS 52nd International Symposium
    Electronic Materials and Processing Monday Sessions
       Session EM-MoA

Paper EM-MoA4
Hafnium Based High K Dielectrics for Advanced ULSI Technology

Monday, October 31, 2005, 3:00 pm, Room 309

Session: High-k Dielectric Growth and Processing
Presenter: S. Muthukrishnan, Applied Materials Inc.
Authors: S. Muthukrishnan, Applied Materials Inc.
S. Kher, Applied Materials Inc.
P. Narwankar, Applied Materials Inc.
R. Sharangapani, Applied Materials Inc.
T. Goyani, Applied Materials Inc.
Y. Ma, Applied Materials Inc.
K. Ahmed, Applied Materials Inc.
G. Conti, Applied Materials Inc.
Correspondent: Click to Email
Hafnium based high k dielectric has emerged as a primary candidate for advanced ULSI technology due to its thermal stability property and leakage current reduction potential in comparison to other high k materials. We have successfully developed a hafnium based gate dielectrics, HfO2 and HfSiOx, using both ALD and MOCVD techniques. The materials are thermally stable up to source/drain activation temperature of 1050C and above when nitrogen is incorporated into the high k film. The nitrogen is incorporated into the high k film through plasma nitridation. We have been able to incorporate as high as 25% nitrogen in the high k film. The benefit of the plasma nitridation is in its capability of engineering the nitrogen profile in the gate stack. The nitrogen can be engineered to maintain the highest concentration in the bulk of the film and prevent nitrogen from going to the dielectric and channel interface. This profile provided the High K film with low leakage current. X-ray Photoelectron Spectral analysis showed that nitrogen is primarily bonded to the silicon. Besides high k deposition, process integration is critical not only for the gate dielectric performance but also for its scaling capability. By controlling the silicon surface coverage prior to high k deposition and surface adsorption from clean room environment, additional scaling can be achieved with processing steps in integrated clustered tools.