AVS 52nd International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoP

Paper PS-MoP12
Extremely Thin Silicon Oxide Formation Using Pulse-Time-Modulated Oxygen Neutral Beam

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Plasma Science and Technology Poster Session
Presenter: C. Taguchi, Tohoku University, Japan
Authors: C. Taguchi, Tohoku University, Japan
S. Fukuda, Tohoku University, Japan
S. Noda, Tohoku University, Japan
S. Samukawa, Tohoku University, Japan
Correspondent: Click to Email
For next generation ULSI devices, high-k gate dielectric film is promising candidate since it provides both low gate-leakage and minimal electrical thickness in inversion. It is also important to form ultra-thin SiO@sub 2@ film between high-k film and Si substrate to avoid forming silicate. To minimize EOT of gate dielectric films, sub-1 nm fine thin SiO@sub 2@ film formation is indispensable. However, it is much difficult for conventional thermal-oxidation-processes to realize the requirement. To break through the problem, we proposed pulse-time-modulated neutral beam oxidation. In this new method, low energy (less than 10 eV) O@sub 2@ neutral beam radiation was modulated to the silicon substrate at the time constant of a few tens of µ seconds. That is, the oxidation process was modulated on the silicon surface. We first found that the SiO@sub 2@ thickness could be precisely controlled by changing the beam-on time in the pulse-time-modulated O@sub 2@ neutral beams without any radiation damages. It is speculated that the injected O@sub 2@ was diffused at a time constant of a few tens of µ seconds in the silicon. As a result, extremely thin SiO@sub 2@ film of less than 1 nm (minimum thickness:0.5 nm) could be formed on the silicon substrate by using the pulsed O@sub 2@ neutral beams. Our newly developed method is promising candidate to replace the thermal-oxidation-processes.