AVS 51st International Symposium
    Plasma Science and Technology Friday Sessions
       Session PS1+DI-FrM

Paper PS1+DI-FrM7
Ion-enhanced Etching of HfO@sub2@ with Cl@super+@, BCl@subx@@super+@(X = 1, 2) and SiCl @subx@@super+@(X = 1, 2,3) Ion

Friday, November 19, 2004, 10:20 am, Room 213A

Session: High K and Difficult Materials Etch
Presenter: K. Karahashi, MIRAI-ASET, JAPAN
Authors: K. Karahashi, MIRAI-ASET, JAPAN
N. Mise, MIRAI-ASET, Japan
T. Horikawa, MIRAI-ASRC/AIST, Japan
A. Toriumi, MIRAI-ASRC/AIST, Univ. of Tokyo, Japan
Correspondent: Click to Email
As advanced high-k gate dielectrics are being developed to replace SiO@sub2@ in the near future generation of microelectronics devices, understanding their plasma etch characteristics becomes vital for introducing new materials into the manufacturing process. We report on the interactions of HfO@sub2@ with ionic species contained in plasma etching environments. To clarify the ion induced reactions of Cl@super+@, BCl@subx@@super+@(X = 1, 2) and SiCl@subx@@super+@ (X = 1, 2,3), we employed the mass-analyzed ion beam apparatus that can irradiate a single ionic species to the sample surface under an ultra-high vacuum condition. Etching yield of SiCl@sub3@@super+@ ion is about 2 times larger than that of Cl@super+@ ion, and etching products are hafnium chlorides and oxygen atom. This result suggests that chlorine atoms play a key role in etching reaction, and that the chemical etching yield increases with increasing number of chlorine atoms contained in the incident ions. The kinetic energy of etching products, which were estimated by the time delay of etching products with respects to the incident ion pulses, was larger than 0.1 eV. Therefore, products are different from thermally desorbed molecules. This indicates that desorption is caused by the momentum transfer to hafnium chloride. This work was supported by NEDO.