TY - JOUR
T1 - Highly anisotropic gate electrode patterning in neutral beam etching using F2 gas chemistry
AU - Noda, Shuichi
AU - Hoshino, Yasuyuki
AU - Ozaki, Takuya
AU - Samukawa, Seiji
PY - 2005
Y1 - 2005
N2 - Pure F2 gas chemistry was evaluated in comparison with SF6 and Cl2 gas chemistries for etching poly-Si gates of metal-oxide-semiconductor field effect transistors in our neutral beam source. In the case of SF6 gas chemistry, the polycrystalline silicon (poly-Si) etch rate was high enough, whereas a large side etching was observed. In the case of Cl2 gas chemistry, the pattern profile was anisotropic, but the etch rate was very low. The tradeoff was caused by differences in the etching reactivity of F and Cl radicals with the poly-Si. Though the SF6 -based neutral beam caused a large side etching due to diffused F radicals, an anisotropic profile was obtained by using the F2 -based neutral beam, and the etch rate was much larger than that in the Cl2 gas chemistry. These notable characteristics were accomplished by suppressing excessive dissociation of F radicals and by generating large amount of negative F ions in a pulse-time-modulated F2 plasma in the neutral beam source.
AB - Pure F2 gas chemistry was evaluated in comparison with SF6 and Cl2 gas chemistries for etching poly-Si gates of metal-oxide-semiconductor field effect transistors in our neutral beam source. In the case of SF6 gas chemistry, the polycrystalline silicon (poly-Si) etch rate was high enough, whereas a large side etching was observed. In the case of Cl2 gas chemistry, the pattern profile was anisotropic, but the etch rate was very low. The tradeoff was caused by differences in the etching reactivity of F and Cl radicals with the poly-Si. Though the SF6 -based neutral beam caused a large side etching due to diffused F radicals, an anisotropic profile was obtained by using the F2 -based neutral beam, and the etch rate was much larger than that in the Cl2 gas chemistry. These notable characteristics were accomplished by suppressing excessive dissociation of F radicals and by generating large amount of negative F ions in a pulse-time-modulated F2 plasma in the neutral beam source.
UR - http://www.scopus.com/inward/record.url?scp=31144463291&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=31144463291&partnerID=8YFLogxK
U2 - 10.1116/1.2050660
DO - 10.1116/1.2050660
M3 - Article
AN - SCOPUS:31144463291
VL - 23
SP - 2063
EP - 2068
JO - Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
JF - Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
SN - 1071-1023
IS - 5
ER -