AVS 51st International Symposium
    MEMS and NEMS Monday Sessions
       Session MN-MoP

Paper MN-MoP5
Deep Quartz and Silicon Etching in Newly Proposed ICCP Plasma

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: Y. Morikawa, ULVAC, Inc., Japan
Authors: Y. Morikawa, ULVAC, Inc., Japan
T. Koidesawa, ULVAC, Inc., Japan
T. Hayashi, ULVAC, Inc., Japan
K. Suu, ULVAC, Inc., Japan
M. Ishikawa, ULVAC, Inc., Japan
Correspondent: Click to Email
We have developed a new etching system for MEMS application. This System provides combined plasma of inductive coupled plasma (ICP or NLD) and a kind of capacitive coupled plasma (CCP), which is named as ICCP (Inductive coupled and capacitive coupled plasma). Using this system, deep silicon etching is capable even if fluorocarbon gas and SF@sub 6@ are not fed in the etching process. So this system is very friendly in view of GWP. SiO@sub 2@ etching is carried out in the NLD@footnote 1,2@ Plasma, which is generated by forming the magnetic neutral loop in the ICP plasma. The NLD plasma has a higher electron density with lower electron temperature at low pressure below 1 Pa, compared with that of ICP. The selectivity of SiO@sub 2@ to PR is improved to obtain more than 50 by tuning the contribution of inductive and capacitive plasma discharge. Silicon deep etching was carried out with the SiO@sub 2@ mask in the ICCP plasma, in which the electrodes were timely modulated for etching and deposition at a high-pressure region above 2 Pa. The selectivity of 300 or more was obtained for SiO@sub 2@ mask. The etch rate was about 15um/min when SF@sub 6@ was fed and about 5um/min when Ar/F@sub 2@ mixed gas was fed. Typically, the depth of 80 um or more with the trench width of 35 um was anisotropically etched at the etch rate of 10 um/min by the electrode modulation method in the ICCP plasma, in which cleaning step was not necessitated. Thus, even if the global warming gases were not used, deep Si etching was achieved. This is the most striking feature of the ICCP etching system. @FootnoteText@ 1)W. Chen et al, J.Vac. Sci. Technol. A19(6) (2001) 2936 2)Y. Morikawa et al., J.Vac. Sci. Technol. B21(4) (2003) 1344 .