Model-Based Analysis of the ZrO2 Etching Mechanism in Inductively Coupled BCl3/Ar and BCl3/CHF3/Ar Plasmas

Mansu Kim, Nam-Ki Min, Sun Jin Yun, Hyun Woo Lee, Alexander M. Efremov, Kwang-Ho kwon
2008 ETRI Journal  
The etching mechanism of ZrO 2 thin films and etch selectivity over some materials in both BCl 3 /Ar and BCl 3 /CHF 3 /Ar plasmas are investigated using a combination of experimental and modeling methods. To obtain the data on plasma composition and fluxes of active species, global (0-dimensional) plasma models are developed with Langmuir probe diagnostics data. In BCl 3 /Ar plasma, changes in gas mixing ratio result in nonlinear changes of both densities and fluxes for Cl, BCl 2 , and BCl 2 +
more » ... In this work, it is shown that the nonmonotonic behavior of the ZrO 2 etch rate as a function of the BCl 3 /Ar mixing ratio could be related to the ionassisted etch mechanism and the ion-flux-limited etch regime. The addition of up to 33% CHF 3 to the BCl 3 -rich BCl 3 /Ar plasma does not influence the ZrO 2 etch rate, but it non-monotonically changes the etch rates of both Si and SiO 2 . The last effect can probably be associated with the corresponding behavior of the F atom density.
doi:10.4218/etrij.08.0107.0206 fatcat:3pa56wgftraejgjqnhiehuom4u