Paper PS-ThA8
Investigation of Plasma Etching of SiO@sub 2@ Contact Holes using a Statistical Method and a Theoretical Profile Evolution Model@footnote 1@
The experimental data@footnote 2@ in the plasma etching of SiO@sub 2@ contact holes in a MERIE reactor with a CF@sub 4@/CHF@sub 3@/Ar gas mixture is analyzed by using a statistical method and our semi-analytical etch profile evolution model. The experimental data is from a 2@super 5-1@ fractional factorial experiment design.@footnote 3@ The five factors which are treated as independent variables are the plasma reactor process variables: CHF@sub 3@ flow rate, CF@sub 4@ flow rate, Ar flow rate, gas pressure, and magnetic field. The DC bias voltage, the etch rate, the sidewall slope and the microtrench depth of the etch profiles are analyzed as response variables. The aim of the statistical analysis is the prediction of the measured response variables as a function of the five plasma reactor process variables. The accuracy of the predicted values of the response variables is reported. To reveal the underlying mechanism of the external processing parameter effects on the etch profiles, we simulate the SEMs etch profiles under different processing conditions using our theoretical etch profile evolution model, which is based on the calculation of particle fluxes arriving at the etching surface. Comparison between the control parameters of our model and the measured variables can give us more insights into how to control the etch rate and the etch profile. The new concept of our approach is the combination of the statistical prediction of the measured properties of the etch profile as a function of the reactor process variables and the theoretical simulation of the etch profile. @FootnoteText@ @footnote 1@This research is supported in part by the Boeing-McDonnell foundation. @footnote 2@Melisa J. Buie and Jeremiah Pender supplyed the data and SEM micrographs. @footnote 3@M. J. Buie, J. T. P. Pender, and P. L. G. Ventzek, Jpn. J. Appl. Phys. Part 1, 36(7B), 4838(1997).