TITLE:
The Implementation of the Surface Charging Effects in Three-Dimensional Simulations of SiO2 Etching Profile Evolution
AUTHORS:
Branislav Radjenović, Marija Radmilović-Radjenović
KEYWORDS:
Plasma Etching; Level Set Method; Profile Charging; Finite Elements Method
JOURNAL NAME:
Engineering,
Vol.6 No.1,
January
10,
2014
ABSTRACT: Refined control
of etched profile in microelectronic devices during plasma etching process is
one of the most important tasks of front-end and back-end microelectronic
devices manufacturing technologies. A comprehensive simulation of etching
profile evolution requires knowledge of the etching rates at all the points of
the profile surface during the etching process. Electrons do not contribute
directly to the material removal, but they are the source, together with
positive ions, of the profile charging that has many negative consequences on
the final outcome of the process especially in the case of insulating material
etching. The ability to simulate feature charging was added to the 3D level set
profile evolution simulator described earlier. The ion and electron fluxes were
computed along the feature using Monte Carlo
method. The surface potential profiles and electric field for the entire
feature were generated by solving Laplace
equation using finite elements method. Calculations were performed in the case
of simplified model of Ar+/CF4 non-equilibrium plasma
etching of SiO2.