Incoming and reflected fluxes of particles
Simulated sidewall for the Bosch process
Profiles of a TSV simulated using ViennaTS

The simulator ViennaTS is a level set based software developed at the Institute for Microelectronics, TU Wien which allows the simulation of sequential etching and processing techniques. The software has its roots in the PhD dissertation of Dr. Ertl, performed at the Institute for Microelectronics [1]. The software calculates rates based on the incoming and reflected fluxes of relevant particles (Figure 1).

The development version of the ViennaTS code provides models for chemical vapor deposition, plasma deposition and etching, anisotropic wet etching, focused ion beam etching [1], thermal oxidation of silicon based on the Deal-Grove and Massoud models, atomic force microscopy deposition, and spray pyrolysis deposition [2].

During the SUPERTHEME project, this software is used in order to generate the profiles after deep reactive ion etching (DRIE), also known as the Bosch process. This process is a combination of polymer deposition and plasma etching steps, resulting in a rough sidewall (Figure 2). In order to etch deep vertical trenches, such as those required for TSVs, the Bosch process is frequently used. In Figure 3, the flat [3] and scalloped [4] profiles of a TSV simulated using ViennaTS is shown.

[1] O. Ertl, Numerical Methods for Topography Simulation. Dissertation, TU Wien, 2010,
[2] L. Filipovic, Topography Simulation of Novel Processing Techniques, Dissertation, TU Wien, 2012,
[3] L. Filipovic et al., Three-dimensional simulation for the reliability and electrical performance of through-silicon vias, Simulation of Semiconductor Processes and Devices (SISPAD) 2014, pp.341-344
[4] L. Filipovic and S. Selberherr, The effects of etching and deposition on the performance and stress evolution of open through silicon vias, Microelectronics Reliability 54 (2014), pp.1953-1958