Modeling Etching Plasmas: Needs and Challenges in Atomic and Molecular Data

Theoretical study of dissociative recombination of Cl2+

“…6, the temperature dependencies of some of the rate coefficients used in the literature are displayed and compared with the rate coefficient here computed. The rate coefficients from Thorsteinsson et al [10] and Ono et al [29] are lower than our rate for all temperatures, while the rate coefficient applied by Margot et al [9] is larger than the computed rate at low temperatures and lower at higher temperatures.…”

“…The result of the fit is displayed with the (green) dotted curve. As can be seen the fit works only for very low temperatures since the "high-energy peak" in the cross section will cause a peak in the thermal rate coefficient centered around 5000 K. [9], Thorsteinsson et al [10], and Ono et al [29].…”

“…This reaction is believed to be one of the main destruction mechanisms of the Cl + 2 ions in chlorine etching plasmas [9]. The thermal rate coefficient for this reaction used in the modeling of the plasmas have typically been estimated using the rate coefficients for DR of other diatomic molecular ions.…”

“…A comprehensive review of current available data on electron interactions with chlorine molecules was later given by Christophorou and Olthoff [8]. A recent survey on the characteristic and modeling of chlorine high-density plasmas was made by Margot [9]. To our knowledge, there has been no theoretical nor experimental investigations of the cross section and rate coefficient for low-energy electron collisions with Cl + 2 leading to dissociative recombination.…”