Title
Role of vibrationally excited HBr in a HBr/He inductively coupled plasma used for etching of silicon Role of vibrationally excited HBr in a HBr/He inductively coupled plasma used for etching of silicon
Author
Faculty/Department
Faculty of Sciences. Chemistry
Publication type
article
Publication
London ,
Subject
Physics
Chemistry
Source (journal)
Journal of physics: D: applied physics. - London
Volume/pages
49(2016) :24 , p. 1-6
ISSN
0022-3727
Carrier
E
Target language
English (eng)
Full text (Publishers DOI)
Affiliation
University of Antwerp
Abstract
In this work, the role of vibrationally excited HBr (HBr(vib)) is computationally investigated for a HBr/He inductively coupled plasma applied for Si etching. It is found that at least 50% of all dissociations of HBr occur through HBr(vib). This additional dissociation pathway through HBr(vib) makes the plasma significantly more atomic. It also results in a slightly higher electron temperature (i.e. about 0.2 eV higher compared to simulation results where HBr(vib) is not included), as well as a higher gas temperature (i.e. about 50 K higher than without including HBr(vib)), due to the enhanced FranckCondon heating through HBr(vib) dissociation, at the conditions investigated. Most importantly, the calculated etch rate with HBr(vib) included in the model is a factor 3 higher than in the case without HBr(vib), due to the higher fluxes of etching species (i.e. H and Br), while the chemical composition of the wafer surface shows no significant difference. Our calculations clearly show the importance of including HBr(vib) for accurate modeling of HBr-containing plasmas.
Full text (open access)
https://repository.uantwerpen.be/docman/irua/136099/133457.pdf
E-info
https://repository.uantwerpen.be/docman/iruaauth/d3a2bd/133457.pdf
Handle