Rf discharge dissociative mode in NF3 and SiH4
This paper shows that the rf capacitive discharge in NF(3) and SiH(4) can burn in three possible modes: weak-current alpha-mode, strong-current gamma-mode and dissociative delta-mode. This new dissociative delta-mode is characterized by a high dissociation degree of gas molecules (actually up to 100% in NF(3) and up to 70% in SiH(4)), higher resistivity and a large discharge current. On increasing rf voltage first we may observe a weak-current alpha-mode (at low NF(3) pressure the alpha-mode is absent). At rather high rf voltage when a sufficiently large number of high energy electrons appear in the discharge, an intense dissociation of gas molecules via electron impact begins, and the discharge experiences a transition to the dissociative delta-mode. The dissociation products of NF(3) and SiH(4) molecules possess lower ionization potentials, and they form an easily ionized admixture to the main gas. At higher rf voltages when near-electrode sheaths are broken down, the discharge experiences a transition to the strong-current gamma-mode.
Bibliographic Reference: An article published in: Journal of Physics D: Applied Physics 40 6631-6640 (2007)
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://dx.doi.org/10.1088/0022-3727/40/21/023
Record Number: 200819685 / Last updated on: 2008-02-15
Original language: en
Available languages: en