SiO2 to Si selectivity mechanisms in high density fluorocarbon plasma etching

Abstract

Articles you may be interested inMechanism of selective SiO2/Si etching with fluorocarbon gases (CF4, C4F8) and hydrogen mixture in electron cyclotron resonance plasma etching system

High-Resolution 19F MAS NMR Spectroscopy of Fluorocarbon Films from Pulsed PECVD of Hexafluoropropylene Oxide

“…The reason for this is not entirely clear, but there may be a favorable reaction pathway involving plausibly the addition of an activated three-carbon HFPO molecule to the network, forming a two-carbon branch and simultaneously eliminating a volatile carbonyl fluoride, COF 2 . The lack of oxygen incorporation within the film, as indicated by XPS, and the presence of COF 2 in some oxygen-containing fluorocarbon plasmas, as shown through gas-phase diagnostics, , seem to support such a hypothesis. Alternatively, the discrepancy may simply be a result of the statistical nature of the film network, with the CF 3 *CF 2 sequence having a larger number of extended bond connectivity permutations than is possible with the CF 2 CF 2 *CF 3 sequence.…”

Study of Surface Reaction and Gas Phase Chemistries in High Density C4F8/O2/Ar and C4F8/O2/Ar/CH2F2Plasma for Contact Hole Etching

“…Assuming that the emission intensities are proportional to the volume densities of the corresponding species in a gas phase, the observed changes in plasma composition can result from a combination of several factors. Particularly, increases in both CF and CF 2 densities are potentially caused by two effects: (i) the increasing density of C 4 F 8 molecules that are the only source of CF x radicals in our system and (ii) the decrease in oxygen partial pressure, which lowers the destruction rate for CF x radicals (CF x + O → COF x-1 + F) both in bulk plasma and on the etched surface [8]. This also explains the decreasing tendency mentioned for the volume density of F atoms.…”

Role of plasma-aided manufacturing in semiconductor fabrication

“…This allows creation of a variety of novel surfaces such as highly cross-linked Teflon or surfaces with novel surface functionalities. Under certain circumstances, ions rather than neutrals can be the precursor of polymers [42]. There is a welldeveloped understanding of the plasma chemistry involved in plasma etching of semiconductor materials by fluorocarbon and Cl plasmas [5], [24].…”