Summary Abstract: Polyimide etching and passivation downstream of an O2–CF4–Ar microwave plasma

Plasma Etching of Organic Polymers

“…For a given number of oxygen atoms in the gas, several means are available for increasing the flux of these atoms at the surface of the polymer. Such effects have been observed downstream from an 0 2 + CF 4 microwave plasma discharge [56], where the etching rate of polyimide increased monotonically with increasing linear gas flow velocity. Brake et al [31] found that a decrease in gas residence time, i.e., a decrease in pressure or an increase in flow rate, increases the amount of oxygen atoms observed at a point downstream from an oxygen microwave discharge.…”

Oxygen plasma etching of hydrocarbon‐like polymers: Part I Modeling

“…For about 10 years, many studies have been devoted to highlighting and understanding the mechanisms responsible for the sharp increase, up to more than a factor of 10, of the etching rates reached by simply adding small amounts (between less than 1% up to 20%) of SF 6 or CF 4 in oxygen plasmas . For a long time, this etch rate increase was attributed to a corresponding increase in oxygen dissociation resulting, according to the authors, from an increase in the electron density or in the electron temperature of the plasma .…”

“…The removal of resists after implantation or etching is generally performed under conditions without ion assistance or very low ion assistance (e.g., at the floating potential or in post‐discharges, and more precisely in remote plasmas) in order not to damage or alter the surfaces exposed to the plasma. In such conditions where the etching induced by the ion bombardment is greatly reduced, the study of the variation of the etch rate as a function of surface temperature, which should in principle allow to determine the activation energy for spontaneous etching from Arrhenius plots, was the subject of many publications . The corresponding results, which have already been thoroughly discussed and listed, are recapitulated in chronological order in Table .…”

In SituFTIR Investigations Of Polymer Surface Modification In Downstream Microwave Plasma Etching

“…The mechanism underlying CF4/0 2 plasma etching of polymer films has been explored through diagnostic techniques such as etch rate measurements by laser interferometry [4], gas phase species monitoring by optical emission spectroscopy [5], and mass spectrometry [6], and polymer surface characterization by Fourier transform infrared spectroscopy (FTIR) [3] and Xray photoelectron spectroscopy (XPS) [3,4,[6][7][8]. Chou et al [3] used in situ XPS, steady-state mass spectroscopy, ex situ FTIR transmission and multiple internal reflections methods to investigate the etch mechanism of polyimide in CF 4 /0 2 microwave plasmas.…”