Carbon loss induced by plasma beam irradiation in porous silica films

Abstract

Plasma-induced damages of porous silica films during plasma processes were investigated by using a plasma beam irradiation apparatus. We used the porous silica films incorporated with methyl groups to achieve high hydrophobicity. The carbon (methyl group) reductions in the film as an index of the level of damages induced by Ar, He, O2, H2, and N2 plasma irradiations were examined by x-ray photoelectron spectroscopy and secondary ion mass spectroscopy. The damage due to Ar and He plasma bombardment increased with an increase in the ion dosage, although it was not strongly affected by the ion energy in the range higher than 130eV. Furthermore, it was found that the damage near the film surface was influenced more by metastable He atoms than by metastable Ar atoms. Both O ions and O atoms caused severe damage. N atoms did not affect the decrease of carbon content but reacted with carbon to form CN bonds. H atoms decreased carbon content slightly, but the amount of decrease was saturated by the further irradiation of H atoms.

Improved characterization of Fourier transform infrared spectra analysis for post-etched ultra-low-κ SiOCH dielectric using chemometric methods

“…H 2 also shows a lower carbon depletion compared to NH 3 and O 2 . During the reactive plasma ashes Si-C bonds are broken and volatile products such as CH 4 , CO, and CO 2 are formed, 3 which leads to the carbon depletion ͑see formed, which can be saturated, e.g., by adspecies such as atmospheric oxygen or by surface reconstruction. 15,16 After carbon is removed from the SiOCH layer a SiO 2 -like structure is remaining, which can be etched using post-ash diluted HF ͑dHF͒ chemical cleaning processes.…”

“…It is reported that during plasma processes the ULK film is damaged, which is related to the carbon loss. 3 This is explained due to smaller dissociation energy for Si-C ͑ϳ447 kJ/ mol͒ compared to Si-O ͑ϳ800 kJ/ mol͒. 4 It was observed that during the carbon depletion dangling bonds occur, 5 which form new Si-O or Si-OH bonds after exposing to the atmosphere.…”

Effect of preliminary VUV irradiation on the reactivity of alkyl-doped silicon dioxide layers

“…It may be assumed that this process has no direct influence on the change of porosity. This assumption is not in conflict with the results reported in [11,13,22]. So, following the approach described by us, we do not consider the effect of the UV radiation of plasma causing rupture of the strong Si-O-Si bonds, though we do not exclude this possibility as well.…”

Unusual Modification of CuCl or CuBr Films by He Plasma Exposure Resulting in Nanowire Formation

“…21 Also the breaking of Si-CH 3 bonds by He and Ar metastable atoms has been reported. 22 We assume thus that the products which are needed to form the nanowires are released from the CuCl or CuBr matrix by the He plasma irradiation. These products can diffuse on the surface or escape to the vapor phase.…”