Remote plasma enhanced cyclic etching of a cyclosiloxane polymer thin film

The continuous evolution of chip manufacturing demands the development of materials with ultra-low dielectric constants.With advantageous dielectric and mechanical properties,initiated chemical vapor deposited(iCVD)poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane)(pV3D3)emerges as a promising candidate.However,previous works have not explored etching for this cyclosiloxane polymer thin film,which is indispensable for potential applications to the back-end-of-line fabrication.Here,we developed an etching process utilizing O2/Ar remote plasma for cyclic removal of iCVD pV3D3 thin film at sub-nanometer scale.We employed in-situ quartz crystal microbalance to investigate the process parameters including the plasma power,plasma duration and O2 flow rate.X-ray photoelectron spectroscopy and cross-sectional microscopy reveal the formation of an oxidized skin layer during the etching process.This skin layer further substantiates an etching mechanism driven by surface oxidation and sputtering.Additionally,this oxidized skin layer leads to improved elastic modulus and hardness and acts as a barrier layer for protecting the bottom cyclosiloxane polymer from further oxidation.

Effects of external parameters on plasma characteristics and uniformity in a dual cylindrical inductively coupled plasma

The dual cylindrical inductively coupled plasma source,compared to the conventional structure of inductively coupled plasma source,can significantly improve the uniformity of plasma.It has an enhanced potential for application in processes,such as etching and ashing.A uniform plasma can be obtained by allowing the remote plasma from the upper chamber modulate the main plasma generated in the lower chamber.In this study,a fluid model was employed to investigate a dual cylindrical inductively coupled Ar/O_(2)discharge.The effects of external parameters on electron density,electron temperature,O atomic density,and plasma uniformity in the main chamber were studied,and the reasons were analyzed.The results of this study show that remote power can control the plasma uniformity and increase the plasma density in the main chamber.As the remote power increased,plasma uniformity improved initially and then deteriorated.The main power affected the plasma density at the edge of the main chamber and can modulate the plasma density in the main chamber.The gas pressure affected both the uniformity and density of the plasma.As the gas pressure increased,the plasma uniformity deteriorated,but the free radical density improved.

Studies of Wettability of Medical PVC by Remote Nitrogen Plasma

The effects of remote nitrogen plasma and nitrogen plasma on medical PVC＇s surface modification are studied. The surface properties are characterized by the contact angle measurement, X-ray photoelectron spectroscopy and scanning electron microscopy. Results show that the remote nitrogen plasma treatments modify the PVC surface in both morphology and composition and the treatment by the remote nitrogen plasma in PVC surface modification is more effective than that by the nitrogen plasma. Remote nitrogen plasma can modify the surface more uniformly. After the PVC surface is treated for 2 man by remote nitrogen plasma, the [w（O）＋ w （N）]/w （C）] value increases from 0.13 to 0.51 and the water contact angle decreases from 89° to 18 .

A Comparative Study of Hydrophilic Modification of Polypropylene Membranes by Remote and Direct Ar Plasma

Surface modification of polypropylene membrane by argon （Ar） plasma-induced graft polymerization with hydrophilic monomer [acrylic acid （AA） in this work] was investigated. It was found that both the distance of the membrane from the Ar plasma center and the plasma power had a strong influence on the surface modification, hydrophilieity and graft yield （GY） of the treated membrane. Results suggest that remote plasma treatment with a proper sample position, plasma power and graft polymerization leads to a membrane surface with not only less damage, but also more permanent hydrophilicity, than direct plasma treatment does. By analyzing the morphology and the chemical composition of the membrane surface by scanning electron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS）, as well as Fourier transform infrared attenuated total reflection spectroscopy （FTIR-ATR） respectively, a possible mechanism was tentatively revealed.

Inactivation of Escherichia Coli Using Remote Low Temperature Glow Discharge Plasma

Low-temperature plasma is distinguished as a developing approach for sterilization which can deal with and overcome those problems such as thermal sensitivity and destruction by heat, formation of toxic by-products, higher costs and inefficiency in performances, caused by conventional methods. In this study, an experimental investigation was undertaken to characterize the effects of the operational parameters, such as treating time, discharge power and gas flow rate, of remote glow discharge air plasma. The results show that the inactivation of Escherichia coli can reach above 99.99% in less than 60 seconds and the optimal operational conditions for treating time, discharge power and gas flow rate were： 40 s, 80 W and 60 cm^3/min, respectively. The contribution of UV radiation during plasma germ deactivation is very limited.