High-aspect-ratio SiO2 contact-hole etching is one of the key processes in the fabrication of ultralarge-scale integrated devices. However, there are many serious problems, such as charge-buildup damage, etching-stop, and microloading effects. Charge accumulation in high-aspect-ratio contact holes during etching is one of the main causes of these problems. In SiO2 etching using fluorocarbon gases, it is well known that fluorocarbon film is deposited on the underlayer surface and sidewall of contact holes. It is expected that such deposited fluorocarbon polymer will exert a great influence on the etching characteristics and charge accumulation in SiO2 contact holes. Therefore, it is necessary to measure the conductivity of the sidewall surfaces of contact holes with deposited fluorocarbon polymer. We made a monitoring device on a silicon wafer to evaluate the sidewall current of SiO2 contact holes and determined the relationship between the chemical structure and electrical conductivity of the fluorocarbon films deposited in the contact holes as a function of fluorocarbon gases and incident ion flux. We found that the electrical conductivity of the sidewall surface in SiO2 Contact holes depends on the chemical structure of the deposited fluorocarbon polymer. It was also clear that the chemical structure of the deposited fluorocarbon polymer depended on nature of the radical species and ion flux incident on the etching surface. These results indicate that by controlling the chemical structure of the deposited fluorocarbon polymer one may be able to mitigate the influence of charge accumulation. (C) 2004 American Vacuum Society.