Removal of Fluoropolimers from the Surface of Silicon Structures by Treatment in an Atomic Hydrogen Flow

Abstract

The possibility of successful removal of fluoropolimers from the surface of silicon structures by treatment in an atomic hydrogen flow is investigated. It is ascertained that the treatment of samples in a direct atomic hydrogen flow with a density of 2 × 1015 cm−2 s−1 at temperatures from 20 to 100°C leads to a decrease in the content of fluorocarbon residues (in particular, CF) by 5 orders of magnitude. Fluorocarbon residues are removed from both the planar surface of silicon structures and the lateral walls and the bottom of contact holes with a diameter of 0.3–0.25 μm and larger and a depth of 0.9 μm, opened in a SiO2 layer by reactive ion etching. A treatment time of 2 min is sufficient for complete removal of the fluoropolimers. This process of dry cleaning can be recommended for use in the fabrication of integrated circuits containing an interlayer of a low-permittivity insulator.