Dry cleaning of fluorocarbon residues by low-power electron cyclotron resonance hydrogen plasma

A low-power (50 W) electron cyclotron resonance hydrogen plasma cleaning pr ocess was demonstrated for the removal of fluorocarbon residue layers forme d by reactive ion etching of silicon dioxide. The absence of residue layers was confirmed by in-situ reflection high energy electron diffraction and c ross-sectional high resolution transmission electron microscopy. The ECR hy drogen plasma cleaning was applied to contact cleaning of a contact string structure, resulting in comparable contact resistance arising during by a c onventional contact cleaning procedure. Ion-assisted chemical reaction invo lving reactive atomic hydrogen species generated in the plasma is attribute d for the removal of fluorocarbon residue layers.