The Capacitively Coupled Plasma (CCP) is produced by applying a single radio frequency (RF) across the sample. Since there is a potential difference between the plasma and the sample, there is a bias potential that effectively gives the sample a negative potential that accelerates the SF 5 + ions towards it. The CCP power controls the energy of the ions hitting the substrate. A higher CCP power also assists in the removal of the fluorocarbon protecting layer and may also contribute to the removal of the protecting layer from the walls at higher pressures (> 10 mtorr) which would lead to unwanted lateral etching.