The Desorption of atoms from a crystal layer by layer which is called polishing is general interest in industrial and scientific study. These layers may include oxygen molecules. To polish a surface we chose appropriate ion that is collided to the surface by different energy and angles. In the present work we investigate the process of binary collision approximation of incident ions ( ) to the urface. For this the energy and angular distribution of desorbed oxygen molecules has been changed to reach a best yield. We have used Binary Collision Approximation (BCA) code with BZL and Firsov potentials. The recoiled atoms up to third layer are included in the investigation.
