SIMULATION OF DRY-ETCHING THROUGH A MASK

The two-dimensional profiles of etched grooves have been calculated as a function of the size of masks and the ion flux of bombarding ions. The model includes processes of adsorption of chemically active specie s arriving from plasma, heterogeneous chemical reactions (formation vo latile compounds on the surface), thermal desorption, physical sputter ing, activation of surface atoms by the bombarding ions and ion beam a ctivated desorption. Special interest is concentrated on the etching a nisotropy, lateral etching and aspect ratio with dependence on the siz e of mask. It is shown that ion irradiation changes etching kinetics a nd etching anisotropy. The main role of ions is related to the activat ion of heterogeneous reactions. It is shown that the profiles of the e tched grooves can be modified by changing irradiation conditions and g eometry of masks. Calculated results are qualitatively in good corresp ondance with ones obtained experimentally.