| 摘要 |
PURPOSE:To enable patterning not causing pinholes and to form a vertical pattern accurately by a method wherein a focused ion beam of oxygen is implanted in small depth in the whole of a region corresponding to a pattern information and in large depth in the peripheral edge portion thereof so as to form an oxidized layer and thereafter selective etching is applied by using an etching solution having a large etching selection ratio. CONSTITUTION:A focused ion beam of oxygen is implanted only in a desired area at a desired position on the surface of an Si substrate 1 with an implanting energy of about 50KeV according to a pattern program. By subjecting this substrate 1 to heat treatment in an inactive gas, implanted layers 3 and 3' turn to be an SiO2 layer 4. Next, when the Si substrate 1 is etched by using anisotropic dry etching, etching of Si alone proceeds, and thus it becomes possible to proceed with digging vertically without attacking the SiO2 layer 4 formed deep in the longitudinal direction. On the occasion, the purpose is attaind by any etching method on condition that the etching method applied has a large etching selection ratio between Si and SiO2. When the etching selection ratio between Si and SiO2 is somewhat inferior, on the other hand, the same effect can be produced by enlarging the radius of the ion beam so that the thickness of the oxidized film can be increased to some degree. Then, lastly, the oxidized film layer 4 is removed. |
