| 摘要 |
PURPOSE:To reduce side etching caused by scattered ions substantially by employing mixed gas of heavy reactive gas and light rare gas. CONSTITUTION:A cathode coupling type reactive sputtering apparatus is employed as an etching apparatus and mixed gas composed of Br2 and He mixed in the ratio of 1 to 9 is employed as etching gas. As a result, the depth of side etching is less than 0.1mum and a quite vertically steep side wall can be obtained. When etching ions are scattered in reactive etching, most of the apponents of the collisions of the ions are etching gas molecules themselves. Therefore, in the case of Br2+90%He mixed gas, 10% of Br<+> ions produced by dissociation of Br2 molecules collide against Br2 molecules and 90% collide against He molecules. As the mass ratio of Br<+>/He=20, Br<+> ions which collide against He molecules hardly turn side from the direction of acceleration and enter a specimen surface. Therefore, in this case, the incident angle distribution of Br<+> ions is concentrated near zero degree and such etching is suitable for highly accurate work.
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