| 摘要 |
PURPOSE:To obtain a groove in sub-micron width, and to improve the degree of integration of an IC such as a RAM by using projection exposure technique, chemical vapor-phase growth technique for a mask film and anisotropic dry etching technique when the U-shaped groove is bored to a semiconductor substrate. CONSTITUTION:A first mask film 22 consisting of SiO2 is grown on an Si substrate 21 through a CVD method, the upper section of the film 22 is coated with a resist film 23, and an opening 24 in width W of approximately 1.2mum is formed to the film 23 by using a projection exposure device. The film 22 exposed into the opening 24 is removed through reactive-ion etching using CHF3 to form an opening 25, the film 23 is removed, and the whole surface is coated with a second mask film 26 composed of SiO2 while filling the opening 25. Anisotropic etching superior in the vertical direction of the surface of the substrate 21, the same ion etching is executed, and the easy film 26 in width (x) is left to the side wall of the opening 25 while removing the film 26. Accordingly, an opening 27 in extremely narrow width is bored to the substrate 21 through etching by using the easy film as a mask. |
