| 摘要 |
PURPOSE:To enable anisotropic etching having high etching velocity, large selection ratio of material to be etched and base etching mask, and excellent processing accuracy by using by mixing SF6 and CHCl2F2. CONSTITUTION:The mixing ratio of SF6 and CHCl2F2 is not specially limited, but preferably 50-85vol% of SF6 and 50-15vol% of CHCl2F2. Carbide or nitride of fluorine such as CF4, C3F8, C2F6, NF3C may be used instead of SF6, and CHCl2F may be used instead of CHClF. By etching using such etching gas polymer is bonded to the side wall of silicon compound of a material to be etched, fluorine radical of excess etching seed and hydrogen react to be removed, thereby obtaining vertical anisotropic shape without underetching. |
