| abstract |
PURPOSE:To enable a highly precise mask to be formed by laminating a layer for shading electromagnetic waves in a specified wavelength region or ionized corpuscle beams specified in energy intensity and a coating layer having etching resistance on a mask base material. CONSTITUTION:The light shading layer of a chromium film 12 and a thin film 13 made of tantalum for forming a micropattern are formed on the mask base material 11 made of glass low in heat expansion coefft. to form a mask substrate. A polymethyl methacrylate film 14 is formed on it, exposed to a light having a desired pattern, and then, developed with isoamyl acetate to form a resist pattern 14. Further, the thin film 13 is selectively removed by using the resist pattern 14 as a mask and the reactive ion etching process, and it is repeated by using a gas mixture of carbon tetrachloride and oxygen to remove chromium 12 selectively. |