| 摘要 |
<p>PURPOSE:To make it possible to utilize polyimide and polyester as membrane material by a method wherein, after a thin film for mask membrane has been formed on a silicon substrate, an etching treatment is conducted thereon in specific current density using an electrolyte mainly composed of acid ammonium fluoride. CONSTITUTION:After a thin film for mask membrane has been formed on a silicon substrate, the thin film is coated with an insulating film leaving the part corresponding to an electrolytic polishing part on the rear side, and then an electrolytic etching treatment is conducted thereon in the thickness of 10 to 1000mA/cm<2> using an electrolyte mainly composed of acid ammonium fluoride. To be more precise, acid ammonium fluoride is used as an electrolytic polishing liquid, and as the buffer action of pH and an electrolytic etchant can be controlled by adding ammonium fluoride and the like to the abovementioned electrolytic liquid, the silicon substrate can be etched under a very gentle condition. As a result, polyimide and polyester, which were difficult to utilize as a membrane material, can be utilized.</p> |
