| 摘要 |
<p>PURPOSE:To form an etching stop layer as a thin layer, by selectively etching a porous region which partially exists in a non-porous Si substrate, while using etching liquid which does not etch the non-porous Si. CONSTITUTION:The surface and the rear of non-porous Si 51 are coated with masks 52, and windows are partially formed. The exposed parts are turned into the porous state 53 from the surface to the rear. After that, the mask material 52 is peeled, and a layer 54 which is an etching stop layer and finally can become a non-retaining thin layer is formed on either one of the surfaces. Buffered hydrofluoric acid or mixed liquid wherein at least one kind out of alcohol and hydrogen peroxide water is added to the buffered hydrofluoric acid is used, and only the porous Si 53 is selectively eliminated by wet chemical etching. Thereby holes having arbitrary shapes and sizes can be formed from the surface to the etching stop layer on the opposite surface.</p> |
