| 摘要 |
PURPOSE:To increase the aspect ratio of a via hole that is formed by reactive ion etching, by making the etching rate on an insulation layer lower than the etching rate on the adhesives layer. CONSTITUTION:The side etching rate of an insulation layer 22 is made lower than the side etching rate of an adhesives layer 3. Thus, after the insulation layer 22 is etched with reactive ion etching, side etching will progresses on the insulation layer 22 while the etching progresses on the insulation layer 22. However, the etching rate of the insulation layer 22 is lower than that of the adhesives layer 3 so that, after the etching on the insulation layer 22 has been terminated, the amount of the side etching on the insulation layer 22 that progresses until the amount of the side etching on the adhesives layer 3 reaches a specified amount will be suppressed lower then the amount of the side etching on the adhesives layer 3, with the smaller diameter of the insulation layer 22. This makes it possible to increase the aspect ratio of the via hole 6. |
