摘要 |
PURPOSE:To form an aperture which has an arbitrary step angle by a method wherein an Si oxide film is irradiated selectively by plasma and after thermal processing the Si oxide is partially removed. CONSTITUTION:A photoresist layer which has a specified aperture is formed on an Si oxide film 2 formed on a P type Si substrate 1. The Si oxide film is irradiated by CF4 gas plasma for 5min using the photoresist layer as a mask and, after thermal processing in N2 at 200-500 deg.C for 30min, is etched by NH4F solution, so that an aperture with a step angle theta is formed. With the above method a very stable step angle can be obtained and, according to conditions such as of thermal processing, a required angle can be specified. |