| 摘要 |
PURPOSE:To monitor etching in progress and completion correctly and conveniently, by using glow discharge plasma to etch silicon oxide, and monitoring spectrum stregth of CO produced in plasma during etching process. CONSTITUTION:An SiO2 film is grown in certain thickness on an Si wafer surface by thermal oxidation. It is covered with a photoresist film having a pattern. It is arranged on a high-frequency electrode of a dry etcher with parallel plate electrode structure via ethylene tetrafluoride resin. Next, C3F8 gas is put in and gas pressure is set to approximately 13Pa. Glow discharge plasma is produced by high-frequency power at 13.56MHz. Co spectrum is measured by light emission intensity with a spectrophotometer. This tells the beginning of glow discharge by the wavelength of 451.09nm. The etching ends when the light emission intensity become constant at a low level after increasing rapidly. The wavelength takes various values by the gas enclosed here. |
