| 摘要 |
PURPOSE:To catch an inter-mode transition sign independently of the etching progress thereby to effect an anisotropic etching with a high reliability, by monitoring by the use of the spectrum of an inert gas. CONSTITUTION:In the discharge by a magnetron in which a magnetic field is formed on the surface of a cathode: a mode (a) in which the excitation light is strong and a discharge area is produced near a discharge path 17 right above the gap between N and S poles, appears more easily as the high-frequency power is larger and as the pressure is lower, and in this case, a vertical anisotropic etching is effected; or a mode (b) appears in which the excitation light is weak and discharge areas 18, 19 are produced in the vicinity of the discharge path 17, and in this case, a completely isotropic etching is effected. When a P- added poly Si is etched by Cl2 solely, the etching speed is maximum at the transition point between the modes (a) and (b). When about 1% Ar is introduced into Cl2 and the Ar spectrum is observed, an eaves part is produced under the state where the relative intensity reduces to about half. According to this method, Si, Al and other high-melting metals can be anisotropically etched with high reliability and high speed selecting proper reaction gases, respectively, in addition to doped poly Si. |
