| 摘要 |
PURPOSE:To make the anisotropy of plasma etching higher accurate by detecting the luminous intensity of given gas plasma, and automatically changing etching conditions according to the variation of intensity. CONSTITUTION:The luminous intensity of plasma generated by reaction in a container 11 is ld out by means of an optical fiber 17, photoelectrically converted 22 and amplified 23 through a filter 21 of a specific wavelength, and then recorded 24. The variation of photo intensity is calculated, and, by corresponding thereto 25, the instruction based on the ratio of SiCl4 to Cl2+BCl2 and the programs such as vacuum degrees and electric power is given, thus controlling valves 18 and 19 and then keeping proper conditions. When complete anisotropic etching is performed, a recorder 24 image-draws the polygonal line (b) of luminous intensity-time passage, and the luminous intensity F immediately before starting becomes equal to the intensity I immediately after finishing, and the intensity G at the starting point becomes equal to the intensity H at the finishing point. In this case, side etching is hardly performed, and anisotropic etching is performed with good accuracy. Thereby, the etched are of an Al film 3 becomes always constant during reaction. |
