| 摘要 |
PURPOSE:To detect the completion of etching with high accuracy by magnifying a striped pattern before and after an etching and binary-coding the pattern in the picture signal processing of the surface of a wafer using a TV camera. CONSTITUTION:A grounded upper electrode 2 and a lower electrode 3 connected to a high-frequency power supply 5 are arranged oppositely in an etching treating chamber 1, and a wafer to be etched 4 is placed on the lower electrode 3. Transparent glass 6 is fitted to the ceiling of the treating chamber 1, beams from a light source 13 for projecting beams are projected to the transparent glass through a semi-light transmitting mirror 16, and the contrast of a striped pattern by ion radicals generated in the wafer 4 is magnified by an observation system 10, and observed by using a TV camera 8. Accordingly, the threshold V1 at a level of the recognition-starting of the striped pattern 22 generated in the wafer 4 and a level V2 of an end-point detection are compared with each other, and the completion of etching is decided when these values are kept within the predetermined values. |
