| 摘要 |
PURPOSE:To suppress etching of side surface and realize high precision patterning by setting a DC bias between opposing electrodes to 250-350V for executing dry etching. CONSTITUTION:BCl3, CCl4, Cl2, etc. are supplied 8 to a reaction chamber 1, these are exhausted 9 to the specified degree of vacuum. Cl2 is then caused to flow with a specified flowing ratio and an RF power 5 is applied between the electrodes 2, 3. A reaction ion and active radical 12 are generated between electrodes, etching an alloy film 7 and simultaneously a part of reactive product adheres to the side surface of etching surface. It suppresses etching at the side surface and allows progress of the etching having a high anisotropy. During this period, a voltage difference between the region 12 where reactive ion is generated and a lower electrode 3, namely a DC bias is detected by a potentiometer 11. When an alloy to be etched 7 is Al-Si, DC bias is set to 250-300V, while it is Al-Si-Cu, bias is set to 300-350V. When the DC bias is set as explained above, etching gas pressure, RF power, Cl2 flow ratio are all relatively set easily to the specified range and a high precision pattern can be formed. |
