| 摘要 |
PURPOSE:To improve the uniformity of etching and the cooling effect of a wafer cassette by forming a large number of injection holes injecting an inert gas for cooling extending over the whole surface opposite to a wafer in the wafer cassette. CONSTITUTION:When a wafer 2 is irradiated by reactive ion beams 1, etching starts, and the temperature of the surface of the wafer 2 rises. An inert gas 8 is introduced from the introducing hole 7 of a substrate 4 in a wafer cassette 3, passes through a large number of injection holes 11 and collides with the back of the wafer 2 to cool the wafer 2, and is discharged to the outside and is sucked into evacuating holes 12. The wafer can be etched without having an effect even on the mean free path of ions because the inert gas 8 uniformly flows and the degree of freedom of device itself is not affected by the flow rate of the inert gas 8. |
