| 摘要 |
PURPOSE:To copy micropatterns more precisely in X-ray lithography by coating the material to be treated, such as wafer, first with a high sensitive positive type resist as a lower layer, and second, a low sensitive negative type resist in a specified thickness as an upper layer to form two coating layers. CONSTITUTION:The material to be treated, such as wafer 5, is coated with a high sensitive positive type resist layer 9 as a lower layer, and a low sensitive negative type resist layer 8 as an upper layer to form two coating layers. The film thickness of this resist layer 8 is set to a value a little thicker than the transit distance of photoelectrons and Auger electrons (secondary electrons) of several hundred nm to use the layer 8 as a buffer layer against the secondary electrons. The coated wafer 5 is irradiated with a proper exact amt. of X-rays based on the film thickness of the lower resist layer 9, the X-rays are transmitted through the upper resist layer 8, and form an X-ray mask pattern in the lower resist layer 9. A large number of photoelectrons and Auger electrons 10 emitted from an Au pattern 7 are absorbed with the layer 8. As a result, all the negative resist layer 8 is dissolved in a development step to leave only the 100% insolubilized parts of the positive type resist layer 9, and a copy having submicron wide high resolution can be ensured in this X-ray lithography. |
