论文部分内容阅读
使用移相掩模能实现亚半微米光学光刻。我们提出了一种用SiO_2作移相器的新的移相掩模。在石英掩模衬底上的SiO_2移相器具有在远紫外区吸收率低和没有多次干涉等优点。SiO_2移相器是通过将蒸发的SiO_2膜剥离而制成的。这种新的移相掩模对远紫外光有高的透明度,并在5X步进机的整个曝光视场内达到2％的移相均匀度。通过使用KrF准分子激光器步进机和这种新的移相掩模提高了分辨率,得到0.25μm的线条和间隔。使用移相掩模后,掩模图形与投影到片子上的图形的一致性降低,因此我们也研究了用移相掩模投影的成像特性,指出了各个窗孔的衍射图形的主、次波瓣之间的干涉的重要性,并阐明了在使用移相掩模的光学光刻中一致性衰减的机理。
Sub-half-micron optical lithography can be achieved using phase-shift masks. We propose a new phase-shifting mask using SiO 2 as a phase shifter. The SiO 2 phase shifter on a quartz mask substrate has the advantages of low absorption in the deep UV region and no multiple interferences. The SiO 2 phase shifter is made by stripping the evaporated SiO 2 film. This new phase-shift mask provides high transparency to deep UV light and up to 2% phase-shift uniformity over the entire exposure field of the 5X stepper. The resolution is increased by using a KrF excimer laser stepper and this new phase-shifting mask, resulting in 0.25 [mu] m lines and spaces. After using the phase-shift mask, the consistency between the mask pattern and the pattern projected on the film is reduced. Therefore, we also study the imaging characteristics projected by the phase-shift mask and point out the major and minor waves of the diffraction pattern in each of the apertures The importance of interference between the lobes, and elucidates the mechanism of consistent attenuation in optical lithography using phase-shift masks.