Formation of Submicron Top Pattern by using Tri-Layer Resist Structure

심층 레지스터 구조를 이용한 서브미크론 상층패턴 형성

The effectiveness of tri layer resist (TLR) technique is compared with that of single layer resist (SLR) technique in order to make a 0.8um pattern with the linewidth deviation of 10 percents. SLR technique is not appropriate to shape the micro-pattern on oxide and aluminum steps because of the standing wave effect and the light scattering effect in shaping the resist pattern. On the contrary, the uniform line with a width of 0.8um on oxide and aluminum steps can be formed by TLR technique, reducting such effects. The planarization and the light absorption coefficient of the bottom layer resist in TLR are optimized by exposing it to ultra violet light after baking it for 30min at 230\ulcorner. An uniform line with a width of 0.8um on oxide step is defined with the light absorption coefficient of 0.85 whereas that on aluminum step is defined with 0.95.