Absorbent liquid immersion angled exposure for 3D photolithography

Photolithography on the sample with vertical side walls is studied. In the angled exposure for patterning side walls or bottoms, the exposure is basically over-dose due to the thinner thickness making the reflection serious for obtaining the defect-free pattern. In addition to the liquid immersion method, the absorbent liquid is introduced. Arbitrary pattern over the trench with aspect ratio of 0.74 is obtained with the better quality than that obtained using the water and the polarization control.