Analysis of dry etch loading effect in mask fabrication

摘要

As the design rule is rapidly decreased, tighter critical dimension (CD) control is highly requested. Considering the mask error enhancement factor (MEEF), higher mask quality below 8nm should be guaranteed for 0.10 μm generation devices. Among a number of factors causing CD errors in e-beam mask fabrication, dry etching plays an important role. Therefore, it is necessary to reduce loading effect for accurate CD control. As the loading effect in the dry etching is closely related to the selectivity of Cr to resist, a clue to reduce the loading effect is to reduce loading. In this paper, we will clarify the relation mechanism between the selectivity and loading effect. We will investigate the degree of loading effect by quantifying the selectivity with different etch processes.