Specialized Rectangular Mask Pattern Design to Neutralize Charging Effects

Abstract

In order to achieve a high-quality transfer of the mask pattern onto the substrate in plasma etching, it is important to minimize charging effects. This study investigates the potential use of a specialized design for rectangular mask holes to counteract charging effects. The research examines the behavior of a single and deformed rectangular mask hole with varying length-to-width ratios and two types of mask arrays. A particle simulation program was utilized to analyze the changes in electric field distribution and simulated opening during etching time. The findings indicate that ions tend to bombard the long side rather than the short side or vertexes, leading to flattening of deformed sides and resulting in an approximately rectangular etched opening. Specialized designs based on specific arrays can aid in achieving nearly perfect rectangular etched openings, with potential underlying mechanisms extensively discussed in this study. These results offer valuable insights into specialized design strategies for plasma etching processes.