A novel hanging bowl-shaped mask for the fabrication of vertical sidewall structures

摘要

Contact exposure is expected to occur in conventional lithography, and can be a source of process deviations (such as shrinking and distortion of templates) during reactive ion etching and inductively coupled plasma etching, as these deviations are induced by ion bombardment. This typically results in undesired sidewall effects, such as lower sidewall angles. Here we report a novel hanging bowl-shaped lithography mask that can effectively minimize sidewall effects in lithography applications. As a test case, standard silicon carbide pillars with vertical sidewalls are fabricated using this mask. The mask could be used for fabrication of high-aspect-ratio structures with ultra-violet lithography.