Skewed ion beam etching: A simple method to obtain a reduction in critical dimensions for magnetoelectronic sensors

The skewed ion beam etching process (SIBE) was contrived as well as implemented to generate a lead-overlaid giant magnetoresistive read sensor structure in submicrometer scale. The key concept of this process is based on the shadowing effect arising from the pattern height and incident ion beam angle. Due to shadowing, the desired critical dimension such as lead-to-lead distance can be smaller compared to the distance between a set of photoresist patterns. The SIBE was performed under Ar and CHF₃ reactive environment where the etch selectivity between the photoresist and sacrificial alumina layer was high. A lead-to-lead distance of 0.35μm was accomplished starting with a 0.9μm photoresist pattern.