STARR: Stepper Test Alignment Resolution Reticle For The Lithographic Characterization Of A Sub-Micron Stepper

This paper describes the design and implementation of a custom reticle developed as part of a sub-micron stepper evaluation program. The 5X reticle was designed so that all major commercially available steppers could be directly compared. It has a unique arrangement of optical and electrical registration test structures allowing for three levels of processing which provides a true measure of the registration capabilities of a system. The reticle has a number of structures which can be used to evaluate the imaging quality of a stepper system. These include a "Focus Star" structure designed to allow easy evaluation of resolution, focus, and astigmatism, a defect structure to measure the printability of commonly seen reticle defects, and L-bar patterns. The remainder of the reticle is intended for use in analyzing other lithographic problems such as proximity effects, substrate induced reflections, step coverage, and critical dimension control.