Comparison of Contact Hole Definition using Laser and Shaped E-Beam Mask Writers and its Influence on Wafer Level Pattern Fidelity

摘要

Contact hole definition in the resist image is investigated as a function of reticle fidelity. It is found that for typical levels of corner rounding on reticle features, whether manufactured using a laser or shaped e-beam mask writer, the printed resist image at wafer level is largely unaffected. The loss of definition, which is also seen in supporting simulations using perfectly formed reticle features, is defined by the resolution limit of the optical system of the stepper rather than the quality of the photomask.