Metallization to improve electromigration resistance

摘要

A new method of metallization using a new design of metal contact shape, contact/via profile, and metal lines having considerably reduced current density and improved electromigration of metal lines is achieved. Metal contacts are formed in a rectangular shape instead of a square shape with the wider side perpendicular to the current direction. Contact openings are made having concavo-concave profiles which can provide a wider conducting cross-sectional area than can conventional openings with a vertical profile near the contact bottom. Gaps are formed within wide and high current metal lines so that current density can be effectively lowered by utilizing the whole metal line uniformly.