Improving Tungsten gap-fill for advanced contact metallization

Abstract

The requirement for Tungsten (W) seamless gap-fill becomes more critical and more challenging as the semiconductor industry moves to 10nm and beyond. Few reports can be found discussing the progress in tackling the challenge of reducing or eliminating the seam typical in W fill processes. This work introduces a breakthrough W chemical vapor deposition (CVD) process for gap-fill improvement and seam suppression. In this novel process, W material can be selectively deposited inside the structure than on the field, thus seam suppressed or even bottom-up fill can be achieved. Electrical results of line resistance reduction are presented. This selective process provides a state-of-the art approach to extend W fill technology for future scaling of advanced Logic and Memory technologies.