Observation of Pattern Sensitivity In Laser anneal : Topic/category Yield Enhancement

Abstract

At advanced nodes, there is a need for high activation of dopants to achieve the required device performance. At the same time, the high-temperature anneal needed to drive the activation might cause excessive diffusion that conflicts with the tight distribution required for devices with very small dimensions. Laser anneal has been successfully used to meet both requirements. One way to gauge the laser anneal performance is measuring the resistance of a doped silicon test structure. While this is generally very dependable that under certain conditions, we have discovered pattern factor can play a role in the laser anneal process. We show what conditions can cause the deviation and discuss how to evaluate resistance data to ensure a correct interpretation of electrical characteristics.