Electrical Linewidth Measurement for Next Generation Lithography

摘要

In recent years electrical linewidth measurement (ELM) has become accepted as an efficient method to gather large amounts of linewidth data rapidly and accurately. However, there are offsets between electrical and SEM measurements. While these have not been a concern for large features, it is important to minimize the bias as the actual linewidth approaches the offset. The purpose of this paper is to demonstrate that ELM can be used to measure linewidths much smaller than 100nm. Our experiments show that out-diffusion and surface ion depletion are the primary sources of bias in electrical linewidth measurement. Silicon nitride capping layers before annealing are helpful to prevent out-diffusion.