Overview of metrology requirements based on the 1994 National Technology Roadmap for semiconductors

During 1994, the Semiconductor Industry Association developed and issued the second integrated circuit manufacturing roadmap: The National Technology Roadmap for Semiconductors (NTRS). Metrology requirements cut across the boundaries of materials and bulk processes (transistor fabrication processes), lithography, interconnect, design and electrical test, and factory integration. In the NTRS, Metrology is referred to as a cross-cut requirement and specific needs can be found in the technology sections. In order to supplement the NTRS, a Metrology Roadmap was published by SEMATECH. The roadmap was developed by representatives from the SEMATECH member companies, NIST, Sandia, and metrology tool suppliers. The measurement requirements in the Metrology Roadmap are taken directly from the NTRS, i.e., the timeline for gate dielectric thickness vs. technology generation. The author provides an overview of the Metrology Roadmap and discusses key trends such as the move toward real time process control.