Superfilling technology: transferring knowledge to industry from the National Institute of Standards and Technology

In the mid-1990s, the semiconductor industry manufactured devices with critical circuit dimensions of between 0.35 and 0.25 μ, and it used aluminum or an aluminum copper alloy to interconnect device components. However, the critical dimension needed to be reduced so that devices could become faster and more efficient. At circuits dimensions of 0.18 μ or less, aluminum no longer conducts electricity well enough to maintain the circuit's efficiency; thus, the industry determined that copper--a superior conducting material--would be needed to help the industry produce smaller and faster semiconductor devices. Still, technical barriers existed, preventing a seamless transition from aluminum to copper. Thus, in the 1990s, the National Institute of Standards and Technology (NIST) began focused research on superfilling aimed at assisting the semiconductor industry during this period. In this paper, we document the net economic benefits (private and social) accruing from NIST's core research investments in superfilling during the late 1990s and early 2000s. Using traditional evaluation methodology and metrics, we calculated economic impact estimates, and the results suggest that NIST's public resources were, from a social perspective, used efficiently.