Research Projects

Hyper-Sensitive Parameter-Identifying Ring Oscillators for Lithography Process Monitoring

Andrew R. Neureuther

IMPACT

Known differences in the sensitivities of layouts to lithographic effects are utilized to create a new class of ring oscillators for monitoring of process variations in CMOS. The circuit performance measurements have been used to identify process variations, and have revealed dominant sources, attributed to lithography [1] [2]. This project extends this identification of processing effects by creating ring oscillators that are several times more sensitive to specific parameters than standard circuits, making it substantially easier to isolate variations in this parameter and quantitatively interpret the results.

[1]

L.-T. Pang, B. Nikolic, “Impact of Layout on 90nm CMOS Process Parameter Fluctuations,” 2006 Symposium on VLSI Circuits, Digest of Technical Papers.

[2]

A.H. Gabor, et al, “Improving the Power-Performance of Multicore Processors Through Optimization of Lithography and Thermal Processing”, SPIE, Volume 6521-18 (2007).