As design rules shrink, hotspot management is becoming increasingly important. In this paper, an automatic system of
hotspot monitoring that is the final step in the hotspot management flow is proposed. The key technology for the
automatic hotspot monitoring is contour-based metrology. It is an effective method of evaluating complex patterns, such
as hotspots, whose efficiency has been proved in the field of optical proximity correction (OPC) calibration. The
contour-based metrology is utilized in our system as a process control tool available on mass-production lines.
The pattern evaluation methodology has been developed in order to achieve high sensitivity. Lithography simulation
decides a hotspot to be monitored and furthermore indicates the most sensitive points in the field of view (FOV) of a
hotspot image. And quantification of the most sensitive points is consistent with an engineer's visual check of a shape of
a hotspot. Its validity has been demonstrated in process window determination. This system has the potential to
substantially shorten turnaround time (TAT) for hotspot monitoring.
A fine pixel CD-SEM system is developed. The convnetional CD-SEM Topcon MI-3080UR system consists of main body, 512 pixel SEM image acquisition system and 1D pattern size measurement system. The fine pixel CD-SEM system is added the conventional CD-SEM TOPCON MI-3080UR system. The fine pixel CD-SEM system consists of 2048pixel SEM image acquisition system is used by adjusting a novel measurement algorithm for the SEM image of 2D patterns. Firstly, the necessity of the fine pixel CD-SEM is discussed from the viewpoint of getting good repeatability of pattern size measurements. Effective factors causing the good repeatability for pattern size measurements are studied. The effective factors are mainly SEM image quality and pattern measurement algorithm. Secondly, repeatability of 2D pattern measurements by using the developed fine pixel CD-SEM image and the novel algorithm are evaluated. The evaluated 2D patterns are used for hammer head type OPC patterns for DRAM cell pattern. Finally, we investigate the usefulness of the fine pixel CD-SEM by usign the same novel algorithm for comparison of the conventional and the fine pixel CD-SEM.