Seismic footstep detection-based systems are very important for various homeland security and military applications. Their performance and usefulness strongly depends on the characteristics of the seismic sensors. Unfortunately, currently available seismic sensors do not provide in satisfactory results. This paper describes the main issues of using seismic sensors for detection purposes and shows the key disadvantages of the most popular commercial seismic sensors/geophones. According to our results, the following are the key issues of poor seismic sensor performance:• Poor response to low frequency signals, leading to decrease of the detection range of targets • Unsatisfactory sensitivity threshold, causing missing low level seismic signals from outlying targets • Long damping signal time and corresponding low accuracy response, leading to problems with outlying target detection in high level noise environments • Low noise immunity from electromagnetic interference making seismic sensor operation in radar installation areas unreliable • Relatively bulky size and high price, which prevents extensive use of seismic sensorsIn addition, we have formulated objective requirements for seismic sensors to be used in defense and security applications.

The problem of quantifying LER in the semiconductor industry has become critical with sub-lOOnm node manufacturing. However, routine methods for LER measurement to meet the needs of industry have not been reported. Even the definition for LER has not been defined unambiguously. Also, the length ofthe photoresist structure, on which LER is measured, has not been standardized.Meanwhile, demands for precision in LER calculations have been put forward without accounting for the statistical nature of this parameter. In addition, the algorithms used for feature edge localization when performing LER measurements frequently have free parameters [1] which makes LER estimation ambiguous and does not allow LER comparisons of the same feature. In particular, without taking into account the influence of signal noise in the SEM video, the LER measurements obtained will have contributions from both the measured feature and measuring tool (SEM). The manner in which this measurement is done results in LER values that exceed the true LER. Moreover, when measured objects have aspect ratios exceeding three, it is not clear where along the cross-section height of the object-bottom, top, or some intermediate position-correspond to the measured values. The above issues make the interpretation of obtained results very difficult, and significantly reduces the reliability and value of LER measurement results present in the referenced literature.Nanometrology has developed a new concept for LER measurements that is free of many of the disadvantages mentioned above. It is based on the definition ofLER as "a standard deviation ofthe factual edge position on SEM scan lines from an approximated straight line". Nanometrology's use of a patented algorithm for edge localization of 3D objects results in the measurement of the bottom CD of photoresist structures. Our algorithms do not have free parameters. These algorithms have been incorporated into a CD measurement software package called CD-LER.

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The problem of enacting an effective Advanced Process Control (APC) system is herein discussed [1]. The schematic structure of the system is represented below: Lithography, Technology Photomask Design Process Engineering Technology SEM Metrology CD/LER/LWRThe creation of such a system with a communication link between the mask designer and lithography and process engineering of consequent operations can be broken down into two problems:1. Organization of the interaction of services performed by APC 2. Reliability of the measurement information obtained in SEM CD metrologyWe will focus on the second problem. The effectiveness of the operation of the APC system depends on the reliability (precision and accuracy) of the measurement outcomes.

The pitch ofa Hitachi Standard Micro Scale was measured using NanoCaP' and a LEO 1560 SEM. The pitch pedigree and certification were intentionally withheld from Nanometrology team members to enable independent measurement and certification ofan unknown Hitachi Micro Scale standard during this work. NanoCal' allows one to achieve pitch measurements with sub-nanometer accuracy and precision as well as to perform SEM magnification calibration with the precision and accuracy required for sub 9Onm SEM metrology.