Impact of sampling on uncertainty: semiconductor dimensional metrology applications

Dimensional metrology with sub-nanometer uncertainty: unique role of AFM as the reference

“…As noted by Bunday et al [6] the "other" term includes cross correlations among the time, tool and sample related sources of measurement variation discussed above the σ P , σ M and σ S , respectively. Simple example of such cross correlation uncertainty terms could be the dependence of tool precision on the set of samples used to estimate it.…”

“…At certain point tool-to-tool matching became a problem [5]. Later component of uncertainty related to sampling attracted our attention [6]. It is important to realize that these three components of MU (distinguished by the ITRS from the "others") can be estimated without knowledge of absolute CD.…”

“…Precision and tool matching can be estimated by repeatable measurements on the set of technology representative samples [7]. Sampling uncertainty can be estimated using statistics through random measurements of relative sample-to-sample CD variation [6]. Importantly, these three components are not the only components contributing to MU.…”

A Literature Review on Sampling Techniques in Semiconductor Manufacturing

“…A Sample Planner is developed by KLATencor to assist in the development of cost-effective defect inspection sampling strategies, and to provide an accurate assessment of whether monitor reduction and/or elimination should be pursued for cost savings. The results of the project indicate that the costs due to defect excursions could com- [33] 1995 * * Kuo et al [34] 1996 * * * Kuo et al [12] 1997 * * Babikian and Engelhard [35] 1998 * Williams et al [36] 1999 * * Williams et al [37] 1999 * * Langford et al [38] 2000 * * Nurani and Shantikumar [39] 2000 * * * Lee et al [40] 2001 * * Wootton et al [41] 2001 * * Allebé et al [42] 2002 * * Lee [43] 2002 * * Song-Bor et al [44] 2003 * * Sullivan et al [45] 2004 * * Moon et al [46] 2005 * * Boussetta and Cross [14] 2005 * * Mouli [13] 2005 * Shantikumar [47] 2007 * Mouli et al [48] 2007 * * Bunday et al [49] 2008 * Veetil et al [50] 2009 * * Chen et al [51] 2009 * * Sahnoun et al [52] 2010 * * Sahnoun et al [53] 2010 * * * Good et al [54] 2010 * * Nduhura Munga et al [55] 2011 * * pletely eradicate any projected savings from monitor reduction activities, due to the additional defect excursions that would be missed by the reduced inspection sampling plan. Wootton et al [41] present a study performed between KLA-Tencor and Motorola.…”

Improvement in metrology on new 3D-AFM platform

“…Recent studies have shown that sampling errors (σ Sampling ) and sample-to-sample bias errors contribute [7] significantly to the combined uncertainty observed for dimensional metrology if sampling strategies and measurement techniques are not appropriately chosen [8]. The sampling uncertainty of cross-sectioning techniques such as TEM increases as the line width roughness becomes a significant portion of the total CD of ever smaller features.…”