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NIST Technical Publication



James R. Ehrstein, M C. Croarck, H Liu


This report documents the selection of material, the certification procedure and its control, and the analysis of measurement uncertainty for a family of improved Standard Reference Materials (SRMs) for sheet resistance and resistivity of silicon wafers, SRMs 2451 through 2547, covering the resistivity range 0.01 ''.cm through 200 ''.cm. These SRMs, made from 100 mm diameter silicon, replace previous SRM sets 1521 through 1523, which used 50.8 mm (2 in) diameter silicon at the same nominal resistivity levels. This revised report replaces both the original 1977 report and a 1999 update. It contains three new appendices: 10, 11 and 12 which summarize the H.-K. Liu''s statistical reports of analysis of second batch certifications for SRMs 2521, 2543 and 2544 as well as an appendix 13 that details the SRM serial numbers that were part of those second batch certifications. This revision also includes updates to tables 10 through 15 to include summaries of the uncertainty component results from those ''second-batch'' certifications The certification of the improved SRMs uses a dual-configuration four-point probe procedure rather than the single-configuration procedure of ASTM F84 [1], as used for previous SRMs. The new SRMs offer better handling compatibility with current user instrumentation, better uniformity of wafer thickness and of resistivity, more extensive spatial characterization of the near-center wafer resisivity, and reduced measurement uncertainty. The general procedures for the certification measurements, the control of the certification process, and the analysis of the results are based on experience gained from numerous preliminary experiments that allowed evaluation of the importance and relative magnitude of many possible measurement effects. The validity and effectiveness of the resulting certification and control procedures were tested during the analysis of results from the first of the SRMs to be certified, that at 200 ''.cm. The body of this report details the background and principles of the certification process and the approach to analyzing the experimental data needed to calculate the uncertainty of the certified values. This report details the evaluation of underlying Type B components of uncertainty that apply to all SRM levels. Additional Type A components, derived from statistical analyses of the actual certification data, are done individually for each SRM level and are reported in separate appendices for each of the SRMs.
Special Publication (NIST SP) - 260-131
Report Number


Four-point probe, reference material, resistivity, semiconductor, silicon, SRM, Standard Reference Material


Ehrstein, J. , Croarck, M. and Liu, H. (2006), NIST Technical Publication, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed May 28, 2024)


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Created January 31, 2006, Updated October 12, 2021