Investigation of machine compliance uniformity for nanoindentation screening of wafer-supported libraries

• Published in: Review of scientific instruments 2005-06, Vol.76 (6), p.062209-062209-6
• Main Authors: Warren, Oden L., Dwivedi, Arpit, Wyrobek, Thomas J., Famodu, Olugbenga O., Takeuchi, Ichiro
• Format: Article
• Language: English
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.1906089

The reliability of nanoindentation results can depend critically on an accurate assessment of the machine compliance term. The common practice is to determine the machine compliance from a small reference specimen, then apply its value to a much larger wafer-supported library. The present study investigates the validity of this approach by thoroughly testing bare 76.2 mm diameter, 410 μ m thick Si(100) wafers mounted on two vacuum chucks of different design. We find that the small-sample value of the machine compliance is adequate for the majority of the wafer, including areas directly over vacuum rings and a circular center port of ordinary dimensions. However, vacuum chucks with a tweezer slot should be avoided in combinatorial materials science applications. But even in the absence of a tweezer slot, it may be necessary to generate an accurate machine compliance map for the wafer perimeter if the thin-film library extends beyond the outermost vacuum ring to the wafer edge. The Young’s modulus and the hardness of silicon are found to be 169 ± 3 GPa and 12.2 ± 0.2 GPa , respectively, over well-mounted regions of the wafer; both values are in good agreement with the literature.