Journal of Vacuum Science & Technology B, Vol.26, No.1, 338-341, 2008
Impact of the environmental conditions on the electrical characteristics of scanning spreading resistance microscopy
Within this study, the authors have investigated scanning spreading resistance microscopy (SSRM) measurements on silicon samples under different environmental conditions. The authors have mainly focused on the possibility to reduce the required force for obtaining a stable electrical contact between the probe and the sample, and to improve the reproducibility of the technique by cleaving and measuring the samples in a controlled ambient. The authors demonstrate that, by measuring samples that were cleaved and maintained in nitrogen (N-2) ambient, the force needed for a stable electrical contact between the probe and the sample was reduced by more than a factor of 3 when compared to the force required in air. This leads to an improved signal to noise ratio and enhanced reproducibility with remaining variations now below 10% for n-type as well as p-type samples. At the same time, tip requirements are relaxed and tip lifetime is improved. Our work has demonstrated that in situ SSRM is a very good candidate to fulfill the stringent ITRS requirements for two-dimensional carrier profiling. (C) 2008 American Vacuum Society.