Advances in experimental technique for quantitative two dimensional dopant profiling by scanning capacitance microscopy

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Publication Type Journal Article
School or College College of Science
Department Physics
Creator Williams, Clayton C.
Other Author Zavyalov, V. V.; McMurray, J. S.
Title Advances in experimental technique for quantitative two dimensional dopant profiling by scanning capacitance microscopy
Date 1999
Description Several advances have been made toward the achievement of quantitative two-dimensional dopant and carrier profiling. To improve the dielectric and charge properties of the oxide-silicon interface, a method of low temperature heat treatment has been developed which produces an insulating layer with consistent quality and reproducibility. After a standard polishing procedure is applied to cross-sectional samples, the samples are heated to 300°C for 30 min under ultraviolet illumination. This additional surface treatment dramatically improves dielectric layer uniformity, scanning capacitance microscopy (SCM) signal to noise ratio, and C-V curve flat band offset. Examples of the improvement in the surface quality and comparisons of converted SCM data with secondary ion mass spectrometry (SIMS) data are shown. A SCM tip study has also been performed that indicates significant tip depletion problems can occur. It is shown that doped silicon tips are often depleted by the applied SCM bias voltage causing errors in the SCM measured profile. Worn metal coated and silicided silicon tips also can cause similar problems. When these effects are tested for and eliminated, excellent agreement can be achieved between quantitative SCM profiles and SIMS data over a five-decade range of dopant density using a proper physical model. The impact of the tip size and shape on SCM spatial accuracy is simulated. A flat tip model gives a good agreement with experimental data. It is found that the dc offset used to compensate the C-V curve flat band shift has a consistently opposite sign on p- and n-type substrates. This corresponds to a positive surface on p-type silicon and to a negative surface on n-type silicon. Rectification of the large capacitance probing voltage is considered as a mechanism responsible for the apparent flat band shift of (0.4-1) V measured on the samples after heating under UV irradiation. To explain the larger flat band shift of (1-5) V, tip induced charging of water-related traps is proposed and discussed.
Type Text
Publisher American Institute of Physics (AIP)
Volume 70
Issue 1
Subject Doping; Scanning capacitance microscope; SCM
Subject LCSH Semiconductor doping; Microscopy
Language eng
Bibliographic Citation Zavyalov, V. V., McMurray, J. S., & Williams, C. C. (1999). Advances in experimental technique for quantitative two dimensional dopant profiling by scanning capacitance microscopy. Review of Scientific Instruments, 70(1), 158.
Rights Management (c)American Institute of Physics. The following article appeared in Zavyalov, V. V., McMurray, J. S., & Williams, C. C. Review of Scientific Instruments, 70(1), 1999. and may be found at http://link.aip.org/?RSINAK/70/158/1
Format Medium application/pdf
Format Extent 502,596 Bytes
Identifier ir-main,5159
ARK ark:/87278/s6c25f2s
Setname ir_uspace
Date Created 2012-06-13
Date Modified 2021-05-06
ID 706899
Reference URL https://collections.lib.utah.edu/ark:/87278/s6c25f2s
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