- SEMI MF43 - Test Method for Resistivity of Semiconductor Materials
This Standard was technically approved by the Silicon Wafer Global Technical Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on February 1, 2016. Available at www.semiviews.org and www.semi.org in March 2016; originally published by ASTM International as ASTM F43-64T; previously published June 2011.
The resistivity of a semiconductor material is an important materials acceptance requirement. Resistivity determinations made during device fabrication are also widely used for quality control purposes.
This Test Method covers two procedures which are widely used for making routine measurements.
The two test methods in this Standard are as follows:
Method A, Two-Probe — This test method requires a bar specimen of measurable cross section and with cross-sectional dimensions small in comparison with the length of the bar. For materials for which no specific referee method has been developed, this test method is recommended for materials acceptance purposes.
Method B, Four-Probe — This test method is rapid and does not require a specimen of regular cross section. This test method may be used on irregularly shaped specimens, provided a flat region is available for the contacting probes. As described in this Standard, this test method is applicable only to specimens such that the thickness of the specimen and the distance from any probe point to the nearest edge are both at least four times the probe spacing. For the special case of specimens of circular cross section with thickness more than one, but less than four, times the probe spacing, measurements by this test method are possible; the required application of approximate geometric corrections results in improved accuracy.
In general, resistivity measurements are most reliable when made on single crystals, since with such material local variations in impurity which affect the resistivity are less severe. Localized impurity segregation at grain boundaries in polycrystalline material may result in large resistivity variations. Such effects are common to either of the measurement test methods but are more severe with the four-probe test method, and its use, therefore, is not recommended for polycrystalline material.
The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
Referenced SEMI Standards
SEMI M1 — Specification for Polished Single Crystal Silicon Wafers
SEMI M59 — Terminology for Silicon Technology
SEMI MF84 — Test Method for Measuring Resistivity of Silicon Wafers with an In-Line Four-Point Probe
SEMI MF374 — Test Method for Sheet Resistance of Silicon Epitaxial, Diffused, Polysilicon, and Ion-Implanted Layers Using an In-Line Four-Point Probe with the Single-Configuration Procedure
SEMI MF397 — Test Method for Resistivity of Silicon Bars Using a Two-Point Probe
SEMI MF533 — Test Method for Thickness and Thickness Variation of Silicon Wafers
SEMI MF2074 — Guide for Measuring Diameter of Silicon and Other Semiconductor Wafers