High spatial resolution mapping of resistivity variations in semiconductors

• Published in: Solid-state electronics 1992-03, Vol.35 (3), p.423-433
• Main Authors: Kopanski, J.J., Lowney, J.R., Miles, D.S., Novotny, D.B., Carver, G.P.
• Format: Article
• Language: English
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/0038-1101(92)90246-9

A new approach to the mapping of resistivity variations in semiconductors uses probe sites provided by an array of lithographically defined contacts with a density of 60,000 sites cm −2. One- or two-probe spreading resistance or four-point-probe resistance measurements can be made. Solutions of the Laplace equation and measurements on Si that had been ion-implanted to form abrupt boundaries in resistivity are used to show that the spatial resolution of the technique is determined primarily by the spacing of the measurement sites, not by the spreading of the current from the contacts. The technique has been implemented with resolution of lateral variations in resistivity of 45 μm in extent and ±5% in magnitude from the background resistivity. As an example application, a study of the resistivity variations of a Si boule with pronounced growth striations is presented.