Novel nanoscale thermal property imaging technique: The 2 omega method. I. Principle and the 2 omega signal measurement

Abstract

In this and the following companion articles, the authors present the 2 omega method, a novel ac mode local thermal property imaging technique with nanoscale spatial resolution. To demonstrate the use of the thermoelectric probe as an active one that can function as both a heater and a temperature sensor, the authors develop and implement the 2 omega signal measurement technique, which can extract thermoelectric signals from a thermocouple junction while electrically heating it simultaneously. The principle of the 2 omega signal measurement technique is explained by a steady periodic electrothermal analysis. The authors use a specially designed test pattern to experimentally verify that the 2 omega signal is caused by the temperature oscillation induced by Joule heating. In addition, based on the results from an experiment using a cross-shaped pattern, the measurement accuracy of the 2 omega method depends on the junction size of the thermoelectric probe. The 2 omega method is implemented and compared with other methods in the following companion paper. (c) 2006 American Vacuum Society.