Imaging of Thermal Conductivity with Sub-Micrometer Resolution Using Scanning Thermal Microscopy

With the development of new emerging technologies, many objects in scientific research and engineering are of sub-micrometer and nanometer size, such as microelectronics, micro-electro-mechanical systems (MEMS), biomedicines, etc. Therefore, thermal conductivity measurements with sub-micrometer resolution are indispensable. This paper reports on the imaging of various micrometer and sub-micrometer size surface variations using a scanning thermal microscope (SThM). The thermal images show the contrasts indicating the differences of the local thermal conductivity in the sample. Thermal resistance circuits for the thermal tip temperature are developed to explain the heat transfer mechanism between the thermal tip and the sample and to explain the coupling between the local thermal conductivity and the topography in the test results.