Dynamic Near-Field Scanning Thermal Microscopy on thin films

• Heat transport within thin films on substrates is investigated locally.
• Thermal transports in cross-plane and in-plane direction have been investigated.
• Thermal conductivity changes within different film thicknesses are not detectable.
• An electrical equivalent circuit for SThM on thin film system is derived.

The thermal transport either in in-plane and cross-plane direction of thin films has been investigated by means of dynamic Near-field Thermal Microscopy. Existing models for large area investigations are conveyed and extended to these high resolution local investigations. A transition for thin films to bulk materials is described by the introduction of a saturating exponential function. In contrast to common analyses the thermal capacitance of the thin film is not negligible and must be considered when performing these local studies. In contrast to the common belief, a decrease of the thermal conductivity with decreasing film thicknesses is not detectable. Finally, an electrical equivalent circuit is introduced for failure analyses and reliability investigations of layer thicknesses smaller than the thermal penetration depth. By use of this equivalent circuit the thermal management of modern devices can be optimized.