Thermal distribution measurement upon micro-resistance lines using Thermoreflectance technique

The shrinking in feature size and the increasing operation frequency of integrated devices make temperature characterization and thermal management a crucial aspect of integrated circuit performance and design. To address these challenges, accurate information of temperature distribution or thermal properties at submicron scale is required. There are diverse methods to measure temperature distribution of devices. Infrared thermal imaging is a common method. However, its spatial resolution is limited to several micrometers due to diffraction effect. And its temporal resolution is limited to 2 ms. As a new emerging technique, thermoreflectance imaging is non-contact, nondestructive and has advantages in high temporal and spatial resolution which is useful for hot spot detection and thermal failures prediction. This paper gives an overview of thermoreflectance thermal imaging technique and a description of a home-made setup. The parameter thermoreflectance coefficient is critical for the technique, as it is material and wavelength dependent. This paper provides a general way to acquire thermoreflectance coefficient. In order to demonstrate the advantages of the technique, transient thermal measurement on a micro-resistor is undertaken using this setup.