Thermal Failure Analysis by IR Lock-in Thermography

Abstract

The basic limitations of thermal failure analysis by infrared (IR) thermography are that its spatial resolution is limited by the wavelength of the used IR radiation to about 5 µm and that the so-called IR-emissivity contrast usually obscures a weak thermal contrast in ICs. However, advantages of IR thermography against other popular thermal techniques like liquid crystal analysis and fluorescent microthermal imaging are its ease of operation without any surface preparation and the fact that it can also be applied as a backside analysis technique. Thermal IR microscopy has recently experienced a decisive technical improvement by the application of lock-in thermography, which is commercially available also for IC analysis now. This technique allows to display the phase image, which is completely free of the disturbing emissivity