Quantitative internal thermal energy mapping of semiconductor devices under short current stress using backside laser interferometry

Automated setup for thermal imaging and electrical degradation study of power DMOS devices

“…The delay between the electrical stress pulse and the two imaging pulses can be adjusted independently. It should be noticed that when thermal effects dominate over the carrier injection ones (as in the present case), the phase shift is directly proportional to a 2D thermal energy density in the silicon [15]. The measured signal cumulates all the previous distributions of heat dissipated sources and therefore indicates where the current has been flowing.…”

ESD characterization of multi-finger RF nMOSFET transistors by TLP and transient interferometric mapping technique

“…A transient thermallyinduced phase shift is measured during and after each applied TLP pulse (repetition rate about 1 Hz). The phase shift is directly proportional to the 2D thermal energy, which, for short times, represents well the dissipated power (current) distribution [5]. The information on temperature can be obtained from reverse modelling using thermal simulation [6].…”

Transient self-heating effects in multifinger AlGaN/GaN HEMTs with metal airbridges

“…The current and voltage waveforms were recorded using a digital oscilloscope. To investigate heat dissipation we use the TIM technique [10,11], where the device is scanned (synchronized with voltage pulses) from the polished backside using an infrared laser beam (see Fig. 1).…”

“…The airbridge technology is used in highpower HEMTs to connect parallel source contacts in a multifinger layout. We use the transient interferometric mapping (TIM) [10,11] and electrical experimental methods [4] combined with a 2D thermal model to analyze the transient temperature increase and thermal cross talk between the fingers. We investigate the role of the airbridge metal in the device thermal management.…”