Thermal Frequency Imaging: A New Application of Laser Voltage Imaging Applied on 40nm Technology

Abstract

For Very Deep submicron Technologies, techniques based on the analysis of reflected laser beam properties are widely used. The Laser Voltage Imaging (LVI) technique, introduced in 2009, allows mapping frequencies through the backside of integrated circuit. In this paper, we propose a new technique based on the LVI technique to debug a scan chain related issue. We describe the method to use LVI, usually dedicated to frequency mapping of digital active parts, in a way that enables localization of resistive leakage. Origin of this signal is investigated on a 40nm case study. This signal can be properly understood when two different effects, charge carrier density variations (LVI) and thermo reflectance effect (Thermal Frequency Imaging, TFI), are taken into account.

Thermal behavior analysis of interconnect structures of Si semiconductor devices using the temperature dependent reflectance of an incoherent light beam

“…By scanning the light beam on the sample, it is possible to know the temperature change distribution on the sample surface. [22][23][24][25]…”