New signal detection methods for thermal beam induced phenomenon

Abstract

Thermal beam induced techniques such as Thermally Induced Voltage Alteration (TIVA), Seebeck Effect Imaging (SEI) and Optical Beam Induced Resistance Change (OBIRCH) have been used for localization of reliability related faults in integrated circuits over the last few years. In this paper, we describe several approaches to optimize the detection of thermal beam induced phenomenon. In the first method, we have improved control of the laser scanning system to define a specific dwell time at each pixel. Secondly, we utilized a voltage source in series with an inductor to detect the induced voltage changes as the laser is scanned across the device. Finally, we employed a pulsed laser and a lock-in signal processing technique to increase the signal-to-noise ratio.