Preliminary Study on the Model of Thermal Laser Stimulation for Defect Localization in Integrated Circuits

Abstract

Thermal Laser Stimulation (TLS) is an efficient technology for integrated circuit defect localization in Failure Analysis (FA) laboratories. It contains Optical Beam-Induced Resistance Change (OBIRCH), Thermally-Induced Voltage Alteration (TIVA), and Seebeck Effect Imaging (SEI). These techniques respectively use the principle of laser-induced resistance change and the Seebeck effect. In this paper, a comprehensive model of TLS technology is proposed. Firstly, the model presents an analytical expression of the temperature variation in Integrated Circuits (IC) after laser irradiation, which quantificationally shows the positive correlation with laser power and the negative correlation with scanning velocity. Secondly, the model describes the opposite influence of laser-induced resistance change and the Seebeck effect in the device. Finally, the relationship between the current variation measured in the experiment and other parameters, especially the voltage bias, is well explained by the model. The comprehensive model provides theoretical guidance for the efficient and accurate defect localization of TLS technology.