Study on image alignment technology based on CCD thermal reflection method

Thermoreflectance imaging technique is a noncontact measurement technology that has attracted much attention in the field of thermal characteristics measurement of semiconductor devices. This technology is often used for steady-state temperature measurement and transient temperature measurement of semiconductor devices, with the advantages of high spatial resolution, high temperature resolution, and high time resolution. However, during the measurement of the device, the thermal expansion of the temperature control table and the sample caused by the temperature rise makes the optical image appear defocused. In order to ensure that the optical image collected by the CCD is not distorted, it is necessary to design an image alignment system for focusing so that the semiconductor device can be measured normally. In this paper, an image alignment system consisting of an imaging module, a high-precision motion control component and an image alignment algorithm is proposed to solve the problem of image defocusing caused by thermal expansion, which can provide references for the optimal design and precise measurement of the thermal reflection imaging system based on CCD.