Abstract: An infrared real time monitoring system was designed to obtain thermal images of H₃PO₄ layer profile during laser assisted chemical etching of high temperature superconducting film (YBa₂Cu₃O_7-δ film). The temperature distribution and heat diffuse of solution were studied, as well as the relation between infrared monitoring data and YBa₂Cu₃O_7-δ laser assisted chemical etching characteristics was analyzed. The major experimental conclusions include: The temperature distribution and heat diffuse of solution can be truly reflected by infrared thermal image, which is valuable for the analysis of thermal circumstance of laser assisted etching; the created heat diffuse height on YBa₂Cu₃O_7-δ film surface and corresponding infrared grey-scale can be achieved at any time to analyze the differences between etching starting duration and etching degree of any small regions on YBa₂Cu₃O_7-δ film surface, which provides a new method for the real time monitoring of laser assisted etching properties of YBa₂Cu₃O_7-δ and other materials.

Key words: laser assisted chemical etching, infrared technique, high temperature superconductor, YBa₂Cu₃O_7-δ