Charge behavior observation on/in plasma processed thin films by LIPP during thermal heating for TSDC analysis

A novel simultaneous space charge measuring system for a charged thin film was developed. The space charge in-depth profile of a charged film is observed by a typical LIPP (laser-induced pressure pulse) method by using a 100 picoseconds YAG laser in a new measuring cell. That new cell can be heated up to 200°C at a constant temperature increasing rate and subpicoampere current flow through a sample thin film can be recorded by a computer system. LIPP method needs only a few second and TSDC current measurement is stopped during that LIPP measuring time that does not affect the final TSDC spectrum which needs much time of roughly an hour. This new combined method can tell us the relationship between the space charge in-depth position and TSDC peaks. Influence of the surface plasma process, which is very popular as anti-static process of a highly insulating polymer film, to the commercially available polymer film is analyzed by this new method. Decrease of some TSDC peaks by the plasma process is observed and their special position can be identified.