Development of laser terahertz emission microscope and its application to LSI defect analysis

点击翻译按钮获取中文摘要

This project aims to develop a laser terahertz (THz) emission microscope (LTEM) and explore its applications. The principle uses the THz radiation excited from many electronic materials with an illumination of femtosecond laser. The research subjects examined here are 1) designing and manufacturing the prototype of LTEM, 2) the evaluation of its performance and improvement, and 3) applications to observe various electronic materials and devices.We developed a free space type and scanning fiber probe type LTEM with either reflection mode or transmission one. The performance has been evaluated by using mode made line and space specimen. The minimum resolution for the free space type and probe one is better than 2 μm and 1.5 μm, respectively.First, the LTEM has been applied to see ferroelectric domain in multiferroic BiFeO_3 (BFO) thin films. We discovered the THz emission effect from BFO for the first time, and successfully visualized the feroelectoric domain. Then we applied LTEM to image an operational amplifier while operating, and successfully visualized the only signal lines related to amplifying process in the device. Finally, we examined its application to LSI defect analysis. We success fully distinguished damaged MOSFET in the Test Element Group from undamaged. The results prove that LTEM is promising new type of microscope for device evaluation such as LSI as well as various electronic materials. One can expect that LTEM can be improved to be available for dynamic microscope.