Laser terahertz emission microscopy toward high-resolution imaging

As an unique terahertz application, we have been developing a laser terahertz emission microscope (LTEM) for not only a study of basic science but also industrial application such as an inspection tool for semiconductor integrated circuits. In order to establish high resolution system, we employed a high-refractive solid immersion lens and a beam expander in LTEM system, by which a focused beam spot size can be minimized effectively. Using the modified LTEM, nondestructive terahertz emission images of samples patterned as line-and-space structure on InP was obtained with a spatial resolution better than 1.5 mum.