In-situ observation of inorganic nanostructures by combined irradiation (ion beam, electron beam, laser) using multi quantum beam high voltage electron microscope

Just after the Second World War, electron microscope was first introduced to Hokkaido University and the metal physics research has been started using the electron microscope. Now days, electron microscopes are widely used from material science to life science as an important research tool for atomic scale analysis. Many efforts have been done to develop higher spatial resolution by increasing the acceleration voltage due to shortening the wavelength of the electrons during the 20th century. In the 1990s, the highest point resolution of high voltage electron microscopes (HVEMs) with top energy type specimen stage with an acceleration voltage of 1250 kV introduced in the Max Planck Institute in Germany and the University of Tokyo reached 0.1 nm. Recently, Cs corrected scanning transmission electron microscope (STEM) has been successfully developed and it's point to point resolution is reached less than 0.1 nm easily. However, HVEM had advantages that high energy electron can penetrate even a thick specimen, has high potential for in-situ observation and operand observation. In this review, we would like to introduce our multi-quantum beam high voltage electron microscope in Hokkaido University and demonstrate inorganic nanostructures formation by the combined irradiation (ion beam, electron beam, laser light). (author)