Cross‐sectional TEM imaging of β‐ G a 2 O 3 thin films formed on c ‐plane and a ‐plane sapphire substrates (Phys. Status Solidi A 9∕2013)

Nakagomi and Kokubun (pp. 1738–1744 ) investigated the micro‐structure of β‐Ga 2 O 3 thin films formed on c ‐plane and a ‐plane sapphire substrates prepared by gallium evaporation in an oxygen plasma. Cross‐sectional transmission electron microscopy (TEM) images and electron diffraction patterns were obtained from a cross section of β‐Ga 2 O 3 on a sapphire substrate. The results indicate that TEM images and electron diffraction patterns can be classified into four types according to the rotation angle of the unit cell of (‐201)‐oriented β‐Ga 2 O 3 . The authors explain the reason for the appearance of the four types of cross sectional TEM image using crystal orientation. The classification was summarized in a table that is expected to be useful for further studies on β‐Ga 2 O 3 .