Satoshi Arakawa, Mitsumasa Ito, Ryuusuke Nakasaki and Akihiko Kasukawa
In-situ etching of compound semiconductor and selective epitaxial growth of an Al-containing material were realized in a metalorganic chemical vapor deposition (MOCVD) reactor using carbon tetrabromide (CBr4). In-situ etching depended on the content of the compound semiconductor. InP was easily etched in proportion to the amount of CBr4, and provided a smooth surface; Al-containing layers could not be etched. This technique was very effective for obtaining a good regrowth interface and reducing the concentration of impurities. When CBr4 was introduced during the selective growth of AlGaInAs layers, there were no polycrystals on the dielectric masks. Because CBr4 did not adversely influence optical properties, this method is effective for fabricating compound semiconductor devices.