Growth of tin oxide film deposited by a hybrid ion beam

Tin oxide thin films were grown on Si(100) substrates by a hybrid ion beam consisting of a partially ionized beam and a cold hollow cathode ion source. Tin metal particles were ionized and accelerated by a partially ionized ion beam source while oxygen gas was introduced or ionized oxygen was introduced upon the Si substrate. When oxygen gas was blown near the substrate during Sn metal evaporation, the composition of deposited tin oxide films revealed mainly Sn metal and SnO, whereas tin dioxide films with highly preferred orientation of SnO₂〈200〉 or SnO₂〈110〉 axis were successfully grown when ionized oxygen was assisted. The calculated value of the composition ratio of oxygen to Sn(O/Sn) by AES for the SnO₂(200) film was approximately 1.98. Moreover, the binding energy of Sn 3d_5/2 was determined to be at 486.74 eV by XPS measurement, and the result coincided well with that of standard SnO₂ powder. Compared with two different deposition processes, ionized oxygen assistance during tin metal evaporation would be considered to effectively improve oxygen content for the formation of tin dioxide thin films.