The optimum heavy ion beam for the compositional analysis of indium nitride films

Ideal growth conditions for the III–V semiconductor indium nitride have not been identified. Indium nitride films have been shown to have excess nitrogen and often contain oxygen and carbon. Elastic recoil detection analysis of indium nitride using a 200 MeV 197Au beam is affected by considerable nitrogen depletion. The composition can, however, accurately be determined with a large solid angle gas ionization detector and through application of the bulk molecular recombination model. To avoid nitrogen depletion, in this work projectiles with atomic numbers lower than that of 197Au have been investigated. Whereas a 19F beam cannot effectively be employed, with a 32S beam the precise compositional analysis of indium nitride is possible. In this case nitrogen depletion is insignificant and accuracy is only limited by counting statistics. The use of a 32S beam is also superior to the use of a 109Ag beam. For the latter nitrogen depletion does occur, albeit somewhat reduced when compared with 197Au. A threshold atomic number may exist below which the depletion of nitrogen is absent.