Defects in as-grown and ion-bombarded p-type crystals were investigated by means of positron lifetime measurements. The results showed that In vacancies existed in as-grown p-type samples. In addition, ZnIn- impurities were also observed which acted as shallow trapping centres at low temperatures. Ion-bombardment at lower doses introduced some monovacancies and, with increasing ion dose, divacancies were also observed which coexisted with monovacancies. The results showed that antisite defects were also produced during bombardment, and these were suggested to be negatively charged InP antisites.

Vacancies and negative ions in as-grown and ion-bombarded p-InP(Zn) observed by positron annihilation Z.Q.Chen, S.J.Wang: Semiconductor Science and Technology, 1999, 14[3], 271-7