Deep level transient spectroscopy study of Pd and Pt sputtering damage in n-type germanium

Defect formation during Pd and Pt germanidation of n-type germanium, using rapid thermal annealing in the range of 300-500 deg. C, is investigated by deep level transient spectroscopy. Small concentrations of an electron trap at ∼EC-0.385 eV are found, which is believed to be associated with vacancy-related sputtering damage. This is supported by the observation of much higher concentrations of vacancy-related deep levels on as-deposited Pt and Pd Schottky barriers. A steep concentration profile rising towards the surface confirms the assignment to Ar ion-related damage. The applied thermal budget points out that the defects observed in the germanide samples are more stable than simple vacancy-related point defects and could correspond to vacancy clusters formed during the deposition and/or the annealing step