The evolution of interstitial-type defects in silicon during platinum diffusion from 400 to 600°C following 2-MeV electron irradiation

Platinum has been diffused into epitaxial n-type silicon for 30 min at temperatures from 400 to 600°C following room temperature irradiation with 2-MeV electrons at a dose of 1×1017 e− cm−2. Platinum has only been detected by deep level transient spectroscopy (DLTS) following the highest diffusion temperature. For lower temperatures defects, not previously reported, arise which are thought to be of interstitial nature. The two principal defect levels are determined to be located at 0.29 and 0. 41 eV below the conduction band. The compensation for the two lowest diffusion temperatures is observed to be extremely strong as manifested by a strong reduction of the steady state reverse bias capacitance during the DLTS measurements. Following thermal treatment at 500°C this capacitance, however, increases. DLTS measurements down to 20 K detected thermal donors as well as a number of other defects not previously reported. Their signatures have been determined by DLTS and TSCap (thermally stimulated capacitance) measurements. The nature of the observed defects is discussed with reference to recent results concerning interstitial defects.