Titanium in silicon as a deep level impurity

Titanium inserted in silicon by diffusion or during Czochralski ingot growth is electrically active to a concentration level of about 4 × 10¹⁴ cm^?3. Hall measurements after diffusion show conversion of lightly doped p type Si to n type due to a Ti donor level at E_C - 0.22 eV. In DLTS measurements of n⁺p structures this level shows as an electron (minority carrier) trap at E_C - 0.26 eV with an electron capture cross section of about 3 × 10^?15 cm² at 300°K. The DLTS curves also reveal a hole trap in the p type material. The e_p (300/T)² activation plot gives the level as E_V + 0.29 eV. The hole capture cross section is about 1.7 × 10^?17 cm² at 300°K and decreases with decreasing temperature and the corrected trap level becomes E_V = 0.26 eV. Ti in lightly doped (360 ohm-cm) n type material does not result in conversion to p type so this level is inferred also to be a donor.A Ti electrically active concentration of about 1.35 × 10¹³ cm^?3 in p type (N_A = 3.35 × 10¹⁵cm^?3) Si results in a minority carrier (electron) lifetime of 50 nsec at 300°K.