IMPURITY STATES IN COBALT-DOPED SILICON

Cobalt was diffused into p+ pn+ silicon structures at 900° and 1150°C for 2-4 hours followed by various quenching conditions. Four primary hole traps and two electron traps associated with cobalt in these devices were observed. The hole traps are labeled H1(Ev + 0.22 eV), H2(Ev + 0.29 eV), H3 (Ev + 0.40 eV) and H4(Ev + 0.45 eV) while the electron traps labeled E1 and E2 are located at Ec - 0.36 eV and Ec - 0.44 eV, respectively. The concentrations, thermal emission rates, and the capture cross sections for the majority carriers at these defects are reported. The behavior of these defects under heat treatment and the emergence of secondary defects, H5(Ev +0.22 eV) and H6 (Ev +0.34 eV), will be discussed. © 1978 AIME.