NATIVE AND TRANSITION METAL DEFECT CENTERS IN INDIUM PHOSPHIDE

The origins and properties of deep level defect associated with native disorder and transition metal impurities in LEC and VPE InP were studied. Native defects and related complexes were examined in 1-2 MeV electron irradiated n and p-type crystals. Primary native defects were found to be unstable at 298 K. The dependence of total defect introduction rates on acceptor concentration levels indicated that the majority of irradiation induced centers are the result of complexes between native defects and shallow acceptors. Seven electron irradiation induced donor levels were detected in high purity n-type VPE InP using deep level transient spectroscopy (DLTS). Individual defect introduction rates in the purest materials were measured to be less than 10{dollar}sp{lcub}-5{rcub}{dollar} cm{dollar}sp{lcub}-1{rcub}{dollar}. Photoluminescence (PL) characterization at 10 K of irradiated materials indicated that these defects are generally non-radiative in nature and are responsible for severely degrading the optical properties of InP.; The importance of the Cu, Ag, Au and Ni transition metals in the formation of deep levels in diffused and ion-mixed InP was examined. All metals except Ni were determined to produce active states. The defect parameters of these centers were characterized with DLTS, steady state photocapacitance (SSPC) and PL and their ionization energies compared with existing theoretical models. Cu was found to act as an acceptor while Ag and Au behaved as donors. Electrical activities of Cu states were determined to depend on diffusion temperature and P{dollar}sb{lcub}4{rcub}{dollar} partial pressure.; Defect stability was investigated using PL by annealing crystals up to 700{dollar}sp{lcub}circ{rcub}{dollar}C under various P{dollar}sb{lcub}4{rcub}{dollar} partial pressures. Changes in the defect structure were observed above 300{dollar}sp{lcub}circ{rcub}{dollar}C. Two dominant PL transitions at 1.07 and 1.20 eV were found to be important. The 1.20 eV band was correlated with a Cu{dollar}sb{lcub}rm In{rcub}{dollar}-V{dollar}sb{lcub}rm P{rcub}{dollar} complex by doping experiments. An antisite pair defect was proposed for the 1.07 eV band.; The importance of process induced defect complexed involving Ge, Si, O{dollar}sb{lcub}2{rcub}{dollar}, N{dollar}sb{lcub}2{rcub}{dollar} and C was investigated. The self-compensation of intentional dopants by native defects was studied as a function of dopant concentration and found to be an important phenomenon in InP.