Correlation between the microstructure and the degradation of rare earth implanted Si-based light emitters


Correlation between the microstructure and the degradation of rare earth implanted Si-based light emitters

Rebohle, L.; Nazarov, A.; Tyagulskii, S.; Tyagulskii, I.; Lehmann, J.; Skorupa, W.

The degradation of rare earth (RE)-implanted light emitters based on a Si-SiO2-SiON-ITO structure was investigated using the example of Tb and Eu as a function of their microstructural, electrical and electroluminescence (EL) properties. As shown by transmission electron microscopy and Rutherford backscattering spectroscopy the different implantation and annealing conditions lead to two different types of microstructures: devices with small RE oxide clusters and devices with large RE oxide clusters and strong RE agglomerations at the SiO2 interfaces. The electrical and EL properties of the devices were characterized by constant current injection measurements, in which the EL and the applied voltage is monitored with time, and IV, CV and EL spectrum measurements. As a result of these investigations it is shown that devices with small RE oxide clusters normally exhibit a high EL intensity and degrade in a two-step process characterized by a negative and a positive net charge trapping. In contrast to this, devices with large RE oxide clusters have a lower EL intensity, but the first step of degradation is suppressed resulting in lower quenching cross sections and thus a longer operation life time. The degradation is explained by a defect shell model in which the RE oxide clusters are surrounded by defect regions of different extensions leading to the different behavior of devices with small and large RE oxide clusters.

Keywords: Electroluminescence; rare earth; MOS capacity; charge trapping; ion implantation

Related publications

  • Lecture (Conference)
    3rd Int. Meeting on Recent Developments in the study of Radiation Effects in Matter, 24.-28.10.2010, Gramado, Brazil

Permalink: https://www.hzdr.de/publications/Publ-14855
Publ.-Id: 14855