Ion channelling analysis of pre-amorphised silicon diodes using a nuclear microprobe

Abstract

Aligned and random ion channelling analysis was performed on p+n diode structures in (100) silicon, with the Surrey nuclear microprobe. Three different types of diode were investigated, each pre-amorphised by a different ion (Si+, Ge+ or Sn') before the p+ region was formed by BF,+ implantation. The ion channelling measurements are presented and compared with previously published electrical measurements on these diodes. Relatively large residual disorder and junction leakage currents were found for the Si+ pre-amorphised diodes; however, all the diodes were leaky ( > lo-6 A cm-2). The results are consistent with dislocation loops within the depletion regions of the diodes causing both the residual disorder and the large leakage currents. Crosssectional transmission electron microscopy studies support this model.