Study of Zn diffusion in n-type GaSb by cathodoluminescence and scanning tunneling spectroscopy

We report here the studies carried out in zinc diffused n-type GaSb by cathodoluminescence (CL) microscopy and by scanning tunneling spectroscopy. Samples with different diffusion profiles measured by secondary ion mass spectrometry (SIMS) were obtained. CL plan-view observations show high homogeneity in the diffused layers. Cross-sectional measurements of the Zn diffused layers were performed by current imaging tunneling spectroscopy (CITS). The junction border was revealed clearly in the CITS images and conductance spectra recorded at differents points of the layers provided information on the local surface band gaps and the conductive behaviour. The results were related to the diffusion profiles and were found to agree with diffusion models suggested previously.