EFFECTS OF INTERMEDIATE ZINC PULSES ON PROPERTIES OF TIN AND NBN FILMS DEPOSITED BY ATOMIC LAYER EPITAXY

The reasons for the improvements gained by using intermediate zinc pul ses in atomic layer epitaxy growth of TiN and NbN films were examined by a comprehensive characterization and comparison of films prepared f rom TiCl4 or NbCl5 and NH3 with and without zinc. The characterization techniques used comprise time-of-flight elastic recoil detection anal ysis, secondary ion mass spectrometry, Rutherford backscattering spect rometry, nuclear resonance broadening, proton backscattering spectrome try, deuteron induced reactions, proton induced X-ray emission, atomic force microscopy, scanning electron microscopy, X-ray diffraction, an d Hall effect and reflectance measurements. The effect of zinc was fou nd to be manifold: both compositional and structural changes were obse rved. In the case of TiN the major improvement gained by using zinc wa s significantly decreased oxygen contamination whereas a marked increa se of, grain size was the dominant effect observed with NbN. A clear c orrelation between the compositional and structural changes and the im provements of the electrical properties was established. (C) 1997 Else vier Science B.V.