Multilayer structures deposited by laser ablation

TiN/Si structures were deposited on Si wafers by pulsed laser deposition te chnique. The highly conductive TiN films were grown on heated (100) Si subs trates by laser ablation of a high purity Ti target in nitrogen reactive at mosphere. Subsequently, the Si layer was deposited by laser ablation of a S i target in vacuum (down to 10(-6) mbar) or in low pressure inert gas. The nitrogen gas pressure and the substrate temperature were found to strongly influence the TiN film structure and orientation. The degree of crystallini ty of the Si layer grown on the TiN film was found to depend on Si/TiN coll ector temperature. Values below 550 degrees C (the threshold of TiN oxidati on activation) were used in the experiments. Techniques as X-ray Diffractio n (XRD), Fourier Transform Infrared Spectroscopy (FTIR), High Resolution Tr ansmission Electron Microscopy (HRTEM), Scanning Force Microscopy (SFM) hav e been used to characterize the deposited structures. The TiN/Si structure rectifying properties were tested. The obtained Si/TiN/Si structure could b e suitable for the building of Permeable Base Transistor (PBT, vertical MES FET) devices. (C) 1999 Elsevier Science S.A. All rights reserved.