Microstructure of TiN films and interfaces formed by ion-beam-enhanced deposition and simple physical vapor deposition

  • PDF / 2,344,901 Bytes
  • 5 Pages / 576 x 792 pts Page_size
  • 18 Downloads / 274 Views

DOWNLOAD

REPORT


X.H. Liu, Xi Wang, and G.Q. Yang Shanghai Institute of Metallurgy, Academia Sinica, Shanghai 200050, China (Received 13 January 1994; accepted 30 November 1994)

The microstructure and composition of TiN films, formed by ion beam enhanced deposition (IBED) with different energy (40 keV and 90 keV) xenon ion bombardment and by simple physical vapor deposition (hereafter S-PVD) without any ion beam enhancement, and the interfaces between TiN films and Si substrates have been studied by cross-sectional view analytical electron microscopy in this work. Both the IBED TiN films prepared by Xe + bombardment with either 40 keV or 90 keV energy ions and the S-PVD TiN film consist of nanocrystals. The TEM observations in the S-PVD case reveal an amorphous layer and a mixed layer of TiN grains and amorphous material at the TiN/Si interface. The thicknesses of the amorphous layer and the mixed layer are about 210 nm and at least 40 nm, respectively. Upon 40 keV Xe + bombardment, an amorphous Si transition layer of about 50 nm thickness is found at the TiN/Si interface, and the TiN grains close to the TiN/Si interface are of weak preferred orientation. Upon 90 keV Xe + bombardment, amorphous TiN and Si layers are found with a total thickness of 80 nm at the TiN/Si interface, and the TiN grains near the TiN/Si interface are of preferred orientation [11 1]TIN II [001]Si- The energy of xenon ion bombardment has a strong effect on the microstructural characteristics of TiN films and the interfaces between the TiN films and the Si substrates, as well as the size and the preferred orientation of TiN grains.

I. INTRODUCTION Ion-beam-enhanced deposition (IBED) is a combination of ion implantation and chemical vapor deposition (CVD) or physical vapor deposition (PVD). It has the advantages of improved adhesion to the substrate, good control of composition and thickness of the film, and facilitation of growth at relatively low temperature. The work of synthesizing TiN thin film by IBED has been previously reported.1"3 Since thin film performance depends strongly on the properties of the thin film and the film-substrate interface, study of the properties is important for both scientific and technological reasons. In most of the reported work, the composition of thin film and film-substrate interface was investigated by means of AES (Auger Electron Spectrum), and the structure of the thin film was studied by x-ray diffraction. It was found that at the interface between the substrate and thin film there exists a mixed transition layer, which contains the elements existing both in the substrate and in the thin film, but the image and structure of the transition layer were not shown.1-2'4 The thickness of the transition layer is affected by the energy and the mass of ion used in the thin film synthesis process.2 TiN films formed by IBED are polycrystalline, and the component ratio of J. Mater. Res., Vol. 10, No. 4, Apr 1995

http://journals.cambridge.org

Downloaded: 14 Mar 2015

N to Ti in TiN films decreases with an increase of either samp