Masaaki Yamazato

Titanium disilicide formation by rf plasma enhanced chemical vapor deposition and film properties

Abstract Titanium disilicide thin films have been deposited on Si(1xa00xa00) substrate by rf plasma enhanced chemical vapor deposition using TiCl4/H2 gas mixture at different deposition temperatures. At low temperature of 650xa0°C excessive silicon substrate etching took place and silicide formation could not be confirmed. While at 700xa0°C Ti5Si3 was the only detected phase as found by X-ray diffraction (XRD) analysis. As the deposition temperature increased from 750 to 900xa0°C, the polycrystalline C54-TiSi2 phase deposited. Morphology of the film surface changed noticeably as the deposition temperature increased. At low temperature of 700xa0°C the film had a flake structure. Increasing the temperature up to 850xa0°C resulted in a continuous film with smoother grains, while at 900xa0°C agglomeration of grains took place resulting in coarse grains and discontinuous film. At the optimum experimental conditions it was possible to deposit a homogeneous film with smooth interface and suppressing silicon etching.

Preparation and properties of TiSi2 thin films from TiCl4/H2 by plasma enhanced chemical vapor deposition

Abstract Titanium silicide films were successfully prepared from TiCl4/H2 by plasma enhanced chemical vapor deposition. X-ray diffraction measurements showed that the films were polycrystalline and have the low resistivity phase C54-TiSi2. Contamination with chlorine could not be detected, however, oxygen contamination on the film surface was detected by X-ray photoelectron spectroscopy. The films were uniform and the TiSi2/substrate interface was clear and smooth. An excessive silicon substrate etching was observed when the substrate was heated by plasma. By controlling the reaction temperature and/or introducing hydrogen to the reaction gas system, it could be possible to deposit homogenous titanium silicide film and reduce silicon etching. These results could be explained reasonably based on thermodynamic calculations.

Formation of titanium silicide thin films on Si(100) substrate by RF plasma CVD

Abstract TiSi 2 thin films were deposited on Si(100) substrate by inductively coupled RF plasma CVD at RF power ranging from 20 to 400 W. TiCl 4 /H 2 were used as the feed gases. As the RF power increased up to 200 W at 850 °C, the morphology of the film surface and the TiSi 2 /Si interface improved due to the enhancement of H 2 and TiCl 4 dissociation into atomic species in the plasma. At higher RF powers the deposition of titanium-rich silicides such as Ti 5 Si 3 and TiSi was observed.

Effect of in situ H2-plasma cleaning on TiSi2 film properties in plasma enhanced chemical vapor deposition

Abstract The effect of in situ H2-plasma cleaning on the properties of TiSi2 film was investigated. At high RF plasma power (350 W), the film surface was rough and had voids due to damage of Si surface. At low RF power (30 W), the film surface was rough due to residual silicon oxide on the Si substrate surface.

RF-plasma enhanced CVD of TiSi2 thin films: effects of TiCl4 flow rate and RF power

Abstract The effects of TiCl 4 flow rate and RF power on PECVD of TiSi 2 thin films using TiCl 4 /H 2 gas mixture have been investigated. In the reaction system used, the low-resistivity phase C54-TiSi 2 film with homogeneous composition and smooth interface was obtained when the TiCl 4 flow rate and the RF power were optimized at 0.4xa0sccm and 200xa0W. The film surface and the film/substrate interface became rough at higher TiCl 4 flow rate whereas the deposition rate was slow and the Ti 5 Si 3 was formed at lower TiCl 4 flow rate. At higher RF power, Ti 5 Si 3 and TiSi phases were formed while at lower RF power the film surface became rough. These results are discussed with reference to the optical emission intensity of the plasma and the estimated temperature of hydrogen atom in the plasma.