| Popis: |
In this paper, we report selective formation of TiSi 2 on Si using SiH 4 and TiCl 4 at low temperatures (600–750°C) by first depositing a thin (20–30 nm) Si-Ge alloy selectively on Si with respect to SiO 2 . The Si-Ge alloy layer, which can be deposited at temperatures around 600°C using SiH 4 and GeH 4 , promotes the nucleation of TiSi 2 by providing an oxide-free surface to the subsequent TiSi 2 deposition process. Using this sequential deposition process, we have achieved selective TiSi 2 deposition at temperatures as low as 625°C. X-ray diffraction analysis showed that the films deposited in the temperature range of 625–750°C were polycrystalline TiSi 2 with orthorhombic C54 crystal structure. These films had resistivities ranging from 15 to 25 μΩ2 cm. The temperature dependence of the deposition rate can be characterized by two activation energies of 0.3 eV and 3.0 eV for temperatures above and below 650°C respectively. |
