REACTION OF TUNGSTEN HEXAFLUORIDE WITH SI AND TIN SURFACES

The reaction of WF6 with Si and TiN surfaces has been investigated by Auger electron spectroscopy. On Si(100), the reaction of WF6 leads to a W thin film whose thickness increases exponentially with temperature and with an activation energy of 0.95 eV. The reaction is linear with WF6 exposure, resulting in a reaction rate of about 1 angstrom s-1 of deposited W at T = 500-degrees-C and 4 Pa WF6 pressure. On TiN, the reaction of WF6 at 4 Pa does not lead to W film growth at the temperatures 400-degrees-C < T < 500-degrees-C and exposure times 20 s < t < 400 s. Instead, the W intermixes throughout the TiN film in a non-activated process.