Tungsten film deposition by hydrogen atom reaction with WF6

The formation of tungsten films using WF6 and molecular hydrogen, H2, usually requires elevated temperatures. Using the reaction of hydrogen atoms with WF6, tungsten atoms can be produced in a gas phase reaction. The atoms then deposit in a near-room temperature process resulting in the formation of tungsten films. The W atoms were measured in situ by atomic absorption spectroscopy during the chemical vapor deposition (CVD) process. The deposited W films were characterized by Auger electron spectroscopy and Rutherford backscattering spectrometry. Surface morphology of the films was studied using scanning electron microscopy. The deposited films were highly adherent to various substrates, including Teflon. The resistivity of the W films was measured and found ≥9 μΩ cm. This method allows deposition of high quality films and has two advantages compared to conventional CVD or plasma-enhanced CVD (PECVD): (1) film growth at low temperatures and (2) deposition in a plasma-free environment