LASER-INDUCED DEPOSITION OF TUNGSTEN FROM TUNGSTEN HEXACHLORIDE

The laser-induced deposition of W from pure WCl6 and with an admixture of H-2 is investigated. Both axial and lateral growth rates are analyzed on the basis of calculated temperature distributions. Deposition from pure WCl6 can only be performed at temperatures above 1400 K, which is explained by model calculations on the gas-phase transport. The admixture of a noble gas reduces the deposition rate due to thermal diffusion and mass transport limitation. In the presence of H-2 the threshold temperature for deposition is correlated with the relative amount of H-2 and WCl6.