Naoki Yahata

Metal Chloride Reduction Chemical Vapor Deposition for Ta, Mo and Ir Films

Tantalum, molybdenum and iridium thin films are deposited by metal chloride reduction chemical vapor deposition (MCR-CVD) process using Cl2 plasma. In the process, Cl2 plasma, which is generated between a substrate and a metal plate, produces volatile chlorides by chlorination of the metal plate and also acts as a reducing agent. A conformal coverage of the tantalum film on a patterned surface is observed. MCR-CVD using Cl2 plasma is expected to be applied to the deposition of extensive metals, whose chlorides exhibit reasonably high vapor pressures at low temperatures.

Structural Evaluation of Cu Films Grown by Cl2 Plasma

We evaluated the morphology and crystallinity of copper films which were grown by the new chemical vapor deposition (CVD) method with Cl2 plasma using field emission scanning electron microscopy (FESEM) and electron back scattering pattern (EBSP). The obtained films consisted of large grains of 0.5–1 µm size, and filling with high crystallinity was indicated. Moreover, we observed the time evolution of the morphology of the films by FESEM. On the basis of the results, the mechanism of the copper film growth and the bottom-up filling by the new CVD method was discussed.