Plasma pretreatments for Cu-MOCVD

For the deposition of Cu on TiN Films by metal organic chemical vapor deposition (MOCVD), precleaning of the TiN film surface by plasma treatments is essential to enhance Cu nucleation. In the present work, effects of hydrogen, oxygen, and nitrogen plasma treatments on the Cu nucleation, deposited by MOCVD, were investigated using scanning electron microscopy, sheet resistance measurements, X-ray photoelectron spectroscopy and Auger electron emission spectrometry. Cu nucleation is enhanced as the rf-power and the plasma exposure time increase in the hydrogen plasma pretreatment. The hydrogen plasma pretreatment is the most effective in enhancing Cu nucleation on the TiN film, since it produces free Ti atoms most effectively by removing nitrogen atoms in the top surface region of the TiN film. Cu nucleates more easily on Ti than on TiN.