Texture of Al/Ti thin films deposited on low dielectric polymer substrates

The texture of Al/Ti thin films deposited on low-dielectric polymer substrates has been investigated. Fifty-nm-thick Ti films and 500-nm-thick Al-1%Si-0.5%Cu (wt%) films were deposited sequentially onto low-k polymers and SiO$_2$ by using a DC magnetron sputtering system. The texture of Al thin film was determined using X-ray diffraction (XRD) theta-2theta ($\theta$-2$\theta$) and rocking curve and the microstructure of Al/Ti films on low-k polymer and SiO$_2$ substrates was characterized by Transmission electron microscopy (TEM). hall thin films deposited on SiO$_2$ had stronger texture than those deposited on low-k polymer. The texture of Al thin films strongly depended on that of Ti films. Cross-sectional TEM resealed that Brains of Ti films on SiO$_2$ substrates had grown perpendicular to the substrate, while the grains of Ti films on SiLK substrates were farmed randomly. The lower degree of 111 texture of Al thin films on low-k polymer was due to Ti underlayer.