CVD TiN films offer promise as a barrier to Al deposition as a result of the improved conformai step coverage of this film in 0.25 μm contact holes. As an underlayer, the TiN performs a secondary role by improving electromigration (EM) resistance. This is a result of the crystal orientation of the TiN film and its influence on the orientation of the subsequent Al layer. A <111>Al orientation shows improved EM resistance; however, CVD TiN has a preferred <200> orientation as opposed to a <111>PVD TiN orientation.

In this study, two parts were investigated: 1) obtain a qualified PVD Al film on a CVD <200> TiN barrier in terms of sheet resistance and reflectivity utilizing MRC's Eclipse™ Mark II PVD system; 2) examine the texture of the Al film utilizing Philips XL30 SEM equipped with EDAX-DX4 EDS system and Electron Back Scatter Pattern (EBSP) system.

The Cr‐CrCu‐Cu metal scheme, as a terminal multistructure metallization for flip chip applications, has been investigated utilizing PVD sputter deposition varying the conditions of deposition power and temperature, and film thickness. A modified Controlled Collapse Chip Connection (C4) process was utilized in order to evaluate the aforementioned deposition of the Cr‐CrCu‐Cu multilayers and the effect of film microstructure on the parameters of shear strength and thermal cycle reliability. Thermal cycle reliability results proved to be a function of both the CrCu alloy and the Cu overlayer thickness. Transmission electron microscopy (TEM) cross‐sections of the Cr‐CrCu‐Cu multilayers suggests that the columnar grain structure of the CrCu layer may provide a sacrificial thermal diffusion barrier between the PbSn alloy solder balls and the Al bond pads during the thermal‐cycle tests.