In this era of the incredible shrinking chip, improving process residue adhesion is one of the thorniest challenges facing chip fabricators. Since adhesion is improved by roughening surfaces, new materials and technologies are being sought to replace or complement such traditional ceramic roughening methods as grit blasting or twin-wire arc spray (TWAS). With marching orders to improve process uptime, drive down manufacturing costs and improve or maintain yield, while decreasing process-related defects, the semiconductor industry is turning to new materials that help meet their needs. The emerging solar technology industry is also using the materials to drive down their costs and increase their competitiveness in the marketplace.

Today’s Thinner Integrated Circuits Demand Better Film Adhesion
The chip fabrication process uses various processes to layer films on wafers, including physical vapor deposition (PVD) and chemical vapor deposition (CVD). As integrated circuit linewidths get thinner, insulation between the layers that make up the chips is becoming even more difficult to achieve. In just a few short years, internal linewidths have been reduced from 65 nanometers (nm) to 45 nm and now to 32 nm, making insulator performance more significant.

This is particularly important for barrier layers, which require denser films that contain more compressive stress, with the potential for spalling failure, blisters and film “firing” off the chip surface. Deposited barrier layers composed of titanium, tantalum, or tungsten nitrides tend to be more stressed than other materials, because the layers have to be very dense to prevent elements within the integrated circuit from migrating.

During the process of layering film on the wafer, there is a build up of residual film on the tops and sides of ceramic reactor chamber components, including domes, shields and cover rings. This residual film is also highly stressed, so the deposits that build up on the chamber components may break off and fall onto wafers, ruining the chip or device.