Novellus' CoolFill CVD Process Advances Tungsten Fill for Sub-32nm High Aspect Ratio Structures

Figure 1: Cross sectional TEM images comparing 32 nm, 18:1 aspect ratio contacts processed using Standard and CoolFill CVD. (PRNewsFoto/Novellus Systems, Inc.)

SAN JOSE, CA UNITED STATES

SAN JOSE, Calif., April 16 /PRNewswire-FirstCall/ -- As semiconductor devices scale to the 32nm technology node and beyond, shrinking contact and via dimensions make chemical vapor deposition (CVD) of tungsten more challenging. Increasing aspect ratios can lead to voids or large seams within device features, resulting in lower yields and decreased performance in microprocessor and memory chips. The International Technology Roadmap for Semiconductors (ITRS) calls for 32nm stacked capacitor DRAM contacts to have aspect ratios of greater than 20:1. Logic devices, though not as aggressive as DRAM, will still have challenges in maintaining low resistivity contacts as aspect ratios grow to more than 10:1. Void-free fill that meets the required electrical properties in aggressive features like these will be problematic using conventional CVD tungsten deposition techniques. Read more...