With each technology node, diffusion barrier layers are becoming increasingly thinner. One of the processing challenges is to deposit thinner, conformal barrier and seed layers over high-aspect ratio structures. With today's fast XRR, diffusion barrier films can be characterized down to the sub nanometer level, which makes XRR uniquely qualified to characterize ultra thin Atomic Layer Deposition (ALD) barriers.
A single and extremely fast XRR measurement can deliver thickness, density and roughness information on a multi-layer stack of diffusion barrier and Cu seed, as well as their interfacial layers.
Ultra thin diffusion barrier materials like this 20 Å ALD TaN can be quickly and accurately measured by the Jordan Valley systems.