The Effect of Moore&s Law on the Growing Role of Transmission Electron Microscopy in the Semiconductor Industry

Abstract

TEM has been used for semiconductor device characterization since the 1980's, when Marcus and Cheng first demonstrated the feasibility and utility of applying TEM to semiconductors. The frequency of use of TEM has accelerated briskly due to the continual shrinkage of devices as predicted by Gordon Moore and now documented in the SIA roadmap (http://public.itrs.net/Home.htm). TEM use has also grown due to application of FIB techniques which make possible high precision cross-sections of specific structures. This relentless shrinking has resulted in difficulties in preparing suitable specimens. Many of the features and interfaces in a device may be curved rather than planar, and as the radius of curvature begins to approach the thickness of a TEM specimen, it can result in “geometrical blurring” of features, both for imaging and microanalysis. The origin of this blurring is illustrated in Figure 1, where it can be seen that a single electron may pass through two different features, and as a result, they are not resolved.