Parallel Auger Spectroscopy with the Hyperbolic Field Analyser

Extract

The analysis of Auger and other excited electrons in the energy range from about 50eV to 2500eV provides a nearly non-destructive means to determine the surface composition of materials. It is both highly surface sensitive (a few atomic monolayers) and capable of high spatial resolution. This makes it an attractive alternative to energy dispersive x-ray analysis for the examination of ever smaller structures such as in semiconductor devices. For many applications however one important drawback has been the relatively long time required to make useful measurements - usually many seconds or minutes. Spectrum-imaging, in which an entire spectrum is acquired for each pixel in a digital scanned image, is one example for which Auger, spectroscopy becomes a prohibitively lengthy process. Similarly, the study of electron beam sensitive materials is difficult because the measurement time is often longer than the damage time. One method of reducing the measurement time is by acquiring the whole energy spectrum of interest in parallel. This is achieved with the Hyperbolic Field Analyser. (In electron energy loss spectroscopy this approach has lead to the highly successful Gatan energy filter.)