PROBING DEEPER WITH EPMA AND FIB: POSSIBILITIES AND LIMITS

摘要

Electron probe microanalysis (EPMA) is a well-established method in microbeam and thin film analysis. Mass coverages of elements in thin layers can be determined with high accuracy and sensitivity [Ammann N, Lubig A and Karduck P (1992) Mikrochim. Acta Supplm. 12 213-219]. Furthermore, the low detection limits of the wavelength-dispersive X-ray technique allow the detection of element specific mass coverages down to 0.01 μg/cm~2. The advantage of the focussed ion beam (FIB) system is the controlled surface removal using a focussed Ga ion beam. With these advantages in mind, the combined technique FIB and EPMA was extended to depth profile analysis on the nanometre scale [Richter S, Lesch N and Karduck P (1998) Mikrochim. Acta Supplm. 15 125-131; Richter S, et al. (2006) Mikrochim. Acta 155 257-262]. In the present paper, the possibilities and limits of FIB-EPMA are discussed with regard to depth resolution, sensitivity of concentration gradients and deconvolution algorithm.