Potential and Limitations of Electron Holography in Silicon Research
We report on electron holography as a promising candidate for diagnostics in silicon technology and research. Electron holography determines the local phase shift of the electron wave passing through a sample. The phase is proportional to the 2D projected electrostatic potential in the sample and thus reveals p-n junctions and, indirectly, doping. We demonstrate detection of submonolayer boron layers in Si and SiGe, measurement of Ge concentration in SiGe and qualitative 2D oxygen mapping in SiO2/Si structures with 0.5 nm resolution, and comparison of doping in two bipolar transistors with different base implant. Resolution and noise limits are discussed.
B. Pichaud, A. Claverie, D. Alquier, H. Richter and M. Kittler
P. Formanek and M. Kittler, "Potential and Limitations of Electron Holography in Silicon Research", Solid State Phenomena, Vols. 108-109, pp. 603-608, 2005