E. Ramsay, K. A. Serrels, M. J. Thomson, A. J. Waddie, R. J. Warburton, M. R. Taghizadeh, D. T. Reid, Heriot-Watt University, Edinburgh, United Kingdom

Summary: We have achieved three-dimensional imaging inside a silicon flip chip by implementing two-photon optical-beam-induced-current microscopy using a solid-immersion lens at a wavelength of 1530nm. This technique allows diffraction-limited lateral resolution of 166nm and an axial resolution capable of resolving features only 100nm in height.