The investigation of boron-doped silicon using atom probe tomography

摘要

Three-dimensional atom-probe (3DAP) is the only analytical microscope able to map out the distribution of elements in 3D at the atomic scale. 3DAP provides quantitative measurements of local chemical composition in a small selected volume. A new generation of instrument, namely, a laser assisted tomographic atom probe (laser assisted wide angle atom probe LaWaTAP) has recently been designed in order to open the instrument to bad electric conductors. The use of ultra-fast laser pulses rather than of high-voltage pulses to field evaporate surface atoms makes the analysis of semiconductors or oxides that are key materials in microelectronics possible. This article is focussed on methodology and applications to boron-doped silicon. Depth profiles related to boron in various samples (boron deltas, SiGe Maya layers, boron-implanted silicon, ...) will be discussed and compared to SIMS results. Spatial resolution and sensitivities will be compared.