Thompson Keith, Flaitz Philip L, Ronsheim Paul, Larson David J, Kelly Thomas F
Imago Scientific Instruments Corporation, 5500 Nobel Drive, Madison, WI 53711, USA.
Science. 2007 Sep 7;317(5843):1370-4. doi: 10.1126/science.1145428.
Discrete control of individual dopant or impurity atoms is critical to the electrical characteristics and fabrication of silicon nanodevices. The unavoidable introduction of defects into silicon during the implantation process may prevent the uniform distribution of dopant atoms. Cottrell atmospheres are one such nonuniformity and occur when interstitial atoms interact with dislocations, pinning the dislocation and trapping the interstitial. Atom probe tomography has been used to quantify the location and elemental identity of the atoms proximate to defects in silicon. We found that Cottrell atmospheres of arsenic atoms form around defects after ion implantation and annealing. Furthermore, these atmospheres persist in surrounding dislocation loops even after considerable thermal treatment. If not properly accommodated, these atmospheres create dopant fluctuations that ultimately limit the scalability of silicon devices.
对单个掺杂剂或杂质原子进行离散控制对于硅纳米器件的电学特性和制造至关重要。在注入过程中不可避免地会在硅中引入缺陷，这可能会阻止掺杂原子的均匀分布。科垂尔气团就是这样一种不均匀性，当间隙原子与位错相互作用时就会出现，使位错固定并俘获间隙原子。原子探针断层扫描已被用于量化硅中缺陷附近原子的位置和元素特性。我们发现，离子注入和退火后，砷原子的科垂尔气团在缺陷周围形成。此外，即使经过大量热处理，这些气团仍存在于周围的位错环中。如果不能妥善处理，这些气团会产生掺杂剂波动，最终限制硅器件的可扩展性。
