School of Chemistry, and Tyndall National Institute, University College Cork , Cork, T12 YN60 Ireland.
CRANN@AMBER, Trinity College Dublin , Dublin 2, Ireland.
ACS Appl Mater Interfaces. 2018 Jan 17;10(2):2191-2201. doi: 10.1021/acsami.7b16950. Epub 2018 Jan 4.
Monolayer doping (MLD) involves the functionalization of semiconductor surfaces followed by an annealing step to diffuse the dopant into the substrate. We report an alternative doping method, oxide-MLD, where ultrathin SiO overlayers are functionalized with phosphonic acids for doping Si. Similar peak carrier concentrations were achieved when compared with hydrosilylated surfaces (∼2 × 10 atoms/cm). Oxide-MLD offers several advantages over conventional MLD, such as ease of sample processing, superior ambient stability, and minimal carbon contamination. The incorporation of an oxide layer minimizes carbon contamination by facilitating attachment of carbon-free precursors or by impeding carbon diffusion. The oxide-MLD strategy allows selection of many inexpensive precursors and therefore allows application to both p- and n-doping. The phosphonic acid-functionalized SiO surfaces were investigated using X-ray photoelectron spectroscopy and attenuated total reflectance Fourier transform infrared spectroscopy, whereas doping was assessed using electrochemical capacitance voltage and Hall measurements.
单层掺杂（MLD）涉及半导体表面的功能化，然后进行退火步骤以使掺杂剂扩散到衬底中。我们报告了一种替代的掺杂方法，即氧化物-MLD，其中超薄膜 SiO 覆盖层用膦酸官能化以掺杂 Si。与氢化硅表面相比，实现了相似的峰值载流子浓度（约 2×10 原子/cm）。氧化物-MLD 相对于传统 MLD 具有几个优势，例如易于处理样品、优异的环境稳定性和最小的碳污染。氧化物层的掺入通过促进无碳前体的附着或阻碍碳扩散来最小化碳污染。氧化物-MLD 策略允许选择许多廉价的前体，因此允许应用于 p 型和 n 型掺杂。使用 X 射线光电子能谱和衰减全反射傅里叶变换红外光谱研究了膦酸官能化的 SiO 表面，而电化学电容电压和 Hall 测量评估了掺杂。
