Univ. Grenoble Alpes, CEA, LETI , MINATEC Campus, F-38000 Grenoble, France.
C2P2, CPE Lyon , 43 Bd du 11 Nov. 1918, 69616 Villeurbanne cedex, France.
ACS Appl Mater Interfaces. 2017 Jun 14;9(23):20179-20187. doi: 10.1021/acsami.7b02645. Epub 2017 Jun 5.
Functionalization of Ge surfaces with the aim of incorporating specific dopant atoms to form high-quality junctions is of particular importance for the development of solid-state devices. In this study, we report the shallow doping of Ge wafers with a monolayer doping strategy that is based on the controlled grafting of Sb precursors and the subsequent diffusion of Sb into the wafer upon annealing. We also highlight the key role of citric acid in passivating the surface before its reaction with the Sb precursors and the benefit of a protective SiO overlayer that enables an efficient incorporation of Sb dopants with a concentration higher than 10 cm. Microscopic four-point probe measurements and photoconductivity experiments show the full electrical activation of the Sb dopants, giving rise to the formation of an n++ Sb-doped layer and an enhanced local field-effect passivation at the surface of the Ge wafer.
用功能化的 Ge 表面来掺入特定的掺杂原子，以形成高质量的结，这对于开发固态器件是特别重要的。在这项研究中，我们报告了 Ge 晶片的浅掺杂，这是一种基于 Sb 前体的控制接枝，以及随后在退火时 Sb 向晶片扩散的单层掺杂策略。我们还强调了在 Sb 前体与其反应之前柠檬酸在钝化表面方面的关键作用，以及保护性 SiO 覆盖层的好处，它可以有效地掺入浓度高于 10 cm 的 Sb 掺杂剂。微观四点探针测量和光电导实验表明 Sb 掺杂剂的完全电激活，导致 n++ Sb 掺杂层的形成和 Ge 晶片表面的局部场效应钝化增强。
