Abstract Due to the increasing complexity of FET structures and the preferred high trench aspect ratios, demanding process challenges exist, not only in the structuring of the contact trenches, but also in the uniform doping of the diffusion area. Previous investigations have mainly analyzed the doping of horizontal contact areas. For this reason, this paper demonstrates how vertical and horizontal contact areas can be doped through the side wall at the same time. For this purpose, relationships between structural geometry and doping methods are studied in order to structure a multitude of contact trenches next to each other in a functional way, which can realize source and drain trenches. By means of an ion implanted test structure, high doping concentrations of up to 10 19 cm − 3 could be achieved at a depth of approx. 250 nm below the 2.5 μm deep contact trench bottom. The concentration which can be obtained by PSG diffusion decreases rapidly with increasing Si depth. For the first time, it is shown that the dopant particle concentration of ion implantation increases with trench height and proximity to the trench side wall. Accordingly, the electrical conductivity is also higher and the SR value lower. A positive effect of the near-surface doping concentrations on the subsequent C 49 - TiSi 2 formation could be demonstrated, which enables uniform film growth. In contrast, dopant deposition generates asymmetric dopant concentrations and prevents uniform silicide formation as the aspect ratio increases, thus causing higher diffusion area resistances.

中文翻译：

---

Si(100)掺杂方法对纵横比增加的垂直和水平FET结构区域中TiSi2形成的影响

摘要 由于 FET 结构的日益复杂和首选的高沟槽纵横比，不仅在接触沟槽的结构化方面，而且在扩散区的均匀掺杂方面都存在着苛刻的工艺挑战。以往的研究主要分析了水平接触区的掺杂。为此，本文展示了如何同时通过侧壁掺杂垂直和水平接触区域。为此，研究了结构几何形状和掺杂方法之间的关系，以便以功能方式构造多个彼此相邻的接触沟槽，从而实现源极和漏极沟槽。通过离子注入测试结构，可以在大约 10 米的深度处实现高达 10 19 cm - 3 的高掺杂浓度。250 纳米以下。5 μm 深的接触沟槽底部。PSG 扩散可以获得的浓度随着 Si 深度的增加而迅速降低。首次表明，离子注入的掺杂粒子浓度随着沟槽高度和靠近沟槽侧壁的程度而增加。因此，电导率也较高且SR值较低。可以证明近表面掺杂浓度对随后的 C 49 - TiSi 2 形成的积极影响，这能够实现均匀的膜生长。相反，随着纵横比的增加，掺杂剂沉积会产生不对称的掺杂剂浓度并阻止均匀的硅化物形成，从而导致更高的扩散区电阻。首次表明，离子注入的掺杂粒子浓度随着沟槽高度和靠近沟槽侧壁的程度而增加。因此，电导率也较高且SR值较低。可以证明近表面掺杂浓度对随后的 C 49 - TiSi 2 形成的积极影响，这能够实现均匀的膜生长。相反，随着纵横比的增加，掺杂剂沉积会产生不对称的掺杂剂浓度并阻止均匀的硅化物形成，从而导致更高的扩散区电阻。首次表明，离子注入的掺杂粒子浓度随着沟槽高度和靠近沟槽侧壁的程度而增加。因此，电导率也较高且SR值较低。可以证明近表面掺杂浓度对随后的 C 49 - TiSi 2 形成的积极影响，这能够实现均匀的膜生长。相反，随着纵横比的增加，掺杂剂沉积会产生不对称的掺杂剂浓度并阻止均匀的硅化物形成，从而导致更高的扩散区电阻。可以证明近表面掺杂浓度对随后的 C 49 - TiSi 2 形成的积极影响，这能够实现均匀的膜生长。相反，随着纵横比的增加，掺杂剂沉积会产生不对称的掺杂剂浓度并阻止均匀的硅化物形成，从而导致更高的扩散区电阻。可以证明近表面掺杂浓度对随后的 C 49 - TiSi 2 形成的积极影响，这能够实现均匀的膜生长。相反，随着纵横比的增加，掺杂剂沉积会产生不对称的掺杂剂浓度并阻止均匀的硅化物形成，从而导致更高的扩散区电阻。