We report the lowering of the formation temperature of spherical-shaped Ge quantum dots (QDs) to 850 °C from our previously-reported 900 °C. This large reduction in QD formation temperature was achieved via the use of a hydrogenated, plasma-enhanced chemical-vapor deposited (PECVD) silicon nitride (SiN). The exquisite interplay between H, Ge, Si and O interstitials, controlling QD formation during the thermal oxidation of poly-SiGe layers deposited over PECVD-Si x N y : H, is further explored in order to understand the underlying mechanisms. We have experimentally observed that the high hydrogen content of the PECVD-Si x N y : H facilitates the lower-temperature (850 °C) oxidation of the nitride layer, while simultaneously being able to generate smaller diameter, fully coalesced Ge QDs within. Such heterostructures of SiN coupled-Ge QDs are a fundamental building block for the ultimate fabrication of active SiN-based Ge photonic devices.

中文翻译：

---

氮化硅工程：氢键在Ge量子点形成中的作用

我们报告了球形Ge量子点（QDs）的形成温度从我们先前报告的900°C降低到850°C。通过使用氢化的等离子体增强化学气相沉积（PECVD）氮化硅（SiN），可以实现QD形成温度的大幅降低。为了了解潜在的机理，进一步探索了H，Ge，Si和O间隙之间的相互作用，以控制在PECVD-Si x N y：H上沉积的多晶SiGe层的热氧化过程中QD的形成。我们已经通过实验观察到，PECVD-Si x N y：H的高氢含量促进了氮化物层的低温（850°C）氧化，同时能够在其中生成更小直径，完全聚结的Ge QD。