Ultra-low temperature synthesis of Ge-based optical materials and devices on Si using GeH 3 Cl
Ultra-low temperature synthesis of Ge-based optical materials and devices on Si using GeH 3 Cl
复制标题
使用GeH 3 Cl在Si上超低温合成Ge基光学材料和器件
DOI：
10.1039/d2tc02862j
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发表时间：
2022
影响因子：
6.4
通讯作者：
Kouvetakis, John
中科院分区：
文献类型：
--
作者：
Zhang, Aixin;Mircovich, Matthew A.;Ringwala, Dhruve A.;Poweleit, Christian D.;Roldan, Manuel A.;Menéndez, José;Kouvetakis, John
我们描述了一种替代策略，通过使用氯锗烷（GeH 3Cl）代替目前用作超低温Ge源的特种Ge卤化物（Ge 2 H6，Ge 3 H8，Ge 4 H10），在Si上制造Ge-Sn基材料。这种更简单且可能更实用的氯化衍生物通过商业GeH 4和SnCl 4的直接反应以高产率和研究级纯度获得，并且表现出有利的物理和化学性质，使其成为广泛的化学气相沉积（CVD）处理条件下的Ge的有效来源。作为概念验证，我们使用GeH 3Cl来演示在大面积Si晶片上沉积纯Ge和GeSn异质结构，其条件与下一代技术的当前专业方法兼容，但具有更高的沉积效率，确保Ge原料的最佳使用。在纯Ge的情况下，GeH 3Cl使得能够在330-360 °C下生长具有平坦表面和弛豫微结构的厚且均匀的Ge层，表现出比通过交替的Ge氢化物方法获得的更低的残留掺杂。GeH 3Cl允许在原位掺杂与相同的设施，作为锗硅，这使得设计和制造的同质结构的针光电探测器表现出低暗电流密度和更接近理想的光收集效率相比，由其他锗硅方法生产的设备。在GeSn的情况下，GeH 3Cl对Sn的高反应性使得能够在200-300 °C之间的超低温和类似于分子束外延（MBE）的条件下形成单晶合金层。结合起来，这些结果表明这种新的CVD工艺在设备应用领域具有诱人的潜力。GeH 3Cl作为高反应性低温Ge源的部署不仅可以改善目前使用GeH 4的浪费方法，而且还可以消除对更高成本的多锗烷的需求。
We describe an alternative strategy to the fabrication of Ge–Sn based materials on Si by using chlorogermane (GeH3Cl) instead of the specialty Ge hydrides (Ge2H6, Ge3H8, Ge4H10) currently employed as ultra-low temperature sources of Ge. This simpler and potentially more practical chlorinated derivative is obtained in high yields and in research-grade purity by direct reactions of commercial GeH4 and SnCl4 and exhibits favorable physical and chemical properties that make it an effective source of Ge for a wide range of chemical vapor deposition (CVD) processing conditions. As a proof-of concept, we have employed GeH3Cl to demonstrate deposition of pure Ge and GeSn hetero-structures on large-area Si wafers, at conditions compatible with current specialty methods for next generation technologies but with higher deposition efficiency, ensuring an optimal use of the Ge feedstock. In the case of pure Ge, GeH3Cl has enabled growth of thick and uniform Ge layers with flat surfaces and relaxed microstructures at 330–360 °C, exhibiting lower residual doping than obtained by alternate Ge hydride methods. GeH3Cl allows for in situ doping with the same facility as the Ge hydrides, and this has enabled the design and fabrication of homo-structure pin photodetectors exhibiting low dark current densities and closer to ideal optical collection efficiencies when compared to devices produced by other Ge-on-Si approaches. In the case of GeSn, the high reactivity of GeH3Cl toward Sn hydrides has enabled the formation of mono-crystalline alloy layers at ultra-low temperatures between 200–300 °C and conditions akin to molecular beam epitaxy (MBE). Combined, these results suggest an intriguing potential for this new CVD process in the device-application space. The deployment of GeH3Cl as a highly reactive low-temperature Ge-source could not only improve on the current wasteful methods that use GeH4, but also eliminate the need for the higher-cost polygermanes.