Chalcogenide compounds are leading a revolution in the electronic memories space. Phase-change-memory (PCM) elements and ovonic threshold switches (OTSs) combined in the cross-point (X-point) architecture produce memory arrays with access and write times orders of magnitude faster than state-of-the-art flash nands and also provide nonvolatile storage, a larger scale of integration compared to traditional memory arrays, and the opportunity to develop beyond von Neumann architectures to support computationally demanding applications such as artificial intelligence. The commercial success of chalcogenide X-point arrays will depend on the ability to integrate chalcogenide films into sophisticated three-dimensional architectures such as vertical structures for economical manufacturing. To do so, highly conformal deposition techniques are required such as atomic layer deposition (ALD). State-of-the-art chalcogenide cross-point devices are currently fabricated using PVD, which fails to provide any film conformality. ALD PCMs with performance comparable to their PVD counterparts have been demonstrated; however, fabricating OTS selectors using ALD remains a challenge. Here, we present an approach to deposit ALD ternary germanium-selenium-tellurium (Ge-Se-Te) spanning a wide range of compositions. The ALD Ge-Se-Te films show excellent conformality, low surface roughness, and good compositional homogeneity. We fabricated OTS devices and demonstrated the ability to produce low leakage selectors with threshold voltage tuning achieved by control over the film composition.

中文翻译：

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锗-硒-碲化合物的原子层沉积，用于低泄漏的可调电子阈值开关

硫族化物化合物正在引领电子存储领域的一场革命。交叉点（X点）体系结构相结合的相变存储器（PCM）元件和电子阈值开关（OTS）产生的存储器阵列的存取时间比最先进的闪存nand快几个数量级并提供非易失性存储，与传统存储阵列相比更大的集成度，并有机会超越冯·诺依曼（von Neumann）架构进行开发，以支持诸如人工智能等对计算有严格要求的应用程序。硫族化物X点阵列的商业成功将取决于将硫族化物膜集成到复杂的三维结构（例如用于经济制造的垂直结构）中的能力。为此，需要高度保形的沉积技术，例如原子层沉积（ALD）。目前，最先进的硫族化物交叉点器件是使用PVD制造的，无法提供任何薄膜保形性。ALD PCM具有与PVD同类产品相当的性能。然而，使用ALD制造OTS选择器仍然是一个挑战。在这里，我们提出了一种沉积跨越多种成分的ALD三元锗-硒-碲（Ge-Se-Te）的方法。ALD Ge-Se-Te膜显示出极好的保形性，低的表面粗糙度和良好的组成均匀性。我们制造了OTS器件，并展示了通过控制薄膜成分实现阈值电压调整的低泄漏选择器生产能力。