Background: With continuous decrease in the technology node of dynamic random access memories (DRAMs) down to sub-20 nm, the self-aligned double patterning (SADP) is an effective approach to generate two-dimensional (2-D) patterns, particularly contact arrays. Aim: We demonstrate a patterning scheme using the SADP technique to produce active trim contacts with anisotropic pattern pitches. Approach: The proposed scheme uses two consecutive spacer-formation processes. Results: By making the ellipsoidal core pillars and minimizing the spacer thickness, 2-D critical dimensions (CDs) for self-generated contacts match well with those for core contacts. In addition, an interesting cross-dependence of X -CD and Y -CD variations for the core and self-generated contacts is observed. Conclusion: This patterning approach is useful for forming active trim contacts in sub-20 nm DRAMs using fewer numbers of ArF immersion photolithography steps.

中文翻译：

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亚 20 nm 动态随机存取存储器中具有各向异性图案间距的有源微调触点的自对准双图案化

背景：随着动态随机存取存储器 (DRAM) 技术节点不断降低到亚 20 nm，自对准双图案 (SADP) 是生成二维 (2-D) 图案的有效方法，特别是接触阵列。目的：我们展示了一种使用 SADP 技术的图案化方案，以产生具有各向异性图案间距的有源装饰触点。方法：所提出的方案使用两个连续的间隔物形成过程。结果：通过制作椭圆形核心柱并最小化隔离层厚度，自生触点的二维临界尺寸 (CD) 与核心触点的二维临界尺寸 (CD) 非常匹配。此外，观察到核心和自生接触的 X -CD 和 Y -CD 变化的有趣的交叉依赖性。结论：