SBIR PHASE I: Self-Patterning Process for Conductive Oxide Contacts for Ferroelectric Thin Film Memory Devices

这个小企业创新研究（SBIR）第一阶段项目将开发一种沉积和图像化RuO2触点的新工艺，用于铁电薄膜电容器存储设备，如非易失性存储器（nvram）和超高密度动态随机存取存储器（dram）。RuO2与PZT （PbZr1-xTixO3）等铁电薄膜形成良好的接触；与具有金属触点（如Pt）的PZT器件相比，这导致了更低的疲劳，更好的I-V特性和改进的时间相关击穿特性。然而，缺乏方便的加工技术阻碍了RuO2触点在实际器件中的实现。新工艺包含两个关键的创新：首先，RuO2薄膜将通过自旋工艺作为金属有机前体沉积，并在烧制前通过湿化学方法进行图案化。这将实现比等离子体蚀刻更简单、破坏性更小、成本更低的工艺，等离子体蚀刻是目前唯一用于RuO2图像化的方法。第二，金属有机前驱体将具有光化学交联的有机基团。该工艺将允许导电氧化物触点的光刻图案化，而不需要使用单独的抗蚀剂，从而节省了工艺步骤。第一阶段将开发具有能够紫外交联的有机取代基的RuO2的可溶性前驱体，通过自旋工艺将这些材料沉积在衬底上，演示光刻图案，并评估烧制的RuO2接触的质量。这一发展将使先进的铁电薄膜器件的实际制造与目前的先进技术相比具有优越的性能。拟议技术的商业应用包括智能卡和寻呼机的非易失性存储器，以及计算机应用的千兆级dram。

9561650 Rice This Small Business Innovation Research (SBIR) Phase I project will develop a new process for depositing and patterning RuO2 contacts for use in ferroelectric thin film capacitor memory devices such as non-volatile memories (NVRAMs) and ultra-high density dynamic random access memories (DRAMs). RuO2 has been shown to form a good contact with ferroelectric films such as PZT (PbZr1-xTixO3); this leads to substantially lower fatigue, better I-V characteristics, and improved time-dependent breakdown properties compared to PZT devices having metal contacts such as Pt. However, the lack of a convenient processing technology has impeded the implementation of RuO2 contacts in practical devices. The new process incorporates two key innovations: first, the RuO2 films will be deposited as metallorganic precursors by a spin-on process, and patterned by wet chemical methods before firing. This will enable a simpler, less damaging, and less expensive process than plasma etching, which is the only current method in use for patterning RuO2. Second, the metallorganic precursor will possess organic groups which are photochemical crosslinkable. The process will allow photolithographic patterning of the conductive oxide contact without requiring the use of a separate resist, thus saving process steps. Phase I will develop soluble precursors to RuO2 having organic substituents capable of UV crosslinking, deposit these materials on substrates by a spin-on process, demonstrate photolithographic patterning, and assess the quality of fired RuO2 contacts. This development will enable the practical fabrication of advanced ferroelectric thin film devices with superior performance compared to the current state-of-the-art. Commercial applications of the proposed technology include non-volatile memories for smart cards and pagers, and gigabit-scale DRAMs for computer applications.