Rate Enhancement and Microstructure Control of Copper CVD Processes

化学气相沉积（CVD）铜薄膜作为未来几代深亚微米集成电路互连金属化的潜在技术正在被研究。随着互连线宽的减小和时钟频率的增加，片上电阻-电容时间延迟成为实现高电路速度的主要限制。更小的线宽也会导致更高的电流密度，这引起了人们对可靠性问题的担忧，例如电迁移和应力诱导的空隙形成。与铝相比，铜具有几个固有的性能优势，铝是目前金属化的首选材料。这包括更低的电阻率，更好的电迁移电阻，以及更强的抗应力致空性。本项目是一个跨学科、多研究者的实验和理论研究相结合的项目，旨在进一步开发用于ULSI器件金属化的化学气相沉积铜薄膜所需的工艺技术。本研究旨在对基于Cu（II）还原化学的沉积过程的反应机制进行基本的定量理解。通过研究这组反应，PI将探索Cu(I)歧化过程的替代方法。后一种工艺中使用的Cu(I)反应物的较高反应性可能最终导致薄膜成核和晶粒尺寸控制的问题，因为微电子工业正逐步向更高的通孔填充物长宽比发展。双（β -二酮酸）还原化学也可以为其他金属的CVD提供更通用的途径（即，挥发性β -二酮酸化合物存在于大多数过渡金属中，而歧化途径基本上是铜所特有的）。

Abstract - Griffin - 9612157 Chemical vapor deposition (CVD) of copper thin films is being studied as a potential technology for interconnect metallization in future generations of deep sub-micron integrated circuits. As interconnect linewidths decrease and clock frequencies increase, the on-chip resistance-capacitance time delays become the major limitation in achieving high circuit speed. Smaller linewidths also lead to higher current densities, which raises concern about reliability issues such as electromigrations and stress-induced void formation. Copper offers several intrinsic property advantages over aluminum, the current material of choice for metallization. These include lower resistivity, improved electromigration resistance, and increased resistance to stress-induced voidage. This project is an inter-disciplinary, multi-investigator program of combined experimental and theoretical research aimed at further developing the process technology needed for the chemical vapor deposition of copper thin films for ULSI device metallization. This research is aimed at developing a fundamental, quantitative understanding of the reaction mechanism for deposition processes based on Cu(II) reduction chemistry. By studying this group of reactions, the PI s will be exploring an alternative to the Cu(I) disproportionation process. The higher reactivity of the Cu(I) reactants used for the latter process may eventually lead to problems with film nucleation and grain size control, as the microelectronics industry moves progressively toward higher aspect ratios for via fills. The bis(beta-diketonate) reduction chemistry can also provide a more versatile pathway for CVD of other metals (i.e., volatile beta-diketonate compounds exist for most transition metals, while the disproportionation pathway is essentially unique to copper).