高纯度钛的应用与制备研究进展

Advancements in the Application and Fabrication Research of High-purity Titanium

纯度不低于4N的高纯钛是集成电路制造所用钛靶材的关键原料,半导体器件的特征尺寸不断减小,不仅对高纯钛的纯度提出了更高的要求,还要求高纯钛必须有极低的氧含量。然而,钛极高的化学活性和吸氧能力限制了高纯低氧钛的稳定、低成本生产。目前,针对钛的这一独特性质,人们往往联合使用多种提纯方法进行高纯钛的工业化生产,并对各种提纯方法中可能引入杂质的种类及途径进行了深入研究,以期最大程度地去除钛中的各种杂质,实现高纯低氧钛的规模化稳定生产。本文对高纯钛工业化生产所涉及的主要方法——Kroll(克罗尔)法、熔盐电解法、碘化法和电子束熔炼法,以及这些方法中涉及到的重要钛卤化物的制备、提纯方法进行了综述,最后对这些主要生产方法进行了分析对比,指出了碘化法在高纯低氧钛工业化生产上的优势和亟待解决的问题。

High-purity titanium with a purity of no less than 4N is a critical raw material for titanium target materials used in integrated circuit manufacturing.The shrinking feature sizes of semiconductor devices impose higher requirements not only on the purity of high-purity titanium but also on its extremely low oxygen content.However,the high chemical reactivity and oxygen affinity of titanium pose challenges to the stable and cost-effective production of high-purity,low-oxygen titanium.To address this unique property of titanium,various purification methods are often combined for industrial-scale production of high-purity titanium,and extensive research has been conducted on the types and pathways of impurities introduced by different purification methods,aiming to remove various impurities from titanium to achieve stable production of high-purity,low-oxygen titanium.This paper discusses the main methods involved in its industrial production,including the Kroll process,molten salt electrolysis,iodide process,and electron beam melting.The preparation and purification methods of important titanium halides involved in these methods are summarized.Finally,a comparative analysis of these main production methods is conducted,highlighting the advantages and challenges of the iodide process in the industrial production of high-purity,low-oxygen titanium.