GOALI: Photoresist Dissolution and Stripping in Gas Expanded Liquids

Hess, Dennis W. / GA Tech Res Corp - GITCarter, Melvin K. /杜邦电子技术公司“目标：气体膨胀液体中的光刻胶溶解和剥离”最先进的集成电路（IC）制造工艺需要超过25个图案或光刻步骤。在图案形成后，控制、有效地去除光刻胶（PR）和相关的蚀刻残留物/污染物对于实现具有高器件良率和可靠性的成功制造工艺至关重要。PR/残留物的去除目前是通过等离子体工艺进行的，然后使用对环境有害的腐蚀性化学处理和广泛的去离子水（DIW）冲洗。这种方法使用大量的化学品和有害化学物质，因此对环境有害。气胀液（gel）代表了广泛用于集成电路制造的传统液相工艺的一个有前途的替代方案。凝胶在分离和反应工程中的研究表明，这些流体也可以在微电子工艺技术中提供许多好处。特别感兴趣的凝胶包括用二氧化碳和用于微电子器件制造的常规溶剂（例如醇）配制的凝胶。凝胶具有优异的质量传输性能，同时保持了PR和蚀刻残留物去除所需的溶剂能力。此外，使用凝胶去除有机膜和污染物的环境效益可能是巨大的。最后，由于凝胶地层所需的压力明显低于超临界流体（SCF）技术所需的压力，因此相对于超临界流体技术，凝胶地层的能源需求和危害将会降低。一个基于质量传输的模型用来描述凝胶中薄膜的溶解，表明凝胶在几个方面可能优于传统液体。例如，相对于纯液体，凝胶中的溶解速率可增加多达50%。此外，在PR去除过程中消耗的溶剂量可能会大大减少。提出的研究将通过实验调查这些模型的准确性，并确定大规模工业过程是否可行。研究将进行解决基本的物理和化学的相互作用，导致膨胀和溶解的有机薄膜在凝胶。与杜邦ekc（一家为IC行业提供抗蚀剂和残留物去除的湿化学配方的制造商和供应商）共同努力，将允许识别、配方和研究能够在IC制造中实施的凝胶。结合凝胶与表面和薄膜相互作用的基础研究（佐治亚理工学院），在原型商业反应器（EKC）中去除8英寸晶圆上的薄膜/残留物，重新配方/设计用于去除抗蚀剂/残留物（EKC）的商业溶剂混合物，以及对这些新型凝胶的基本特性的研究（佐治亚理工学院）将确保将基础研究与直接应用于未来几代集成电路的制造操作联系起来。更广泛的影响：拟议的研究将导致未来集成电路制造中更环保工艺的发展。在实验室设施和微电子处理专业知识方面，赫斯教授的小组装备精良，可以进行这项研究。这项工作将建立凝胶的性质及其与PR层的相互作用之间的关系；这些结果将为集成电路工艺工程中使用凝胶的表面清洁和制备提供基本的理解，而EKC将确保将这些知识转化为制造专业知识。该研究项目是化学工程研究生的理想选择，因为实验工作与基础热力学和动力学研究相结合；与EKC的合作将使学生能够直接与IC行业的化学配方供应商合作。该项目将带来：(1)通过开发新颖的、更环保的清洁和表面制备工艺，改进集成电路制造的技术、环境问题、安全性和经济性；(2)提供有关凝胶与聚合物材料相互作用的分子水平信息；(3)开发集成电路和环境领域的新例子/案例研究，将其纳入核心本科和研究生ChE课程。(4)每年夏天培训参加佐治亚理工学院暑期本科生工程研究项目（SURE）的少数民族本科生；(5)对高中学生和教师进行集成电路制造和环境问题的教育。

Hess, Dennis W. / GA Tech Res Corp - GITCarter, Melvin K. / DuPont Electronic Technologies "GOALI: Photoresist Dissolution and Stripping in Gas-Expanded Liquids"State-of-the-art integrated circuit (IC) fabrication processes require more than 25 patterning or photolithography steps. Controlled, effective removal of photoresist (PR) and associated etch residues/contaminants after pattern formation is critical to achieve successful manufacturing processes with high device yield and reliability. PR/residue removal is currently performed by plasma processes followed by the use of environmentally hazardous, corrosive chemical treatments and extensive deionized water (DIW) rinses. Such approaches use large quantities of chemicals and DIW and thus are environmentally harmful.Gas-expanded liquids (GELs) represent a promising alternative to the traditional liquid-phase processes used extensively in the fabrication of ICs. Research with GELs in separations and reaction engineering suggests that these fluids may also offer numerous benefits in microelectronics process technology. GELs of particular interest include those formulated with carbon dioxide and conventional solvents (e.g., alcohols) used in microelectronic device fabrication. GELs have superior mass-transport properties while maintaining the solvent ability necessary for PR and etch residue removal. In addition, environmental benefits associated with organic film and contaminant removal using GELs may be substantial. Finally, since the pressures needed for GEL formation are significantly lower than those required to implement supercritical fluid (SCF) technology, energy requirements and hazards associated with GELs will be reduced relative to SCFs.A mass transport-based model formulated to describe the dissolution of films in GELs suggests that GELs may be superior to traditional liquids in several respects. For instance, dissolution rates can be increased by as much as 50% in a GEL relative to a pure liquid. Furthermore, the amount of solvent consumed in a PR removal process may be significantly reduced. The proposed research will experimentally investigate the accuracy of these models and establish if large-scale industrial processes are feasible. Investigations will be performed to address the fundamental physical and chemical interactions causing swelling and dissolution of organic films in GELs. Joint efforts with Dupont-EKC, a manufacturer and supplier of wet chemical formulations to the IC industry for resist and residue removal will permit the identification, formulation, and investigation of GELs capable of implementation into IC manufacturing.The combination of fundamental investigations of GEL interactions with surfaces and films (Georgia Tech), removal of films/residues on 8-inch wafers in a prototype commercial reactor (EKC), reformulation/design of commercial solvent mixtures expressly for the purpose of resist/residue removal (EKC), and investigation of the fundamental properties of these new GELs (Georgia Tech) will ensure the connection of fundamental studies with direct application to manufacturing operations for future generations of ICs. Broader Impacts:The proposed research will lead to the development of more environmentally benign processes for the fabrication of future ICs. Professor Hess' group is well equipped to perform this research, with regard to laboratory facilities and microelectronics processing expertise. This work will establish relationships between the properties of GELs and their interaction with PR layers; such results will supply a fundamental understanding of surface cleaning and preparation using GELs in IC process engineering, while EKC will ensure the transfer of this knowledge into manufacturing expertise. The proposed research project is ideal for chemical engineering graduate students in that experimental work is combined with fundamental thermodynamic and kinetics studies; the joint effort with EKC will allow students to work directly with a supplier of chemical formulations to the IC industry. The project will result in: (1) improved technology, environmental concerns, safety, and economics in IC fabrication by developing novel, more environmentally benign cleaning and surface preparation processes, (2) provide molecular level information concerning the interaction of GELs with polymer materials, (3) development of novel examples/case studies in the IC and environmental areas to be incorporated into core undergraduate and graduate ChE courses, (4) train minority undergraduate students each summer who are participants in the Georgia Tech Summer Undergraduate Research in Engineering Program (SURE), (5) educate high school students and teachers in IC fabrication and environmental issues.