GOALI: Photoresist Dissolution and Stripping in Gas Expanded Liquids

Hess，Dennis W./GA Tech res Corp-GITCarter，Melvin K./DuPont Electronics Technologies“GALI：光致抗蚀剂在气体膨胀液体中的溶解和剥离”最先进的集成电路(IC)制造工艺需要超过25个图案化或光刻步骤。在图案形成后，受控、有效地去除光致抗蚀剂(PR)和相关的蚀刻残留物/污染物，对于实现高成品率和可靠性的成功制造工艺至关重要。目前，PR/残留物的去除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)漂洗。这种方法使用大量的化学品和DIW，因此对环境有害。气体膨胀液体(凝胶)是一种很有前途的替代方法，可以替代在集成电路制造中广泛使用的传统液体工艺。凝胶在分离和反应工程中的研究表明，这些流体还可能在微电子工艺技术中提供许多好处。特别令人感兴趣的凝胶包括那些用二氧化碳和微电子设备制造中使用的传统溶剂(例如，醇)配制的凝胶。凝胶具有优异的传质性能，同时保持了去除PR和蚀刻残留物所需的溶剂能力。此外，与使用凝胶去除有机薄膜和污染物相关的环境效益可能是巨大的。最后，由于凝胶形成所需的压力远低于实施超临界流体(SCF)技术所需的压力，因此与超临界流体(SCF)相比，凝胶的能量需求和相关危害将会降低。一个基于质量传输的模型用来描述凝胶中薄膜的溶解，该模型表明，凝胶在几个方面可能优于传统液体。例如，与纯液体相比，凝胶中的溶解速度可以提高50%。此外，PR去除过程中的溶剂量可以显著减少。这项拟议的研究将对这些模型的准确性进行实验研究，并确定大规模工业过程是否可行。将进行研究，以解决导致凝胶中有机薄膜膨胀和溶解的基本物理和化学相互作用。与集成电路工业湿化学配方制造商和供应商杜邦-EKC的合作将使能够应用于IC制造的凝胶的识别、配方和研究成为可能(佐治亚理工学院)，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英寸晶片上的薄膜/残留物，明确以抗蚀剂/残留物去除(EKC)为目的的商业溶剂混合物的重新配方/设计，以及对这些新凝胶的基本性质的调查(佐治亚理工学院)将确保基础研究与直接应用于未来几代IC的制造操作相结合。更广泛的影响：拟议的研究将导致开发更环保的工艺，以制造未来的集成电路。赫斯教授的团队在实验室设施和微电子加工专业知识方面做好了这项研究的准备。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；这样的结果将使人们对IC工艺工程中使用凝胶进行表面清洁和准备有一个基本的了解，而EKC将确保将这些知识转化为制造专业知识。建议的研究项目非常适合化学工程研究生，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。该项目的成果将是：(1)通过开发新的、更环保的清洗和表面处理工艺，提高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型范例/案例研究，并将其纳入本科和研究生的核心课程；(4)每年夏季培训参加佐治亚理工学院夏季本科生工程研究计划(SURE)的少数族裔本科生；(5)就集成电路制造和环境问题对高中生和教师进行教育。

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.