SBIR Phase II: High Power Pulsed Fiber Laser for EUV Lithography

该小型企业创新研究第二阶段项目的核心目标是基于高效光纤激光器的最新创新，开发模块化激光功率缩放概念。所提出的概念使用大模面积、手性耦合芯光纤来构建高功率脉冲光纤激光器模块，该模块可以在光谱上组合成单个共线光束，提供数千瓦的平均功率。 具有适于产生极紫外（EUV）辐射的特性的激光源的功率缩放是EUV光刻技术成熟的关键障碍。 EUV光刻是下一代半导体集成电路大批量制造的领先候选技术，关键尺寸为22 nm或更小。第二阶段的工作建立在成功的第一阶段可行性和设计结果的基础上，通过开发关键部件和构建原型激光模块。这项工作的预期结果包括能够承受高激光峰值功率的关键激光元件的构造和表征，以及试验板的演示，原型光纤激光器能够在50-200 kHz范围内的脉冲重复率下产生1毫焦耳或更大的脉冲能量，脉冲长度为5-30纳秒。该项目的商业潜力在于半导体集成电路性能的持续进步。 这一进步的一个关键指标是在这些设备的制造中可以实现的最小关键尺寸。光刻技术的进步使得这一尺寸每两年减少约30%，这导致集成电路上的晶体管数量每18个月翻一番。这一趋势被称为摩尔定律，推动了微电子器件的处理能力、存储容量、效率和可负担性的爆炸式增长。目前正在开发的EUV光刻技术是在五到十年内维持这一趋势所需的关键制造技术。在纳秒脉冲范围内工作的功率可调节激光器的发展是EUV光刻实际实现的关键要素。这一奋进的成功将有助于微电子器件的持续进步，使遗传工程、电信、计算机工程和运输等不同的研究和工业领域受益。

This Small Business Innovation Research Phase II project has the core objective to develop a modular, laser power scaling concept based on recent innovations in high efficiency fiber lasers. The proposed concept uses large mode area, chirally-coupled core fiber to construct high power, pulsed fiber laser modules that can be spectrally combined into a single, collinear beam delivering multi-kilowatts of average power. Power scaling of a laser source with characteristics appropriate for the generation of extreme ultraviolet (EUV) radiation is a key obstacle to the technical maturity of EUV lithography. EUV lithography is the leading candidate for high volume manufacturing of the next generation of semiconductor integrated circuits with critical dimensions of 22 nm or less. The Phase II effort builds on the successful Phase I feasibility and design results by developing the critical components and constructing a prototype laser module. Results expected from this work include construction and characterization of key laser components capable of withstanding high laser peak powers and demonstration of a breadboard, prototype fiber laser capable of producing pulse energy of 1 millijoule or more with pulse lengths of 5-30 nanoseconds at pulse repetition rates in the range of 50-200 kHz.The broader impact/commercial potential of this project is the continued advancement of semiconductor integrated circuit performance. A key metric in this advancement is the minimum critical dimension that can be realized in the manufacture of these devices. Advances in lithography have enabled a decrease of approximately 30% in this dimension every two years, which has led to a doubling every eighteen months in the number of transistors on an integrated circuit. This trend, known as Moore's Law, has fueled an explosion in the processing power, storage capacity, efficiency and affordability of microelectronic devices. EUV lithography, currently under development, is the critical manufacturing technology that is needed to sustain this trend on the five to ten year horizon. Development of a power scalable laser, operating in the nanosecond pulse regime, is a critical element in the practical realization of EUV lithography. Success in this endeavor will help to deliver continued advances in microelectronic devices that benefit fields of study and industry as diverse as genetic engineering, telecommunications, computer engineering and transportation.