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

这个小型企业创新研究第二阶段项目的核心目标是基于高效率光纤激光器的最新创新，开发模块化的激光功率扩展概念。提出的概念使用大模面积、弦耦合的纤芯光纤来构建高功率脉冲光纤激光器模块，这些模块可以被光谱地组合成提供数千瓦平均功率的单个共线光束。具有适合产生极紫外线(EUV)辐射的特性的激光光源的功率定标是EUV光刻技术成熟的关键障碍。极紫外光刻技术是大批量生产关键尺寸为22 nm或更小的下一代半导体集成电路的主要候选者。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，开发了关键部件并建造了一个原型激光模块。这项工作的预期成果包括能够承受高激光峰值功率的关键激光部件的构造和表征，以及能够以50-200 kHz的脉冲重复频率产生脉冲长度为5-30纳秒、脉冲能量为1毫焦耳或更多的光纤激光器原型。该项目的更广泛的影响/商业潜力是半导体集成电路性能的持续进步。在这一进步中的一个关键指标是在这些设备的制造中可以实现的最小临界尺寸。光刻技术的进步使这一维度每两年减少约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，推动了微电子设备在处理能力、存储容量、效率和可负担性方面的爆炸性增长。目前正在开发的EUV光刻技术是在五到十年内保持这一趋势所需的关键制造技术。研制一种工作在纳秒脉冲范围内的功率可调激光器是极紫外光刻实用化的关键。这一努力的成功将有助于实现微电子设备的持续进步，使基因工程、电信、计算机工程和运输等不同领域的研究和工业受益。

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.