1 中国科学院半导体研究所光电子器件国家工程研究中心,北京 100083
2 中国科学院大学材料科学与光电技术学院,北京 100049
半导体可饱和吸收镜(SESAM)作为超快激光技术中最常用的被动锁模器件,由于可自启动、插入损耗小、集成度高和设计灵活等优点,具有广泛的应用范围和极佳的商业前景。本文主要介绍SESAM的锁模原理和发展现状,对目前SESAM的外延结构、生长方式和参数性能进行总结归纳,详尽描述其在固体激光器、半导体激光器和光纤激光器的锁模最新进展,并指出各类锁模激光器的性能特点和未来发展方向。
半导体可饱和吸收镜 被动锁模 激光器 超快激光 激光与光电子学进展
2024, 61(9): 0900008
1 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室,上海 201800
2 超强激光科学与技术重点实验室(中国科学院),上海 201800
极紫外(EUV)光刻是7 nm及以下技术节点芯片大规模量产的关键技术。随着技术节点的减小、工艺复杂性的增加,芯片的良率面临着巨大挑战。边缘放置误差(EPE)是量化多重曝光技术过程中制造图案保真度的最重要指标。EPE控制已成为多重曝光和EUV融合光刻时代最大的挑战之一。EPE是关键尺寸(CD)误差和套刻误差的结合。在EUV光刻中,光学邻近效应和随机效应是引起光刻误差的重要因素。光学邻近效应校正(OPC)可以使EPE最小化。对于最先进的技术节点,EPE通常由随机效应主导,因此需要对EPE进行建模,尤其是需要对随机效应进行严格的建模,以分析影响EPE的关键参数。选择不同的测量手段对关键参数进行测量并优化EPE是提高芯片良率的重要途径。本文首先综述了EPE在EUV光刻中的重要作用,然后讨论了OPC和随机效应、EPE模型及涉及的关键参数,并介绍了关键参数的测量方法,最后总结和展望了与EPE相关的技术。
测量 极紫外光刻光源 套刻 光学邻近效应校正 对准
Author Affiliations
Abstract
1 National Engineering Research Center for Optoelectronic Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
2 College of Materials Science and Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
Output power and reliability are the most important characteristic parameters of semiconductor lasers. However, catastrophic optical damage (COD), which usually occurs on the cavity surface, will seriously damage the further improvement of the output power and affect the reliability. To improve the anti-optical disaster ability of the cavity surface, a non-absorption window (NAW) is adopted for the 915 nm InGaAsP/GaAsP single-quantum well semiconductor laser using quantum well mixing (QWI) induced by impurity-free vacancy. Both the principle and the process of point defect diffusion are described in detail in this paper. We also studied the effects of annealing temperature, annealing time, and the thickness of SiO2 film on the quantum well mixing in a semiconductor laser with a primary epitaxial structure, which is distinct from the previous structures. We found that when compared with the complete epitaxial structure, the blue shift of the semiconductor laser with the primary epitaxial structure is larger under the same conditions. To obtain the appropriate blue shift window, the primary epitaxial structure can use a lower annealing temperature and shorter annealing time. In addition, the process is less expensive. We also provide references for upcoming device fabrication.
catastrophic optical damage primary epitaxial structure impurity-free vacancy disordering quantum well intermixing non-absorption window Journal of Semiconductors
2023, 44(10): 102302
1 中国科学院上海光学精密机械研究所超强激光科学与技术重点实验室,上海 201800
2 中国科学院上海光学精密机械研究所信息光学与光电技术实验室,上海 201800
3 中国科学院大学,北京 100049
4 中国科学院上海光学精密机械研究所精密光学工程部(筹),上海 201800
锡液滴发生器是激光等离子体型极紫外(LPP-EUV)光刻光源中最重要的核心部件之一。光刻光源要求锡液滴靶具备高重复频率、小直径且稳定性好的特性。综述了中国科学院上海光学精密机械研究所EUV光源团队近年来在液滴发生器方面的研究进展,包括液滴直径、重复频率、间距、位置和稳定性等。现阶段研制的锡液滴发生器,在100 kHz频率下喷射的锡液滴直径约为40 μm,间距约为230 μm,工作时长接近5 h。锡液滴在10 s短时间内,竖直和水平方向的位置不稳定性分别约为2 μm和1 μm。未来锡液滴的可用性性能(如液滴直径、工作时长和长时间的位置稳定性)还需进一步提升。
极紫外 光刻光源 液滴发生器 锡液滴 激光与光电子学进展
2023, 60(23): 2314001
1 中国科学院半导体研究所光电子器件国家工程研究中心,北京 100083
2 中国科学院大学材料科学与光电技术学院,北京 100049
3 北京大学信息科学技术学院,北京 100871
为了提高应用于光纤激光器的多量子阱半导体可饱和吸收镜(SESAM)的特性参数,对其结构进行优化,模拟分析了不同量子阱周期数对器件电场分布、调制深度及反射光谱等参数的影响,结果表明,SESAM中吸收层量子阱周期数越大,SESAM在1064 nm处的反射率越低,调制深度越高,在低反射率处的带宽越窄,可饱和吸收镜对生长误差的容忍度也越小。利用金属有机化合物气相沉积(MOCVD)方法对3种量子阱周期数结构的SESAM进行外延生长,通过非线性测试及锁模实验对3种结构的样品进行测量与表征,结果表明,3种结构的SESAM均实现了自启动锁模,其稳定锁模的泵浦区间为150~200 mW。采用泵浦探测技术对15个量子阱周期的SESAM进行动态响应测试,其响应恢复时间为5 ps。
激光器 超快激光器 半导体可饱和吸收镜 泵浦探测 光学学报
2023, 43(22): 2214001
Author Affiliations
Abstract
1 School of Microelectronics, Shanghai University, Shanghai, China
2 Department of Precision Optics Engineering, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China
With the development of high-volume manufacturing for very-large-scale integrated circuits, the purity of the light source in the extreme ultraviolet lithography (EUVL) system needs to fulfil extreme requirements in order to avoid thermal effect, optical distortion and critical dimension errors caused by out-of-band radiations. This paper reviews the key technologies and developments of the spectral purity systems for both a free-standing system and a built-in system integrated with the collector. The main challenges and developing trends are also discussed, with a view towards practical applications for further improvement. Designing and manufacturing spectral purity systems for EUVL is not a single task; rather, it requires systematic considerations for all relevant modules. Moreover, the requirement of spectral purity filters drives the innovation in filtering technologies, optical micromachining and advanced metrology.
collector mirror extreme ultraviolet lithography spectral purity filter High Power Laser Science and Engineering
2023, 11(5): 05000e64
Author Affiliations
Abstract
1 School of Microelectronics, Shanghai University, Shanghai 200072, China
2 Department of Precision Optics Engineering, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
Overlay (OVL) for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process. The tolerance of OVL metrology for the latest microchip needs to be at nanometer scale. This paper discusses the influence on the accuracy and sensitivity of diffraction-based overlay (DBO) after developing inspection and after etching inspection by the asymmetrical deformation of the OVL mark induced by chemical mechanical polishing or etching. We show that the accuracy and sensitivity of DBO metrology can be significantly improved by matching the measuring light wavelength to the thickness between layers and by collecting high-order diffraction signals, promising a solution for future OVL metrology equipment.
diffraction-based overlay overlay metrology accuracy lithography semiconductor microchip Chinese Optics Letters
2023, 21(7): 071204