| [1] | Moore, G. E. Cramming more components onto integrated circuits. Electronics 38, 114-117 (1965). doi: 10.7551/mitpress/12274.003.0027 |
| [2] | Nishi, Y. Advances in Non-Volatile Memory and Storage Technology. (Cambridge: Woodhead Publishing, 2014). |
| [3] | Orji, N. G. et al. Metrology for the next generation of semiconductor devices. Nature Electronics 1, 532-547 (2018). doi: 10.1038/s41928-018-0150-9 |
| [4] | den Boef, A. J. Optical wafer metrology sensors for process-robust CD and overlay control in semiconductor device manufacturing. Surface Topography: Metrology and Properties 4, 023001 (2016). doi: 10.1088/2051-672X/4/2/023001 |
| [5] | Adel, M. et al. Optimized overlay metrology marks: theory and experiment. IEEE Transactions on Semiconductor Manufacturing 17, 166-179 (2004). doi: 10.1109/TSM.2004.826955 |
| [6] | Wittekoek, S. et al. Precision wafer-stepper alignment and metrology using diffraction gratings and laser interferometry. Proceedings of SPIE 0565, Micron and Submicron Integrated Circuit Metrology. San Diego, CA, USA: SPIE, 1986, 22-31. |
| [7] | Keij, S. et al. Advances in phase-grating-based wafer alignment systems. Proceedings of SPIE 5752, Metrology, Inspection, and Process Control for Microlithography XIX. San Jose, CA, USA: SPIE, 2005, 948-960. |
| [8] | Smilde, H. J. H. et al. Target design optimization for overlay scatterometry to improve on-product overlay. Proceedings of SPIE 9424, Metrology, Inspection, and Process Control for Microlithography XXIX. San Jose, CA, USA: SPIE, 2015, 942412. |
| [9] | van Gardingen-Cromwijk, T. et al. Non-isoplanatic lens aberration correction in dark-field digital holographic microscopy for semiconductor metrology. Light: Advanced Manufacturing 4, 453-465 (2023). doi: 10.37188/lam.2023.041 |
| [10] | Jiang, Z., Zhu, H. & Sun, Q. Q. Process optimization of amorphous carbon hard mask in advanced 3D-NAND flash memory applications. Electronics 10, 1374 (2021). doi: 10.3390/electronics10121374 |
| [11] | Matsuda, O. et al. Fundamentals of picosecond laser ultrasonics. Ultrasonics 56, 3-20 (2015). doi: 10.1016/j.ultras.2014.06.005 |
| [12] | Thomsen, C. et al. Surface generation and detection of phonons by picosecond light pulses. Physical Review B 34, 4129-4138 (1986). doi: 10.1103/PhysRevB.34.4129 |
| [13] | Rogers, J. A. et al. Optical generation and characterization of acoustic waves in thin films: fundamentals and applications. Annual Review of Materials Research 30, 117-157 (2000). doi: 10.1146/annurev.matsci.30.1.117 |
| [14] | Ruello, P. & Gusev, V. E. Physical mechanisms of coherent acoustic phonons generation by ultrafast laser action. Ultrasonics 56, 21-35 (2015). doi: 10.1016/j.ultras.2014.06.004 |
| [15] | Zhang, H. et al. Unraveling phononic, optoacoustic, and mechanical properties of metals with light-driven hypersound. Physical Review Applied 13, 014010 (2020). doi: 10.1103/PhysRevApplied.13.014010 |
| [16] | Ng, R. C. et al. Excitation and detection of acoustic phonons in nanoscale systems. Nanoscale 14, 13428-13451 (2022). doi: 10.1039/D2NR04100F |
| [17] | Slayton, R. M., Nelson, K. A. & Maznev, A. A. Transient grating measurements of film thickness in multilayer metal films. Journal of Applied Physics 90, 4392-4402 (2001). doi: 10.1063/1.1399031 |
| [18] | Dehoux, T. et al. Optical tracking of picosecond coherent phonon pulse focusing inside a sub-micron object. Light: Science & Applications 5, e16082 (2016). |
| [19] | Lomonosov, A. M. et al. Nanoscale noncontact subsurface investigations of mechanical and optical properties of nanoporous low-k material thin film. ACS Nano 6, 1410-1415 (2012). doi: 10.1021/nn204210u |
| [20] | Hoogeboom-Pot, K. M. et al. A new regime of nanoscale thermal transport: collective diffusion increases dissipation efficiency. Proceedings of the National Academy of Sciences of the United States of America 112, 4846-4851 (2015). doi: 10.1364/up.2014.10.thu.e.1 |
| [21] | Maznev, A. A. et al. Lifetime of sub-THz coherent acoustic phonons in a GaAs-AlAs superlattice. Applied Physics Letters 102, 041901 (2013). doi: 10.1063/1.4789520 |
| [22] | Zhang, H. et al. Ultrafast laser-induced guided elastic waves in a freestanding aluminum membrane. Physical Review B 103, 064303 (2021). doi: 10.1103/PhysRevB.103.064303 |
| [23] | Pontecorvo, E. et al. Visualizing coherent phonon propagation in the 100 GHz range: a broadband picosecond acoustics approach. Applied Physics Letters 98, 011901 (2011). doi: 10.1063/1.3532961 |
| [24] | Ng, T. W., Tay, A. & Wang, Y. H. Spot focus size effect in spectroscopic ellipsometry of thin films. Optics Communications 282, 172-176 (2009). doi: 10.1016/j.optcom.2008.09.081 |
| [25] | Daly, B. C. et al. Imaging nanostructures with coherent phonon pulses. Applied Physics Letters 84, 5180-5182 (2004). doi: 10.1063/1.1764599 |
| [26] | Edward, S. et al. Detection of hidden gratings through multilayer nanostructures using light and sound. Physical Review Applied 14, 014015 (2020). doi: 10.1103/PhysRevApplied.14.014015 |
| [27] | Antoncecchi, A. et al. High-resolution microscopy through optically opaque media using ultrafast photoacoustics. Optics Express 28, 33937-33947 (2020). doi: 10.1364/OE.405875 |
| [28] | Pérez-Cota, F. et al. High resolution 3D imaging of living cells with sub-optical wavelength phonons. Scientific Reports 6, 39326 (2016). doi: 10.1038/srep39326 |
| [29] | Lin, K. H. et al. Spatial manipulation of nanoacoustic waves with nanoscale spot sizes. Nature Nanotechnology 2, 704-708 (2007). doi: 10.1038/nnano.2007.319 |
| [30] | Illienko, M. et al. Characterization of sub-optical-wavelength structures through optically opaque films using picosecond ultrasonics. Nano Letters 25, 8909-8914 (2025). doi: 10.1021/acs.nanolett.5c00800 |
| [31] | Thomsen, C. et al. Coherent phonon generation and detection by picosecond light pulses. Physical Review Letters 53, 989-992 (1984). doi: 10.1103/PhysRevLett.53.989 |
| [32] | Rice, S. O. Mathematical analysis of random noise. The Bell System Technical Journal 23, 282-332 (1944). doi: 10.1002/j.1538-7305.1944.tb00874.x |
| [33] | Arlein, J. L. et al. Optical pump-probe measurements of sound velocity and thermal conductivity of hydrogenated amorphous carbon films. Journal of Applied Physics 104, 033508 (2008). doi: 10.1063/1.2963366 |
| [34] | Illienko, M., Velsink, M. C. & Witte, S. Understanding photoacoustic signal formation in the presence of transparent thin films. Photoacoustics 38, 100617 (2024). doi: 10.1016/j.pacs.2024.100617 |
| [35] | Snedecor, G. W. & Cochran, W. G. Statistical Methods. 8th edn. (Ames: Iowa State University Press, 1989). |
| [36] | Velsink, M. C. et al. Improving signal-to-noise ratios in pump-probe spectroscopy on light-sensitive samples by adapting pulse repetition rates. Optics Express 33, 23632-23644 (2025). doi: 10.1364/OE.558894 |
| [37] | Crimmins, T. F., Maznev, A. A. & Nelson, K. A. Transient grating measurements of picosecond acoustic pulses in metal films. Applied Physics Letters 74, 1344-1346 (1999). doi: 10.1063/1.123545 |
| [38] | Paolillo, S. et al. Direct metal etch of ruthenium for advanced interconnect. Journal of Vacuum Science & Technology B 36, 03E103 (2018). doi: 10.1116/1.5022283 |
| [39] | Mitchell, W. J. et al. Highly selective and vertical etch of silicon dioxide using ruthenium films as an etch mask. Journal of Vacuum Science & Technology A 39, 043204 (2021). doi: 10.1116/6.0001030 |
| [40] | de Haan, G., van den Hooven, T. J. & Planken, P. C. M. Ultrafast laser-induced strain waves in thin ruthenium layers. Optics Express 29, 32051-32067 (2021). doi: 10.1364/OE.438286 |
| [41] | Devos, A. Colored ultrafast acoustics: from fundamentals to applications. Ultrasonics 56, 90-97 (2015). doi: 10.1016/j.ultras.2014.02.009 |
| [42] | Elzinga, P. A. et al. Pump/probe spectroscopy by asynchronous optical sampling. Applied Spectroscopy 41, 2-4 (1987). doi: 10.1366/0003702874868025 |
| [43] | Velsink, M. C. et al. Optimizing pump–probe reflectivity measurements of ultrafast photoacoustics with modulated asynchronous optical sampling. Review of Scientific Instruments 94, 103002 (2023). doi: 10.1063/5.0155006 |