Research Papers

Nanosecond Time-Resolved Measurements of Transient Hole Opening During Laser Micromachining of an Aluminum Film

[+] Author and Article Information
David A. Willis

e-mail: dwillis@lyle.smu.edu
Department of Mechanical Engineering,
Southern Methodist University,
Dallas, TX 75275

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received July 12, 2012; final manuscript received January 15, 2013; published online July 26, 2013. Assoc. Editor: Pamela M. Norris.

J. Heat Transfer 135(9), 091202 (Jul 26, 2013) (7 pages) Paper No: HT-12-1364; doi: 10.1115/1.4024389 History: Received July 12, 2012; Revised January 15, 2013

Laser micromachining of an aluminum film on a glass substrate is investigated using a time-resolved transmission imaging technique with nanosecond resolution. Micromachining is performed using a 7 ns pulse-width Nd:YAG laser operating at the 1064 nm wavelength for fluences ranging from 2.2 to 14.5 J/cm2. A nitrogen laser-pumped dye laser with a 3 ns pulse-width and 500 nm wavelength is used as a light source for visualizing the transient hole area. The dye laser is incident on the free surface and a CCD camera behind the sample captures the transmitted light. Images are taken from the back of the sample at various time delays with respect to the beginning of the ablation process, allowing the transient hole area to be measured. For low fluences, the hole opening process is delayed long after the laser pulse and there is significant scatter in the data due to weak driving forces for hole opening. However, for fluences at and above 3.5 J/cm2, the starting time of the process converges to a limiting minimum value of 12 ns, independent of laser fluence. At these fluences, the rate of hole opening is rapid, with the major portion of the holes opened within 25 ns. The second stage of the process is slower and lasts between 100 and 200 ns. The rapid hole opening process at high fluences can be attributed to recoil pressure from explosive phase change. Measurements of the transient shock wave position using the imaging apparatus in shadowgraph mode are used to estimate the pressure behind the shock wave. Recoil pressure estimates indicate pressure values over 90 atm at the highest fluence, which decays rapidly with time due to expansion of the ablation plume. The recoil pressure for all fluences above 3.1 J/cm2 is higher than that required for recoil pressure driven flow due to the transition to explosive phase change above this fluence.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.


Bovatsek, J., Tamhankar, A., Patel, R. S., Bulgakova, N. M., and J.Bonse, 2010, “Thin Film Removal Mechanisms in ns-Laser Processing of Photovoltaic Materials,” Thin Solid Films, 518, pp. 2897–2904. [CrossRef]
Yavas, O., and Takai, M., 1999, “Effect of Substrate Absorption on the Efficiency of Laser Patterning of Indium Tin Oxide Thin Films,” J. Appl. Phys., 85, pp. 4207–4212. [CrossRef]
Andrew, J. E., Dyer, P. E., Greenough, R. D., Key, P. H., 1983, “Metal Film Removal and Patterning Using a XeCl Laser,” Appl. Phys. Lett., 43, pp. 1076–1078. [CrossRef]
Lecours, A., Caron, M., Ciureanu, P., Turcotte, G., Ivanov, D., Yelon, A., Currie, J. F., 1996, “Laser Patterning of Thin-Film Electrochemical Gas Sensors,” Appl. Surf. Sci., 96-98, pp. 341–346. [CrossRef]
Pfleging, W., Ludwig, A., Seemann, K., Preu, R., Mäckel, H., Glunz, S. W., 2000, “Laser Micromachining for Applications in Thin Film Technology,” Appl. Surf. Sci., 154-155, pp. 633–639. [CrossRef]
Kripesh, V., Gust, W., Bhatnager, S. K., Osterwinter, H., 2000, “Effect of Nd:YAG Laser Micromachining on Gold Conductor Printed over Ceramic Substrates,” Mater. Lett., 44, pp. 347–351. [CrossRef]
E.Matthias, E., Reichling, M., Siegel, J., Kading, O. W., Petzoldt, S., Skurk, H., Bizenberger, P., and Neske, E., 1994, “The Influence of Thermal Diffusion on Laser Ablation of Metal Films,” Appl. Phys. A, 58, pp. 129–136. [CrossRef]
Cline, H. E., 1981, “Surface Rippling Induced in Thin Films by a Scanning Laser,” J. Appl. Phys., 52, pp. 443–448. [CrossRef]
Zhang, X., Chu, S. S., Ho, J. R., and Grigoropoulos, C. P., 1997, “Excimer Laser Ablation of Thin Gold Films on Quartz Crystal Microbalance at Various Argon Background Pressures,” Appl. Phys. A, 64, pp. 545–552. [CrossRef]
Lee, S. K., and Na, S. J., 1999, “KrF Excimer Laser Ablation of Thin Cr Film on Glass Substrate,” Appl. Phys. A, 68, pp. 417–423. [CrossRef]
Veiko, V. P., Metev, S. M., Kaidanov, A. I., Libenson, M. N., and Jakovlev, E. B., 1980, “Two-Phase Mechanism of Laser-Induced Removal of Thin Absorbing Films: I. Theory,” J. Phys. D, 13, pp. 1565–1570. [CrossRef]
Veiko, V. P., Metev, S. M., Stamenov, K. V., Kalev, H. A., and Jurkevitch, B. M., 1980, “Two-Phase Mechanism of Laser-Induced Removal of Thin Absorbing Films: II. Experiment,” J. Phys. D, 13, pp. 1571–1575. [CrossRef]
Dömer, H., and Bostanjoglo, O., 2003, “Phase Explosion in Laser-Pulsed Metal Films,” Appl. Surf. Sci., 208-209, pp. 442–446. [CrossRef]
Willis, D. A., and Xu, X., 2000, “Transport Phenomena and Droplet Formation during Pulsed Laser Interaction With Thin Films,” ASME J. Heat Transfer, 122, pp. 763–770. [CrossRef]
Ajaev, V. S., and Willis, D. A., 2003, “Thermocapillary Flow and Rupture in Films of Molten Metal on a Substrate,” Phys. Fluids, 15, pp. 3144–3150. [CrossRef]
Kopač, S., Pirš, J., and Možina, J., 1996, “Optodynamic Analysis of Direct Laser Writing of Graduation Lines,” Appl. Phys. A, 62, pp. 77–82. [CrossRef]
Simon, P., and Ihlemann, J., 1996, “Machining of Submicron Structures on Metals and Semiconductors by Ultrashort UV-Laser Pulses,” Appl. Phys. A, 53, pp. 505–508. [CrossRef]
Ben-Yakar, A., Harkin, A., Ashmore, J., Byer, R. L., and Stone, H. A., 2007, “Thermal and Fluid Processes of a Thin Melt Zone During Femtosecond Laser Ablation of Glass: The Formation of Rims by Single Laser Pulses,” J. Phys. D: Appl. Phys., 40, pp. 1447–1459. [CrossRef]
Miotello, A., and Kelly, R., 1995, “Critical Assessment of Thermal Models for Laser Sputtering at High Fluences,” Appl. Phys. Lett., 67, pp. 3535–3537. [CrossRef]
Song, K. H., and Xu, X., 1998, “Explosive Phase Transformation in Excimer Laser Ablation,” Appl. Surf. Sci., 127-129, pp. 111–116. [CrossRef]
Porneala, C., and Willis, D. A.2009, “Time-Resolved Dynamics of Nanosecond Laser-Induced Phase Explosion,” J. Phys. D, 42, 155503. [CrossRef]
Porneala, C., and Willis, D. A., 2006, “Observation of Nanosecond Laser-Induced Phase Explosion in Aluminum,” Appl. Phys. Lett., 89, 211121. [CrossRef]
Fishburn, J. M., Withford, M. J., Coutts, D. W., and Piper, J. A., 2006, “Study of the Fluence Dependent Interplay Between Laser Induced Material Removal Mechanisms in Metals: Vaporization, Melt Displacement, and Melt Ejection,” Appl. Surf. Sci., 252, pp. 5182–5188. [CrossRef]
Xu, X., and Willis, D. A., 2002, “Non-Equilibrium Phase Change in Metal Induced by Nanosecond Pulsed Laser Irradiation,” ASME J. Heat Transfer, 124, pp. 293–298. [CrossRef]
Stafe, M., Vladoiu, I., and Popescu, I. M., 2008, “Impact of the Laser Wavelength and Fluence on the Ablation Rate of Aluminum,” Cent. Eur. J. Phys., 6, pp. 327–331. [CrossRef]
Iida, T., and Guthrie, R. I. L., 1993, The Physical Properties of Liquid Materials, Clarendon Press, Oxford, UK.
Hendijanifard, M. and Willis, D. A., 2011, “An Improved Method to Experimentally Determine Temperature and Pressure Behind Laser-Induced Shock Waves at Low Mach Numbers,” J. Phys. D: Appl. Phys., 44, 145501. [CrossRef]


Grahic Jump Location
Fig. 1

Illustration of physical mechanisms of hole opening during laser interaction with a metal film on an insulating substrate

Grahic Jump Location
Fig. 2

Experimental apparatus for transmission imaging

Grahic Jump Location
Fig. 3

A sequence of snapshots at F = 12.2 J/cm2 for 200 nm aluminum films. Transient photos are shown on the top row with the corresponding final hole image is shown below each transient photo. The horizontal and vertical scale bars on the pictures are equivalent to 52 μm and 54 μm, respectively.

Grahic Jump Location
Fig. 4

Final radii of opened holes measured by imaging apparatus

Grahic Jump Location
Fig. 5

Optical micrographs of holes formed at (a) 2.6 and (b) 6.6 J/cm2

Grahic Jump Location
Fig. 6

Square of the ratio of the equivalent radii of the hole during opening and the hole long after being opened

Grahic Jump Location
Fig. 7

Two-curve empirical fit function to data points for F = 12.2 J/cm2 (two parameter iteration)

Grahic Jump Location
Fig. 8

Shock wave pressure as a function of time and fluence. Pressure values are nondimensionalized with respect to atmospheric pressure.

Grahic Jump Location
Fig. 9

Laser-induced recoil pressure for F = 14.5 J/cm2 (from Ref. [27] for 200 nm Al) and dimensionless hole opening for F = 14.5 J/cm2 versus time on the same graph




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In