Drilling of aluminum and copper films with femtosecond double-pulse laser

Abstract Aluminum and copper films are drilled with femtosecond double-pulse laser. The double-pulse delay is scanned from −75 ps to 90 ps. The drilling process is monitored by recording the light transmitted through the sample, and the morphology of the drilled holes is analyzed by optical microscopy. It is found that, the breakthrough time, the hole evolution during drilling, the redeposited material, the diameters of the redeposited area and the hole, change as functions of double-pulse delay, and are different for the two metals. Along the double-pulse delay axis, three different time constants are observed, a slow one of a few tens of picoseconds, a fast one of a few picoseconds, and an oscillation pattern. Results are discussed based on the mechanisms of plasma shielding, electron–phonon coupling, strong coupling of laser with liquid phase, oxidation of aluminum, laser induced temperature and pressure oscillations, and the atomization of plume particles.

[1]  C. Fotakis,et al.  Laser induced forward transfer of metals by temporally shaped femtosecond laser pulses. , 2008, Optics express.

[2]  T. Baumert,et al.  Emission signal enhancement of laser ablation of metals (aluminum and titanium) by time delayed femtosecond double pulses from femtoseconds to nanoseconds , 2014 .

[3]  J. M. Khosrofian,et al.  Measurement of a Gaussian laser beam diameter through the direct inversion of knife-edge data. , 1983, Applied optics.

[4]  B. Stuart,et al.  Rate dependence of short-pulse laser ablation of metals in air and vacuum , 2003 .

[5]  V. Babushok,et al.  Double pulse laser ablation and plasma: Laser induced breakdown spectroscopy signal enhancement , 2006 .

[6]  A. Tünnermann,et al.  Femtosecond, picosecond and nanosecond laser ablation of solids , 1996 .

[7]  R. Russo,et al.  Experimental investigation of ablation efficiency and plasma expansion during femtosecond and nanosecond laser ablation of silicon , 2005 .

[8]  E. Ling,et al.  Introducing a new optimization tool for femtosecond laser-induced surface texturing on titanium, stainless steel, aluminum and copper , 2015 .

[9]  Razvan Stoian,et al.  Temporal pulse manipulation and ion generation in ultrafast laser ablation of silicon , 2003 .

[10]  Andrew M. Weiner,et al.  Ultrafast double-pulse ablation of fused silica , 2005 .

[11]  J. Hermann,et al.  Investigation of plumes produced by material ablation with two time-delayed femtosecond laser pulses , 2009 .

[12]  Herbert M. Urbassek,et al.  Ultrashort-pulse laser irradiation of metal films: the effect of a double-peak laser pulse , 2010 .

[13]  P. A. Atanasov,et al.  Mechanism of ultrashort laser ablation of metals: molecular dynamics simulation , 2005 .

[14]  M. Späth,et al.  Time resolved dynamics of subpicosecond laser ablation. , 1993 .

[15]  J. Limpert,et al.  High speed laser drilling of metals using a high repetition rate, high average power ultrafast fiber CPA system. , 2008, Optics express.

[16]  Changhe Zhou,et al.  Ultrafast double pulses ablation of Cr film on glass , 2008 .

[17]  David Ashkenasi,et al.  Pulse-width influence on the laser-induced structuring of CaF2 (111) , 1996 .

[18]  T. Choi,et al.  Femtosecond laser induced ablation of crystalline silicon upon double beam irradiation , 2002 .

[19]  P. Levashov,et al.  Suppression of ablation in femtosecond double-pulse experiments. , 2009, Physical review letters.

[20]  Lan Jiang,et al.  Simulation of rippled structure adjustments based on localized transient electron dynamics control by femtosecond laser pulse trains , 2013 .

[21]  H. Sawada,et al.  Development of dicing technique for thin semiconductor substrate using temporally shaped femtosecond laser , 2004 .

[22]  A. Ostendorf,et al.  Polarization effects in ultrashort-pulse laser drilling , 1999 .

[23]  Lan Jiang,et al.  Femtosecond laser high-efficiency drilling of high-aspect-ratio microholes based on free-electron-density adjustments. , 2014, Applied optics.

[24]  C. Fotakis,et al.  Elimination of cracking during UV laser ablation of SrTiO3 single crystals by employing a femtosecond laser , 2005 .

[25]  J. Roth,et al.  Simulation of laser ablation in aluminum: the effectivity of double pulses , 2014, 1404.7323.

[26]  John S. Preston,et al.  Laser drilling of high aspect ratio holes in copper with femtosecond, picosecond and nanosecond pulses , 2008 .

[27]  J. Hermann,et al.  Reducing nanoparticles in metal ablation plumes produced by two delayed short laser pulses , 2009 .

[28]  P. Pronko,et al.  Ion characteristics of laser-produced plasma using a pair of collinear femtosecond laser pulses , 2003 .

[29]  V. Hommes,et al.  Silicon surface morphology study after exposure to tailored femtosecond pulses , 2006 .

[30]  L. Botha,et al.  Femtosecond laser ablation of silver foil with single and double pulses , 2010 .

[31]  R. Gordon,et al.  Ablation and plasma emission produced by dual femtosecond laser pulses , 2008 .

[32]  J. Güdde,et al.  Electron and lattice dynamics following optical excitation of metals , 2000 .

[33]  A. Semerok,et al.  Ultrashort double pulse laser ablation of metals , 2004 .

[34]  R. X. Li,et al.  Optical breakdown for silica and silicon with double femtosecond laser pulses. , 2005, Optics express.

[35]  V. Schmidt,et al.  Ultrashort laser ablation of metals: pump–probe experiments, the role of ballistic electrons and the two-temperature model , 2002 .

[36]  Zhan Hu,et al.  The influence of double pulse delay and ambient pressure on femtosecond laser ablation of silicon , 2015 .

[37]  A. Tünnermann,et al.  Influence of ambient pressure on the hole formation in laser deep drilling , 2013 .

[38]  A. Ostendorf,et al.  Deep drilling of metals by femtosecond laser pulses , 2003 .

[39]  K. Sokolowski-Tinten,et al.  Timescales in the response of materials to femtosecond laser excitation , 2004 .

[40]  A. N. Smith,et al.  Measurement of the electron-phonon coupling factor dependence on film thickness and grain size in Au, Cr, and Al. , 1999, Applied optics.

[41]  W. Husinsky,et al.  Thresholds of plasma formation in silicon identified by optimizing the ablation laser pulse form. , 2006, Physical review letters.

[42]  K. Y. Kim,et al.  Measurements of terahertz electrical conductivity of intense laser-heated dense aluminum plasmas. , 2008, Physical review letters.