Laser processing and in-situ diagnostics for crystallization: from thin films to nanostructures

Recent work on laser-induced crystallization of thin films and nanostructures is presented. Characterization of the morphology of the crystallized area reveals the optimum conditions for sequential lateral growth in a-Si thin films under high-pulsed laser irradiation. Silicon crystal grains of several micrometers in lateral dimensions can be obtained reproducibly. Laser-induced grain morphology change is observed in silicon nanopillars under a transmission electron microscopy (TEM) environment. The TEM is coupled with a near-field scanning optical microscopy (NSOM) pulsed laser processing system. This combination enables immediate scrutiny on the grain morphologies that the pulsed laser irradiation produces. The tip of the amorphous or polycrystalline silicon pillar is transformed into a single crystalline domain via melt-mediated crystallization. The microscopic observation provides a fundamental basis for laser-induced conversion of amorphous nanostructures into coarse-grained crystals. A laser beam shaping strategy is introduced to control the stochastic dewetting of ultrathin silicon film on a foreign substrate under thermal stimulation. Upon a single pulse irradiation of the shaped laser beam, the thermodynamically unstable ultrathin silicon film is dewetted from the glass substrate and transformed to a nanodome. The results suggest that the laser beam shaping strategy for the thermocapillary-induced de-wetting combined with the isotropic etching is a simple alternative for scalable manufacturing of array of nanostructures.

[1]  James S. Im,et al.  On the super lateral growth phenomenon observed in excimer laser-induced crystallization of thin Si films , 1994 .

[2]  Seiichiro Higashi,et al.  Direct observation of grain growth from molten silicon formed by micro-thermal-plasma-jet irradiation. , 2012, Applied physics letters.

[3]  Nathan S. Lewis,et al.  Growth of vertically aligned Si wire arrays over large areas (>1 cm^2) with Au and Cu catalysts , 2007 .

[4]  Costas P. Grigoropoulos,et al.  Large area crystallization of amorphous Si with overlapping high repetition rate laser pulses , 2012 .

[5]  Takahiko Endo,et al.  Crystal Growth of Silicon Thin Films on Glass by Excimer Laser Annealing: A Molecular-Dynamics Study , 2006 .

[6]  C. Grigoropoulos,et al.  Relationship between fluence gradient and lateral grain growth in spatially controlled excimer laser crystallization of amorphous silicon films , 2000 .

[7]  G. J. Galvin,et al.  Melting temperature and explosive crystallization of amorphous silicon during pulsed laser irradiation , 1984 .

[8]  Yu Zhang,et al.  Evolutionary Selection Growth: Towards Template‐Insensitive Preparation of Single‐Crystal Layers , 2013, Advanced materials.

[9]  Ajeet Rohatgi,et al.  Impurity effects in silicon for high efficiency solar cells , 1986 .

[10]  B. Chichkov,et al.  Laser printing of silicon nanoparticles with resonant optical electric and magnetic responses , 2014, Nature Communications.

[11]  Teruaki Motooka,et al.  Surface nucleation of the (111) plane of excimer laser annealed Si on SiO2 substrates: A molecular dynamics study , 2007 .

[12]  David J. Hwang,et al.  Generation of single-crystalline domain in nano-scale silicon pillars by near-field short pulsed laser , 2014 .

[13]  Jurgen Michel,et al.  Surface-energy-driven dewetting theory of silicon-on-insulator agglomeration , 2006 .

[14]  Mark A. Crowder,et al.  Single-crystal Si films for thin-film transistor devices , 1997 .

[15]  Hidayat Kisdarjono,et al.  Three-dimensional simulation of rapid melting and resolidification of thin Si films by excimer laser annealing , 2003 .

[16]  Xiaolin Zheng,et al.  Shrinking and growing: grain boundary density reduction for efficient polysilicon thin-film solar cells. , 2012, Nano letters.

[17]  Paul W. Leu,et al.  Single-crystal germanium layers grown on silicon by nanowire seeding. , 2009, Nature nanotechnology.

[18]  Ryoichi Ishihara,et al.  Formation of location-controlled crystalline islands using substrate-embedded seeds in excimer-laser crystallization of silicon films , 2001 .

[19]  Jae-Hyuck Yoo,et al.  In situ TEM near-field optical probing of nanoscale silicon crystallization. , 2012, Nano letters.

[20]  R. Müller,et al.  Three‐dimensional analysis of light propagation through uncoated near‐field fibre probes , 2001, Journal of microscopy.

[21]  A. Chimmalgi,et al.  Ablation of thin metal films by short-pulsed lasers coupled through near-field scanning optical microscopy probes , 2006 .

[22]  James S. Im,et al.  Stochastic modeling of solid nucleation in supercooled liquids , 2001 .

[23]  E. Ose,et al.  In-situ diagnostics for preparation of laser crystallized silicon films on glass for solar cells , 1999 .

[24]  S. D. Brotherton.  Polycrystalline silicon thin film transistors , 1995 .

[25]  Gerhard Willeke,et al.  Fast simulation code for heating, phase changes and dopant diffusion in silicon laser processing using the alternating direction explicit (ADE) method , 2009 .

[26]  Amit Goyal,et al.  Heteroepitaxial film silicon solar cell grown on Ni-W foils , 2012 .

[27]  Zhida Xu,et al.  Ultrahigh throughput silicon nanomanufacturing by simultaneous reactive ion synthesis and etching. , 2011, ACS nano.

[28]  Tatsuya Shimoda,et al.  Single-grain Si thin-film transistors on flexible polyimide substrate fabricated from doctor-blade coated liquid-Si , 2013 .