Hollowing and Transfer of Polymethyl Methacrylate Film    Propelled by Laser Ablation of Triazeno Polymer Film

Mito, Takashi; Tsujita, Takuji; Masuhara, Hiroshi; Hayashi, Nobuaki; Suzuki, Kenkichi

doi:10.1143/jjap.40.l805

Cited by 23 publications

(13 citation statements)

References 32 publications

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“…For LIFT applications which require excellent film‐forming properties,2b,16 only thin polymer films with thickness of a few hundred nanometers at most are used. Until now, use of TP ‐ 6a as thin‐film DRL was impeded due to its poor solubility and the formation of inhomogeneous solutions with crosslinked gel‐type swollen lumps that are caused by undesirable side reactions.…”

Section: Introductionmentioning

confidence: 99%

Aryltriazene Photopolymers for UV‐Laser Applications: Improved Synthesis and Photodecomposition Study

Nagel

Hany

Lippert

et al. 2007

Macro Chemistry & Physics

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An improved synthesis of photosensitive homopolymers containing aryltriazene chromophores covalently incorporated into the polymer backbone is reported. Such photopolymers proved to have promising properties for novel UV‐laser applications. A homologous series of new aryltriazene polymers with increasingly branched side chains (R = Me, Et, iPr, tBu) was synthesized and characterized. Homogeneous thin films with thicknesses from ≈15 to >150 nm were prepared by spin‐coating. Photodecomposition was studied in solution and on thin films. Polymers with increasingly branched and bulky substituents showed decreasing photodissociation rates. NMR studies suggested an enhanced hindrance of the N(2)–N(3) bond rotation in the aryltriazene moiety with increasing steric demand of the substituents.

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Section: Introductionmentioning

confidence: 99%

Aryltriazene Photopolymers for UV‐Laser Applications: Improved Synthesis and Photodecomposition Study

Nagel

Hany

Lippert

et al. 2007

Macro Chemistry & Physics

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“…The principle is the application of a twolayer system: a sacrificial layer acting as an absorber and the transfer material are successively coated on the donor substrate. Upon receiving the laser pulse, the sacrificial layer absorbs the energy, is decomposed into gaseous fragments and provides the thrust for propelling the top layer onto the receiver [15]. Furthermore, the absorbing material protects the top layer from the laser pulse and is specially designed to decompose at low fluences.…”

Section: Introductionmentioning

confidence: 99%

Influence of thermal diffusion on the laser ablation of thin polymer films

et al. 2007

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The laser ablation of a photosensitive triazene polymer was investigated with a ns XeCl excimer laser over a broad range of thicknesses (10-400 nm). We found that the ablation threshold fluence increased dramatically with decreasing film thickness for films thinner than 50 nm. Ablation on substrates with different thermal properties (sapphire, fused silica, PMMA) was investigated as well, and a clear influence of the substrate material was obtained. A mathematical model combining thermal diffusion and absorption effects was used to explain the experimental data. The model is in good agreement with the experimental data and shows that heat diffusion into the substrate plays a crucial role for the ablation process of very thin films.PACS 52.38.Mf; 44.05.+e; 81.05.Lg IntroductionLaser ablation finds a broad range of applications because it allows us to create microstructures by dry etching, deposit material from a target to a substrate, perform analysis of fragments and is also used for some special applications, such as laser plasma thrusters [1,2].Material deposition by laser ablation is a useful tool in the field of materials processing. The pulsed laser deposition (PLD) technique allows us to transfer and produce films of inorganic [3,4] and organic materials [5][6][7][8]. Matrix-assisted pulsed laser evaporation (MAPLE) can be applied to transfer small molecules from a frozen matrix to a substrate [8,9]. One of the most promising techniques to transfer organic thin films is laser-induced forward transfer (LIFT), which allows us to deposit and pattern materials in the same process [10][11][12][13][14]. It consists of the following steps: a transparent substrate is coated with the material that has to be transferred. This so-called donor substrate is placed in front of a receiver plate and a laser pulse is applied through the donor. The coated material absorbs the laser pulse and is ablatively ejected and deposited on the receiver. This method is appropriate for metal deposition but not for sensitive materials, such as polymers, because these may be damaged by the thermal load and photochemical reactions due to irradiation. A modification of the technique can solve this problem. The principle is the application of a twolayer system: a sacrificial layer acting as an absorber and the transfer material are successively coated on the donor substrate. Upon receiving the laser pulse, the sacrificial layer absorbs the energy, is decomposed into gaseous fragments and provides the thrust for propelling the top layer onto the receiver [15]. Furthermore, the absorbing material protects the top layer from the laser pulse and is specially designed to decompose at low fluences. Among various polymers, triazenebased polymers (TP) show the lowest ablation threshold at 308 nm and are therefore the most promising materials for this application [16][17][18].It has been shown that this sacrificial layer allows us to transfer quantum dots [19], living cells embedded in a matrix [20] and even functional pixels of organic ligh...

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“…Examples for the second group are polymers as fuel in the micro laser plasma thruster (mLPT), PLD of polymers, matrix-assisted pulsed laser evaporation (MAPLE), which is a deposition technique that can be used to deposit highly uniform thin films [26], or laser-induced forward transfer (LIFT) [27][28][29], which can be used to produce microstructures by transferring an irradiated area of a target film to an acceptor substrate. The polymer can be the transferred material, or just functions as driving force in the transfer.…”

Section: Introductionmentioning

confidence: 99%