Research on Periodic Structures Aroused by Femtosecond Laser Irradiation on Single-Crystalline Silicon Wafer

Author(s):  
Yan Shen Wang ◽  
Shen Dong ◽  
Yan Qiang Yang ◽  
Ying Chun Liang ◽  
Y.H. Wang
2006 ◽  
Vol 315-316 ◽  
pp. 779-783
Author(s):  
Yan Shen Wang ◽  
Shen Dong ◽  
Yan Qiang Yang ◽  
Ying Chun Liang ◽  
Y.H. Wang

Ripples in the area of femtosecond laser irradiated discrete points and continuous lines were studied. The characteristics of interference-induced ripples (LSFL) in the area irradiated by single shot were investigated by AFM. During single point irradiation, morphology of the irradiated area changed with energy deposition. Morphologies of the irradiated continuous lines with and without ablated groove inside were both investigated. The intensity of interfered light waves varied in different positions of each energy stripes. Thus the characteristics of ripples in the irradiated area varied with different positions. Ripples much larger than LSFL were found perpendicular to laser polarization.


2006 ◽  
Vol 315-316 ◽  
pp. 159-163
Author(s):  
Yan Shen Wang ◽  
Ying Chun Liang ◽  
Shen Dong ◽  
Wei Wei An ◽  
Bo Wang

High-energy femtosecond laser pulses were utilized to ablate single-crystalline silicon wafer. Collateral damage areas around the ablation zone can be observed in microscope. The morphology in such areas changes gradually. The microscopic morphology and nanomechanical properties of the pre-polished back surface were measured by AFM and Hysitron TriboIndenter respectively. The topography and roughness in the ablated, metamorphic and unaffected zone are almost equal. Yet the elastic ratio and hardness on the back surface vary gradually with indent positions, which coincide with the gradual morphological changes in the metamorphic zone on the front surface. Such regular changes in nanomechanical properties, to some extent, reflect the distribution of collateral damages near the ablated zone on the back surface. And they also testify the occurrence of the ill effects that go against micromachining during high-energy femtosecond laser irradiation.


2007 ◽  
Vol 46 (1) ◽  
pp. 21-23 ◽  
Author(s):  
Norihito Kawaguchi ◽  
Ryusuke Kawakami ◽  
Ken-ichiro Nishida ◽  
Naoya Yamamoto ◽  
Miyuki Masaki ◽  
...  

2009 ◽  
Vol 3 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Atsushi Mitani ◽  
◽  
Shinichi Hirai ◽  

Femtosecond laser technology forms minute, stable gratings on such materials as silicon and stainless steel. Forming a periodic structure on the surfaces of sliding parts improves tribology characteristics because adhesion decreases with reductions in area of contact. Double-pulsed femtosecond laser irradiation generates periodic structures with asymmetric profiles, along which, as we have shown elsewhere, microparts such as ceramic chip capacitors and resistors can be fed using simple symmetric planar vibration. Microparts move unidirectionally because they adhere to these surfaces asymmetrically. In testing the feasibility of feeding 0402 capacitors 0.4 × 0.2 × 0.2 mm in size and 0.1 mg weighting along an asymmetric surface fabricated using double-pulsed femtosecond laser irradiation, we evaluated differences in the profiles of the two inclined surfaces, effects of decreased adhesion, the forward and backward coefficient of friction, and the bidirectional friction angle of 0402 capacitors. Based on feed experimental results, we assessed the relationship between drive frequency and feed velocity and, by calculating variations in feed velocity, feed stability.


2006 ◽  
Vol 34 (11) ◽  
pp. 773-778 ◽  
Author(s):  
Yusaku IZAWA ◽  
Shigeki TOKITA ◽  
Masaki HASHIDA ◽  
Masayuki FUJITA ◽  
Yasukazu IZAWA

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