Effect of Laser Power on the Surface Texture Transition of the Thin Silicon-Films from Grain-Boundary Free (100) to Twinned (211) in CW Laser Lateral Crystallization

Sasaki, N.; Arif, Muhammad; Uraoka, Yukiharu

doi:10.7567/ssdm.2018.n-2-02

Cited by 3 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The nucleus with the {100} SD orientation is not always included in the nuclei randomly nucleated at the scan starting point in a limited space for nucleation if the crystallization stripe is narrow and thin. On the other hand, the geometry selection works well for the wider linear beam even in thin film, like our study [49][50][51][52][53][54], or for thick film, like the experiments of Kühnapfel et al [37,38].…”

Section: Discussionsupporting

confidence: 59%

“…This paper describes a recently found {100}-oriented grain-boundary-free film obtained by the unseeded CW-laser lateral crystallization with a single scan [44,[49][50][51][52][53][54], with a highly top-flat line beam at the room temperature substrate. The grain boundary generation is suppressed in the crystallized region even with the simple line beam and without complicated beam shaping to grow the crystal from the central region outwards.…”

Section: Comparison Between Continuous-wave (Cw)-laser Lateral Crysta...mentioning

confidence: 99%

See 1 more Smart Citation

Unseeded Crystal Growth of (100)-Oriented Grain-Boundary-Free Si Thin-Film by a Single Scan of the CW-Laser Lateral Crystallization of a-Si on Insulator

et al. 2020

View full text Add to dashboard Cite

Laser crystallization of a-Si film on insulating substrate is a promising technology to fabricate three-dimensional integrations (3D ICs), flat panel displays (FPDs), or flexible electronics, because the crystallization can be performed on room temperature substrate to avoid damage to the underlying devices or supporting plane. Orientation-controlled grain-boundary-free films are required to improve the uniformity in electrical characteristics of field-effect-transistors (FETs)fabricated in those films. This paper describes the recently found simple method to obtain {100}-oriented grain-boundary-free Si thin-films stably, by using a single scan of continuous-wave (CW)-laser lateral crystallization of a-Si with a highly top-flat line beam with 532 nm wavelength at room temperature in air. It was difficult to control crystal orientations in the grain-boundary-free film crystallized by the artificial modulation of solid-liquid interface, and any other trial to obtain preferential surface orientation with multiple irradiations resulted in grain boundaries. The self-organized growth of the {100}-oriented grain-boundary-free films were realized by satisfying the following conditions: (1) highly uniform top-flat line beam, (2) SiO2 cap, (3) low laser power density in the vicinity of the lateral growth threshold, and (4) single scan crystallization. Higher scan velocity makes the process window wide for the {100}-oriented grain-boundary-free film. This crystallization is very simple, because it is performed by a single unseeded scan with a line beam at room temperature substrate in air.

show abstract

Section: Discussionsupporting

confidence: 59%

Section: Comparison Between Continuous-wave (Cw)-laser Lateral Crysta...mentioning

confidence: 99%

Unseeded Crystal Growth of (100)-Oriented Grain-Boundary-Free Si Thin-Film by a Single Scan of the CW-Laser Lateral Crystallization of a-Si on Insulator

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The {100} ND are observed at 2.0 to 2.4 W in the center and at 2.0 to 2.8 W in the peripheral. The deformation twinning 18,19) is observed at 2.6 and 2.8 W in the center. For the non-capped samples (Fig.…”

mentioning

confidence: 93%

“…A highly-uniform top-flat line beam was used. [15][16][17][18][19] The standard deviation of the power density along the long axis was 1.3%. The spot size was 492 μm × 8 μm.…”

mentioning

confidence: 95%

“…Recently we have found that grain-boundary free {100} oriented films can be obtained by CLC on the room temperature substrate. [15][16][17][18][19] The laser scanned region shows grain-boundary free {100} textures in all the three directions of the surface normal (ND), scan (SD) and transverse (TD) directions, with a crystal width of more than 100 μm throughout the full scan length of 1.8 mm. 16) The amount of (100) texture is more than 99.5% within 10°.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Effect of surface tension on crystal growth of Si thin films by a continuous-wave laser lateral crystallization

Sasaki

Arif

Uraoka

2019

Appl. Phys. Express

View full text Add to dashboard Cite

Effect of surface tension and temperature distribution on the crystal growth of Si thin films by continuous wave laser lateral crystallization is experimentally investigated in comparison with the capped and non-capped samples. It is proposed that the grain-boundary free (100) film is realized by the averaged solid–liquid interface which holds an angle of ∼45° to the substrate. This theory explains well the effects of surface tension and laser power.

show abstract

Transition mechanism of the thin Si-films obtained by the CW laser lateral crystallization from the grain-boundary free highly {100} oriented crystal to the twinned {211} crystal depending on the laser power

Sasaki

Arif

Uraoka

2019

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Surface texture transition from grain-boundary free {100} crystals to twinned {211} was observed with increasing laser power in the crystal growth of low-temperature silicon films by the cw laser lateral crystallization of a-Si. This transition is explained by two step mechanism. Firstly a crystal having ∼{110} texture grows in the scan direction (SD) rotated from {100} texture keeping the {100} surface normal texture with increasing laser power, and secondly the deformation twinning occurs in the solidified crystal having an in-plane rotation angle of 35°–45° by the compressive stress due to the Si volume expansion with further increasing power, but the twinning does not occur even with the same compressive stress in the crystal having an in-plane rotation angle of 0°–33.5°, where the rotation angle is defined as the angle between 〈100〉 axis of the grown crystal and the SD. The reason is explained by the Schmidt factor calculated as a function of the in-grain rotation with the laser power, assuming the compressive stress is applied parallel to the isotherms. The maximum value in the Schmidt factors for possible partial dislocation glides was 0.471 for the crystal having {110} texture in the SD and 0.236 for the crystal having {100} texture in the SD. Resolved stress to move the twinning partial dislocation in the crystal having {110} texture in the SD is higher than that in the crystal having {100} texture in the SD by a factor of 2.

show abstract

Effect of Laser Power on the Surface Texture Transition of the Thin Silicon-Films from Grain-Boundary Free (100) to Twinned (211) in CW Laser Lateral Crystallization

Cited by 3 publications

References 0 publications

Unseeded Crystal Growth of (100)-Oriented Grain-Boundary-Free Si Thin-Film by a Single Scan of the CW-Laser Lateral Crystallization of a-Si on Insulator

Unseeded Crystal Growth of (100)-Oriented Grain-Boundary-Free Si Thin-Film by a Single Scan of the CW-Laser Lateral Crystallization of a-Si on Insulator

Effect of surface tension on crystal growth of Si thin films by a continuous-wave laser lateral crystallization

Transition mechanism of the thin Si-films obtained by the CW laser lateral crystallization from the grain-boundary free highly {100} oriented crystal to the twinned {211} crystal depending on the laser power

Contact Info

Product

Resources

About