Nano-pulsed laser irradiation scanning system for phase-change materials

Kim, Sookyung; Li, Xue Zhe; Lee, Sangbin; Lee, Seung-Yop

doi:10.1016/j.ultramic.2008.04.068

Cited by 5 publications

(4 citation statements)

References 6 publications

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“…A static tester (PST-1, NANO Storage Co. Ltd., Korea) consisting of a laser diode and monitoring and positioning units 18 was used to irradiate the films and record their optical response. The laser spot size was 1 μm.…”

Section: Methodsmentioning

confidence: 99%

“…During Raman spectra measurements, power density on the sample was kept at a low level of ∼0.2 mW μm –2 to avoid any structural deformation induced by laser radiation. A static tester (PST-1, NANO Storage Co. Ltd., Korea) consisting of a laser diode and monitoring and positioning units was used to irradiate the films and record their optical response. The laser spot size was 1 μm.…”

Section: Experimental Sectionmentioning

confidence: 99%

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Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn₁Sb₇Te₁₂ Pseudo-Binary Alloy

et al. 2018

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Zn1Sb7Te12 thin films have been deposited by magnetron co-sputtering of ZnTe and Sb2Te3 targets. The microstructure, phase-change speed, optical cycling stability, and crystallization kinetics have been investigated during thermal annealing and laser irradiation. The thermal-annealed and laser-irradiated films give a clear evidence of the coexistence of trigonal Sb2Te3 and cubic ZnTe phases, which are homogeneously distributed in a single alloy as confirmed by advanced scanning transmission electron microscopy. The formation of both phases increases the initial nucleation sites, leading to the rapid phase-change speed in the Zn1Sb7Te12 film. The film has a minimum crystallization time of ∼3 ns at 70 mW with almost no incubation period for the formation of critical nuclei compared to Ge2Sb2Te5 and other Zn-based films. Moreover, the complete crystallization of Zn1Sb7Te12 thin films is achieved within 10 ns. The ultrafast two-dimensional nucleation and crystal growth speed in Zn1Sb7Te12 obtained from the laser-irradiated system is almost 7 times faster compared to that in Ge2Sb2Te5 film. Controlling the crystallization process through doping ZnTe into Sb2Te3 is thus promising for the development of high-speed optical switching technology.

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Section: Methodsmentioning

confidence: 99%

Section: Experimental Sectionmentioning

confidence: 99%

Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn₁Sb₇Te₁₂ Pseudo-Binary Alloy

et al. 2018

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“…The static tester system (Nanostorage Inc.) consisted of a commercial DVD optical pick-up with one laser source at a wavelength of 650 nm. 34 These recorded data were plotted in a power time effect (PTE) diagram with the laser power on the vertical axis and the laser duration on the horizontal axis. Aer the cycling test, the laser-irradiated areas of the BN2 and GST lms were capped with a SiO 2 layer and vertically sliced by the focused ion beam equipment to prepare the HRTEM samples.…”

Section: Methodsmentioning

confidence: 99%

Ultrafast phase change and long durability of BN-incorporated GeSbTe

et al. 2015

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BN-incorporated amorphous Ge 2 Sb 2 Te 5 (GST) films were deposited by an ion beam sputtering deposition (IBSD) method using GST and BN targets. Based on in situ sheet resistance measurements, we confirmed that as the amount of BN increased, the crystallization temperature (T c ) increased from 150 o C to 260 o C. It was demonstrated that the phase change speed of BN-incorporated GST is ten times faster than that of GST using a nanosecond laser.By evaluating Johnson-Mehl-Avrami (JMA) plots and scanning electron microscope (SEM) images, it was confirmed that the one-dimensional grain growth is dominant during the fast phase change of BN-incorporated GST because BN impurities can act like nuclei during the initial stage of crystal growth. After the 100 iteration test under rigorous acceleration conditions of SET/RESET switching using the pulsed laser system, it was confirmed that the void formation and thickness variation are very limited in the BN-incorporated GST, as compared to GST. This result originates from the low phase change stress of the BN-incorporated GST films during one-dimensional growth. The electrical SET speed and cyclability of the BNincorporated GST device also improved significantly compared to GST.

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“…The phase change speed of the oxygen-incorporated GST film was measured using an optical activation system (static tester system). 11 Reflectivity changes, due to laser-induced crystallization (reflectivity increment) and/or amorphization (reflectivity decrement), could be recorded by appropriate adjustment of the laser power and the duration of the laser pulse. The sample, on a movable XY-stage, was automatically moved after every measurement.…”

Section: Methodsmentioning

confidence: 99%

The Phase Change Effect of Oxygen-Incorporation in GeSbTe Films

Jang

Park

Lim

et al. 2011

J. Electrochem. Soc.

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Reflectivity changes in oxygen-incorporated Ge2Sb2Te5 (GST) films were investigated via a laser-induced crystallization process. The crystallization process showed that the phase change speed and the laser power required for crystallization become faster and larger in GST films with a characteristic quantity of oxygen. We confirmed that a dominant grain growth mode during the laser crystallization is a major determinant for the speed of phase change in GST films with a characteristic quantity of oxygen. JMA results and changes in surface morphology indicate that the origin of the growth mode change is due to an increase in the number of initial nucleation sites produced in the oxygen-incorporated GST films. After the re-amorphization process, oxygen-incorpo-rated GST films show more rapid and more stable phase change properties than that of GST films. VC 2011 The Electrochemical Society. [DOI: 10.1149/1.3556609] All rights reserved. Manuscript submitted December 10, 2010; revised manuscript received January 19, 2011. Published March 8, 2011. GeSbTe-based materials, especially Ge2Sb2Te5 (GST), which is located on the tie-line in the ternary diagram of the GeTe-Sb2Te3 system, have been the subject of extensive studies. GST has many potential applications such as in optical storage media and phase change random access memory devices (PRAM).1–3 Even though GST has many potential uses it also has some disadvantages, whic

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Nano-pulsed laser irradiation scanning system for phase-change materials

Cited by 5 publications

References 6 publications

Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn₁Sb₇Te₁₂ Pseudo-Binary Alloy

Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn₁Sb₇Te₁₂ Pseudo-Binary Alloy

Ultrafast phase change and long durability of BN-incorporated GeSbTe

The Phase Change Effect of Oxygen-Incorporation in GeSbTe Films

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Nano-pulsed laser irradiation scanning system for phase-change materials

Cited by 5 publications

References 6 publications

Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn1Sb7Te12 Pseudo-Binary Alloy

Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn1Sb7Te12 Pseudo-Binary Alloy

Ultrafast phase change and long durability of BN-incorporated GeSbTe

The Phase Change Effect of Oxygen-Incorporation in GeSbTe Films

Contact Info

Product

Resources

About

Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn₁Sb₇Te₁₂ Pseudo-Binary Alloy

Shortening Nucleation Time to Enable Ultrafast Phase Transition in Zn₁Sb₇Te₁₂ Pseudo-Binary Alloy