• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.118-119
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• 2006

In the present work, we investigate the basic physical and thermal properties and electrical resistance change due to phase change in chalcogenide-based $Ge_1Se_1Te_2$ and $Ge_2Se_2Te_5$ thin films. The phase transition from amorphous to crystalline states, and vice versa, of $Ge_1Se_1Te_2$ and $Ge_2Se_2Te_5$ thin films by applying electrical pulses have been studied. The reversible phase transition between the amorphous and crystalline states, which is accompanied by a considerable change in electrical resistivity, is exploited as means to store bits of information.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.83-84
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• 2006

For phase transition method, good recording sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, A retention time is very important part for phase transition. In our presentation wall, we chose Ge-Se-Te material to use a Se material which has good optical sensitivity than Sb. A Ge-Se-Te sample was fabricated and Irradiated with He-Ne laser and DPSS laser to investigate a reversible phase change by light.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.416-419
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• 2003

There is a growing need for a nonvolatile memory technology with faster speed than existing nonvolatile memories. We studied of phase-change according to temperature and voltage in chalcogenide thin film base on $Ge_2Sb_2Te_5$. Searching for Tg(Glass transition temperature) temperature controlled on hotplate with RT quenching. We measure I-V characteristic through out bottom electrode(ITO) and top electrode(Al) between $Ge_2Sb_2Te_5$. And compared with I-V characteristics after impress the variable stress.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.447-448
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• 2008

In this paper, we investigated the diffraction grating efficiency on AsSeS and Ag-doped amorphous chalcogenide Ag/AsSeS thin film for used to volume hologram. The film thickness was 0.5um and diffraction efficiency was obtained from (P:P) polarized He-Ne (632.8nm)laser beam on AsSeS and Ag/AsSeS thin films. As a results, diffraction grating was not formed at AsSeS thin film but at Ag-doped AsSeS thin film, diffraction grating was formed well compare with the former.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1727-1729
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• 2000

We has investigated the birefringence by the assisted electric field effect on $As_{40}Ge_{10}Se_{15}S_{35}$ thin films. Photoinduced birefringence has been studied in a chalcogenide material. We induced this thin films using linearly polarized He-Ne laser light(633nm) and detected polarized semiconductor laser light(780nm). To investigate the effect of electric field, various bias voltages applied. The result is shown that the birefringence has a higher value in +2V than others. We obtained the birefringence in the electric field effects by various voltages.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.162-163
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• 2007

In this paper, we fabrication of 2-D photonic crytal using holographic lithography. We used Ag doped chalcogenide AsGeSeS film and He-Ne (632.8nm) (P:P) Polarized laser beam. The thickness of Ag thin film was varied from 60nm and the thickness of chalcogenide thin film was varied from 2um. Frist, holographic lithography with 1-D photonic crystal on Ag/AsGeSeS film. And than revolved the sample $90^{\circ}$ to fabricate 2-D photonic crystal with holographic lithography.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.110-111
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• 2006

In this paper, we investigated resistance characteristic of chalcogenide material for next generation ReRAM nonvolatile memory device with laser irradiation. A AES is used to test Ag doping ratio into a As-Ge-Se-S thin film. A sample resistance was observed in real time with He-Ne laser(632.8nm). As a result, resistance of thermal treated As-Ge-Se-S thin film was $500{\Omega}$ which is smaller than initial $1.3M{\Omega}$. A resistance of non-treated Ag/As-Ge-Se-S thin film was $200{\Omega}$ which is lower than $35M{\Omega}$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.69-70
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• 2006

A detailed Investigation of cell structure and electrical characteristic in chalcogenide-based phase-change random access memory(PRAM) devices is presented. We used compound of Ge-Sb-Te material for phase-change cell. A novel bottom electrode structure and manufacture are described. We used heat radiator structure for improved reset characteristic. A resistance change measurement is performed on the test chip. From the resistance change, we could observe faster reset characteristic.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.268-271
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• 2004

The phase transition from amorphous to crystalline states, and vice versa, of $Ge_2Sb_2Te_5$ films by applying electrical pulses have been studied. This material can be used as nonvolatile memory. The reversible phase transition between the amorphous and crystalline states, which is accompanied by a considerable change in electrical resistivity, is exploited as means to store bits of information. The nonvolatile memory cells are composed of a simple sandwich (metal/chalcogenide/metal). It was formed that the threshold voltage depends on thickness, electrode distance, annealing time and temperature, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.80-81
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• 2005

Chalcogenide phase change memory has high performance to be next generation memory, because it is a nonvolatile memory processing high programming speed, low programming voltage, high sensing margin, low consumption and long cycle duration. We have developed a sample of PRAM with thermal protected layer. We have investigated the phase transition behaviors in function of process factor including thermal protect layer. As a result, we have observed that set voltage and duration of protect layer are more improved than no protect layer.