• Transactions on Electrical and Electronic Materials
• /
• 제5권6호
• /
• pp.219-222
• /
• 2004

This paper discovers that there are some peculiar properties that can remove holography grating, which was made in chacogenide thin film by impressed voltage. The thin films were used are $As_{40}Ge_{10}Se_{15}S_{35}$, and we use He-Ne laser in order to form thin films. I-V curved line in a thin film before a lattice was made has the critical point, about 3.7 V. Moreover, the I-V curved line increased current intensity at over 4 V after it made thin film. In addition, while holography grating is being made, and when it has the highest diffraction efficiency, a lattice can be deleted if put more voltage into it.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.189-190
• /
• 2007

본 논문에서는 칼코게나이드 박막의 Ag 포토 도핑시 기판의 변화에 따른 Ag 이온의 도핑 특성을 예측하고자 하였다. 도핑 특성은 Ag 이온의 도핑으로 인한 굴절률 변화를 이용하여 진폭혈 회절격자 효율을 측정하여 확인하였다. 시료는 5N의 순도를 갖는 Ge, Se, Ag 물질을 준비하였고, 이중 GeSe를 조성의 비에 맞추어서 석영관에 진공 봉입후 용융 혼합하고 급냉하여 비정질 빌크를 제작한다. 만들어진 비정질 벌크와 Ag를 열 증착법을 이용하여 기판에 올리는 방법으로 샘플을 제작한다. 제작된 샘플에 레이저와 몇몇 광학 소자로 구성된 흩로-리소그라피 장치를 이용하여 격자구조로 442nm 의 빛을 조사 시킨다. 결론으로는 기판은 칼코게나이드 박막에의 Ag 도핑에 영향을 미친다는 것을 확인하였다.

• 반도체디스플레이기술학회지
• /
• 제8권1호
• /
• pp.13-17
• /
• 2009

In PRAM applications, the devices can be made for both binary and multi-state storage. The ability to attain intermediate stages comes either from the fact that some chalcogenide materials can exist in configurations that range from completely amorphous to completely crystalline or from designing device structure such a way that mimics multiple phase chase phenomena in single cell. We have designed stack-structured phase change memory cell which operates as multi-state storage. Amorphous $Ge_xTe_{100-x}$ chalcogenide materials were stacked and a diffusion barrier was chosen for each stack layers. The device is operated by crystallizing each chalcogenide material as sequential manner from the bottom layer to the top layer. The amplitude of current pulse and the duration of pulse width was fixed and number of pulses were controlled to change overall resistance of the phase change memory cell. To optimize operational performance the thickness of each chalcogenide was controlled based on simulation results.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.174-175
• /
• 2007

A programmable metallization cell (PMC) memory structure with copper-saturated GeTe solid electrolyte films doped by nitrogen was prepared on a TiW bottom electrode by a co-sputtering technique at room temperature. The $Ge_{45}Te_{55}$ solid electrolyte films deposited with various $N_2$/Ar flow ratios showed an increase of crystallization temperature and especially, the electrolyte films deposited at $N_2$/Ar ratios above 30% showed a crystallization temperature above $400^{\circ}C$, resulting in surviving in a back-end process in semiconductor memory devices. The device with a 200 nm thick $Cu_{1-x}(Ge_{45}Te_{55})_x$ electrolyte switches at 1 V from an "off " state resistance, $R_{off}$, close to $10^5$ to an "on" resistance state, Ron, more than 20rders of magnitude lower for this programming current.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.52-52
• /
• 2009

To date, chalcogenide alloy such as $Ge_2Sb_2Te_5$(GST) have not only been rigorously studied for use in Phase Change Random Access Memory(PRAM) applications, but also temperature gap to make different states is not enough to apply to device between amorphous and crystalline state. In this study, we have investigated a new system of phase change media based on the In-Sb-Te(IST) ternary alloys for PRAM. IST chalcogenide thin films were prepared in trench structure (aspect ratio 5:1 of length=500nm, width=100nm) using Tri methyl Indium $(In(CH_3)_4$), $Sb(iPr)_3$ $(Sb(C_3H_7)_3)$ and $Te(iPr)_2(Te(C_3H_7)_2)$ precursors. MOCVD process is very powerful system to deposit in ultra integrated device like 100nm scaled trench structure. And IST materials for PRAM can be grown at low deposition temperature below $200^{\circ}C$ in comparison with GST materials. Although Melting temperature of 1ST materials was $\sim 630^{\circ}C$ like GST, Crystalline temperature of them was ~$290^{\circ}C$; one of GST were $130^{\circ}C$. In-Sb-Te materials will be good candidate materials for PRAM applications. And MOCVD system is powerful for applying ultra scale integration cell.

• 한국자기학회지
• /
• 제11권4호
• /
• pp.151-156
• /
• 2001

최근 망간산화물 Ln$_{1-x}$A$_{x}$MnO$_3$(Ln=La, Pr, Nd등의 lanthannide; A=Ca, Sr, Ba, Pb 등의 +2가 이온)는 초거대자기저항(CMR) 특성으로 많은 연구그룹의 주목을 받고 있다. 그런데 chalcogenide spinels에서도 CMR특성이 관측되는 것으로 보고되고 있다. 본 논문에서는 chalcogenide Ni$_{x}$Fe$_{1-x}$Cr$_2$S$_4$에서 Ni이온이 CMR 특성에 미치는 효과를 X선 회절 실험, 자기저항측정, 그리고 Mossbauer 분광실험으로 조사하였다. 그 결과 Ni이온의 치환은 Jahn-Teller distortion을 심화시키고, 또한 T$_{c}$ 값에 증가를 초래하여 CMR현상에 영향을 준다. T$_{c}$ 부근에서 일어나는 CMR현상은 망간산화물에서의 $Mn^{3+}$ 와 $Mn^{4+}$ 사이의 이중교환상호작용과는 다르게 동적 Jahn-Teller효과에 기인한 도체-반도체전이와 자기장하에서 절반 금속성의 에너지밴드구조를 갖는 시료의 스핀편향에 의한 전도현상 그리고 자기구역의 정렬에 의하여 발생되는 것으로 나타났다.