• 전자공학회논문지A
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• 제32A권8호
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• pp.78-85
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• 1995

We fabricated the Pb$_{1-0.28{\alpha}}La_{0.28}TiO_{3}$ (PLT(28)) thin film successfully by using the sol-gel method and characterized it to evaluate its potential for being utilized as the capacitor dielectrics of ULSI DRAMs. In our sol-gel process, the acetates were used as the starting materials. Through the TGA-DTA analysis, we established the excellent fabrication conditions of the sol-gel method for the PLT(28) thin film. We obtained the dense and crack-free PLT(28) thin film of 100% perovskite phase by drying at 350$^{\circ}C$ after each coating and final annealing at 650$^{\circ}C$. Its electrical properties were measured from the planar capacitors fabricated on the Pt/Ti/SiO$_{2}$/Si substrate. By the P-E hysteresis measurement, its paraelectric phase was identified and its dielectric constant and leakage current density were measured as 936 and 1.1${\mu}A/cm^{2}$, respectively. Those electrical values indicate that the PLT(28) thin film is the most successful candidate for the capacitor dielectrics of ULSI DRAMs at the present.

• 한국재료학회지
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• 제6권12호
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• pp.1233-1241
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• 1996

본 연구에서는 BPSG(borophosphosilicate glass)/SiO2/Si 기판상에 5000$\AA$의 구리박막을 화학증착한 후 Ar 분위기하 250-55$0^{\circ}C$, 5-90초 급속열처리하여 열처리 전후의 결정구조, 면저항, 미세구조의 박막특성 변화를 분석하였다. 후열처리된 구리박막에서는 결정성 및 (111) 배향의개선과 함께 결정립 성장이 확인되었으나, 구리의 표면산화반응과 BPSG 내로의 급속한 확산에 의해 전기적 특성의 개선은 미미하였다. 그리고 열처리 박막내에는 구리 실리사이드상의 형성이 발견되지 않았으며, 25$0^{\circ}C$/90초의 저온 장시간 또는 55$0^{\circ}C$/20초의 고온 단시간 조건에서 전형적으로 나타나는 Cu2O 상이 시편의 전기비저항 증가와 표면열화에 직접적으로 영향을 미쳤다. 또한, 이들 결과로부터 급속열처리법에 의한 Cu/BPSG 열처리의 공정범위를 규명할 수 있었다.

• ETRI Journal
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• 제31권6호
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• pp.660-666
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• 2009

We investigate the effects of interfacial dielectric layers (IDLs) on the electrical properties of top-gate In-Ga-Zn-oxide (IGZO) thin film transistors (TFTs) fabricated at low temperatures below $200^{\circ}C$, using a target composition of In:Ga:Zn = 2:1:2 (atomic ratio). Using four types of TFT structures combined with such dielectric materials as $Si_3N_4$ and $Al_2O_3$, the electrical properties are analyzed. After post-annealing at $200^{\circ}C$ for 1 hour in an $O_2$ ambient, the sub-threshold swing is improved in all TFT types, which indicates a reduction of the interfacial trap sites. During negative-bias stress tests on TFTs with a $Si_3N_4$ IDL, the degradation sources are closely related to unstable bond states, such as Si-based broken bonds and hydrogen-based bonds. From constant-current stress tests of $I_d$ = 3 ${\mu}A$, an IGZO-TFT with heat-treated $Si_3N_4$ IDL shows a good stability performance, which is attributed to the compensation effect of the original charge-injection and electron-trapping behavior.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2007년도 추계학술연구발표회 및 정기총회
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• pp.42-42
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• 2007

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권4호
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• pp.266-272
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• 2009

In the present work three dimensional process and device simulations were employed to study the performance variations with RTA. It is observed that with the increase in RTA temperature, the arsenic dopants from the source /drain region diffuse laterally under the spacer region and simultaneously acceptors (Boron) are redistributed from the central axis region of the fin towards the Si/SiO2 interface. As a consequence both drive current and peak cut-off frequency of an n-FinFET are observed to improve with RTA temperatures. Volume inversion and hence the flow of carries through the central axis region of the fin due to reduced scattering was found behind the performance improvements with increasing RTA temperature.

• 한국분말재료학회지
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• 제10권3호
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• pp.190-194
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• 2003

Thin Ag films deposited onto $SiO_2/Si$ substrates by DC magnetron sputtering and thereafter annealed ,it temperatures 100-50$0^{\circ}C$ are investigated by scanning tunneling and atomic forte microscopy. It is shown that the film surface topography and microstructure are considerably changed as a result of annealing. To provide a quantitative estimation of the surface topography changes of Ag films the surface fractal dimension was calculated. Elasticity and hardness of the films are studied by a nanoindentation technique. The films are found to have value of elastic modulus close to that of bulk silver while their hardness and yield stress are essentially higher.

• 한국재료학회지
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• 제4권2호
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• pp.143-151
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• 1994

$(PbZr_{52},Ti_{48})O_{3}$인 composite ceramic target을 사용하여 R. F. 마그네트론 스퍼터링 방법으로 기판온도 $300^{\circ}C$에서 Pt/Ti/Si 기판위에 PZT 박막을 증착하였다. 페롭스 카이트 PZT박막을 얻기 위하여 PbO분위기에서 로열처리를 행하였다. 하부전극으로 Pt를 사용하였으며 Pt(205$\AA$)/Ti(500 $\AA$)/Si 및 Pt(1000$\AA$)/Ti(500$\AA$)/Si기판을 준비하여 Pt두께화 Ti층이 산소의sink로 작용함으로서 이를 가속화하였다. Ti층의 상부는 산소의 확산으로 인하여 TiOx층으로 변태하였고 하부는 in diffused Pt와 함께 실리사이드층을 형성하였다. TiOx 층의 형성은PZT층의 방향성에 영향을 주었다. 유전상수 (10kHz), 누설전류, 파괴전압, 잔류분극 및 항전계는 각각 571, 32,65$\mu A /\textrm{cm}^2$, 0.40MV/cm, 3.3$\mu C /\textrm{cm}^2$, 0.15MV/cm이었다.

• KIEE International Transactions on Electrophysics and Applications
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• 제12C권4호
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• pp.208-213
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• 2002

The present study describe the electrical performance of amorphous T $a_2$ $O_{5-X}$ fabricated on the buffer layers Ti and Ti $O_2$. T $a_2$ $O_{5-X}$ thin films were grown on the Ti and Ti $O_2$ layers as a capacitor layer using reactive sputtering method. The X-ray pattern analysis indicated that the two as-deposited films were amorphous and the amorphous state was kept stable on the RTA(rapid thermal annealing) at even $700^{\circ}C$. Measurements of dielectric properties of the reactive sputtered T $a_2$ $O_{5-X}$ thin films fabricated in two simple MIS(metal insulator semiconductor), structures, (Cu/T $a_2$ $O_{5}$ Ti/Si and CuT $a_2$ $O_{5}$ Ti $O_2$Si) show that the amorphous T $a_2$ $O_{5}$ grown on Ti showed high dielectric constant (23～39) and high leakage current density(10$^{-3}$ ～10$^{-4}$ (A/$\textrm{cm}^2$)), whereas relatively low dielectric constant (～15) and tow leakage current density(10$^{-9}$ ～10$^{-10}$ (A/$\textrm{cm}^2$)) were observed in the amorphous T $a_2$ $O_{5}$ deposited on the Ti $O_2$ layer. The electrical behaviors of the T $a_2$ $O^{5}$ thin films were attributed to the contribution of Ti- $O_2$ and the compositionally gradient Ta-Ti-0, being the low dielectric layer and high leakage current barrier. In additional, The T $a_2$ $O_{5}$ Ti $O_2$ thin films exhibited dominant conduction mechanism contributed by the Poole-Frenkel emission at high electric field. In the case of T $a_2$ $O_{5}$ Ti $O_2$ thin films were related to the diffusion of Ta, Ti and O, followed by the creation of vacancies, in the rapid thermal treated thin films.films.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.60.2-60.2
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• 2011

A study of the non-linear optical properties of nanocrystal-Si embedded in SiO2 has been performed by using the z-scan method in the nanosecond and femtosecond ranges. Substoichiometric SiOx films were grown by plasma-enhanced chemical-vapor deposition(PECVD) on silica substrates for Si excesses up to 24 at/%. An annealing at $1250^{\circ}C$ for 1 hour was performed in order to precipitate nanocrystal-Si, as shown by EFTEM images. Z-scan results have shown that, by using 5-ns pulses, the non-linear process is ruled by thermal effects and only a negative contribution can be observed in the non-linear refractive index, with typical values around $-10-10cm^2/W$. On the other hand, femtosecond excitation has revealed a pure electronic contribution to the nonlinear refractive index, obtaining values in the order of 10-12 cm2/W. Simulations of heat propagation have shown that the onset of the temperature rise is delayed more than half pulse-width respect to the starting edge of the excitation. A maximum temperature increase of ${\Delta}T=123.1^{\circ}C$ has been found after 3.5ns of the laser pulse maximum. In order to minimize the thermal contribution to the z-scan transmittance and extract the electronic part, the sample response has been analyzed during the first few nanoseconds. By this method we found a reduction of 20% in the thermal effects. So that, shorter pulses have to be used obtain just pure electronic nonlinearities.

• 한국진공학회지
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• 제19권4호
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• pp.293-299
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• 2010

수열합성법으로 실리콘 (111) 기판 위에 산화아연 나노막대를 성장하였다. 산화아연 나노막대를 성장하기 전, 실리콘 기판에 스핀코팅법으로 씨앗층을 성장하였다. 산화아연 나노막대는 오토클레이브(autoclave)로 $140^{\circ}C$에서 6시간 동안 성장하였고, 아르곤 분위기에서 300, 500, $700^{\circ}C$의 온도로 20분 동안 열처리하였다. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), photoluminescence (PL)를 이용하여 열처리한 산화아연 나노막대의 구조적, 광학적 특성을 분석하였다. 모든 산화아연 나노막대 시료에서 c-축 배향성을 나타내는 강한 ZnO (002) 회절 피크와 약한 ZnO (004) 회절 피크가 나타났다. 열처리 온도가 증가함에 따라 산화아연 나노로드의 residual stress는 compressive에서 tensile로 변하였다. Hexagonal 형태의 산화아연 나노로드를 관찰하였다. 산화아연 나노로드의 PL 스펙트럼은 free-exciton recombination에 의해 3.2 eV에서 좁은 near-band-edge emission (NBE) 피크와 산화아연 나노막대의 결함에 의해 2.12~1.96 eV에서 넓은 deep-level emission (DLE) 피크가 나타났다. 산화아연 나노막대를 열처리함에 따라, NBE 피크의 세기는 감소하였고 DLE 피크는 열처리에 의해 발생한 산소 관련 결함에 의하여 적색편이 하였다.