• Korean Journal of Materials Research
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• v.19 no.1
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• pp.37-43
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• 2009

Silicon dioxide as gate dielectrics was grown at $400^{\circ}C$ on a polycrystalline Si substrate by inductively coupled plasma oxidation using a mixture of $O_2$ and $N_2O$ to improve the performance of polycrystalline Si thin film transistors. In conventional high-temperature $N_2O$ annealing, nitrogen can be supplied to the $Si/SiO_2$ interface because a NO molecule can diffuse through the oxide. However, it was found that nitrogen cannot be supplied to the Si/$SiO_2$ interface by plasma oxidation as the $N_2O$ molecule is broken in the plasma and because a dense Si-N bond is formed at the $SiO_2$ surface, preventing further diffusion of nitrogen into the oxide. Nitrogen was added to the $Si/SiO_2$ interface by the plasma oxidation of mixtures of $O_2/N_2O$ gas, leading to an enhancement of the field effect mobility of polycrystalline Si TFTs due to the reduction in the number of trap densities at the interface and at the Si grain boundaries due to nitrogen passivation.

• Transactions on Electrical and Electronic Materials
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• v.10 no.1
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• pp.24-27
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• 2009

N-doped ZnO thin films were deposited on n-type Si(100) and homo-buffer layer, and undoped ZnO thin film was also deposited on homo-buffer layer by RF magnetron sputtering method. After deposition, all films were in-situ annealed at $800^{\circ}C$ for 5 minutes in ambient of $O_2$ with pressure of 10Torr. X -ray diffraction shows that the homo-buffer layer is beneficial to the crystalline of N-doped ZnO thin films and all films have preferable c-axis orientation. Atomic force microscopy shows that undoped ZnO thin film grown on homo-buffer layer has an evident improvement of smoothness compared with N-dope ZnO thin films. Hall-effect measurements show that all ZnO films annealed at $800^{\circ}C$ possess p-type conductivities. The undoped ZnO film has the highest carrier concentration of $1.145{\times}10^{17}cm{-3}$. The photoluminescence spectra show the emissions related to FE, DAP and many defects such as $V_{Zn}$, $Zn_O$, $O_i$ and $O_{Zn}$. The p-type defects ($O_i$, $V_{Zn}$, and $O_{Zn}$) are dominant. The undoped ZnO thin film has a better p-type conductivity compared with N-doped ZnO thin film.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1529-1530
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• 2007

The manganese co-doped $Ca_8Mg_1(SiO_4)_4Cl_2:Eu^{2+}$,$Mn^{2+}$ phosphor was synthesized by solid-state reaction and its photoluminescence characteristics were investigated. The synthesized phosphor show two emission spetrums: green band of 512nm and yellow band of 550nm. White light-emitting diodes (LEDs) were fabricated through combination of a 405nm-emitting InGaN chip and a synthesis phosphor in a single package. Under 20mA current, its CIE chromaticity coordinates are x=0.40 and y=0.45 and a color temperature of 4053K.

• Journal of Information Display
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• v.13 no.3
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• pp.107-111
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• 2012

An almost pure phase of $Ba_3Si_6O_{12}N_2$ doped with $Eu^{2+}$ was successfully synthesized through the ammonia nitridation of an oxide precursor prepared through an aqueous-solution method, using propylene- glycol-modified silane. The emission peak intensity of the obtained $Ba_3Si_6O_{12}N_2:Eu^{2+}$ was -2.2 times higher than that of the sample prepared through a solid-state reaction method.

• Journal of the Korean Ceramic Society
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• v.38 no.12
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• pp.1144-1149
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• 2001

In this research, the fabrication of Si/SiO$_2$optical waveguide amplifier by FHD(Flame Hydrolysis Deposition) and Solution Doping was carried out. It was observed that the reduction of fluorescence was prevented up to 0.14 wt% Er whn 0.48 wt% Al was doped and the FWHA of $1.5mutextrm{m}$ fluorescence band increased by 5 nm as increasing amount of Al. Therefore from these results, we could confirm depressing concentration quenching of Er ions and increasing FWHM of fluorescence spectrum by addition of Al.

• Transactions on Electrical and Electronic Materials
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• v.10 no.3
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• pp.89-92
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• 2009

High-quality Al-N doped p-type ZnO thin films were deposited on Si and buffer layer/Si by DC magnetron sputtering in a mixture of $N_2$ and $O_2$ gas. The target was ceramic ZnO mixed with $Al_2O_3$ (2 wt%). The p-type ZnO thin films showed a carrier concentration in the range of $1.5{\times}10^{15}{\sim}2.93{\times}10^{17}\;cm^{-3}$, resistivity in the range of 131.2${\sim}$2.864 ${\Omega}cm$, mobility in the range of 3.99${\sim}$31.6 $cm^2V^{-1}s^{-l}$, respectively. It was easier to dope p-type ZnO films on Si substrates than on buffer layer/Si. The film grown on Si showed the highest quality of photoluminescence (PL) characteristics. The Al donor energy level depth $(E_d)$ of Al-N codoped ZnO films was reduced to about 50 meV, and the N acceptor energy level depth $(E_a)$ was reduced to 63 meV.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.2
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• pp.178-183
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• 2004

PBT thin film was known to be a representative for the FeRAM devices because of its good ferroelectric proporties and the ease in fabricating the thin film. However, there have been several problems such as polarization fatigue and leakage current in memory devices with a PZT thin film. In this study, Sm-dolled PZT thin films were fabricated by the so1-gel method, and their ferroelectric and dielectric proportrics were compared as a function of Sm content. We investigated the effect of the Sm dopant on structural and electrical properties of PZT film. Sm-doped PZT thin films on the Pt/Ti/SiO$_2$/Si substrates have been prepared by a sol-gel method. The remanent polarization and coercive field decreased with increasing the concentration of Sm. The dielectric constant and dielectric loss decreased with Increasing Sm content. Sm-doped PZT thin films showed improved fatigue characteristics compared to the undoped PZT thin film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.218-218
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• 2010

본 연구에서는 투명 전극 대체 물질로써 유망한 ZnO의 전기적 특성 향상을 위하여 IV족 원소인 Si을 1, 3, 5 wt% 첨가하여 SZO 박막을 제작하여 dopant의 앙, 온도 변화에 따른 전기적, 광학적, 구조적 특성을 분석하였다. Rf-magnetron sputtering system을 이용하여 slide glass위에 증착 하였으며 $100{\sim}500^{\circ}C$ 온도 변화를 주었다. 결정성 분석을 위한 XRD 분석 결과 온도 증가에 따라 (002) peak의 세기가 증가하며, Si 첨가량과 관계없이 동일한 2 theta에서 peak가 관측되었다. 미세 구조 분석 결과 입자 크기 또한 온도 증가에 따라 증가함을 확인하였으며, 박막 두께는 대략 300nm로 확인하였다. 모든 SZO 박막은 가시광선 영역에서 80% 이상의 투과율을 보였으며 PL 분석 결과 Si 첨가량과 관계없이 동일한 스펙트럼을 가지며 380 nm, 540 nm 근처에서 peak를 확인하였다. 최소 비저항 값은 5SZO 막에서 $2.44{\times}10^{-3}\;{\Omega}cm^{-1}$을 보였다.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.134-135
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• 2002

Sm$^{2＋}$가 도핑된 불화물 결정은 실온에서 영구적 스펙트럼 홀 생성이 나타나며, 이러한 실온에서의 영구적 스펙트럼 홀 생성은 새로운 광 메모리의 개발에 매우 중요하므로 많은 관심을 받고 있다. 본 연구에서는 Sm$^{2＋}$가 도핑된 10Al$_2$O$_3$.90SiO$_2$ 박막을 제조하여 SEM 및 발광 스펙트럼(Photo-Luminescence; PL)을 측정함으로서 제조된 박막의 구조적, 광학적 특성을 조사하였다. (중략)

• Transactions on Electrical and Electronic Materials
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• v.13 no.4
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• pp.192-195
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• 2012

We reported diborane ($B_2H_6$) doped wide bandgap hydrogenated amorphous silicon oxide (p-type a-SiOx:H) films prepared by using silane ($SiH_4$) hydrogen ($H_2$) and nitrous oxide ($N_2O$) in a radio frequency (RF) plasma enhanced chemical vapor deposition (PECVD) system. We improved the $E_{opt}$ and conductivity of p-type a-SiOx:H films with various $N_2O$ and $B_2H_6$ ratios and applied those films in regards to the a-Si thin film solar cells. For the single layer p-type a-SiOx:H films, we achieved an optical band gap energy ($E_{opt}$) of 1.91 and 1.99 eV, electrical conductivity of approximately $10^{-7}$ S/cm and activation energy ($E_a$) of 0.57 to 0.52 eV with various $N_2O$ and $B_2H_6$ ratios. We applied those films for the a-Si thin film solar cell and the current-voltage characteristics are as given as: $V_{oc}$ = 853 and 842 mV, $J_{sc}$ = 13.87 and 15.13 $mA/cm^2$. FF = 0.645 and 0.656 and ${\eta}$ = 7.54 and 8.36% with $B_2H_6$ ratios of 0.5 and 1% respectively.