• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.54-57
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• 2003

[ $HfO_xN_y$ ] films using a hafnium tertiary-butoxide $(Hf[OC(CH_3)_3]_4)$ in plasma and $N_2$ ambient were prepared to improve the thermal stability of hafnium-based gate dielectrics. A 10% nitrogen incorporation into $HfO_2$ films showed a smooth surface morphology and a crystallization temperature as high as $200^{\circ}C$ compared with pure $HfO_2$ films. The $TaN/HfO_xN_y/Si$ capacitors showed a stable capacitance-voltage characteristics even at post-metal annealing temperature of $1000^{\circ}C$ in $N_2$ ambient and a constant value of 1.6 nm EOT (equivalent oxide thickness) irrespective of an increase of PDA and PMA temperature. Leakage current densities of $HfO_xN_y$ capacitors annealed at PDA temperature of 800 and $900^{\circ}C$, respectively were approximately one order of magnitude lower than that of $HfO_2$ capacitors.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.187-187
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• 2012

Solution-processed metal-alloy oxides such as indium zinc oxide (IZO), indium gallium zinc oxide (IGZO) has been extensively researched due to their high electron mobility, environmental stability, optical transparency, and solution-processibility. In spite of their excellent material properties, however, there remains a challenging problem for utilizing IZO or IGZO in electronic devices: the supply shortage of indium (In). The cost of indium is high, what is more, indium is becoming more expensive and scarce and thus strategically important. Therefore, developing an alternative route to improve carrier mobility of solution-processable ZnO is critical and essential. Here, we introduce a simple route to achieve high-performance and low-temperature solution-processed ZnO thin film transistors (TFTs) by employing alkali-metal doping such as Li, Na, K or Rb. Li-doped ZnO TFTs exhibited excellent device performance with a field-effect mobility of $7.3cm^2{\cdot}V-1{\cdot}s-1$ and an on/off current ratio of more than 107. Also, in case of higher drain voltage operation (VD=60V), the field effect mobility increased up to $11.45cm^2{\cdot}V-1{\cdot}s-1$. These all alkali metal doped ZnO TFTs were fabricated at maximum process temperature as low as $300^{\circ}C$. Moreover, low-voltage operating ZnO TFTs was fabricated with the ion gel gate dielectrics. The ultra high capacitance of the ion gel gate dielectrics allowed high on-current operation at low voltage. These devices also showed excellent operational stability.

• 한국응용과학기술학회지
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• 제29권2호
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• pp.184-192
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• 2012

본 논문은 절연유 불포함 재활용 가능 전력케이블 절연체에 동일배열 폴리프로필렌(IPP) 기반 열가소성 폴리올레핀 엘라스토머(TPO) 나노복합체 사용 가능성을 문헌적으로 고찰한 리뷰논문이다. 2010년 IPP 기반 나노복합 유전체는 파워 커패시터 연구에서 유전손실을 제외한 고전압 특성이 크게 향상되었다. IPP 기반 TPO 나노복합체 사용 자동차 외장부품 연구에서는 나노충전제 최대 3 wt% 함유로 전력케이블 절연체의 필수특성인 저온 충격성을 비롯한 기계적 특성향상이 보고 되었다. 특히 유전손실의 원천인 상용화제 사용의 최소화 기술이 보고되어, 3 wt% 이하 나노충전제 함유 IPP 기반 TPO의 전기적 특성조사가 필요하다.

• 한국재료학회지
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• 제11권1호
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• pp.44-47
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• 2001

Ni 전극을 사용하는 $BaTiO_3$계 내환원성 X7R 조성에서 $Er_2$$O_3$ 첨가가 유전특성에 미치는 영향에 대하여 환원성 분위기에서 연구하였다. $MnO_2-MgO$가 첨가된 내환원조성에서 첨가량이 조절된 $Er_2O_3$의 복합첨가로 유전율의 온도안정성이 향상되어 X7R 규격을 만족시켰으며 2,970 이상의 상온 유전상수와 1.0% 이하의 유전손실율이 관찰되었다. $Er_2O_3$가 3.0 mol% 이상으로 과량 첨가되었을 경우 유전체의 온도특성은 향상되었으나 상온 유전상수가 현저히 감소하였다. 다른 첨가조성(1.5 mol% $Er_2O_3$2.0 mol% MgO)이 고정될 때 TCC곡선은 $MnO_2$첨가량이 증가함에 따라 시계방향으로 회전하였으며, 온도안정성을 향상시켰다.

• 한국세라믹학회지
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• 제44권11호
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• pp.613-617
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• 2007

The variations of physical and dielectric properties of low temperature dielectrics based on typical aluminoborosilicate glasses modified with several divalent oxides were investigated. The divalent oxides studied here included CaO, MgO, BaO, SrO and ZnO. All samples containing either 35 wt% or 45 wt% alumina filler were prepared at the same processing condition and then fired at $850^{\circ}C$ for 30 min. The resultant characteristics of fired samples depended on the choice of the divalent ion and the content of the alumina filler. Except for the ZnO modification, all other samples containing 35 wt% filler demonstrated promising densification as they exhibited reasonably high densities of 3.07-3.31 $g/cm^3$ and high shrinkages of 14.0-16.4%. Particularly, the sample containing ZnO was distinguished with large variations compared to the base sample, which can be highlighted with earlier densification and crystallization at unexpectedly low temperatures. The negative effects of the ZnO modification on densification and dielectric properties were thought to be associated with earlier crystallization potentially by influencing effective densification via viscous flow. As an optimum composition, the sample containing only CaO showed the most promising characteristics such as $k{\sim}8.05$ and $tan{\delta}{\sim}0.0018$ when 35 wt% alumina filler was used.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.829-831
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• 1992

Ultrathin metal-oxide-semiconductor(MOS) gate dielectrics have been fabricated by conventional thermal oxidation in $N_2O$ ambient. Compared to oxides grown in $O_2$, $N_2O$ oxides exhibit significantly low flatband voltage and small shift in flatband voltage. $N_2O$ oxidation induces a slight decrease in mobile ionic charge density($N_m$), fixed charge density($N_f$) and surface state charge density($N_{ss}$). This study establishes that $N_2O$ oxides may have a great impact on future MOS ULSI technology in which ultrathin gate dielectrics are required.

• 한국전기전자재료학회논문지
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• 제15권7호
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• pp.576-582
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• 2002

Nonvolatile semiconductor memory devices with reoxidized nitrided oxide(RONO) gate dielectrics were fabricated, and nitrogen distribution and bonding species which contribute to memory characteristics were analyzed. Also, memory characteristics of devices depending on the anneal temperatures were investigated. The devices were fabricated by retrograde twin well CMOS processes with $0.35\mu m$ design rule. The processes could be simple by in-situ process in growing dielectric. The nitrogen distribution and bonding states of gate dielectrics were investigated by Dynamic Secondary Ion Mass Spectrometry(D-SIMS), Time-of-Flight Secondary Ion Mass Spectrometry(ToF-SIMS), and X-ray Photoelectron Spectroscopy(XPS). As the nitridation temperature increased, nitrogen concentration increased linearly, and more time was required to form the same reoxidized layer thickness. ToF-SIMS results showed that SiON species were detected at the initial oxide interface which had formed after NO annealing and $Si_2NO$ species within the reoxidized layer formed after reoxidation. As the anneal temperatures increased, the device showed worse retention and degradation properties. It could be said that nitrogen concentration near initial interface is limited to a certain quantity, so the excess nitrogen is redistributed within reoxidized layer and contribute to electron trap generation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.277.2-277.2
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• 2014

For next-generation electronic applications, human-machine interface devices have recently been demonstrated such as the wearable computer as well as the electronic skin (e-skin). For integration of those systems, it is essential to develop many kinds of components including displays, energy generators and sensors. In particular, flexible sensing devices to detect some stimuli like strain, pressure, light, temperature, gase and humidity have been investigated for last few decades. Among many condidates, a pressure sensing device based on organic field-effect transistors (OFETs) is one of interesting structure in flexible touch displays, bio-monitoring and e-skin because of their flexibility. In this study, we have investigated a flexible e-skin based on highly sensitive, pressure-responsive OFETs using microstructured ferroelectric gate dielectrics, which simulates both rapidly adapting (RA) and slowly adatping (SA) mechanoreceptors in human skin. In SA-type static pressure, furthermore, we also demonstrate that the FET array can detect thermal stimuli for thermoreception through decoupling of the input signals from simultaneously applied pressure. The microstructured highly crystalline poly(vinylidene fluoride-trifluoroethylene) possessing piezoelectric-pyroelectric properties in OFETs allowed monitoring RA- and SA-mode responses in dyanamic and static pressurizing conditions, which enables to apply the e-skin to bio-monitoring of human and robotics.

• 한국세라믹학회지
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• 제34권6호
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• pp.583-590
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• 1997

The effects of Mn2O3 and Y2O3 additives on the microstructure and dielectric properties of Sr(Zr, Ti)O3 have been investigated. Powders with Sr(Zr1-xTix)O3(0$\leq$x$\leq$0.1) composition were prepared by the conventional solid state processing from commercial TiO2 and precipitation-processed ZrO2. The powders containing sintering additives of Mn2O3 and Y2O3 were compacted and then sintered at 1,55$0^{\circ}C$ for 4 h to get>97% relative density. Mn2O3 suppressed the grain growth and Y2O3 enhanced the density of sintered body. The oxidation state of Mn ions were determined by a chemical wet method and EPR spectroscopy. Mn ions were present as Mn2+ and Mn4+ in SrZrO3, while as Mn3+ and Mn4+ in Ti-substituted Sr(Zr, Ti)O3. With the substitution of Ti, the lattice parameters of SrZrO3 decreased and its dielectric constant increased with remarkable decrease in Q value. The dielectric constant of Sr(Zr, Ti)O3 was in the range of 30 to 40, Q values 1,200~5,400 at 6 GHz and temperature coefficient of resonant frequency -67~100 ppm/K.

• E2M - 전기 전자와 첨단 소재
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• 제6권1호
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• pp.55-62
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• 1993

수소 관련된 species를 포함하지 않고 자기제한특성으로 초박막 성장을 용이하게 제어할 수 있는 N$_{2}$O 가스 분위기에서 실리콘의 산화는 질화된 산화막의 재산화공정 보다 훨씬 간단한 공정이다. N$_{2}$O산화로 형성된 Si-SiO$_{2}$ 계면에서 nitrogen-rich층은 산화막 구조를 강화할 뿐만 아니라 게이트 유전체의 질을 개선하고 산화율을 감소시키는 산화제의 확산 장벽으로 작용한다. 초박막 oxynitride 게이트 유전체가 종래의 열산화 방법으로 제작되었고 oxynitride막의 특성이 AES와 I-V 특성 측정의 결과를 분석하여 연구하였다.