• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2007년도 추계종합학술대회
• /
• pp.785-788
• /
• 2007

새롭게 제안된 밴드갭 기준전압 발생기는 PVT변동에 둔감하면서 기존의 밴드갭 기준전압 발생기보다 안정적인 동작을 하기 위해 요구되는 최소 전원전압(VDD)의 크기을 낮추었다. 모의실험 결과 전원전압(VDD)이 1.0V의 낮은 전압에서 안정적인 동작을 하는 것을 확인 하였다. 매그나칩 반도체 $0.18{\mu}m$ DDI 공정을 이용하여 Layout 하였고, 사이즈는 $409.36{\mu}m$ ${\times}$ $435.46{\mu}m$ 이다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.340.1-340.1
• /
• 2014

본 실험에서는 Ag두께 변화에 따른 투과율과 Energy bandgap의 변화를 알아보기 위해 RF Sputter장비와 Evaporator장비를 사용하여 IGZO, ZnO, AZO OMO 구조로 Low-e 코팅된 Glass를 제작하였다. $3cm{\times}3cm$의 Corning1737 유리기판에 RF Sputtering 방식으로 Oxide layer를 증착 하였고 Evaporator장비로는 Metal layer인 Ag막을 증착하였다. Oxide layer 증착 시 RF Sputter장비의 조건은 $3.0{\times}10^{-6}Torr$이하로 하였으며, 증착압력은 $6.0{\times}10^{-3}Torr$, 증착온도는 실온으로 고정하였다. Metal layer 증착 시 Evaporator장비의 조건은 $5.0{\times}10^{-6}Torr$이하, 전압은 0.3 V, Rotate 2 rpm으로 고정하였다. 실험 변수로는 Ag 두께를 5,7,9,11,13 nm로 변화를 주어 실험을 진행하였다. 투과도 측정 장비를 사용하여 각 샘플을 측정한 결과 IGZO의 경우 가시광영역의 평균 투과율이 80% 이상이며 Ag두께가 5nm일 때부터 자외선 영역의 빛을 차단하여 low-e 특성을 나타내었다. 이는 산화물인 IGZO가 결정질인 AZO, ZnO 보다 낮은 표면거칠기를 가지기 때문이다. Ag 두께에 따른 각 물질의 Optical energy bandgap 분석결과 Ag 두께가 증가할수록 IGZO는 4.65~4.5 eV, AZO는 4.6~4.4 eV, ZnO는 4.55~4.45 eV로 Energy bandgap은 감소하였다. AFM장비를 이용하여 각 샘플의 표면 Roughness 측정 결과 Ag 두께가 증가할수록 표면거칠기도 증가하는 경향을 나타내었다.

• 반도체디스플레이기술학회지
• /
• 제17권2호
• /
• pp.53-56
• /
• 2018

In this paper, a CMOS bandgap voltage reference that is not sensitive to changes in the external environment is presented. Large OLED display panels need high supply voltage. MOSFET devices with high voltage are sensitive to the output voltage due to the channel length modulation effect. The self-cascode circuit was applied to the bandgap reference circuit. Simulation results show that the maximum output voltage change of the basic circuit is 77mV when the supply voltage is changed from 10.5V to 13.5V, but the proposed circuit change is improved to 0.0422mV. The improved circuit has a low temperature coefficient of $9.1ppm/^{\circ}C$ when changing the temperature from $-40^{\circ}C$ to $140^{\circ}C$. Therefore, the proposed circuit can be used as a reference voltage source for circuits that require a high supply voltage.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.39.2-39.2
• /
• 2010

In this work we have investigated electrical and optical properties of interface for ITO/Si with shallow doped emitter. The ITO is prepared by DC magnetron sputter on p-type monocrystalline silicon substrate. As an experimental result, The transmittance at 640nm spectra is obtained an average transmittance over 85% in the visible range of the optical spectrum. The energy bandgap of ITO at oxygen flow from 0% to 4% obtained between 3.57eV and 3.68eV (ITO : 3.75eV). The energy bandgap of ITO is depending on the thickness, sturcture and doping concentration. Because the bandgap and position of absorption edge for degenerated semiconductor oxide are determined by two competing mechanism; i) bandgap narrowing due to electron-electron and electron-impurity effects on the valance and conduction bands (> 3.38eV), ii) bandgap widening by the Burstein-Moss effect, a blocking of the lowest states of the conduction band by excess electrons( < 4.15eV). The resistivity of ITO layer obtained about $6{\times}10^{-4}{\Omega}cm$ at 4% of oxygen flow. In case of decrease resistivity of ITO, the carrier concentration and carrier mobility of ITO film will be increased. The contact resistance of ITO/Si with shallow doped emitter was measured by the transmission line method(TLM). As an experimental result, the contact resistance was obtained $0.0705{\Omega}cm^2$ at 2% oxygen flow. It is formed ohmic-contact of interface ITO/Si substrate. The emitter series resistance of ITO/Si with shallow doped emitter was obtained $0.1821{\Omega}cm^2$. Therefore, As an PC1D simulation result, the fill factor of EWT solar cell obtained above 80%. The details will be presented in conference.

• 마이크로전자및패키징학회지
• /
• 제30권1호
• /
• pp.1-16
• /
• 2023

전기차용 전력변환모듈의 성능향상 요구와 종래의 Si 전력반도체의 한계 극복을 위해 차세대 전력반도체인 wide-bandgap (WBG) 기반 전력반도체로의 전환이 가속화되고 있다. WBG 전력반도체로의 전환을 위해 전력변환모듈 패키징 소재 역시 높은 고온 내구성을 요구받고 있다. 전력변환모듈 패키징 공정 중 하나인 Ag 소결 다이접합 기술은 종래의 고온용 Pb 솔더링의 대체 기술로 주목받고 있다. 본 논문에서는 Ag 소결 다이접합 기술 관련 최신 연구동향에 대해 소개하고자 한다. 소결 다이접합 공정 조건에 따른 접합부 특성을 비교하고 Ag 소결층의 3차원 이미지 구현에 따른 다공성 Ag 소결 접합부의 물성 측정 방법론에 대해 고찰하였다. 또한 열충격 및 파워사이클 신뢰성 평가 연구동향을 분석하였다.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
• /
• pp.111-111
• /
• 2003

The peroxo titanic acid solution was successfully prepared using titanium trichloride as a precursor. The basic properties of the TiO2 film prepared by the solution were investigated in view of phase change, bandgap energy, crystalline size etc. The film displayed amorphous TiO$_2$ at room temperature, anatase above 281$^{\circ}C$ and a mixture of anatase and rutile at 99$0^{\circ}C$, The crystalline size increases with annealing temperatures, while the bandgap energies decrease due to the quantum size effect and the formation of rutile phase which has low bandgap energy. As a result of TG-DTA, it was found that annealing treatment at 99$0^{\circ}C$ for 2h formed a mixtures of anatase and rutile through three steps: (1) the removal of physically adsorbed water (2) the decomposition of peroxo group (3) amorphous-anatase or anatase-rutile phase transformation.

• Journal of information and communication convergence engineering
• /
• 제14권3호
• /
• pp.184-190
• /
• 2016

We present experimental demonstrations of electromagnetic bandgap (EBG) structures for the wideband suppression of radiated emissions from a power bus in high-speed printed circuit boards (PCBs). In most of the PCB designs, a parallel plate waveguide (PPW) structure is employed for a power bus. This structure significantly produces the wideband-radiated emissions resulting from parallel plate modes. To suppress the parallel plate modes in the wideband frequency range, the power buses based on the electromagnetic bandgap structure with a defected ground structure (DGS) are presented. DGSs are applied to a metal plane that is connected to a rectangular EBG patch by using a via structure. The use of the DGS increases the characteristic impedance value of a unit cell, thereby substantially improving the suppression bandwidth of the radiated emissions. It is experimentally demonstrated that the DGS-EBG structure significantly mitigates the radiated emissions over the frequency range of 0.5 GHz to 2 GHz as compared to the PPW.

• Journal of Korean Vacuum Science & Technology
• /
• 제6권4호
• /
• pp.139-142
• /
• 2002

Contactless electroreflectance measurements at room temperature were used to determine the bandgap energies of Zn$_{1-x}$ Mg$_{x}$O thin films grown by metal-organic vapor phase epitaxy. It is found that the bandgap energy increases monotonically with the Mg composition x, up to the highest composition measured (x=0.45). The obtained correlation between the bandgap energy and the Mg composition can be used in the analysis of the electronic structure of ZnO/Zn$_{1-x}$ Mg$_{x}$O heterostructures at room temperature.ature.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
• /
• pp.1447-1450
• /
• 2007

The electrical properties of organic lightemitting devices (OLEDs) with wide-bandgap impurity-doped emitting layers (EML) were investigated. While the luminous efficiency of OLEDs with a NPB or a DPVBi-doped $Alq_3$ EML did not vary significantly with the current density, that of the OLEDs with a BCP-doped $Alq_3$ EML changed dramatically.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
• /
• pp.609-611
• /
• 2006

This paper describes a CMOS sub-bandgap reference using Pseudo-Resistors which can be widely used in flash memory, DRAM, ADC and Power management circuits. Bandgap reference circuit operates weak inversion for reducing power consumption and uses Pseudo-Resistors for reducing the chip area, instead of big resistor. It is implemented in 0.35um Standard 1P4M CMOS process. The temperature coefficient is 5ppm/$^{\circ}C$ from $40^{\circ}C$ to $100^{\circ}C$ and minimum power supply voltage is 1.2V The core area is 1177um${\times}$617um. Total current is below 2.8uA and output voltage is 0.598V at $27^{\circ}C$.