• Journal of Electrical Engineering and information Science
• /
• 제2권6호
• /
• pp.212-216
• /
• 1997

A new metal tip fabrication process for low voltage operation is reported in this paper. The key element of the fabrication process is that isotropic silicon etching and oxidation process used in silicon tip fabrication is utilized for gate hole size reduction and gate oxide layer. A metal FEA with 625 tips was fabricated in order to demonstrate the validity of the new process and submicron gate apertures were successfully obtained from originally 1.7$\mu\textrm{m}$ diameter mask. The emission current above noise level was observed at the gate bias of 50V. The required gate voltage to obtain the anode current of 0.1${\mu}\textrm{A}$/tip was 74V and the emission current was stable above 2${\mu}\textrm{A}$/tip without any disruption. The local field conversion factor and the emitting area were calculated as 7.981${\times}$10\ulcornercm\ulcorner and 3.2${\times}$10\ulcorner$\textrm{cm}^2$/tip, respectively.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 추계학술대회 논문집
• /
• pp.245-245
• /
• 2009

l-D nanostructured materials have much more attention because of their outstanding properties and wide applicability in device fabrication. Copper oxide(CuO) has been realized as a p-type metal oxide semiconductor with narrow band gap of 1.2 -1.5eV. Copper oxide nanostructures can be synthesized by various growth method such as oxidation reaction, thermal evaporation thermal decomposition, sol-gel. and Mostly CuO nanowire prepared on the Cu substrate such as Copper foil, grid, plate. In this study, CuO NWs were grown by thermal oxidation (at various temperatures in air (1 atm)) of Cu metal deposited on CuO (20nm)/$SiO_2$(250nm)/Si. A 20nm-thick CuO layer was used as an adhesion layer between Cu metal and $SiO_2$

• Bulletin of the Korean Chemical Society
• /
• 제33권6호
• /
• pp.1925-1928
• /
• 2012

Adsorption of alkali metals (Li, Na, and K) on the surface of magnesium oxide nanotubes (MgONTs) with different diameters was investigated using density functional theory. According to the obtained results, the most stable adsorption site was found to be atop the oxygen atom of the tube surface with adsorption energies in the range of -0.25 to -0.74 eV. HOMO-LUMO gap ($E_g$) of the tubes dramatically decreases upon the adsorption of the alkali metals, resulting in enhancement of their electrical conductivity enhancement. The order of $E_g$ decrement caused by the metal adsorption is as follows: K > Na > Li. The results suggest that the MgONTs were transformed from semi-insulator to semiconductor upon the alkali metal adsorption. Increasing the tube diameter, the HOMO/LUMO gap of the pristine tube is enhanced and adsorption energies of the alkali metals are decreased.

• Transactions on Electrical and Electronic Materials
• /
• 제3권3호
• /
• pp.14-17
• /
• 2002

The HDP (High Density Plasma) CVD process consists of a simultaneous sputter etch and chemical vapor deposition. As CMOS process continues to scale down to sub- quarter micron technology, HDP process has been widely used fur the gap-fill of small geometry metal spacing in inter-metal dielectric process. However, HBP CVD system has some potential problems including plasma-induced damage. Plasma-induced gate oxide damage has been an increasingly important issue for integrated circuit process technology. In this paper, thin gate oxide charge damage caused by HDP deposition of inter-metal dielectric was studied. Multiple step HDP deposition process was demonstrated in this work to prevent plasma-induced damage by introducing an in-situ top SiH$_4$ unbiased liner deposition before conventional deposition.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
• /
• pp.692-696
• /
• 1997

본 연구에서는 BJT(Bipolar Junction Transistor)와 MOSFET (Metal Oxide Semiconductor Field Effect Transistor) 등을 1MeV에너지의 전자빔을 선량을 변화시켜가며 조사시켜 그 특성 변화를 분석하였다. BJT에 대해서는 조사 전, 후의 전류 이득의 측정을 통해 base 에서의 minority-carrie의 수명 변화에 의해서 전류 이득이 감소하는 것으로 나타났으며, MOSFET의 경우는 oxide 지역의 전하량 변화에 의해서 문턱 전압이 영향을 받음을 확인할 수 있었다. BJT의 minority-carrier의 수명 감소량은 조사 선량이 증가함에 따라 직선적으로 변화함을 알 수 있었고, MOSFET의 문턱 전압의 변화는 nMOS와 pMOS의 경우 서로 다름을 관찰할 수 있었는데 이는 oxide내에서 발생하는 전하에 의해 차이가 남을 알 수 있었다.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2013년도 춘계학술대회 논문집
• /
• pp.102-103
• /
• 2013

As an important p-type semiconductor metal oxide with a narrow band gap (1.2 - 2.6eV), copper oxide (Cu2O) has been studied because of its various applications as material for heterogeneous catalysts, gas sensors, optical switch, lithium-ion electrode materials, field emission devices, solar cells. The fundamental properties of oxide-semiconductor can be greatly affected by the surface morphology, size, geometry and spatial orientation.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
• /
• pp.401-406
• /
• 1997

This paper presents preliminary results on the degradation of BJTs(Bipolar Junction Transistors) and MOSFETs(Metal Oxide Semiconductor Field Effect Transistors) by 1MeV electron beam. Exposure experimental results show that the change of minority-carrier life time in base region dominates the behavior of BJTs and that the buildup of charges in oxide region can affect the value of threshold voltage for MOSFETs. It was possible to correlate the decrease of the minority-carrier life time of BJTs with irradiation dose, while the shift of MOSFETs' threshold voltage was not only a function of charge buildup in oxide region.

• 반도체디스플레이기술학회지
• /
• 제20권2호
• /
• pp.87-91
• /
• 2021

Various Cu ions are discharged into water from various industries, which results in a severe trouble for groundwater, soil, air, and eventually animals and humans. In this work, graphene oxide (GO) is introduced as a Cu removal absorber and the real-time monitoring method is demonstrated. The results show that GO is a very effective material to absorb Cu ions in the solution. In addition, the residual Cu ions in the solution is monitored via optical transmittance method, which well match with Inductively Coupled Plasma Mass Spectrometer (ICP-MS) analysis.

• Korean Chemical Engineering Research
• /
• 제47권2호
• /
• pp.141-149
• /
• 2009

초고속 연산용 CMOS(complementary Metal Oxide Semiconductor) 배선재료로 사용되고 있는 구리(Cu)가, 기가급 메모리 소자용 금속 배선 물질에도 사용이 시작되면서 구리 박막에 대한 재료 및 공정이 새로운 조명을 받고 있다. 반도체 금속 배선에 사용하는 수 nm 두께의 구리 박막의 형성에 전해도금(electrodeposition)과 무전해 도금(electroless deposition) 같은 전기화학적 방법을 이용하게 되어서 표면 처리, 전해액 조성과 같은 중요한 요소에 대한 최신 연구 동향을 요약하였다. 구리 박막에서 구리 배선을 제작하여야 하므로 새로운 패턴 기술인 상감기법이 도입되어, 구리도금과 상감기법과의 공정 일치성 관점에서 전해도금과 무전해 도금의 요소 기술에 대해 기술하였다. 구리보다 비저항이 낮아 차세대 소자용 배선에 있어서 적용이 예상되는 은(Ag)을 전기화학적 방법으로 금속 배선에 적용하는 최신 연구에 대하여도 소개하였다.

• 센서학회지
• /
• 제28권6호
• /
• pp.377-384
• /
• 2019

People currently spend more than 80% of their time indoors; therefore, the management of indoor air quality has become an important issue. The contamination of indoor air can cause sick house syndrome and various environmental diseases such as atopy and nephropathy. Formaldehyde gas, which is the main contaminant of indoor air, is lethal even with microscopic exposure; however, it is commonly used as an adhesive and waterproofing agent for indoor building materials. Therefore, there is a need for a gas sensor capable of detecting trace amounts of formaldehyde gas. In this review, we summarize recent studies on metal oxide-based semiconductor gas sensors for formaldehyde gas detection, methods to improve the gas-sensing properties of metal oxides of various dimensions, and the effects of catalysts for the detection of parts-per-billion level gases. Through this, we discuss the necessary characteristics of the metal oxidebased semiconductors for gas sensors for the development of next-generation sensors.