한국의 4M DRAM 공동연구개발 사례연구(상(上))

주대영,Joo, Dae-Young 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.1

4M D램 공동연구 개발사업(1986.10~89.03)은 당시 미 일의 강력한 기술보호주의를 극복하기 위한 자구책으로 시작되었다. 국내 반도체업계는 선진국의 높은 기술장벽 및 기술보호주의를 극복하고, 강력한 경쟁력확보 및 기술축적을 위해 정부에 건의하였다. 이에 정부는 적극적인 자금지원을 통해 4M D램 개발 및 주변기술 개발을 목표로 초고집적반도체기술공동개발사업을 수행하게 되었다. 본 공동R&D사업은 ETRI의 주관으로 당시 금성반도체, 삼성전자, 현대전자산업 등의 반도체 업체와 학계가 참여하였고, 1986년 10월부터 1989년 3월까지 3단계에 걸쳐 수행되었다. 공동연구의 목적은 설계, 공정, 조립, 검사 등 4M D램 제조와 관련되는 기본기술개발과 함께 $0.8{\mu}m$ 선폭의 4M D램을 개발하는 것이며, 이를 위해 단계별 목표를 설정하고 관민연의 혼연일치로 추진되었다. 1차년에는 중요 핵심기술개발, 2차년에는 $0.8{\mu}m$ 4M D램 Working-die개발, 3차년에는 수율 20%의 $0.8{\mu}m$ 4M D램 양산시 제품을 목표대로 완료하였다. 각 연구단계별로 주요 핵심기술에 대한 연구평가가 실시되었으며, 관련기술에 대한 중복투자 방지를 위해 2차년도부터 분담연구가 수행되었고, 상호 기술공유를 위한 기술교류회가 활발히 이루어졌다. 또한 R&D수행을 통해 4M D램 Working-die를 2차년도 중반에 개발완료하였으며, 3차년도에는 4M D램의 20% 수율확보와 공정기술의 최적화 및 DB 구축을 수행했다. 공동R&D 방식에서도 기업간 경쟁체제 도입에 입각하여 동기유발 형태로 진행되었다. 정부는 자금적 지원으로 기업간의 경쟁 심리를 자극하는 전략을 추진했다. 선두기업인 삼성에게는 선행적 개발 지위에 비례하여 더 많은 지원을 부여하는 대신에, 삼성의 기술성과를 다른 기업에게로 확산시킴으로써 반도체 3사 전체의 기술능력을 향상시키는 전략을 추진했다. 본 사업이 성공적으로 수행되어 반도체 제품의 세계시장 점유율제고, 국제수지 개선, 반도체 핵심기술 조기확보뿐만 아니라 16M D램급 이상 차세대 반도체기술 개발의 교도보가 되었다.

플라즈마 디스플레이의 기술과 현황

강정원,김영섭 한국반도체디스플레이기술학회 2004 반도체디스플레이기술학회지 Vol.3 No.4

21세기에 접어들면서 Digital시험방송의 시작과 다양한 Contents의 유입으로 평판디스플레이 (Flat Panel Display)에 관한 관심과 수요가 증가하고 있다. 이 중 PDP는 90년대 후반부터 양산 및 개발을 시작하여 현재는 40 inch에서 60 inch 화면 크기의 제품을 시장에서 구입할 수 있으며, 03년도에는 80 inch 크기의 Proto-type Model을 공개한 바 있다. PDP는 40 inch 이상의 대면적 구현이 용이하다는 점, CRT와 동등 수준의 화상 구현이 가능하다는 점, 제조공법이 간단하고 제조원가가 저렴하다는 점 등을 특징으로 시장을 확대하고 있으나, 좀 더 대중적인 디스플레이가 되기 위해서는 고휘도 및 고효율화, 화질개선 그리고 저가격화 등과 같은 과제를 해결하여야 한다. 본 논문에서는 PDP의 개발역사 및 시장현황, 구조 및 구동 방법 그리고 해결과제 및 전망에 대해서 포괄적으로 살펴보기로 한다.

Stretched-Exponential 형태의 문턱전압 이동 모델의 SPICE구현

정태호,Jung, Taeho 한국반도체디스플레이기술학회 2020 반도체디스플레이기술학회지 Vol.19 No.1

Threshold voltage shift occurring during operation is implemented in a SPICE simulation tool. Among the shift models the stretched-exponential function model, which is frequently observed from both single-crystal silicon and thin-film transistors regardless of the nature of causes, is selected, adapted to transient simulation, and added to BSIM4 developed by BSIM Research Group at the University of California, Berkeley. The adaptation method used in this research is to select degradation and recovery models based on the comparison between the gate and threshold voltages. The threshold voltage shift is extracted from SPICE transient simulation and shows the stretched-exponential time dependence for both degradation and recovery situations. The implementation method developed in this research is not limited to the stretched-exponential function model and BSIM model. The proposed method enables to perform transient simulation with threshold voltage shift in situ and will help to verify the reliability of a circuit.

SnO2 기반 고체상의 투과도 가변 소자 제조

신동균,서유석,이진영,박종운 한국반도체디스플레이기술학회 2020 반도체디스플레이기술학회지 Vol.19 No.3

Electrochromic (EC) device is an element whose transmittance is changed by electrical energy. Coloring and decoloring states can be easily controlled and thus used in buildings and automobiles for energy saving. There exist several types of EC devices; EC using electrolytes, polymer dispersed liquid crystal (PDLC), and suspended particle device (SPD) using polarized molecules. However, these devices involve solutions such as electrolytes and liquid crystals, limiting their applications in high temperature environments. In this study, we have studied all-solid-state EC device based on Tin(IV) oxide (SnO2). A coloring phase is achieved when electrons are accumulated in the ultraviolet (UV)-treated SnO2 layer, whereas a decoloring mode is obtained when electrons are empty there. The UV treatment of SnO2 layer brings in a number of localized states in the bandgap, which traps electrons near the conduction band. The SnO2-based EC device shows a transmittance of 70.7% in the decoloring mode and 41% in the coloring mode at a voltage of 2.5 V. We have achieved a transmittance change as large as 29.7% at the wavelength of 550 nm. It also exhibits fast and stable driving characteristics, which have been demonstrated by the cyclic experiments of coloration and decoloration. It has also showed the memory effects induced by the insulating layer of titanium dioxide (TiO2) and silicone (Si).

반도체 전공정의 하드마스크 스트립 검사시스템 개발

이종환,정성욱,김민제 한국반도체디스플레이기술학회 2020 반도체디스플레이기술학회지 Vol.19 No.3

The hard mask photo-resist strip inspection system for the semiconductor wafer manufacturing process inspects the position of the circuit pattern formed on the wafer by measuring the distance from the edge of the wafer to the strip processing area. After that, it is an inspection system that enables you to check the process status in real time. Process defects can be significantly reduced by applying a tester that has not been applied to the existing wafer strip process, edge etching process, and wafer ashing process. In addition, it is a technology for localizing semiconductor process inspection equipment that can analyze the outer diameter of the wafer and the state of pattern formation, which can secure process stability and improve wafer edge yield.

고효율 AC PDP용 MgO 보호막 형성을 위한 중성빔 보조 증착 장비에 관한 연구

이조휘,권상직,Li, Zhao-Hui,Kwon, Sang-Jik 한국반도체디스플레이기술학회 2008 반도체디스플레이기술학회지 Vol.7 No.2

The MgO protective layer plays an important role in plasma display panels (PDPs). Our previous work demonstrated that the properties of MgO thin film could be improved, which were deposited by ion beam assisted deposition (IBAD). However arc discharge always occurs during the IBAD process. To avoid this problem, oxygen neutral beam assisted deposition (NBAD) is used to deposit MgO thin films in this paper. The energy of the oxygen neutral beam was used as the parameter to control the deposition. The experimental results showed that the oxygen neutral beam energy was effective in determining in F/$F^+$ centers, crystal orientation, surface morphology of the MgO thin film, and the discharge characteristics of AC PDP. The lowest firing voltage $(V_f)$ and the highest secondary electron emission coefficient $(\gamma)$ were obtained when the neutral beam energy was 300 eV.

구조 안정성 향상을 위한 유압프레스 설계개선

신윤호,노승훈,김영조,이대웅,김상화,길사근,이일환 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.2

In this study, a hydraulic press structure has been investigated in order to enhance the precision machining and the productivity, which are generally damaged by the structural deformation from the pressure and the vibrations originated from the centrifugal forces from the rotating parts of the machine. Computer simulation based on the finite element method has been utilized for the analysis of static and dynamic characteristics to investigate each component`s critical points, and to further improve the static and dynamic stabilities of a hydraulic press structure. The result shows that the deformations and the vibrations of the machine could be reduced 35% without increasing the weight of the machine.

머신 러닝을 이용한 인공지지체 기공 크기 예측 모델에 관한 연구

이송연,허용정 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.4

In this paper, We used the regression model of machine learning for improve the print quantity problem when which print scaffold with 400 ㎛ pore using FDM 3d printer. We have difficult to experiment with changing all factors in the field. So we reduced print quantity by selected two factors that most impact the pore size. We printed and measured scaffold 5 times under same conditions. We created regression model using scaffold pore size and print conditions. We predicted pore size of untested print condition using the regression model. After print scaffold with 400 ㎛ pore, we printed scaffold 5 times under same conditions. We compare the predicted scaffold pore size and the measured scaffold pore size. We confirmed that error is less than 1 % and we verified the results quantitatively.

지하역사내 식생바이오필터의 입자상 오염물질 저감특성 연구

김태한,오지은,김미주 한국반도체디스플레이기술학회 2022 반도체디스플레이기술학회지 Vol.21 No.4

Public attention to the indoor environment of underground subway stations, which is a representative multi-use facility, has been increasing along with the increase in indoor activities. In underground stations, fine iron oxide, which affects the health of users, is generated because of the friction between wheels and rails. Among particulate pollutant reduction technologies, plants have been considered as a non-chemical air purification method, and their effects in reducing certain chemical species have been identified in previous studies. The present study aimed to derive the total quantitative and qualitative reduction effects of a bio-filter system comprising air purifying plants, installed in an underground subway station. The experiment proceeded in two ways. First, PM(particulate matter) reduction effect by vegetation biofilter was monitored with the IAQ(indoor air quality) station. In addition, chemical speciation analysis conducted on the samples collected from the experimental and control areas where plants and irrigation using SEM-EDS(scanning electron microscopy-energy dispersive X-ray spectroscopy). This study confirmed the effect of the vegetation bio-filter system in reducing the accumulation of particulate pollutants and transition and other metals that are harmful to the human body.

기판의 코로나 표면처리에 의한 탄소 나노튜브투명전극의 물성 향상

한상훈,박진석,김부종 한국반도체디스플레이기술학회 2014 반도체디스플레이기술학회지 Vol.13 No.1

In this study, we investigate the effects of corona-discharge pre-treatment on the properties of carbon nanotubes (CNTs) which are used as flexible transparent electrodes. The CNTs are deposited on PET (polyethylene terephthalate) substrates using a spray coating method. Prior to the deposition of CNTs, the PET substrates are corona-treated by varying the feeding directions of the PET substrate and the numbers of treatments. The variations in the surface morphologies and roughnesses of the PET substrates due to corona-treatment are characterized via atomic force microscopy (AFM). Dynamic contact angles (DCAs) of the corona-treated PET substrates are measured and analyzed as functions of the treatment conditions. Also, the sheet resistances and visible-range transmittances of the CNTs deposited on PET substrates are measured before and after bending test. The experimental results obtained in this study provide strong evidences that the adhesive forces between CNTs and PET substrates can be substantially enhanced by corona-discharge pretreatment.