• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.228-231
• /
• 2002

We report the effect of density of thin films on moisture adsorption and hydration of MgO thin film, usually used as a protective layer in AC-PDP After hydration, lots of hemispherical shaped clusters, $Mg(OH)_2$, formed on the surface of MgO thin films. However clusters formed on low-density thin films were bigger than those on high-density films. From ERD spectra, it seemed that the concentration of hydrogen was very high in the region 20 nm from the surface of MgO thin film. The low-density thin film had more hydrogen than high-density thin film. From simulation results of ERD and RBS it was found that hydration reaction also occurred in the inner part of the film. So diffusion of Mg atoms from the inner part of the film to the surface and $H_2O$ molecules from the surface to the inner part of the film is important. And because low density thin film has many short paths for diffusion of Mg atoms and $H_2O$ molecules, low-density thin film is more hydrated. So to suppress hydration of MgO thin films, high-density thin film is needed.

• 한국결정성장학회지
• /
• 제9권2호
• /
• pp.168-172
• /
• 1999

HVPE 법으로 sapphire 기판 위에 두께 9$\mu\textrm{m}$의 GaN film을 성장하였다. Sapphire위에 직접 성장된 GaN film은 crack free로 mirror surface를 나타내었고 dislocation density는 $2{\times}10^9/cm^2$이었다.$SiO_2$ mask pattern을 사용하여 성장된 ELO GaN film도 대부분이 mirror surface를 나타내었으나 표면 일부에서 coalescence가 덜 이루어져 stripe 방향으로 hole이 존재하였다. ELO GaN film의 mask 윗부분은 window 부분에 비해 낮은 dislocation density를 나타냈다. 특히 mask center와 window사이 영역에서는 거의 dislocation이 없었다. ELO GaN film의 dislocation density는 평균 $8{\times}10^7/cm^2$.이었다.

• 한국세라믹학회지
• /
• 제37권7호
• /
• pp.686-692
• /
• 2000

Tin-doped In2O3 (ITO) films were fabricated using a d.c. magnetron reactive sputteirng of a In-10 wt% Sn alloy target in an Ar and O2 gas mixture. To understand the behavior of the carrier mobility in ITO films with O2 partial pressure, the resistivity, carrier concentration and mobility, film density, and intrinsic stress in the films were measured with O2 partial pressure. It was found experimentally that the carrier mobility increased rapidly as the film density increased. In the ITO film with the density close to theoretical one, the mean free path was the same as the columnar diameter. This indicated that the mobility in ITO films was strongly influenced by the crystall size. However, in the case where the film density was smaller than a theoretical density, the mean free paths were also smaller the columnar diameter. It was analyzed that the electron scattering at pores and holes within the crystalline was the major obstacle for electron conduction in ITO films. The measurement of intrinsic stress in ITO films also made it clear that the density of ITO films was controlled by the bombardment of oxygen neutrals on the growing film.

• Imaging Science in Dentistry
• /
• 제31권1호
• /
• pp.17-22
• /
• 2001

Purpose: To compare the film density of Insight dental X-ray film (Eastman Kodak Co., Rochester, NY, USA) with that of Ektaspeed Plus film (Eastman Kodak) under manual and automatic processing conditions. Materials and Methods : Insight and Ektaspeed Plus films were exposed at three different exposure conditions with an aluminum step wedge on the films under the three different exposure times. The exposed films were processed by both manual and automatic ways. The Base plus fog density and the optical density made by exposing step wedge were calculated using a digital densitometer (model 07-443, Victoreen Inc, Cleveland, Ohio, USA). The optical densities of the Insight and Ektaspeed film versus thickness of alumimun wedge at the same exposure time were plotted on the graphs. Statistical analyses were applied for comparing the optical densities of the two films. Results: The film density of both Insight films and Ektaspeed Plus films under automatic processing condition was significantly higher over the manual processing. The film density of Insight films was significantly higher than that of Ektaspeed Plus films on both automatic and manual processing conditions. Conclusion: The radiation exposure time can be reduced when using Insight over Ektaspeed Plus film. To take the full advantage of reducing exposure time, Insight film should be processed automatically.

• 치과방사선
• /
• 제29권1호
• /
• pp.299-308
• /
• 1999

Purpose: The purpose of this study was to compare the qualities of the four different processing chemicals (solutions). Materials and Methods: With EP 21 films(Ektaspeed plus film, Kodak Co., USA), nine unexposed and nine exposed films of a step wedge were processed utilizing automatic film processor(XR 24, Durr Co., Germany) for 5 days. During 5 days, the total number of processed films including out-patient' s intraoral films were about 400-500 for each brand. Base plus fog density, film density, contrast of processed films were measured with densitometer(model 07-443 digital densitometer, Victoreen Co., USA). These measurements were analyzed for comparison. Results: The results were as follows, 1. For the base plus fog density. there was significant difference among the four chemicals (p<0.05). The sequence of the base plus fog densities was in ascending order by Kodak, X-dol 90. Agfa and Konica. 2. For the film density. all chemicals showed useful range of photographic densities(0.25-2.5). The sequence of the film densities was in ascending order by Kodak, X-dol 90, Konica and Agfa. But there was no statistically significant difference of film density between X-dol and Kodak (p<0.05). 3. The sequence of the contrasts was in ascending order by Konica, X-dol 90, Kodak and Agfa. But there was no statistically significant difference of contrast between X-dol and Konica (p<0.05). Conclusion: These results indicated that the four processing chemicals had clinically useful film density and contrast. but only Kodak processing chemical had useful base plus fog density.

• 대한방사선기술학회지:방사선기술과학
• /
• 제22권1호
• /
• pp.13-20
• /
• 1999

This study is to calculate the exposed radiation dose using Bit method, NDD calculation method and monogram method without dosimeter. In addition, we can calculate the radiation dose from x-ray film density as a film badge. The authors examined the entrance skin dose from $2{\sim}3$ intercostal chest x-ray film density. We also studied the relationship between film density and equivalent dose in the each screen film system under the different radiation quality and the poor geometry condition of grid ratio. As results, we established the deductive method to define the entrance skindose from chest x-ray film density. The error range was found in the range $-13%{\sim}+l7%$ for between deductive entrance skindose and the $2{\sim}3$ intercostal chest x-ray film density to actual detective radiation dose with dosimeter.

• Current Applied Physics
• /
• 제18권11호
• /
• pp.1447-1450
• /
• 2018

The electron spin resonance (ESR) detects point defect of the In-Ga-Zn oxide (IGZO) like singly ionized oxygen vacancies and excess oxygen, and get spin density as a parameter of defect state. So, we demonstrated the spin density measurement of the IGZO film with various deposition conditions and it has linear relationship. Moreover, we matched the spin density with the total BTS and the threshold voltage ($V_{th}$) distribution of the IGZO thin film transistors. The total BTS ${\Delta}V_{th}$ and the $V_{th}$ distribution were degraded due to the spin density increases. The spin density is the useful indicator to predict $V_{th}$ instability of IGZO TFTs.

• 한국정밀공학회지
• /
• 제25권8호
• /
• pp.88-95
• /
• 2008

Young's modulus of electroplated nickel thin film is systematically investigated using the resonance method of atomic force microscope. Thin layers of nickel to be measured are electroplated onto the surface of an AFM silicon cantilever and Young's modulus of plated nickel film is investigated as a function of process conditions such as the plating temperature and applied current density. It is found that Young's modulus of plated nickel thin film is as high as that of bulk nickel at low plating temperature or low current density, but decreases with increasing plating temperature or current density. The results imply that the plating rate increases as increasing the plating temperature or current density, therefore, slow plating rate produces a dense plating material due to the sufficient time fur nickel ions to form a dense coating.

• Imaging Science in Dentistry
• /
• 제33권1호
• /
• pp.21-26
• /
• 2003

Purpose: To investigate the characteristics of the newly marketed, Insight dental X-ray film. Materials and Methods: Kodak Ultraspeed (DF-58), E-speed, Agfa Dentus M2, and Kodak Insight (IP-21) films were radiographed using a Trophy intra-oral radiographic machine. 10 step exposure times were prepared and each step exposure was monitored using a FH 40G (ESM Eberline Instruments) dosimeter for each of the 4 types of intra-oral film. All films were manually processed and the radiographic densities at 6 sites of each processed film were measured, and the characteristic curves of each of the 4 types intra-oral films were created utilizing these dosimetric data and radiographic densities, based on ISO 5779. The film contrast, speed, and base plus fog density of Insight film were compared with those of the 3 other films examined in this experiment. Results : E-speed film showed greatest average gradients followed by Insight film. E-speed and Ultraspeed film showed great average gradients at low density levels. Insight film showed the fastest speed followed by E-speed, Dentus M2 and Ultraspeed film. Dentus M2 film showed greatest base plus fog density level followed by Insight film. Conclusion : Kodak Insight film showed fastest film speed with comparable film contrast on characteristic curve.

• 한국항공우주학회지
• /
• 제49권10호
• /
• pp.841-847
• /
• 2021

본 논문에서는 저밀도 표면필름 구리망에 대한 비행체 적용 가능성을 분석하였다. 최근 기존 표면 필름 구리망에서 중량 및 비용을 절감할 수 있도록 표면 필름의 두께를 낮춘 저밀도 표면 필름 구리망이 개발되었다. 이러한 저밀도 표면필름 구리망을 비행체에 적용하기 위해서는 샌드위치 구조에서의 핀 홀 방지 효과와 같은 제작성 확인과 함께 적용 시 전자기 영향성에 대한 분석이 필요하다. 따라서 본 연구에서는 저밀도 필름 구리망 2종과 기존 비행체 적용 구리망 1종에 대해 제작성 및 전자기 영향성을 분석하였다. 표면 구리망에 대한 제작성은 샌드위치 복합재와 표면 구리망을 결합하여 핀 홀 방지효과를 확인하였다. 전자기 영향성 분석은 3D 전자기파 시뮬레이션을 통해 각 샘플에 대한 주기구조를 이용하여 해석하였으며, 자유공간 측정방법을 이용한 저밀도 필름 구리망의 전자기파 투과특성 측정결과를 통해 시뮬레이션 결과가 유효함을 확인하였다. 위 결과로 비행체 적용이 필요한 저밀도 표면필름 구리망에 대한 해석 및 비행체 적용 가능성을 판단할 수 있다.