• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07b
• /
• pp.1082-1085
• /
• 2003

본 연구에서는 고분자를 사용하여 만든 유기EL소자인 PLED (Polymer Light Emitting Diode)의 제조공정 변화에 따른 소자성능을 연구하였다. PLED의 제작은 크게 ITO 기판 제작, 발광층 및 전극 증착 등의 공정으로 나누어진다. ITO 기판은 사진식각공정으로, 발광층의 증착은 스핀코팅법으로, 전극은 진공증착법으로 각각 제작하였다. 코팅 시 스핀속도 및 점도 조절을 통하여 발광층의 두께를 조절하였고, 스핀코팅 후 건조방법에 따라서 표면의 uniformity와 발광특성을 비교해 보았다. 실험결과 특정 두께에서 발광특성이 우수하게 나타나는 것을 확인할 수 있었다. 그리고 건조방법에 따라 발광층의 표면 uniformity에 차이가 있었으며, 표면 uniformity에 따라 diode의 I-V 특성 경향이 달리 나타났다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.711-714
• /
• 2004

Chemical mechanical polishing (CMP) has been widely accepted for the global planarization of multi-layer structures in semiconductor manufacturing. However, it still has various problems to the CMP equipment, in particular, among the CMP components, process variables are very important parameters in determining the removal rate and non-uniformity. Using a design of experiment (DOE) approach, this study was performed investigating the interaction between the various parameters such as turntable and head speed, down force and back pressure during CMP. Using statistical analysis techniques, a better understanding of the interaction behavior between the various parameters and the effect on removal rate, no-uniformity and ETC (edge to center) is achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.129-131
• /
• 2004

전 세계적으로 반도체 연마제용으로 silica를 많이 사용하고 있으며, 주로 fumed silica 및 colloidal silica로 구분되어진다. 반도체 연마제로서의 가장 중요한 요소는 연마율, defect 및 uniformity 등이 있으며, 현재 defect 및 uniformity는 많은 연구개발을 통하여 증진되었지만 반도체 생산량과 직접 관련된 연마율을 증가시키는 기술은 화학약품 및 slurry의 농도 증가로만 가능하다. 이에 연마제의 전반적인 기능을 상승시켜 기존보다 연마율은 높이고, 결함율을 낮추며, 120nm 이상의 입자크기를 제조하여도 근일한 입도 분포도를 나타내어주고, 장기간 안정하게 사용가능하고, 친환경적인 반도체 연마제를 개발하였다.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.462-463
• /
• 2008

36,000lbs porcelain insulators (D-1995, D-1997, D-2002) investigated mechanical and electrical qualities, which were installed in the Korea 154kV transmission lines. This paper assessed Weibull distribution function, quality index, and uniformity index to forecast the remaining life expectancies of insulators. Applying Weibull distribution function on year lapse change test, electro-mechanical failing load test, and HRB values confirmed a significant degree of correlation. Statistically calculating the life expectancy through quality indices for aging and new products and uniformity indices that are associated with uniformity of insulation materials revealed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.145-148
• /
• 2001

A large area plasma source using parallel $2{\times}2$ ICP antennas showed improved etching uniformity by the E-ICP operation. ITO etching process with $CH_4$ gas chemistry is optimized with the DOE (Design of Experiment) based on Taguchi method. Various methane ratios in methane and argon mixture are compared to confirm the effect of polymerization. The analysis shows that the effect of bias power is the largeset. We obtained higher ITO etching rate and better uniformity on $350{\times}300mm$ substrate at the 50Hz magnetization frequency of the E-ICP operation technique,

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.2
• /
• pp.139-139
• /
• 1999

In this paper, the result of study in artificial lighting uniformity ratio yield method subject to lecture room are reported. It is desirable that the application of equation ① U=Ei/Ex×100 cannot be used to the mean value in place to be effective of light and darkness. And it is desirable that the application of equation ② U=Ei/Ea×100 or equation ③ U=(Ea-Ei)/Ea×100 be used to the mean Value equality illumination conditions. Also, requiring preparation of judgement standard, uniformity ratio equation agree with actual circumstances in this country. It must be considered intensity of illumination and specificity of space in established standard.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.145-148
• /
• 2001

A large area plasma source using parallel 2x2 ICP antennas showed improved etching uniformity by the E-ICP operation. ITO etching process with CH$_4$ gas chemistry is optimized with the DOE(Design of Experiment) based on Taguchi method. Various methane ratios in methane and argon mixture are compared to confirm the effect of polymerization. The analysis shows that the effect of bias power is the largeset. We obtained higher ITO etching rate and better uniformity on 350x300mm substrate at the 50Hz magnetization frequency of the E-ICP operation technique.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.3
• /
• pp.195-202
• /
• 1998

The LPCVD system of batch type for the massproduction of semiconductor fabrication has a problem of phosphorous concentration uniformity in the boat. In this paper we study an improvement of the uniformity for phosphorous concentration and sheet resistance. These property was improved by using the nitrogen process and modified long nozzle for gas injection tube in the doped polysilicon deposition system. The phosphorous concentration and its uniformity for polysilicon film are measured by XRF(X-ray Fluorescence) for the conventional process condition and nitrogen process. In conventional process condition, the phosphorous concentration, it uniformity and sheet resistance for polysilicon film are in the range of 3.8~5.4$\times$10\ulcorner atoms/㎤, 17.3% and 59~$\Omega$/ , respectively. For the case of nitrogen process the corresponding measurements exhibited between 4.3~5.3$\times$10\ulcorner atoms/㎤, 10.6% and 58~81$\Omega$/ . We find that in the nitrogen process the uniformity of phosphorous concentration improved compared with conventional process condition, however, the sheet resistance in the up zone of the boat increased about 12 $\Omega$/ . In modified long nozzle, the phosphorous concentration, its uniformity and sheet resistance for polysilicon films are in the range of 4.5~5.1$\times$10\ulcorner atoms/㎤, 5.3% and 60~65$\Omega$/ respectively. Annealing after $N_2$process gives the increment of grain size and the decrement of roughness. Modification of nozzle gives the increment of injection amount of PH$_3$. Both of these suggestion result in the stable phosphorous concentration and sheet resistance. The results obtained in this study are also applicable to process control of batch type system for memory device fabrication.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.1 no.2
• /
• pp.132-139
• /
• 2001

We considered the uniformity of fabricated micromirror arrays by characterizing the fabrication process and calculating the appropriate driving voltages of micromirrors used as virtual photomask in maskless photolithography. The uniformity of the micromirror array in terms of driving voltage and optical characteristics is adversely affected by factors, such as the air gap between the bottom electrode and the mirror plate, the spring shape and the deformation of the mirror plate or torsion spring. The thickness deviation of the photoresist sacrificial layer, the misalignment between mirror plate and bottom electrode, the aluminum deposition condition used to produce the spring and the mirror plate, and initial mirror deflection were identified as key factors. Their importance lies in the fact that they are related to air gap deviations under the mirror plate, asymmetric driving voltages in left and right mirror directions, and the deformation of the Al sring or mirror plate after removal of the sacrificial layer. The plasma ashing conditions used for removing the sacrificial layer also contributed to the deformation of the mirror plate and spring. Driving voltages were calculated for the pixel operation of the micromirror array, and the non-uniform characteristics of fabricated micromirrors were taken into consideration to improve driving performance reliability.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.73-76
• /
• 2009

The optical structure of edge-lit LED backlight has been optimized via simulation study in order to remove bright spots appearing on the entrance region of the light guide plate (LGP) and thus to improve the luminance uniformity. The density of scattering dots located on the back surface of LGP was adjusted according to the location of LED's. In addition, lenticular lenses or a diffuse transmissive surface were formed on the side surface of LGP facing the LED's, and the density of lenticular lenses was optimized for redistributing rays emitted from LED's into wider angles. The bright spots which could be seen from conventional LED backlight were removed by the combination of these two optical structures. The application of diffuse surface to the entrance face gave better uniformity than the application of lenticular lenses. However, dark regions still appear on the entrance region of LGP, which should be removed by more appropriate optical design for achieving better luminance uniformity on the LED backlight.