• 한국진공학회지
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• 제19권3호
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• pp.190-198
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• 2010

450 mm의 웨이퍼 공정용 플라즈마 장비의 개발을 위하여 안테나 형상, 챔버의 직경, 웨이퍼까지의 거리에 따른 플라즈마 균일도를 Ar과 $CF_4$에 대하여 축대칭 2차원으로 수치 모델링하였다. 챔버의 종횡비를 직경, 기판까지의 거리, 배기구의 면적으로 나누어서 결정하고 여기에 안테나 구조를 변경하여서 최적의 플라즈마 균일도를 갖는 조건을 도출하였다. Drift diffusion식과 준중성 조건을 이용한 간략화를 이용하였으며 표면 재결합과 식각 반응을 이온에너지의 함수로 처리하였다. 반응기판 표면에서의 플라즈마 밀도 균일도는 기판 홀더와 챔버 벽면과의 거리, 기판과 소스와의 거리가 멀수록 좋아졌으며, 안테나의 디자인이 4 turn으로 1층인 경우, 두 번째, 네 번째 turn만 사용하여 전류비 1 : 4에서 기판표면에서의 플라즈마 균일도를 4.7%까지 낮출 수 있었다. Ar과 $CF_4$의 반경 방향으로 전자 온도 균일도 50%, 전자 밀도 균일도 19%의 차이가 있었다.

• 한국진공학회지
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• 제4권S1호
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• pp.190-195
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• 1995

The feature scale model for selective chemical vapor deopsition process was proposed and the simulation was performed to study the selectivity and uniformity of deposited thin film using Monte Carlo method and string algorithm. The effect of model parameters such as sticking coefficient, aspect ratio, and surface diffusion coefficient on the deposited thin film pattern was improved for lower sticking coefficient and higher aspect ratio. It was revealed that the selectivity loss ascrives to the surface diffusion. Different values of sticking coefficients on Si and on SiO2 surface greatly influenced the deopsited thin film profile. In addition, as the lateral wall angle decreased, the selectively deposited film had improved uniformity except the vicinity of trench wall. The optimum eondition for the most flat selective film deposition pattern is the case with low sticking coefficient and slightly increased surface diffusion coefficient.

• 한국표면공학회지
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• 제41권6호
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• pp.279-286
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• 2008

Numerical analysis is done to investigate which would be the most influencing process parameter in determining the uniformity of deposition thickness in TiN ICP-CVD(inductively coupled plasma chemical vapor deposition). Two configurations of ICP antenna are modeled; side and top planar. Side and top gas inlets are considered with each ICP antenna geometries. Precursor for TiN deposition was TDMAT(Tetrakis Diethyl Methyl Amido Titanium). Two step volume dissociation of TDMAT is used and absorption, desorption and deposition surface reactions are included. Most influencing factors are H and N concentration dissociated by electron impact collisions in plasma volume which depends on the relative positions of gas inlet and ICP antenna generated hot plasma region. Low surface recombination of N shows hollow type concentration, but H gives a bell type distribution. Film thickness at substrate edges is sensitive to gas flow rate and at high pressures getting more dependent on flow characteristics.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.635-639
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• 2007

In this study, optimal design and test of flat-plate heat pipe were carried out in order to improve both thermal response and surface temperature uniformity of heating plate. Experimental results show that the thermal response of flat-plate heat pipe is faster than that of a conventional heating type ones along with less weight and cost. The surface temperature uniformity is also improved.

• 반도체디스플레이기술학회지
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• 제16권3호
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• pp.116-120
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• 2017

Temperature uniformity of a wafer in a semiconductor process is a very important factor that determines the overall yield. Therefore, it is very important to confirm the temperature characteristics of the chuck surface on which the wafer is lifted. The temperature characteristics of the chuck depend on the external heat source, the shape of the cooling channel inside the chuck, the material on the chuck surface, and so on. In this study, CFD confirms the change of temperature characteristics according to the stacking order of ceramic materials on the chuck surface, and suggests the best lamination method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.111-114
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• 2003

In order to improve the surface uniformity and the conduction properties of the fabricated YBCO thick films, a system that applies alternating field vertically to the EPD field has been developed for the first time and applied to the electrophoretic deposition process. The applied alternating electric field caused a force to be exerted on each YBCO particle and resulted in a shaking of the particle in the direction of applied electric field, accomplishing a uniform particle orientation. The usual commercial electrical power was used for the vertically applied alternating voltage and the induced electric field was 25-120 V/cm at 60Hz. The thick film fabricated by the method developed in this paper showed better surface uniformity without crack and porosity and improved film characteristics such as critical temperature ($T_{c,zero}$ : 90 K) and critical current density ($2354\;A/cm^2$). Therefore, it is expected that the shaky-aligned electrophoretic deposition method can be used to fabricate superconductor films through a simpler process and at less expense.

• 한국전기전자재료학회논문지
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• 제16권11호
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• pp.1041-1046
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• 2003

In order to improve the surface uniformity and the conduction properties of the fabricated YBCO thick films, a system that applies alternating field vertically to the EPD field has been developed for the first time and applied to the electrophoretic deposition process. The applied alternating electric field, so called Shaky Alternating Assisted Field, caused a force to be exerted on each YBCO particle and resulted in a shaking of the particle in the direction of applied electric field, accomplishing a uniform particle orientation. The usual commercial electrical power was used for the vertically applied alternating voltage and the induced electric field was 25-120 V/cm at 60Hz. The thick film fabricated by the method developed in this paper showed better surface uniformity without crack and porosity and improved film characteristics such as critical temperature (Tc,zero = 90 K) and critical current density (2354 A/$\textrm{cm}^2$), Therefore, it is expected that the shaky-aligned electrophoretic deposition method can be used to fabricate superconductor films through a simpler process and at less expense.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.3714-3721
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• 2015

서셉터 히터에서 쉬스 열선을 사용하는 방법이 일반화되어 있지만, 대면적 초고온 조건에서는 서셉터의 온도 균일도 성능 저하의 문제가 있다. 본 연구에서는 온도균일도 성능을 향상시킬 수 있도록 판형 형태의 열선을 기본으로 새로운 서셉터를 설계하여 프로토타입을 개발하였다. 표면 온도 $450^{\circ}C$의 고온에서 1.4% 이내로 온도 균일도가 시제작된 서셉터에서 검증될 수 있었다. 또한 온도 학습 데이터를 이용하여 측정 온도 데이터를 예측할 수 있는 커널 회귀 알고리즘을 개발하고, 이러한 예측 데이터와 측정 데이터의 비교 분석으로 균일도 측정 온도의 신뢰성을 확인할 수 있었다.

• 한국레이저가공학회지
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• 제10권1호
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• pp.29-34
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• 2007

We propose a novel application of laser engraving to patterning of light guide panel (LGP) for backlight. The feasibility of three-dimensional engraved pattern in the LGP was verified by measuring brightness and uniformity. To improve the overall uniformity, we have modified proposed patterns and found improved design for patterns. The tailoring of pattern by using laser engraving method could endow the controllability of uniformity. The proposed LGPs are more efficient in both average brightness and uniformity of illumination than the conventional LGPs which have surface pattern on the panel.

• 한국축산시설환경학회지
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• 제6권1호
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• pp.37-44
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• 2000

A new hose slurry spreader with improved spreading uniformity is developed to distribute the slurrynear to the soil surface and to reduce odor problems. The precision of distributed slurry was investigated using 3 types of slurry and found to be dependent on the rotor speed. For the solid matter separated fluid containing 0.1% of dry matter rotor speed of 150 rpm showed best uniformity with CV of 10% In the case of slurry from dairy cattle which contains 8.2% of dry matter high rotor speed of 330 rpm showed best result with CV of 7.2% Also swine slurry which has a 13.6% of dry matter content showed the best result of 8.1% CV at the high rotor speed of 250rpm. A high rotor speed generates enough pressure in the central distributor and as a result uniform distribution of slurry can be achieved. In conclusion it is highly recommended rotor speed of 300 rpm to get the best performance.