• Title/Summary/Keyword: Uniform flatness

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Susceptor design by numerical analysis in horizontal CVD reactor

  • Lee, Jung-Hun;Yoo, Jin-Bok;Bae, So-Ik
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.15 no.4
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    • pp.135-140
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    • 2005
  • Thermal-fluid analysis was performed to understand the thermal behavior in the horizontal CVD reactor thereby to design a susceptor which has a uniform deposition rate during silicon EPI growing. Four different types of susceptor designs, standard (no hole susceptor), hole $\sharp$1 (240 mm), hole $\sharp$2 (150 mm) and hole $\sharp$3 (60 mm), were simulated by CFD (Computational Fluid Dynamics) tool. Temperature, gas flow, deposition rate and growth rate were calculated and analyzed. The degree of flatness of EPI wafer loaded on the susceptor was computed in terms of silicon growth rate. The simulation results show that the temperature and thermal distribution in the wafer are greatly dependent on inner diameter of hole susceptor and demonstrate that the introduction of hole in the susceptor can degrade wafer flatness. Maximum temperature difference appeared around holes. As the diameter of the hole decreases, flatness of the wafer becomes poor. Among the threes types of susceptors with the hole, optimal design which resulted a good uniform flatness ($5\%$) was obtained when using hole $\sharp$1.

U-FLATNESS AND NON-EXPANSIVE MAPPINGS IN BANACH SPACES

  • Gao, Ji;Saejung, Satit
    • Journal of the Korean Mathematical Society
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    • v.54 no.2
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    • pp.493-506
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    • 2017
  • In this paper, we define the modulus of n-dimensional U-flatness as the determinant of an $(n+1){\times}(n+1)$ matrix. The properties of the modulus are investigated and the relationships between this modulus and other geometric parameters of Banach spaces are studied. Some results on fixed point theory for non-expansive mappings and normal structure in Banach spaces are obtained.

A Study on the Cross Rolling for Improvement of Flatness of Plate (판재의 편평도 향상을 위한 교차압연에 관한 연구)

  • Nam K. O.;Seo K. S.;Rho B. R.;Hong S. I.
    • Transactions of Materials Processing
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    • v.14 no.1 s.73
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    • pp.43-48
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    • 2005
  • The production of metal strip with uniform thickness and flatness are two important problems associated thin strip rolling. The thickness and flatness of strip are affected by the flattening of contact surface between strip and roll, the elastic recovery and the bending of roll. Especially, the flatness of the strip is greatly affected by bending deflection of roll. The roll must be designed considered the elastic deformation of roll. This study describes the measurement of thickness and flatness of strip and shows the crown roll for producing flat strip. But it is difficult to produce the crown roller. The cross rolling that is a simple method which can produce the flat strip is introduced and it is found the optimal cross angle for improvement of flatness of plate. These problems are solved by the MARC code on the basis of elastic-plastic material and the updated Lagrangian formulation.

The uniform polycrystalline 3C-SiC thin film growth by the gas flow control (가스흐름 제어에 의한 균일한 다결정 3C-SiC 박막 성장)

  • Yoon, Kyu-Hyung;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.92-92
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    • 2008
  • The surface flatness of heteroepitaxially grown 3C-SiC thin films is a key factor affecting electronic and mechanical device applications. This paper describes the surface flatness of polycrystalline 3C-SiC thin films by the gas flow control according to the location change of geometric structure. The polycrystalline 3C-SiC thin film was deposited by APCVD(Atmospheric pressure chemical vapor deposition) at $1200^{\circ}C$ using HMDS(Hexamethyildisilane : $Si_2(CH_3)_6)$ as single precursor, and 5 slm Ar as the main flow gas. According to the location of geometric structure, surface fringes and flatness changed. It shows the distribution of thickness is formed uniformly in the specific location of the geometric structure.

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Crystal growth of uniform 3C-SiC thin films by CVD (CVD에 의한 균일한 다결정 3C-SiC 박막 결정 성장)

  • Yoon, Kyu-Hyung;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.234-235
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    • 2008
  • The surface flatness of heteroepitaxially grown 3C-SiC thin films is a key factor affecting electronic and mechanical device applications. This paper describes the surface flatness of poly(polycrystalline) 3C-SiC thin films according to Ar flow rates and the geometric structures of reaction tube, respectively. The poly 3C-SiC thin film was deposited by APCVD (Atmospheric pressure chemical vapor deposition) at $1200^{\circ}C$ using HMDS (Hexamethyildisilane : $Si_2(CH_3)_6)$ as single precursor, and 1~10 slm Ar as the main flow gas. According to the increase of main carrier gas, surface fringes and flatness are improved. It shows the distribution of thickness is formed uniformly.

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Optimization of Product's Tipping Position in Designing Die Face for Manufacturing Automobile Outer Panels (차체 외판의 제작을 위한 다이페이스 설계에 있어서 제품 성형방향의 최적화)

  • 박종천;조경호;이건우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.6
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    • pp.1389-1403
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    • 1993
  • A procedure has be developed to optimize the product's tipping position in designing a die face for manufacturing automobile outer panels. Two design requirements are considered in optimizing the tipping position. One is to satisfy that all the points on the product should have a uniform distribution of drawing depths. The other is to guarantee that the user-specified area on the product should first contact with the binder wrap. The problem to satisfy the design requirements described above is analogous to the flatness calculation problem in the area of metrology if some constraints can be imposed. Thus the problem can be solved by the simulated annealing method, which is one of the optimization methods. The developed procedure was tested with the real die face design problem and the usefulness was verified by the diagram of the drawing depth.

Flatness of a SOB SOI Substrate Fabricated by Electrochemical Etch-stop (전기화학적 식각정지에 의해 제조된 SDB SOI기판의 평탄도)

  • Chung, Gwiy-Sang;Kang, Kyung-Doo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04b
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    • pp.126-129
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    • 2000
  • This paper describes on the fabrication of a SOI substrate by SDB technology and electrochemical etch-stop. The surface of the thinned SDB SOI substrate is more uniform than that of grinding or polishing by mechanical method, and this process was found to be very accurate method for SOI thickness control. During electrochemical etch-stop, leakage current versus voltage curves were measured for analysis of the open current potential (OCP) point, the passivation potential (PP) point and anodic passivation potential. The surface roughness and the controlled thickness selectivity of the fabricated a SDB SOI substrate were evaluated by using AFM and SEM, respectively.

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New Fabrication method of Planar Micro Gas Sesnor Array (집적도를 높인 평면형 가스감지소자 어레이 제작기술)

  • 정완영
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.727-730
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    • 2003
  • Thin tin oxide film with nano-size particle was prepared on silicon substrate by hydrothermal synthetic method and successive sol-gel spin coating method. The fabrication method of tin oxide film with ultrafine nano-size crystalline structure was tried to be applied to fabrication of micro gas sensor array on silicon substrate. The tin oxide film on silicon substrate was well patterned by chemical etching upto 5${\mu}{\textrm}{m}$width and showed very uniform flatness. The tin oxide film preparation method and patterning method were successfully applied to newly proposed 2-dimensional micro sensor fabrication.

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Fundamental Research on Polishing of Glass Plates by Coated-type Magnetic Abrasives (자성체 피복형 연마입자를 이용한 유리의 평면 래핑의 기초 연구)

  • Moon, Bong-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.3
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    • pp.108-112
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    • 2011
  • In order to obtain excellent flatness and surface roughness of glass substrate disk, uniform distribution of abrasives should be important for uniform polishing. We introduced coated-type magnetic abrasives and magnetic field to a lapping for the improvement of surface roughness and removal rate. Polishing properties with the conventional diamond abrasives and the coated-type magnetic abrasives were compared. As a result, the coated-type magnetic abrasives showed small surface roughness and large removal rate by applying magnetic field. And it also was shown that coated-type magnetic abrasives could save the more amount of polishing liquid under the same removal rate than the conventional diamond abrasives can.

Development of High-definition PDP(Plasma Display Panel) Barrier Ribs Using Watersoluble UV-curing Resin (수용성 UV경화성 수지를 이용한 고품질 PDP용 격벽제작 기술 개발)

  • Nam, Su-Yong;Woo, Jin-Ho;Lee, Mi-Young;Lee, Gab-Hee;Kim, Goang-Young
    • Journal of the Korean Graphic Arts Communication Society
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    • v.21 no.2
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    • pp.67-74
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    • 2003
  • Barrier ribs for PDP(plasma display panel) are commonly utilized to have uniform height and width and to prevent opical crosstalk between adjacent cells. The requirements for such barrier ribs are uniform height and shape, low outgassing rate and low porosity, high aspect ratio, and fine resolution. In this study, we are studied about that to make efficiency of material and high quality barrier ribs for PDP. As a result, could got high barrier ribs of $140{\mu}m$ evenly in 1th phenomenon using watersoluble UV curing resin and know that flatness of upper part is also very good.

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