http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김필규,문승재,정성호,Kim, P.K.,Moon, S.J.,Jeong, S.H. 한국레이저가공학회 2010 한국레이저가공학회지 Vol.13 No.1
Crystallization of 100 nm thick amorphous silicon (a-Si) films on glass substrates was carried out by using a double laser irradiation method. Depending on a-Si deposition method or glass types, the quality of crystallized silicon film varies significantly. For a-Si films deposited with high concentration of impurities, large grains or high crystallinity can not be achieved. Crystallization with different a-Si deposition methods confirmed that for the polycrystallization of a-Si films on glass substrates, controlling the impurity density during substrate preparation is critical.
He-Cd 레이저와 근접장현미경을 이용한 폴리머박막 나노리소그라피 공정의 특성분석
권상진(S. J. Kwon),김필규(P. K. Kim),천채민(C. M. Chun),김동유(D. Y. Kim),장원석(W. S. Chang),정성호(S. H. Jeong) 한국레이저가공학회 2004 한국레이저가공학회지 Vol.7 No.3
The shape and size variations of the nanopatterns produced on a polymer film using a near-field scanning optical microscope(NSOM) are investigated with respect to the process variables. A cantilever type nanoprobe having a 100nm aperture at the apex of the pyramidal tip is used with the NSOM and a He-Cd laser at a wavelength of 442nm as the illumination source. Patterning characteristics are examined for different laser beam power at the entrance side of the aperture(P<SUB>in</SUB>), scan speed of the piezo stage(V), repeated scanning over the same pattern, and operation modes of the NSOM(DC and AC modes). The pattern size remained almost the same for equal linear energy density. Pattern size decreased for lower laser beam power and greater scan speed, leading to a minimum pattern width of around 50nm at P<SUB>in</SUB>=1.2㎼ and V=12㎛/s. Direct writing of an arbitrary pattern with a line width of about 150㎚ was demonstrated to verify the feasibility of this technique for nanomask fabrication. Application on high-density data storage in discussed.
김필규(P.K. Kim),문승재(S.J. Moon),정성호(S.H. Jeong) 한국레이저가공학회 2010 한국레이저가공학회지 Vol.13 No.1
Crystallization of 100 nm thick amorphous silicon (a-Si) films on glass substrates was carried out by using a double laser irradiation method. Depending on a-Si deposition method or glass types, the quality of crystallized silicon film, varies significantly. For a-Si films deposited with high concentration of impurities, large grains or high crystallinity can not be achieved. Crystallization with different a-Si deposition methods confirmed that for the polyclystallization of a-Si films on glass substrates, controlling the impurity density during substrate preparation is critical.
김필규(P. K. Kim),이명화(M. H. Lee),정성호(S. H. Jeong) 한국레이저가공학회 2008 한국레이저가공학회 학술대회 논문집 Vol.2008 No.-
Duplex stainless steel is a preferred material for a high temperature and pressure pump of a seawater desalination plant due to its high corrosion resistance and hardness. Despite the good hardness of duplex stainless steel, rotating pump components such as ring, bush, or sleeve require regular replacements due to friction wear, requiring surface treatment of those rotating components for obtaining higher surface hardness. In this work, experimental results for CW laser heat treatment and laser peening of duplex stainless steel for an enhancement of surface hardness are reported. In CW laser heat treatment, irradiation with a Nd-YAG laser and quenching with liquid nitrogen was carried out. while in laser peening a pulsed Nd-YAG laser irradiation was conducted in a water chamber. The results revealed that CW laser irradiation could not improve surface hardness of duplex stainless steel, whereas laser peening showed evidences of surface hardness improvement.
근접장현미경을 이용한 폴리머박막 나노리쏘그라피 공정의 특성분석
권상진(S. J. Kwon),김필규(P. K. Kim),장원석(W. S. Chang),정성호(S. H. Jeong) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월
The shape and size variations of the nanopatterns produced on a positive photoresist using a near-field scanning optical microscope(NSOM) are investigated with respect to the process variables. A cantilever type nanoprobe having a 100㎚ aperture at the apex of the pyramidal tip is used with the NSOM and a He-Cd laser at a wavelength of 442㎚ as the illumination source. Patterning characteristics are examined for different laser beam power at the entrance side of the aperture(Pin), scan speed of the piezo stage(V), repeated scanning over the same pattern, and operation modes of the NSOM(DC and AC modes). The pattern size remained almost the same for equal linear energy density. Pattern size decreased for lower laser beam power and greater scan speed, leading to a minimum pattern width of around 50㎚ at Pin=1.2μW and V=12㎛/. Direct writing of an arbitrary pattern with a line width of about 150㎚ was demonstrated to erify the feasibility of this technique for nanomask fabrication. Application on high-density data storage using azopolymer is discussed at the end.
레이저 쇼크 피닝에 의한 2205 듀플렉스 스테인리스강의 표면 경도 향상과 표면 변화 관찰
임현택(H. T. Lim),정회민(H. M. Jeong),김필규(P. K. Kim),정성호(SungHo Jeong) 한국레이저가공학회 2011 한국레이저가공학회지 Vol.14 No.1
This work reports the results for laser shock peening of duplex stainless steel (22% Chromium - 5% Nickel) using a pulsed Nd:YAG laser (wavelength = 532nm, pulse width = 8ns). for the application to high-capacity pumps for seawater desalination plants. By properly selecting the process parameters such as laser intensity of 10GW/cm2, laser pulse density of 75pulse/mm2, and 100μm thick aluminum foil as an absorbent coating layer, the surface hardness of duplex stainless steel could be enhanced by 26%, from 256HV to 323HV with little changes in surface morphology and roughness. The depth of laser shock peened layer was measured to be around 2mm. The large enhancement of surface hardness is considered to have high practical importance in minimizing abrasive and corrosive deterioration of pump parts.
임현택(H. T. Lim),이명화(M. H. Lee),김필규(P. K. Kim),박종복(J. B. Park),정성호(S. H. Jeong) 한국레이저가공학회 2009 한국레이저가공학회지 Vol.12 No.3
Experimental results for the laser shock peening of stainless steels, duplex stainless steel and STS304, for the enhancement of surface hardness are reported. A high power Nd:YAG laser (532 nm, 2nd harmonics) was used to irradiate the workpiece in water at the irradiances of 5, 10, 15 GW/cm2. The surface of a workpiece was covered with Fe or Al foil for protection of the original surface and reduction of laser reflection. The laser pulse densities were varied from 25 pulse/mm2 to 75 pulse/mm2. In the case of the STS304, the surface hardness increased with increasing pulse density and the maximum increase of about 29% was achieved using Fe foil at 10 GW/cm2 and 75 pulse/mm2 conditions. The maximum increase in surface hardness of duplex stainless steel was about 8% at 10 GW/cm2 and 75 pulse/mm2 with also Fe foil. In the case of the Al foil, less increase of surface hardness was obtained, possibly due to the thermal expansion effect.