• 한국결정성장학회지
• /
• 제8권2호
• /
• pp.233-239
• /
• 1998

화학기상증착법을 이용하여 tetramethylsilane(TMS)과 hexamethyldisilane(HMDS)으로부터 SiC층을 증착시켰다. 반응관 내의 압력은 1torr를 유지시켰으며, $H_2$ 가스를 사용하여 precursor를 반응로내로 수송하였고 $1200^{\circ}C$의 반응온도로 SiC 증착이 이루어졌다. 기판은 tantalum으로 masking한 Si-wafer와 platinum, molybdenum으로 masking한 MgO 단결정을 사용하였다. 금속층(Ta, Pt, Mo)에서의 SiC 증착 양상과 Si, MgO 위에서의 SiC 증착 양상을 비교함으로써 SiC 증착의 선택성을 관찰하였다. 증착층의 주된 상은 X-선 회절분석에 의해 $\beta-SiC$로 확인되었다. 또한 전자현미경 분석을 통해 각 층에서의 증착 양상의 차이를 조사하였다.

• 한국세라믹학회지
• /
• 제40권8호
• /
• pp.770-776
• /
• 2003

(111) 및 (100) 단결정 실리콘 웨이퍼에 대하여 #140 mesh와 #600 mesh의 연삭숫돌을 사용하여 연삭가공을 행하고 가공에 의한 표면품위의 변화를 관찰하였다. 이를 위하여 Atomic Force Microscope(Am)을 사용하여 미세거칠기를 분석하고 라만 분광법(Raman spectroscopy)을 통하여 결정구조, 상변화 및 잔류응력을 분석하였다. 그 결과 연삭가공 후에 (111) 면에서 미세거칠기가 더 크게 나타났으며 실리콘이 다이아몬드구조의 Si-I에서 Si-III(body centered tetragonal) 및 Si-XII(rhombohedral)로 전이하는 현상을 라만스펙트럼 분석을 통해 확인하였다. 또한 연삭가공에 의하여 패인 구덩이에서는 일반적인 가공표면과 다른 라만스펙트럼이 관찰되어, 표면에 인가된 잔류응력이 새로운 표면생성으로 해소되었음을 알수 있었다. 또한 열처리에 의한 재료의 표면품위개선효과를 분석하기 위하여 대기 중에서 열처리를 시행한 결과 열처리는 잔류응력의 해소와 상전이의 회복에 효과적인 것으로 나타났다.

• Tribology and Lubricants
• /
• 제18권1호
• /
• pp.1-8
• /
• 2002

Nano adhesion and friction between a $Si_{3}N_{4}$ AFM(atomic force microscope) tip and thin silver films were experimentally studied. Tests were performed to measure the nano adhesion and friction in both AFM and LFM(lateral force microscope) modes in various range of normal loads. Thin silver films deposited by IBAD (ion beam assisted deposition) on Si-wafer (100) and other Si-wafers of different surface roughness were used. Results showed that nano adhesion and friction decreased with the surface roughness. When the Si surfaces were coated by pure silver, the adhesion and friction decreased. But the adhesion and friction were not affected by the thickness of IBAD silver coating. As the normal force increased, the adhesion forces of bare Si-wafer and IBAD silver coating film remained constant, but the friction forces increased linearly. Test results suggested that the friction was mainly governed by the adhesion as long as the load was low.

• 한국재료학회지
• /
• 제4권4호
• /
• pp.379-384
• /
• 1994

$HF-HNO_{3}$계의 화학용액에서 실리콘웨이퍼를 식각함으로써 실온에서 자외선 조사에 의해 가시광을 발광하는 다공질실리콘(porous-Si)을 형성하였으며, 이렇게 형성시킨 다공질 실리콘의 발광특성고 표면형상을 각각 photoluminescence(PL)측정과 atomic force microscopy(AFM)를 이용하여 조사하였다. $HF:HNO_{3}: H_{2}O$=1 : 5 : 10인 용액을 이용하여 다공질실리콘을 형성시킬때 식각시간에 따른 다공질실리콘의 PL강도 및 표면형상의 변화를 관찰한 결과 1-10분의 영역에서 식각시간을 변화시켰을때 식각시간에 따라 표면의 색깔이 변하였으며 5분간 식각시켰을 경우 표면의색깔은 오렌지 색을 가지고 가장 강한 PL 강도를 보였다. 그리고 AFM관측결과 식각시간이 길어짐에 따라 다공질실리콘의 표면형상크기(surface feature size)가 점점 작아져 5분간 식각시킨 시료의 표면형상 크기는 1,5000~2,000$\AA$범위이며, PL강도가 다공질실리콘의 표면형상과 관계가 있음을 알 수 있었다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.328-328
• /
• 2011

Wetting phenomena have been heavily studied for industrial and academic researches especially tuning the wettability between hydrophilicity and hydrophobicity. Wicking through the surface texture is shown on superhydrophilic surface while rolling (or dewetting) on the patterns of superhydrophobic surface. These wetting phenomena are known to be affected by surface wettability determined with physical surface patterns as well as chemical composition of surface layer. In this research, we introduce a method to control the wettability of a thin C-SiOx film from hydrophobic to hydrophilic using a mixture gas of HMDSO/$O_2$ by plasma polymerization with rf-CVD (radio frequency-Chemical Vapor Deposition). Wettability was finely controlled by changing the ratio of HMDSO/$O_2$. Hydrophilicity increased as the ratio decreased, while hydrophobicity was enhanced by the ratio. Moreover, fine control from superhydrophilicity to superhydrophobicity was achieved by C-SiOx coating on the Si wafer with prepatterns of submicron-sized pillar array formed by $CF_4$ plasma etching.

• 한국표면공학회지
• /
• 제34권5호
• /
• pp.516-521
• /
• 2001

Dry etching of Si wafer and $SiO_2$ layers was performed using He/Cl$_2$ mixture plasma by diode-type reactive ion etcher (RIE) system. For Si etching, the Cl molecules react with the Si molecules on the surface and become chemically stable, indicating that the reactants need energetic ion bombardment. During the ion assisted desorption, energetic ions would damage the photoresist (PR) and produce the bad etch Si-profile. Moreover, we have examined the characteristics of the Cl-Si reaction system, and developed the new fabrication procedures with a $Cl_2$/He mixture for Si and $SiO_2$-etching. The developed novel fabrication procedure allows the RIE to be unexpensive and useful a Si deep etching system. Since the etch rate was proved to increase linearly with fHe and the selectivity of Si to $SiO_2$ etch rate was observed to be inversely proportional to fHe.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.545-545
• /
• 2008

Poly-Si is an essential material for floating gate in NAND Flash memory. To fabricate this material within region of floating gate, chemical mechanical polishing (CMP) is commonly used process for manufacturing NAND flash memory. We use colloidal silica abrasive with alkaline agent, polymeric additive and organic surfactant to obtain high Poly-Si to SiO2 film selectivity and reduce surface defect in Poly-Si CMP. We already studied about the effects of alkaline agent and polymeric additive. But the effect of organic surfactant in Poly-Si CMP is not clearly defined. So we will examine the function of organic surfactant in Poly-Si CMP with concentration separation test. We expect that surface roughness will be improved with the addition of organic surfactant as the case of wafering CMP. Poly-Si wafer are deposited by low pressure chemical vapor deposition (LPCVD) and oxide film are prepared by the method of plasma-enhanced tetra ethyl ortho silicate (PETEOS). The polishing test will be performed by a Strasbaugh 6EC polisher with an IC1000/Suba IV stacked pad and the pad will be conditioned by ex situ diamond disk. And the thickness difference of wafer between before and after polishing test will be measured by Ellipsometer and Nanospec. The roughness of Poly-Si film will be analyzed by atomic force microscope.

• 한국전기전자재료학회논문지
• /
• 제21권12호
• /
• pp.1083-1089
• /
• 2008

We studied the dielectric characteristics of low-k SiOCH thin films by Ellipsometry. The SiOCH thin films were prepared by deposition of BTMSM precursors on p-Si wafer by CCP-PECVD method. The nano-porous structural organic/inorganic hybrid-type of SiOCH thin films correlated directly to the formation of low dielectrics close to pore(k=1). The structural groups including highly dense pores in SiOCH thin films originated the anisotropic geometry type of network structure directing to complex refractive characteristics of SiOCH single layer on the p-Si wafer. The linearly polarized beam of Xe-ramp in the range from 190 nm to 2100 nm introduced to the surface of SiOCH thin film, and the reflected beam was Elliptically polarized by complex refractive coefficients of SiOCH dipole groups. The amplitude variation $\Psi$ and phase variation $\Delta$ of the relative reflective coefficients between perpendicular and parallel components to the incident plane were measured by Ellipsometry. The complex optical constants n and k as well as the dielectric constant and thickness of SiOCH thin films were driven by the measured value of $\Psi$ and $\Delta$.

• 한국결정성장학회지
• /
• 제10권1호
• /
• pp.42-47
• /
• 2000

일반적인 쵸크랄스키(CZ)방법으로 성장된 실리콘 단결정봉(Ingot)을 가공하여 경면 연마한 후 RTA법으로 수소 분위기에서 열처리하여 실리콘 웨이퍼 표면 및 표면 근처의 특성 변화에 대하여 고찰하였다 수소 열처리를 통하여 표면의 COP (결정결함)가 현저히 감소하는 것을 확인하였고 깊이 5um까지의 영역에서도 결정결함의 밀도가 감소하였다. 또한 수소 열처리에 의해 실리콘 웨이퍼 표면이 에칭 및 실리콘의 재배열에 의해 형성되는 테라스(Terrace) 형태도 관찰되었다.

• 한국표면공학회지
• /
• 제49권3호
• /
• pp.301-306
• /
• 2016

The effects of nanotexturing and post-etching on the reflection and quantum efficiency properties of diamond wire sawn (DWS) multicrystalline silicon (mc-Si) solar cell have been investigated. The chemical solutions, which are acidic etching solution (HF-$HNO_3$), metal assisted chemical etching (MAC etch) solutions ($AgNO_3$-HF-DI, HF-$H_2O_2$-DI) and post-etching solution (diluted KOH at $80^{\circ}C$), were used for micro- and nano-texturing at the surface of diamond wire sawn (DWS) mc-Si wafer. Experiments were performed with various post-etching time conditions in order to determine the optimized etching condition for solar cell. The reflectance of mc-Si wafer texturing with acidic etching solution showed a very high reflectance value of about 30% (w/o anti-reflection coating), which indicates the insufficient light absorption for solar cell. The formation of nano-texture on the surface of mc-Si contributed to the enhancement of light absorption. Also, post-etching time condition of 240 s was found adequate to the nano-texturing of mc-Si due to its high external quantum efficiency of about 30% at short wavelengths and high short circuit current density ($J_{sc}$) of $35.4mA/cm^2$.