• Transactions on Electrical and Electronic Materials
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• 제9권1호
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• pp.12-15
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• 2008

Hafnium oxynitride films have been deposited onto a silicon substrate by means of radio frequency (RF) reactive sputtering using a hafnium dioxide $(HfO_2)$ target with a variety of nitrogen! argon $(N_2/Ar)$ gas flow ratios. Auger electron spectroscopy (AES)results confirm that $N_2$ was successfully incorporated into the HfON films. An increase in the $N_2/Ar$ gas flow ratio resulted in metal oxynitride formation. The films prepared with a $N_2/Ar$ flow ratio of 20/20 sccm show (222), (530), and (611) directions of $HfO_2N_2$, and the (-111), (311) directions of $HfO_2$. From X-ray reflectometry measurements, it can be concluded that with $N_2$ incorporated into the HfON films, the film density increases. The density increases from 9.8 to $10.1g/cm^3$. XRR also reveals that the surface roughness is related to the $N_2/Ar$ flow ratio.

• 한국전기전자재료학회논문지
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• 제28권8호
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• pp.481-485
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• 2015

We investigated the effects of annealing on the electrical and thermal properties of ZTO/4H-SiC heterojunction diodes. A ZTO thin film layer was grown on p-type 4H-SiC substrate by using solution process. The ZTO/SiC heterojunction structures annealed at $500^{\circ}C$ show that $I_{on}/I_{off}$ increases from ${\sim}5.13{\times}10^7$ to ${\sim}1.11{\times}10^9$ owing to the increased electron concentration of ZTO layer as confirmed by capacitance-voltage characteristics. In addition, the electrical characterization of ZTO/SiC heterojunction has been carried out in the temperature range of 300~500 K. When the measurement temperature increased from 300 K to 500 K, the reverse current variation of annealed device is higher than as-grown device, which is related to barrier height in the ZTO/SiC interface. It is shown that annealing process is possible to control the electrical characteristics of ZTO/SiC heterojunction diode.

• 한국입자에어로졸학회지
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• 제5권2호
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• pp.83-90
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• 2009

This paper describes a condensation-evaporation method (CEM) to produce size-controlled spherical silver nanoparticles by perturbing coagulation and coalescence processes in the gas phase. Polydisperse silver nanoparticles generated by the CEM were first introduced into a differential mobility analyzer (DMA) to select a group of silver nanoparticles with same electrical mobility, which also enables to make a group of nanoparticles with elongated structures and same projected area. These silver nanoparticles selected by the DMA were then in-situ sintered at ${\sim}600^{\circ}C$, and then they were observed to turn into spherical shaped nanoparticles by the rapid coalescence process. With the assistance of modified converging-typed quartz reactor, we can also produce the 10 times higher number concentration of silver nanoparticles compared with a general quartz reactor with uniform diameter. Finally, the spherical silver nanoparticles with 30 nm were electrostatically deposited on the surface of silicon substrate with the coverage rate of ~4%/hr. This useful preparation method of size-controlled monodisperse silver nanoparticles developed in this work can be applied to the various studies for characterizing the physical, chemical, optical, and biological properties of nanoparticles as a function of their size.

• 한국정보통신학회논문지
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• 제9권3호
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• pp.595-600
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• 2005

마이크로 흐름센서는 반도체 집적기술을 이용할 수 있어, 소형으로 제작이 가능하며 빠른 응답특성을 가져 다양한 분야에 응용되고 있다. 본 연구에서는 넓은 흐름의 세기 영역에서 정밀한 감도를 가지는 2차원의 마이크로 흐름센서를 실리콘 기판위에 적충시켜 제작하였다. 흐름센서의 중앙에 하나의 히터와 양측에 온도를 검출할 수 있는 3쌍의 감지막을 가진 새로운 센서 구조를 제안하고, 온도 검출에 대한 성능평가를 위하여 시간영역에서의 유한차분법을 이용하여 공기흐름의 세기 변화에 따른 온도분포를 계산하였다. 계산결과를 통하여 실제 흐름센서의 동작을 정량적으로 분석하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.180-180
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• 2010

The design and implementation of high rate deposition process and anti-scratch property of silicon oxide film by PECVD with UHF power were investigated according to the effect of UHF input power with HF bias. New regime of high rate deposition of SiOx films by hybrid plasma process was investigated. The dissociation of OMCTS (C8H24Si4O4) precursor was controlled by plasma processes. SiOx films were deposited on polyethylene terephthalate (PET) and polycarbonate substrate by plasma enhanced chemical vapor deposition (PECVD) using OMCTS with oxygen carrier gas. As the input energy increased, the deposition rate of SiOx film increased. The plasma diagnostics were performed by optical emission spectrometry. The deposition rate was characterized by alpha-step. The mechanical properties of the coatings were examined by nano-indenter and pencil hardness, respectively. The deposition rate of the SiOx films could be controlled by the appropriate intensity of excited neutrals, ionized atoms and UHF input power with HF bias at room temperature, as well as the dissociation of OMCTS.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.251.1-251.1
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• 2014

Oraganic Light Emitting Diodes (OLED) 소자의 광추출 효율을 향상시키기 위한 방안으로 나노급 사이즈의 고 굴절률 패턴을 기판의 내부 패턴에 적용하였다. 100 nm 및 300 nm의 직경을 갖는 Si3N4 나노 패턴을 나노 임프린트 리소그래피와 건식 식각 공정을 통하여 OLED의 유리기판에 형성을 하였다. 그리고 Silicon On Glass (SOG) 물질을 패턴이 전사된 기판에 스핀 코팅으로 평탄화 공정을 진행 함으로써 OLED소자의 전기적인 특성이 떨어지는 문제점을 개선하였다. 그러고 나서 Si3N4 나노 패턴이 형성되고 평탄화 공정을 마친 기판상 OLED 소자를 제작하였다. OLED의 발광층에서 발생한 빛은 Si3N4 나노패턴에 의해 산란되어 광 추출 효율을 개선할 수 있다. 본 연구에서 두 가지 종류 100nm, 300nm 높이의 Si3N4 나노패턴으로 높이에 따른 광 추출 효율을 비교하고자 OLED 소자를 제작하였다. 기판에 Si3N4 패턴이 형성된 OLED의 효율은 Si3N4 300nm에서 13.1% 증가하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.563-566
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• 2002

We investigated to decrease the leakage current of SiNx film by employing $N_2$ plasma treatment. The insulator layers were prepared by two step process; the $N_2$ plasma treatment and then PECVD SiNx deposition with $SiH_4$, $N_2$ gases. To prove the influence of the $N_2$ plasma treatment, the Si substrate was exposed to the plasma, which was generated in Ne gas ambient. Without plasma treatment SiNx film grow at the rate of 7. 03 nm/min, has a refractive index n = 1.77 and hydrogen content of $2.16{\times}10^{22}cm^{-3}$ for $N_2/SiH_4$ gas flow ratio of 20. The obtained films were analyzed in terms of deposition rates, refractive index, hydrogen concentration, and electrical properties. By employing $N_2$ plasma treatment, interface traps such as mobile charges and injected charges were removed, hysteresis of capacitance-voltage (C-V) disappeared. We observed plasma treated sample were decreased the leakage current density reduces by 2 orders with respect to the sample having no plasma treatment.

• Korean Chemical Engineering Research
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• 제47권3호
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• pp.316-320
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• 2009

폴리카보네이트(polycarbonate)는 가볍고, 내충격성 및 가공성이 우수하여 광학기기의 렌즈 및 각종 건축물의 투명 소재 등에 유리의 대체품으로서 널리 이용되고 있으나 낮은 표면경도를 가지고 있어 유통 또는 사용시의 접촉으로 인하여 제품에 손상을 줄 염려가 있다. 따라서 본 연구에서는 폴리카보네이트 필름에 아크릴레이트 올리고머, 모노머, 용매, 염료, 실리콘 아크릴레이트, 그리고 광개시제 등을 다양한 함량비율에 따라 혼합한 코팅용액을 제조하고, 구성 성분의 비율에 따른 폴리카보네이트 필름의 표면 경도, 접착력, 그리고 투과율의 변화를 실험하였다. 그 결과 최대 연필 경도가 2H이고, 접착력과 가시광선 투과율이 우수한 코팅용액의 조성을 얻었다. 색상코팅 실험 결과, 기존 산화물 증착에 의해 구현하던 색상을 본 실험에서 제조한 코팅 용액을 사용하여 거의 대부분 구현할 수 있었으며, 이를 바탕으로 색상 윈도우 렌즈를 제작한 결과, 매우 깨끗하고 균일한 색상과 표면을 가졌다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.533-536
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• 2001

Single crystal cubic silicon carbide(3C-SiC) thin film were deposited on Si(100) substrate up to a thickness of $4.3{\mu}m$ by APCVD(atmospheric pressure chemical vapor deposition) method using hexamethyildisilane(HMDS) at $1350^{\circ}C$. The HMDS flow rate was 0.5 sccm and the carrier gas flow rate was 2.5 slm. The HMDS flow rate was important to get a mirror-like. The growth rate of the 3C-SiC films was $4.3{\mu}m/hr$. The 3C-SiC epitaxical layers on Si(100) were characterized by XRD(X-ray diffraction), raman scattering and RHEED(reflection high-energy electron diffraction), respectively. The 3C-SiC distinct phonons of TO(transverse optical) near $796cm^{-1}$ and LO(longitudinal optical) near $974{\pm}1cm^{-1}$ were recorded by raman scattering measurement. The deposition films were identified as the single crystal 3C-SiC phase by XRD spectra($2{\theta}=41.5^{\circ}$). Also, with increase of films thickness, RHEED patterns gradually changed from a spot pattern to a streak pattern.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.303-304
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• 2005

In this paper, we report a fluxless eutectic die bonding process which uses 80Au-20Sn eutectic alloy. The chip LEDs are picked and placed on silicon substrate wafers. The bonding process temperatures and force are $305\sim345^{\circ}C$ and 10$\sim$100gf, respectively. The bonding process was performed on graphite heater with nitrogen atmosphere. The quality of bonding are evaluated by shear test and thermal resistance. Results of fluxless eutectic die bonding show that shear strength is Max. 3.85kgf at 345$^{\circ}C$ /100gf and thermal resistance of junction to die bonding is Min. 3.09K/W at 325$^{\circ}C$/100gf.