• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.112.1-112.1
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• 2011

The back contact solar cell (BCSC) has several advantages compared to the conventional solar cell since it can reduce grid shadowing loss and contact resistance between the electrode and the silicon substrate. This paper presents the effect of the surface texturing of the silicon BCSC by varying the texturing depth or the texturing gap in the commercially available simulation software, ATHENA and ATLAS of the company SILVACO. The texturing depth was varied from $5{\mu}m$ to $150{\mu}m$ and the texturing gap was varied from $1{\mu}m$ to $100{\mu}m$ in the simulation. The resulting efficiency of the silicon BCSC was evaluated depending on the texturing condition. The quantum efficiency and the I-V curve of the designed silicon BCSC was also obtained for the analysis since they are closely related with the solar cell efficiency. Other parameters of the simulated silicon BCSC are as follows. The substrate was an n-type silicon, which was doped with phosphorous at $6{\times}10^{15}cm^{-3}$, and its thickness was $180{\mu}m$, a typical thickness of commercial solar cell substrate thickness. The back surface field (BSF) was $1{\times}10^{20}\;cm^{-3}$ and the doping concentration of a boron doped emitter was $8.5{\times}10^{19}\;cm^{-3}$. The pitch of the silicon BCSC was $1250{\mu}m$ and the anti-reflection coating (ARC) SiN thickness was $0.079{\mu}m$. It was assumed that the texturing was anisotropic etching of crystalline silicon, resulting in texturing angle of 54.7 degrees. The best efficiency was 25.6264% when texturing depth was $50{\mu}m$ with zero texturing gap in case of low texturing depth (< $100{\mu}m$).

• 한국전기전자재료학회논문지
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• 제29권8호
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• pp.505-509
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• 2016

We have investigated the characteristics of amorphous silicon (a-Si) thin-film solar cell by inserting barrier layer. The conversion efficiency of a-Si thin-film solar cells on graphite substrate shows nearly zero because of the surface roughness of the graphite substrate. To enhance the performance of solar cells, the surface morphology of the back side were modified by changing the barrier layer on graphite. The surface roughness of graphite substrate with the barrier layer grown by plasma enhanced chemical vapor deposition (PECVD) reduced from ~2 um to ~75 nm. In this study, the combination of the barrier layer on graphite substrate is important to increase solar cell efficiency. We achieved ~ 7.8% cell efficiency for an a-Si thin-film solar cell on graphite substrate with SiNx/SiOx stack barrier layer.

• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.149-153
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• 2019

The technology of electronic packaging among semiconductor technologies is evolving as an axis of the market in its own field beyond the simple assembly process of the past. In the field of electronic packaging technology, the packaging of power modules plays an important role for green electric vehicles. In this power module packaging, the thermal reliability is an important factor, and silicon nitride plays an important part of package substrates, Silicon nitride is a compound that is not found in nature and is made by chemical reaction between silicon and nitrogen. In this study, this core material, silicon nitride, was fabricated by reaction bonded silicon nitride. The fabricated silicon nitride was studied for thermo-mechanical properties, and through this, the structure of power module packaging was made using reaction bonded silicon nitride. And the characteristics of stress were evaluated using finite element analysis conditions. Through this, it was confirmed that reaction bonded silicon nitride could replace the silicon nitride as a package substrate.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.509-512
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• 1987

We report that the optimum substrate temperature to fabricate a-Si:H $n^+-p-p^+$ cell decreases with increasing the boron concentration in the Player. The results can be explained as the dependence of substrate temperature for the relaxation of silicon atoms and the bonded hydrogen concentration in the player.

• 센서학회지
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• 제8권2호
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• pp.202-209
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• 1999

본 연구에서는 기존의 열산화막과 거의 버금가는 전기적 및 화학적인 성질을 가진다고 알려져 있는 다공질 실리콘 산화막을 이용하여 마이크로스트립 전송선을 제작하였다. 실리콘 기판의 결정상태를 유지하면서 표면적과 화학적 활성이 큰 다공질 실리콘층(porous silicon layer)을 형성한 다음, 이를 열산화 하여 수 십 ${\mu}m$ 두께의 산화막을 실리콘 기판 상에 제조하였다. 수십 ${\mu}m$ 이상의 양질의 산화막을 얻기 위한 다공질 실리콘의 산화시에 스트레스에 의한 웨이퍼의 휘어짐을 방지하기 위하여 다단계의 열산화 공정을 수행하였다. 제조된 실리콘 산화막 상에 마이크로스트립 전송선을 제작하고 그 마이크로웨이브 특성을 측정하여 MMIC 기판으로서의 응용 가능성을 조사하였다.

• 전자공학회논문지C
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• 제36C권3호
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• pp.26-34
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• 1999

실리콘 집적회로 인터컨넥트에서 전송선 파라미터를 추출하는 새로운 방법을 제시하고 이를 실험적으로 고찰 한다. 실리콘 기판 위에 있는 전송선에서의 신호는 PCB (printed circuit board)혹은 MCM (multi-chip module)의 인터컨넥트와 같은 마이크로 스트립 구조에서 가정하는 quasi-TEM 모드가 아니라 slow wave mode (SWM)로 대부분의 에너지가 전송되기 때문에 기판의 효과를 고려하여 전송선 파라미터를 추출한다. 실리콘 기판에서 전계 및 자계의 특성을 고려하여 커패시턴스 파라미터의 계산을 실리콘 표면을 그라운드로 설정하고 계산하고 인덕턴스는 단일 전송선 모델로부터 추출한 실효 유전상수를 도입하여 계산한다. 제안한 전송선 파라미터 추출 방법의 타당성을 검증하기 위하여 테스트 패턴을 제작하여 실험적 파리미터 추출 값이 제시한 방법의 결과와 약 10% 이내에서 일치한다는 것을 보여 계산 방법의 타당성을 입증한다. 또한 고속 샘플링 오실로스코프(TDR/TDT 메터) 측정을 통하여 제시한 방법이 크로스톡 노이즈를 정확히 예측 할 수 있는 반면 흔히 사용하고 있는 기판의 효과를 고려하지 않는 RC 모델 혹은 ？ 모델은 약 20∼25% 정도 과소 오차(underestimation error)를 보인다는 것을 보인다.

• 대한금속재료학회지
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• 제49권4호
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• pp.321-328
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• 2011

The 30 nm-thick Ni layers was deposited on a flexible polyimide substrate with an e-beam evaporation. Subsequently, we deposited a Si layer using a catalytic CVD (Cat-CVD) in a hydride amorphous silicon (${\alpha}$-Si:H) process of $T_{s}=180^{\circ}C$ with varying thicknesses of 55, 75, 145, and 220 nm. The sheet resistance, phase, degree of the crystallization, microstructure, composition, and surface roughness were measured by a four-point probe, HRXRD, micro-Raman spectroscopy, FE-SEM, TEM, AES, and SPM. We confirmed that our newly proposed Cat-CVD process simultaneously formed both NiSi and crystallized Si without additional annealing. The NiSi showed low sheet resistance of < $13{\Omega}$□, while carbon (C) diffused from the substrate led the resistance fluctuation with silicon deposition thickness. HRXRD and micro-Raman analysis also supported the existence of NiSi and crystallized (>66%) Si layers. TEM analysis showed uniform NiSi and silicon layers, and the thickness of the NiSi increased as Si deposition time increased. Based on the AES depth profiling, we confirmed that the carbon from the polyimide substrate diffused into the NiSi and Si layers during the Cat-CVD, which caused a pile-up of C at the interface. This carbon diffusion might lessen NiSi formation and increase the resistance of the NiSi.

• 한국표면공학회지
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• 제25권6호
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• pp.287-292
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• 1992

Silicon nitride thin film (SiNx) was deposited onto the 3inch silicon wafer using an electron cyclotron resonance (ECR) plasma apparatus. The thin films which were deposited by changing the SiH4N2 gas flow rate ratio at 1.5mTorr without substrate heating were analyzed through the x-ray photo spectroscopy (XPS) and ellipsometer measurements, etc. Silicon nitride thin films prepared by the electron cyclotron resonance plasma chemical vapor deposition method at low substrate temperature (<10$0^{\circ}C$) exhibited excellent physical and electrical properties. The very uniform and good quality silicon nitride thin films were obtained. The characteristics of electron cyclotron resonance plasma were inferred from the analyzed results of the deposited films.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.43.2-43.2
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• 2011

Minority Carrier recombination should be suppressed for high efficiency solar cells. However, impurities in the silicon bulk region deteriorate the minority carrier lifetimes, causes conversion efficiency drop. In this study, we introduced phosphorus external gettering for silicon heterojunction solar cell substrates. Gettering was undergone at 750, 800, 850 and $900^{\circ}C$ in furnace for 30 minutes. Bulk lifetimes and calculated diffusion length were improved. We applied phosphorus gettering to silicon heterojunction solar cells. Gettered group and ungettered group were used as substrate of silicon heterojunction solar cells. After fabrication, characteristics of solar cells were analyzed. The results were observed to see the enhancement of substrate quality which directly connects with solar cell properties.

• Journal of Korean Vacuum Science & Technology
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• 제2권1호
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• pp.49-54
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• 1998

The effect of deposition paratmeters on the solid-phase crystallization of amorphous silicon films deposited by plasma-enhanced chemical vapor deposition has been investigated by x-ray diffraction. The amorphous silicon films were prepared on Si(100) wafers using SiH4 gas with and without H2 dilution at the substrate temperatures between 12$^{\circ}C$ and 38$0^{\circ}C$. The R. F. powers and the deposition pressures were also varied. After crystallizing at $600^{\circ}C$ for 24h, the films exhibited (111), (220), and (311) x-ray diffraction peaks. The (111) peak intensity increased as the substrate temperature decreased, and the H dilution suppressed the crystallization. Increasing R.F. powers within the limits of etching level and increasing deposition pressures also have enhanced the peak intensity. The peak intensity was closely related to the deposition rate, which may be an indirect indicator of structural disorder in amorphous silicon films. Our results are consistent with the fact that an increase of the structural disorder I amorphous silicon films enhances the grain size in the crystallized films.