• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.357-357
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• 2012

The doping process of the solar cell has been used by furnace or laser. But these equipment are so expensive as well as those need high maintenance costs and production costs. The atmospheric pressure plasma doping process can enable to the cost reduction. Moreover the atmospheric pressure plasma can do the selective doping, this means is that the atmospheric pressure plasma regulates the junction depth and doping concentration. In this study, we analysis the atmospheric pressure plasma doping compared to the conventional furnace doping. the single crystal silicon wafer doped with dopant forms a P-N junction by using the atmospheric pressure plasma. We use a P type wafer and it is doped by controlling the plasma process time and concentration of dopant and plasma intensity. We measure the wafer's doping concentration and depth by using Secondary Ion Mass Spectrometry (SIMS), and we use the Hall measurement because of investigating the carrier concentration and sheet resistance. We also analysis the composed element of the surface structure by using X-ray photoelectron spectroscopy (XPS), and we confirm the structure of the doped section by using Scanning electron microscope (SEM), we also generally grasp the carrier life time through using microwave detected photoconductive decay (u-PCD). As the result of experiment, we confirm that the electrical character of the atmospheric pressure plasma doping is similar with the electrical character of the conventional furnace doping.

• 센서학회지
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• 제4권1호
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• pp.64-71
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• 1995

스테인 에칭기법을 이용하여 실리콘의 도핑 농도가 높은 영역을 선택적으로 식각하는 방법을 개발하였다. 이 방법은 양극반응을 이용한 마이크로머시닝 방법에서와 같이 반응 시편의 뒷면에 전극을 연결하거나 특수한 반응기를 이용해 전류를 공급할 필요성이 없으므로 공정 단계가 간단해지고 표준적인 집적회로 공정에서도 응용될 수 있을 것이다. 또한 양극반응에서는 불가능한 구조의 시편에서도 도핑 농도가 높은 영역의 선택적인 식각이 가능하다. 본 연구에서는 스테인 에칭기법을 이용하여 $n/n^{+}/n$ 3층 구조의 시편으로 캔틸레버 및 에어 브릿지 등을 실현하였고, 또한 양극반응에서는 불가능한 $p/p^{+}$ 구조의 선택적 식각을 이용하여 에어 브릿지를 실현함으로써 미세기계구조의 제조 가능성을 확인하였다.

• 통합자연과학논문집
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• 제3권3호
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• pp.168-173
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• 2010

Novel porous silicon chip exhibiting dual optical properties, both Frbry-Perot fringe (optical reflectivity) and photoluminescence had been developed and used as chemical sensors. Porous silicon samples were prepared by an electrochemical etch of p-type sillicon wafer (boron-doped, <100> orientation, resistivity 1 - 10 ${\Omega}$). The ething solution was prepared by adding an equal volume of pure ethanol to an aqueous solution of HF (48% by weight). The porous silicon was illuminated with a 300 W tungsten lamp for the duration of etch. Ething was carried out as a two-electrode Kithley 2420 preocedure at an anodic current. The surface of porous silicon was characterized by FT-IR instrument. The porosity of samples was about 80%. Three different types of porous silicon, fresh porous silicon (Si-H termianated), oxidized porous silicon (Si-OH terminated), and surface-derivatized porous silicon (Si-R terminated), were prepared by the thermal oxidation and hydrosilylation. Then the samples were exposed to the wapor of various organics vapors. such as chloroform, hexane, methanol, benzene, isopropanol, and toluene. Both reflectivity and photoluminescence were simultaneously measured under the exposure of organic wapors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1547-1549
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• 1996

The electrical and optical switching characteristics of gold-doped silicon p-i-n diodes have been investigated. The device shows a dark switching voltage of about 500 V. The switching voltage decreases rapidly when the illumination level is increased. The differential sensitivity of optical gating over linear region is $d(V_{Th}/V_{Tho})/dP_{Ph}$=0.25/uW. The turn-on delay time and the turn-on rise time decrease with increasing optical pulse power. The turn-off delay and the fall time are negligible.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.207-207
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• 2012

Si quantum dot (QD) imbedded in a $SiO_2$ matrix is a promising material for the next generation optoelectronic devices, such as solar cells and light emission diodes (LEDs). However, low conductivity of the Si quantum dot layer is a great hindrance for the performance of the Si QD-based optoelectronic devices. The effective doping of the Si QDs by semiconducting elements is one of the most important factors for the improvement of conductivity. High dielectric constant of the matrix material $SiO_2$ is an additional source of the low conductivity. Active doping of B was observed in nanometer silicon layers confined in $SiO_2$ layers by secondary ion mass spectrometry (SIMS) depth profiling analysis and confirmed by Hall effect measurements. The uniformly distributed boron atoms in the B-doped silicon layers of $[SiO_2(8nm)/B-doped\;Si(10nm)]_5$ films turned out to be segregated into the $Si/SiO_2$ interfaces and the Si bulk, forming a distinct bimodal distribution by annealing at high temperature. B atoms in the Si layers were found to preferentially substitute inactive three-fold Si atoms in the grain boundaries and then substitute the four-fold Si atoms to achieve electrically active doping. As a result, active doping of B is initiated at high doping concentrations above $1.1{\times}10^{20}atoms/cm^3$ and high active doping of $3{\times}10^{20}atoms/cm^3$ could be achieved. The active doping in ultra-thin Si layers were implemented to silicon quantum dots (QDs) to realize a Si QD solar cell. A high energy conversion efficiency of 13.4% was realized from a p-type Si QD solar cell with B concentration of $4{\times}1^{20}atoms/cm^3$. We will present the diffusion behaviors of the various dopants in silicon nanostructures and the performance of the Si quantum dot solar cell with the optimized structures.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.426.1-426.1
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• 2016

We report high work function Aluminum doped zinc oxide (AZO) films as insertion layer as a function of O2 flow rate between transparent conducting oxides (TCO) and hydrogenated amorphous silicon oxide (a-SiOx:H) layer to improve open circuit voltage (Voc) and fill factor (FF) for high efficiency thin film solar cell. However, amorphous silicon (a-Si:H) solar cells exhibit poor fill factors due to a Schottky barrier like impedance at the interface between a-SiOx:H windows and TCO. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiOx:H. In this study, we report on the silicon thin film solar cell by using as insertion layer of O2 reactive AZO films between TCO and p-type a-SiOx:H. Significant efficiency enhancement was demonstrated by using high work-function layers (4.95 eV at O2=2 sccm) for engineering the work function at the key interfaces to raise FF as well as Voc. Therefore, we can be obtained the conversion efficiency of 7 % at 13mA/cm2 of the current density (Jsc) and 63.35 % of FF.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.480.1-480.1
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• 2014

In this study, we suggest the new emitter formation applied solid phase epitaxy (SPE) growth process using rapid thermal process (RTP). Preferentially, we describe the SPE growth of intrinsic a-Si thin film through RTP heat treatment by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD). Phase transition of intrinsic a-Si thin films were taken place under $600^{\circ}C$ for 5 min annealing condition measured by spectroscopic ellipsometer (SE) applied to effective medium approximation (EMA). We confirmed the SPE growth using high resolution transmission electron microscope (HR-TEM) analysis. Similarly, phase transition of P doped a-Si thin films were arisen $700^{\circ}C$ for 1 min, however, crystallinity is lower than intrinsic a-Si thin films. It is referable to the interference of the dopant. Based on this, we fabricated 16.7% solar cell to apply emitter layer formed SPE growth of P doped a-Si thin films using RTP. We considered that is a relative short process time compare to make the phosphorus emitter such as diffusion using furnace. Also, it is causing process simplification that can be omitted phosphorus silicate glass (PSG) removal and edge isolation process.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1205-1208
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• 1995

The optically-gated p-i-n diode switches have been fabricated with gold-compensated silicon. The turn-on and turn-off delay times and the rise and fall times were measured as a function of optical power level, bias, and pulse width. The turn-on characteristics shows a strong dependence an optical pulse power and a delay time(${\delta}{\iota}$) between two pulses, but a weak dependence on the width of optical pulse. Actually there is no turn-off delay in gold-doped p-i-n switches and the fall time is negligible.

• 센서학회지
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• 제17권5호
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• pp.346-349
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• 2008

A metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) is proposed as an effective UV sensing device for integration with a GaN n-channel MISFET on auto-doped p-type GaN grown on a silicon substrate. Due to the high hole barrier of the metal-p-GaN contact, the dark current density of the fabricated MSM PD was less than $3\;nA/cm^2$ at a bias of up to 5 V. Meanwhile, the UV/visible rejection ratio was 400 and the cutoff wavelength of the spectral responsivity was 365 nm. However, the UV/visible ratio was limited by the sub-bandgap response, which was attributed to defectrelated deep traps in the p-GaN layer of the MSM PD. In conclusion, an MSM PD has a high process compatibility with the n-channel GaN Schottky barrier MISFET fabrication process and epitaxy on a silicon substrate.

• 통합자연과학논문집
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• 제2권3호
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• pp.207-210
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• 2009

Multiple rugate structures can be etched on a silicon wafer and placed in the same physical location, showing that many sharp spectral lines can be obtained in the optical reflectivity spectrum. Porous silicon samples were prepared by electrochemical etch of heavily doped p-type silicon wafers. The etching solution consisted of a 3:1 volume mixture of aqueous 48% hydrofluoric acid and absolute ethanol. Galvanostatic etch was carried out in a Teflon cell by using a two-electrode configuration with a Pt mesh counterelectrode. A sinusoidal current density waveform varying between 51.5 and $74.6mA/cm^2$ is applied. The anodization current was supplied by a Keithley 2420 high-precision constant current source which is controlled by a computer to allow the formation of PSi multilayer.