• Transactions on Electrical and Electronic Materials
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• 제2권2호
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• pp.32-36
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• 2001

A new solid source for low temperature diffusion into silicon was developed. The source wafer consists of an “active” compound, which is sol-gel prepared phosphosilicate glass-ceramics containing 56% P$_2$O$\sub$5/, embedded in a skeletal foam-like, inert substrate. Phosphorus diffusion from the new solid sources at low temperatures (800-875$^{\circ}C$) produced reprodecible sheet resistances and shallow junctions. From a series of one hour doping runs, the life time of the phosphosilicate source was determined to be over 40 hours. The effective diffusion coefficient of phosphorus into silicon and the corresponding activation energy at 850$^{\circ}C$ were determined to be 7.5${\times}$10$\^$-15/ $\textrm{cm}^2$/sec and ∼3.9 eV, respectively.

• 대한전자공학회논문지
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• 제27권9호
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• pp.1409-1418
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• 1990

Characteristics of NMOS transistors with phosphorus source/drain junctions formed by two-step rapid thermal diffusion (RTD) process using a solid diffusion source have been investigated. Phosphorus profiles after RTD were measured by SIMS analysis. In the case of 1100\ulcorner, 10sec RTD of, P, the specific contact resistance of n+ Si-Al was 2.4x10**-7 \ulcorner-cm\ulcorner which is 1/5 of the As junction The comparison fo P junction devices formed by RTD and conventional As junction devices shows that both short channel effect and hot carrier effect of P junction devices are smaller than those of As junction devices when the devices have same junction depths. P junction device had maximum of 0.4 times lower Isub/Id than As junction device. Characteristics of P junction formed by several different RTD conditions have been compared and 1000\ulcorner RTD sample had the smaller hot carrier generation. Also, it has been shown that the hot carrier generation can be futher reduced by forming the P junctions by 3-step RTD which has RTO-driven-in process additionally.

• 한국세라믹학회지
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• 제49권6호
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• pp.637-641
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• 2012

Due to its high production cost and relatively high energy consumption during the Siemens process, poly-silicon makers have been continuously and eagerly sought another silicon route for decades. One candidate that consumes less energy and has a simpler acidic and metallurgical purification procedure is upgraded metallurgical-grade (UMG) silicon. Owing to its low purity, UMG silicon often requires special steps to minimize the impurity effects and to remove or segregate the metal atoms in the bulk and to remove interfacial defects such as precipitates and grain boundaries. A process often called the 'gettering process' is used with phosphorus diffusion in this experiment in an effort to improve the performance of silicon solar cells using UMG silicon. The phosphorous gettering processes were optimized and compared to the standard POCl process so as to increase the minority carrier lifetime(MCLT) with the duration time and temperature as variables. In order to analyze the metal impurity concentration and distribution, secondary ion mass spectroscopy (SIMS) was utilized before and after the phosphorous gettering process.

• 대한전자공학회논문지
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• 제22권2호
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• pp.97-105
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• 1985

PECVD 방법으로 만들어진 도핑한 박막에서 실리콘으로의 인이나 붕소의 확산 특성이 연구되었다. CVD PSC 박막도 역시 만들어면 PECVD PSG에 있는 인의 확산특성과 나란히 비교되었다. 인의 부산은 N2와 O2 분위기 및 1000℃, 1,050℃, 1,100℃의 온도에서 수행되었다. 붕소의 확산 변수들은 B2H2유량 및 박막형성 온도를 달리하여 만들어진 박막에 관하여 고찰되었다. 실리콘으로의 주입물 확산 계수와 확산 Profile이 측정된 혹산 깊이 및 불순물 표면 농도를 써서 Barry의 모델을 적용하여 계산되었다.

• Journal of Korean Vacuum Science & Technology
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• 제4권3호
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• pp.73-77
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• 2000

Single crystal and polycrystalline Si thin films were doped with phosphorus by a 2-zone diffusion method to develop the low-resistivity polycrystalline Si electrode for a hemispherical grain. Solid phosphorus source was used in order to achieve uniformly and highly doped surface region of polycrystalline Si films having rough surface morphology. In case of 2-zone diffusion method, it is proved that the heavy doping near the surface area can be achieved even at a relatively low temperature. SIMS analysis revealed that phosphorus doping concentration in case of using solid P as a doping source was about 50 times as that of phosphine source at 750$^{\circ}C$. Also, ASR analysis revealed that the carrier concentration was about 50 times as that of phosphine. In order to evaluate the electrical characteristics of doped polycrystalline Si films for semiconductor devices, MOS capacitors were fabricated to measure capacitance of polycrystalline Si films. In ${\pm}$2 V measuring condition, Si films, doped with solid source, have 8% higher $C_{min}$ than that of unadditional doped Si films and 3% higher $C_{min}$ than that of Si films doped with $PH_3$ source. The leakage current of these films was a few fA/${\mu}m^2$. As a result, a 2-zone diffusion method is suggested as an effective method to achieve highly doped polycrystalline Si films even at low temperature.

• 한국표면공학회지
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• 제47권5호
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• pp.227-232
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• 2014

In this study, we propose the application of doping process technology for atmospheric pressure plasma. The plasma treatment means the wafer is warmed via resistance heating from current paths. These paths are induced by the surface charge density in the presence of illuminating Argon atmospheric plasmas. Furthermore, it is investigated on the high-concentration doping to a selective partial region in P type solar cell wafer. It is identified that diffusion of impurities is related to the wafer temperature. For the fixed plasma treatment time, plasma currents were set with 40, 70, 120 mA. For the processing time, IR(Infra-Red) images are analyzed via a camera dependent on the temperature of the P type wafer. Phosphorus concentrations are also analyzed through SIMS profiles from doped wafer. According to the analysis for doping process, as applied plasma currents increase, so the doping depth becomes deeper. As the junction depth is deeper, so the surface resistance is to be lowered. In addition, the surface charge density has a tendency inversely proportional to the initial phosphorus concentration. Overall, when the plasma current increases, then it becomes higher temperatures in wafer. It is shown that the diffusion of the impurity is critically dependent on the temperature of wafers.

• 전기의세계
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• 제27권6호
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• pp.69-75
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• 1978

Diffusion processes of boron, phosphorus, and arsenic into silicon have been investigated using a new diffusion source called "spin-on source". Diffusion coefficients of these impurities have been calculated from the experimental results and are compared with the published values. Reasonable agreements have been found between the calculated and the published values. From this study, it is concluded that the spin-on source can be used as the diffusion source for integrated circuit fabricaticon.ricaticon.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.236-236
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• 2010

P-type의 단결정, 다결정, UMG 기판을 이용하여 phosphorus툴 확산시킨 후 열처리한 external gettering 방식으로 실리콘 내부에 있는 불순물을 제거하였고, 기판의 lifetime 변화를 $\mu$-PCD를 이용하여 측정하였다. phosphorus를 $850^{\circ}C$에서 기판 내부로 20분 확산시킨 후 기판의 온도와 시간을 변화시키면서 gettering 공정을 시행하였다. 에미터층으로 인해 기판의 bulk lifetime이 부정확해 지는 것을 방지하기 위해서 NaOH를 이용하여 에미터층을 제거한 후 $\mu$-PCD를 이용하여 lifetime을 측정하였다. 또한 기판의 표면효과를 최소화하기 위해서 lifetime 측정전에 iodine을 이용하여 표면 passivation을 하였다.

• Current Photovoltaic Research
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• 제4권2호
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• pp.31-41
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• 2016

n-type PERT (passivated emitter, rear totally diffused) bifacial solar cells with boron and phosphorus diffusion as p+ emitter and n+ BSF (back surface field) have attracted significant research interest recently. In this work, the influences of wafer thickness, bulk lifetime, emitter, BSF on the photovoltaic characteristics of solar cells are discussed. The performance of the solar cell is determined by using one-dimensional solar cell simulation software PC1D. The simulation results show that the key role of the BSF is to decrease the surface doping concentration reducing the recombination and thus, increasing the cell efficiency. A lightly phosphorus doped BSF (LD BSF) was experimentally optimized to get low surface dopant concentration for n type bifacial solar cells. Pre-oxidation combined with a multi-plateau drive-in, using limited source diffusion was carried out before pre-deposition. It could reduce the surface dopant concentration with minimal impact on the sheet resistance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.97-98
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• 2005

To investigate the ZnO thin films which is interested in the next generation of short wavelength LEDs and Lasers, our ZnO thin films were deposited by RF sputtering system. Phosphorus (P) and arsenic (As) were diffused into about 2.1${\mu}m$ ZnO thin films sputtered by RF magnetron sputtering system mn ampoule tube which was below $5\times10^{-7}$ Torr. The dopant sources of phosphorus and arsenic were $Zn_3P_2$ and $ZnAs_2$. Those diffusion was perform at 500, 600, and 700$^{\circ}C$ during 3hr. We find the condition of p-type ZnO whose diffusion condition is 700$^{\circ}C$, 3hr Our p-type ZnO thin film has not only very high carrier concentration of above $10^{19}/cm^3$ but also low resistivity of $5\times10^{-3}{\Omega}cm$.