• Korean Journal of Materials Research
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• v.30 no.5
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• pp.262-266
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• 2020

In this paper, we investigated the effect of the passivation stack with Al₂O₃, hydrogenated silicon nitride (SiN_x:H) stack and Al₂O₃, silicon oxynitride (SiON_x) stack in the n type bifacial solar cell on monocrystalline silicon. SiNx:H and SiON_x films were deposited by plasma enhanced chemical vapor deposition on the Al₂O₃ thin film deposited by thermal atomic layer deposition. We focus on passivation properties of the two stack structure after laser ablation process in order to improve bifaciality of the cell. Our results showed SiN_x:H with Al₂O₃ stack is 10 mV higher in implied open circuit voltage and 60 ㎲ higher in minority carrier lifetime than SiON_x with Al₂O₃ stack at Ni silicide formation temperature for 1.8% open area ratio. This can be explained by hydrogen passivation at the Al₂O₃/Si interface and Al₂O₃ layer of laser damaged area during annealing.

• Korean Journal of Materials Research
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• v.13 no.5
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• pp.279-284
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• 2003

The $CoSi_2$ process is widely employed in a salicide as well as an ohmic layer process. In this experiment, we investigated the characteristics of $CoSi_2$ films by combinations of I-type (TiN 100$\AA$/Co 150$\AA$), II-type(TiN 100$\AA$/Co 150$\AA$/Ti 50$\AA$), III-type(Ti 100$\AA$/Co 150$\AA$/Ti 50$\AA$), and IV-type(Ti 100$\AA$/Co 150$\AA$/Ti 100$\AA$). Sheet resistances of $CoSi_2$ show the lowest resistance with 2.9 $\Omega$/sq. in a TiN/Co condition and much higher resistances in conditions simultaneously applying Ti capping layers and Ti interlayers. Though we couldn't observe a $CoSi_2$roughness dependence on the film stacks from RMS values, Ti capping layers turned into 78∼94$\AA$ thick TiN layers of (200) preferred orientation at $N_2$ambient. In addition, Ti interlayers helped to form the epitaxial $CoSi_2$with (200) preferred orientation and ternary compounds of Co-Ti-Si. We propose that film structures of II-type and III-type may be appropriate in the salicide process and the ohmic layer process from the viewpoint of Co diffusion kinetics and the CoSi$_2$epitaxy.

• Journal of the Korean Magnetics Society
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• v.12 no.6
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• pp.201-205
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• 2002

The tunneling magnetoresistance (TMR) of a ramp-edge type junction has been studied. The samples with a structure of NiO(60)/Co(10)/NiO(60)/Si$_3$N$_4$(2-6)/NiFe(10) (nm) were prepared by the sputtering and etched by the electron cyclotron (ECR) argon ion milling. Nonlinear I-V characteristics was obtained from a ramp-type tunneling junctions having the dominant difference between zero and ＋90 Oe perpendicular to the junction edge line. The voltage dependence of TMR was stable up to a bias volt of $\pm$10 V with a TMR ratio of about -10%, which may be very peculiar magnetic tunneling properties with asymmetric tunneling process between wedge Co pinned layer and NiFe free layer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.501-504
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• 2003

In this paper, for enhancement of property on a-Si:H TFTs We measure interface characteristics of ferroelectrics thin film and a-Si:H thin film. First, SrTiO$_3$ thin film is deposited bye-beam evaporation. Deposited films are annealed for 1 hour in N2 ambient at 150$^{\circ}C$ ∼ 600$^{\circ}C$. Dielectric characteristics of deposited SrTiO$_3$ films are very good because dielectric constant shows 50∼100 and breakdown electric field are 1∼1.5MV/cm. a-SiN:H,a-Si:H(n-type a-Si:H) are deposited onto SrTiO$_3$ film to make MFNS(Metal/ferroelectric/a-SiN:H/a-Si:H) by PECVD. After the C-V measurement for interface characteristics, MFNS structure shows no difference with MNS(Metal/a-SiN:H/a-Si:H) structure in C-V characteristics but the insulator capacitance value of MFNS structure is much higher than the MNS because of high dielectric constant of ferroelectrics.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.04a
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• pp.23-23
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• 1999

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.10a
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• pp.32-32
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• 1999

• Journal of Sensor Science and Technology
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• v.7 no.6
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• pp.426-431
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• 1998

This paper describes electrochemical etch-stop characteristics in THAH/IPA/pyrazine solution. I-V curves of n- and p-type Si in THAH/IPA/pyrazine solution were obtained. OCP(Open Circuit Potential) and PP (Passivation Potential) of p-type Si were -1.2 V and 0.1 V, and of n-type Si were -1.3 V and -0.2 V, respectively. Both n- and p-type Si, etching rates were abruptly decreased at potentials anodic to the PP. The etch-stop characteristics in THAH/IPA/pyrazine solution were observed. Since accurate etching stop occurs at pn junction, Si diaphragms having thickness of epi-layer were fabricated. Etching rate is highest at optimum etching condition, TMAH 25wt.%/IPA 17vol.%/pyrazine 0.1g/100ml. thus the elapsed time of etch-stop was reduced.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.290-293
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• 2003

Ohmic contact characteristics of Al ion implanted n-type SiC wafer were investigated. Al ions implanted with high dose to obtain the final concentration of $5{\times}10^{19}/cm^3$, then annealed at high temperature. Firstly, B ion ion implanted p-well region were formed which is needed for fabrication of SiC devices such as DIMOSFET and un diode. Secondly, Al implanted high dose region for ohmic contact were formed. After ion implantation, the samples were annealed at high temperature up to $1600^{\circ}C\;and\;1700^{\circ}C$ for 30 min in order to activate the implanted ions electrically. Both the inear TLM and circular TLM method were used for characterization. Ni/Ti metal layer was used for contact metal which is widely used in fabrication of ohmic contacts for n-type SiC. The metal layer was deposited by using RF sputtering and rapid thermal annealed at $950^{\circ}C$ for 90sec. Good ohmic contact characteristics could be obtained regardless of measuring methods. The measured specific contact resistivity for the samples annealed at $1600^{\circ}C\;and\;1700^{\circ}C$ were $1.8{\times}10^{-3}{\Omega}cm^2$, $5.6{\times}10^{-5}{\Omega}cm^2$, respectively. Using the same metal and same process of the ohmic contacts in n-type SiC, it is found possible to make a good ohmic contacts to p-type SiC. It is very helpful for fabricating a integrated SiC devices. In addition, we obtained that the ratio of the electrically activated ions to the implanted Al ions were 10% and 60% for the samples annealed at $1600^{\circ}C\;and\;1700^{\circ}C$, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.448-449
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• 2008

HIT(Heterojunction with intrinsic thin layer) solar cell은 결정 실리콘 (c-Si)을 n-type으로 제작시 수율이 어렵고 결정 실리콘 (c-Si)을 p-type위에 제조하는 것이 보다 보편적인 방법이므로 베이스의 결정 실리콘에는 p-type을, 그 위에는 진성 층(intrinsic layer) 그리고 반투명 전극의 아래에 제조되는 비정질 실리콘 (a-Si)을 n-type으로 하여 베이스 층과 TCO 후면 층의 두께, 도핑 농도 (doping concentration)와의 관계를 확인하여 본다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.5
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• pp.179-183
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• 2008

Employing screen printing technology, aluminum is applied to the back side of the n-type silicon wafer to see the effect of the heat treatment parameters on the Voc of the solar cell, Heat treatment at $850^{\circ}C$ produces the highest Voc among various heat treatment conditions. Heat treatment at the temperatures higher than $850^{\circ}C$ results in lower Voc, which is due to the destruction of the Al-Si alloy emitter layer. The destruction of Al-Si layer observed to be caused by the vigorous movement of silicon atoms toward aluminum layer during the heat treatment.