• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
• /
• pp.338-341
• /
• 1997

According to reports, it is impossible to make Ohmic Contact with high resistivity p type CdTe or CdZnTe semiconductor theoretically. But it is in need of making Ohmic Contact to fabricate semiconductor radiation detector By electroless deposition method using gold chloride solution, we made Ohmic Contact of Au and p-Cd$_{80}$Zn$_{20}$Te which grown by High Presure Bridgman Method in Aurora Technologies Corporation. We investigated the interface with Rutherford Backscattering Spectrometry and Auger electron spectroscopy. And we evaluated the degree of Ohmic Contact for the Au/CdZnTe interface by the I/V characteristic curve. As a result, we concluded that it showed excellent Ohmic Contact property by tunneling mechanism through the interface.e.

• 센서학회지
• /
• 제15권6호
• /
• pp.386-390
• /
• 2006

This paper describes the ohmic contact formation of polycrystalline 3C-SiC films deposited on thermally grown Si wafers. In this work, a TiW (titanium tungsten) film as a contact material was deposited by RF magnetron sputter and annealed with the vacuum process. The specific contact resistance (${\rho}_{c}$) of the TiW contact was measured by using the C-TLM (circular transmission line method). The contact phase and interfacial reaction between TiW and 3C-SiC at high-temperature as also analyzed by XRD (X-ray diffraction) and SEM (scanning electron microscope). All of the samples didn't show cracks of the TiW film and any interfacial reaction after annealing. Especially, when the sample was annealed at $800^{\circ}$ for 30 min., the lowest contact resistivity of $2.90{\times}10{\Omega}cm^{2}$ was obtained due to the improved interfacial adhesion. Therefore, the good ohmic contact of polycrystalline 3C-SiC films using the TiW film is very suitable for high-temperature MEMS applications.

• E2M - 전기 전자와 첨단 소재
• /
• 제10권1호
• /
• pp.8-14
• /
• 1997

The UV/O$_{3}$ dry cleaning has been well known in removing organic molecules. The UV/O$_{3}$ dry cleaning method was performed to clean the Si wafer surfaces and contact holes contaminated by organic molecules such as residual PR. During the cleaning process, the Si surfaces were analyzed with X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and ellipsometer. When the UV/O$_{3}$ dry cleaning at 200'C was performed for 3 minutes, the residual photoresist was almost removed on Si wafer surfaces, but Si surfaces were oxidized. For UV/O$_{3}$ application of contact hole cleaning, the contact string were formed using the equipment of ISRC (Inter-university Semiconductor Research Center). Before Al deposition, UV/O$_{3}$ (at 200.deg. C) dry cleaning was performed for 3 minutes. After metal annealing, the specific contact resistivity was measured. Because UV/O$_{3}$ dry cleaning removed organic contaminants in contact holes, the specific contact resistivity decreased. Each contact hole size was different, but the specific contact resistivities were all much the same. Thus, it is expected that the UV/O$_{3}$ dry cleaning method will be useful method of removal of the organic contaminants at smaller contact hole cleaning.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 하계학술대회 논문집
• /
• pp.159-159
• /
• 2010

We conducted bum-in test by current stress to evaluate acceleration reliability characteristics about p-resistivity influence of GaN-based light-emitting diodes. The LEDs used in this study are the polarization field-induced LED(PF-LED) having low p-resistivity and the highly resistive LED(HR-LED) having high p-resistivity. The result of high stress experiment shows that current crowding phenomenon is occurred from the center of between p-bonding pad and n-bonding pad to either electrodes. In addition, series resistance and optical power decrease dramatically. These results means that the resistance of between p-bonding pad and p-GaN affect reliability. That's why we need to consider the ohmic contact of p-bonding pad when design the high efficiency and high reliability LEDs.

• Applied Science and Convergence Technology
• /
• 제26권1호
• /
• pp.11-15
• /
• 2017

To improve the adhesion of Mo thin film as a back contact material, a DC magnetron sputtering system was used to deposit in the form of a bi-layer on soda-lime glass. Films with low resistivity and good adhesion were obtained from this deposition, even though the two qualities were found be hard to obtain at the same time. The best Mo bi-layer showed a resistivity of $8.13{\times}10^{-4}{\Omega}{\cdot}cm$ at $500^{\circ}C$ and $3.0{\times}10^{-3}\;Torr$. The XRD measurements showed that the crystallites of the films were mainly oriented in the (110) direction, the FE-SEM images revealed that the resistivity of the Mo films decreased with increasing substrate temperature, which temperature reduction is accompanied by an increase of the grain size. These experimental results were analyzed using the Fuchs-Sondheimer theory. Our Mo bi-layer film with better crystallinity and lower resistivity can be suitably used as a back-contact layer for CIGS solar cells.

• 한국전기전자재료학회논문지
• /
• 제14권2호
• /
• pp.123-129
• /
• 2001

The optimal high temperature processing conditions for the formation of Ohmic contact of Ti/Al/Pt/Au multiple layers were established for the fabrication of n$^{+}$-GaN/AlGaN/GaN HFET device. Contact resistivity as low as 3.4x10$^{-6}$ ohm-$\textrm{cm}^2$ was achieved by the annealing of the sample at 100$0^{\circ}C$ for 10 sec. using the RTA (Rapid Thermal Annealing) system. The fabricated HFET (Heterostructure Field Effect Transistor) with a structure of n'-GaN/undoped AlGaN/undoped GaN exhibited a low knee voltage of 3.5 V and a maximum source-drain current density of 180 mA/mm at Vg=0V.V.

• 대한전자공학회논문지
• /
• 제26권9호
• /
• pp.1381-1387
• /
• 1989

For the fabrication of ohmic contact to p-type GaAs, In Liquid Metal Ions were implanted into p-type GaAs (Zn:1.5x10**19/cm**3). After the samples were processed by Infrared rapid thermal annealing (IRTA0 or Furance Annealing (FA), I-V and specific contact contact resistivity were measured. Specific contact resistivity was found to be 1.7x10**-5 \ulcorner-cm\ulcornerin IRTA 750\ulcorner, 10 sec annealed sample. The surface characteristics of the samples were investigated with SEM, RHEED, AES. From these results we can know that implanted In ions were formed mixing layer of InAs at the surface.

• Journal of Radiation Protection and Research
• /
• 제34권2호
• /
• pp.65-68
• /
• 2009

Metal-semiconductor contact is very important for the operating property of semiconductor detector. $Cd_{0.96}$ $Zn_{0.04}$ Te semiconductor crystal was grown with Bridgman method, and the crystal was cut and polished. EPMA (Electron Probe Micro Analyzer) and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) analysis were done to obtain the chemical composition and impurity of the crystal. Metal contact was deposited with thermal evaporator on both sides of the crystal. Detectors with Au/CZT/Au and In/CZT/Au structure were made, and I-V curve and the energy spectrum were measured with the detectors. It could be seen that the detector with the In/CZT/Au structure has superior property than the detector with Au/CZT/Au structure when the crystal resistivity was low. However, the metal contact structure effect becomes low when the crystal resistivity was high.

• Current Photovoltaic Research
• /
• 제9권4호
• /
• pp.128-132
• /
• 2021

Advances in screen printing technology have been led to development of high efficiency silicon solar cells. As a post PERx structure, an n-type wafer-based rear side TOPCon structure has been actively researched for further open-circuit voltage (Voc) improvement. In the case of the metal contact of the TOPCon structure, the poly-Si thickness is very important because the passivation of the substrate will be degraded when the metal paste penetrates until substrate. However, the thin poly-Si layer has advantages in terms of current density due to reduction of parasitic absorption. Therefore, poly-Si thickness and firing temperature must be considered to optimize the metal contact of the TOPCon structure. In this paper, we varied poly-Si thickness and firing peak temperature to evaluate metal induced recombination (Jom) and contact resistivity. Jom was evaluated by using PL imaging technique which does not require both side metal contact. As a results, we realized that the SiN_x deposition conditions can affect the metal contact of the TOPCon structure.

• 마이크로전자및패키징학회지
• /
• 제10권4호
• /
• pp.29-33
• /
• 2003

n-형 탄화규소 반도체에 대한 구리금속을 이용하여 오옴성 접촉 구조를 제작하였다. 제작된 구리접촉에 대해 후속열처리 조건과 금속접촉 구조에 따른 재료적, 전기적 성질의 변화를 조사하였다. 금속접촉의 오옴성 성질은 금속박막의 구조 뿐 아니라 열처리조건에 대해서도 크게 좌우됨을 알 수 있었다. 열처리는 급속열처리 장치를 이용한 진공상태 및 환원 분위기에서 2단계 열처리방식을 통하여 시행하였다. 접촉비저항의 측정을 위해 TLM 구조를 만들었으며 면저항 ($R_{s}$), 접합저항 ($R_{c}$), 이동거리 ($L_{T}$), 패드간거리 (d), 전체저항 ($R_{T}$) 값을 구하여 알려진 계산식에 의해 접촉비저항 ($p_{c}$) 값을 추정하였다. 진공보다 환원분위기에서 후속 열처리를 수행한 시편이 양호한 전기적 성질을 가짐을 알 수 있었다. 가장 양호한 결과는 Cu/Si/Cu 구조를 가진 금속접촉 결과이었으며 접촉비저항 ($p_{c}$)은 $1.2\times 10^{-6} \Omega \textrm{cm}^2$의 낮은 값을 얻을 수 있었다. 재료적 성질은 XRD를 이용하여 분석하였고 SiC 계면 상에 구리와 실리콘이 결합한 구리 실리사이드가 형성됨을 알 수 있었다.