• Title/Summary/Keyword: 금속 접합층

Search Result 137, Processing Time 0.027 seconds

Recent Advances in Fine Pitch Cu Pillar Bumps for Advanced Semiconductor Packaging (첨단 반도체 패키징을 위한 미세 피치 Cu Pillar Bump 연구 동향)

  • Eun-Chae Noh;Hyo-Won Lee;Jeong-Won Yoon
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.30 no.3
    • /
    • pp.1-10
    • /
    • 2023
  • Recently, as the demand for high-performance computers and mobile products increases, semiconductor packages are becoming high-integration and high-density. Therefore, in order to transmit a large amount of data at once, micro bumps such as flip-chip and Cu pillar that can reduce bump size and pitch and increase I/O density are used. However, when the size of the bumps is smaller than 70 ㎛, the brittleness increases and electrical properties decrease due to the rapid increase of the IMC volume fraction in the solder joint, which deteriorates the reliability of the solder joint. Therefore, in order to improve these issues, a layer that serves to prevent diffusion is inserted between the UBM (Under Bump Metallization) or pillar and the solder cap. In this review paper, various studies to improve bonding properties by suppressing excessive IMC growth of micro-bumps through additional layer insertion were compared and analyzed.

증착방법을 달리한 $TiO_2$ 박막의 표면처리에 따른 저항변화 특성 연구

  • Seong, Yong-Heon;Kim, Sang-Yeon;Do, Gi-Hun;Seo, Dong-Chan;Jo, Man-Ho;Go, Dae-Hong
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.02a
    • /
    • pp.206-206
    • /
    • 2010
  • 정보화 기술이 급속히 발전함에 따라서 보다 많은 양의 data를 전송, 처리, 저장 하게 되면서 이를 처리 할 수 있는 대용량, 고속, 비휘발성의 차세대 메모리의 개발이 요구 되고 있다. 이 중 저항 변화 메모리(ReRAM)는 일반적으로 전이금속산화물을 이용한 MIM 구조로서 적당한 전기 신호를 가하면 저항이 높아서 전도되지 않는 상태(Off state)에서 저항이 낮아져 전도가 가능한 상태(On state)로 바뀌는 메모리 특성을 가진다. ReRAM은 비휘발성 메모리이며 종래의 비휘발성 기억소자인 Flash memory 보다 access time이 $10^5$배 이상 빠르며, 2~5V 이하의 낮은 전압에서 동작이 가능하다. 또한 구조가 간단하여 공정상의 결함을 현저히 줄일 수 있다는 점 등 많은 장점들이 있어서 Flash memory를 대체할 수 있는 유력한 후보로 여겨지고 있다. 저항 변화의 특징을 잘 나타내는 물질에는 $TiO_2$, $Al_2O_3$, $NiO_2$, $HfO_2$, $ZrO_2$등의 많은 전이금속산화물들이 있다. 본 연구에서는 Reactive DC-magnetron Sputtering 방법과 DC-magnetron sputter를 이용하여 Ti를 증착한 후 Oxidation 방법으로 각각 증착한 $TiO_2$박막을 사용하여 저항변화특성을 관찰하였다. $TiO_2$상부에 Atomic Layer Deposition (ALD)를 이용하여 $HfO_2$ 박막을 증착하여 표면처리를 하고, 또한 $TiO_2$에 다른 전이 금속박막 층을 추가 증착하여 저항변화 특성에 접합한 조건을 찾는 연구를 진행하였다. 하부 전극과 상부 전극 물질로는 Si 100 wafer 위에 Pt 또는 TiN을 사용하였다. 저항변화 특성을 평가하기 위해 Agilent E5270B를 이용하여 current-voltage (I-V)를 측정하였다. X-ray Diffraction (XRD)를 이용하여 증착 된 전기금속 박막 물질의 결정성을 관찰했으며, Atomic Force Microscopy (AFM)을 이용하여 증착 된 샘플의 표면을 관찰했다. SEM과 TEM을 통해서는 sample의 미세구조를 확인 하였다.

  • PDF

Improvement of Wear Resistance of Aluminum by Metal-Ceramic Particle Composite Layer (알루미늄표면에 금속-세라믹입자 복합첨가에 의한 내마모성개선)

  • ;;;中田一博;松田福久
    • Journal of Welding and Joining
    • /
    • v.15 no.6
    • /
    • pp.96-104
    • /
    • 1997
  • The present study was aimed to correlate the microstructure and the hardness as well as the wear resistance of the metal-ceramic particulated composite layer on the pure Al plate. The composite layers were constructed by the addition of TiC particles on the surface of Al-Cu alloyed layers by PTA overlaying process. Initially, the Al-Cu alloyed layers were achieved by the deposition of Al-(25 ~ 48%) Cu alloys on the pure Al plate by TIG process. It was revealed that TiC particles were uniformly dispersed without any reaction with matrix in the composite layer. The volume fraction of TiC particles (TiC V F) increased from 12% to 55% with increasing the number of pass of composite layer. Hardnesses of (Al-48%Cu + TiC (3&4layers)) composite layer were Hv450 and Hv560, respectively, due to the increase of TiC V/F. Hardnesses of (Al-Cu + TiC) composite layers decreased gradually with insreasing temperature from 100$^{\circ}$C to 400$^{\circ}$C, and hardnesses at 400$^{\circ}$C were then reached to 1/5 - 1/10 of room temperature hardness depending on the construction of composite layers. The Specific wear of (Al + Tic) layer and Al-48%Cu alloyed layer decreased to 1/10 of the of pure Al, while the specific wear of (Al-48%Cu + TiC (4 layers)) composite layer exhibited 1/15 of that of steel such as SS400 and STS304.

  • PDF

A Study on the Diffusion Behaviors in Weld Interface of Cr-Mo Steel/Austenitic Stainless Steel (Cr-Mo강/오스테나이트계 스테인리스강 용접재의 용접계면에서의 확산거동에 관한 연구)

  • 김동배;이상율;이종훈;이상용;양성철
    • Journal of Welding and Joining
    • /
    • v.17 no.4
    • /
    • pp.46-52
    • /
    • 1999
  • Some of the pressurized reactor pressure vessels used in many chemical plants are made of low alloy carbon steel plates internally clad with an austenitic stainless steel for improved anti-corrosion properties. In this study, metallurgic structure of the weld interface of A 387 Grade12Class1 low alloy carbon steel claded with A182-F321 austenitic stainless steel after thermal exposure simulation heat treatment was investigated to display a characteristic behavior of dissimilar metal weld interface with thermal exposure during service at high temperature and pressure. EPMA, STEM, vickers-hardness test were performed and the results were correlated with the microstructure. To estimate the depth of the carburized/decarburized bands quantitatively, a model for carbon diffusion was proposed. The validity of the proposed theoretical relationships was confirmed by the directly measured data from the welded parts failed during service.

  • PDF

TMR 시료의 fabrication 전 후의 열처리 효과

  • Jun, K-I;Lee, J. H.;Shin, Kyung-Ho;Park, S. Y.;K. Rhie;J. R. Rhee;I. W. Jang;Lee, K. N.;Kim, C. S.
    • Proceedings of the Korean Magnestics Society Conference
    • /
    • 2002.12a
    • /
    • pp.158-159
    • /
    • 2002
  • 스핀 밸브에서는 NiFe, CoFe, Cu등 주요 금속들이 면심입방체(111)로 배향이 용이하지만, 자기 터널 접합 소자에서는 $Al_2$O$_3$ 장벽층이 비정질로서 상부 강자성 전극이 충분히 (111) 배향을 할 수 없기 때문에 top bias 방식의 사용이 거의 불가능하며, bottom bias의 경우에도 교환 바이어스의 크기는 상대적으로 작다[1]. 이를 극복하기 위해 인공 초격자를 이용한 인공 반강자성층(synthetic antiferromagnet - SAF)을 이용하여 높은 교환 바이어스 효과를 구현하고자 하였다. (중략)

  • PDF

Effect of Doubly Plasma Oxidation Time on TMR Devices (이중절연층 산화공정에서 플라즈마 산화시간에 따른 터널자기저항 효과)

  • Lee, Ki-Yung;Song, Oh-Sung
    • Journal of the Korean Magnetics Society
    • /
    • v.12 no.4
    • /
    • pp.127-131
    • /
    • 2002
  • We fabricated MTJ devices that have doubly oxidized tunnel barrier using plasma oxidation method to from oxidized AlO$\sub$x/ tunnel barrier. Doubly oxidation I, which sputtered 10 ${\AA}$-bottom Al layer and oxidized it with oxidation time of 10 s. Subsequent sputtering of 13 ${\AA}$-Al was performed and the metallic layer was oxidized for 50, 80 and 120 s., respectively. Doubly oxidation II, which sputtered 10 ${\AA}$-bottom Al layer and oxidized it varying oxidation time for 30∼120 s. Subsequent sputtering of 13 ${\AA}$-Al was performed and the metallic layer was oxidized for 210 sec. Double oxidation process specimen showed MR ratio of above 27% in all experiment range. Singly oxidation process. 13 ${\AA}$-Al layer and oxidized up to 210 s, showed less MR ratio and more narrow process window than those of doubly oxidation. Cross-sectional TEM images would that doubly oxidized barrowers were thinner and denser than singly oxidized ones. XPS characterization confirmed that doubly oxidation of Fe with bottom insulating layer. As a result, doubly oxidation could have superior MR ratio in process extent during long oxidation time because of preventing oxidation of bottom magnetic layer than singly oxidation.

A Characteristic of Microstructures in Bonding Interlayer of Brazed Titanium to Copper (브레이징한 Ti/Cu 접합계면부의 미세조직 특성)

  • 김우열;정병호;이성렬
    • Journal of Welding and Joining
    • /
    • v.13 no.3
    • /
    • pp.106-115
    • /
    • 1995
  • To know the bonding phenomena of Ti/Cu brazed joint, a characteristic of microstructures in bonding interlayer of vacuum brazed pure Ti to Cu has been studied in the temperature range from 1088 to 1133K for various bonding times using Ag-28wt%Cu filler metal. Also intermediate phases formed in bonded interlayer and behavior of layer growth have been investigated. The obtained results in this study are as follows: 1) Liquid insert metal width at the each brazing temperature was proportional to the square root of brazing time, and it was considered that the liquid insert metal width was controlled by the diffusion rate process of primary .alpha.-Cu formed at the Ti side. 2) Intermediate phases formed near the Ti interface were .betha.-Ti and intermetallic compounds TiCu, Ti$_{2}$Cu, Ti$_{3}$Cu, and TiCu. 3) .betha.-Ti formed in Ti base metal durig brazing transformed to lamellar structure, .alpha.-Ti + Ti$_{2}$Cu. The structure came from the eutectoil decomposition reaction in cooling. And the width of .betha.-Ti layer was proportional to the square root of brazing time, and it was considered that the growth of .betha.-Ti layer was controlled by interdiffusion rate process in .betha.-Ti. 4) The layer growth of TiCu, Ti$_{3}$Cu$_{4}$ and TiCu, phases formed near the Ti interface was linerface was linearly proportional to the brazing time, and it was considered that the layer growth of these phases was controlled by the chemical reaction rate at the interface.

  • PDF

Standardization of Bending Impact Test Methods of Sn-Ag-Cu Lead Free Solder Ball (Sn-Ag-Cu계 무연 솔더볼 접합부의 굽힘충격 시험방법 표준화)

  • Jang, Im-Nam;Park, Jai-Hyun;Ahn, Yong-Sik
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.17 no.1
    • /
    • pp.55-61
    • /
    • 2010
  • An impact bending test method was used to evaluate the reliability for the solder joint of lead-free solder ball. In order to standardize the test method, the four point impact bending test was applied under the conditions of various frequencies and amounts of +/-amplitude respectively. Effects on the results were analysed. The optimum condition for impact bending test achieved in this study was the frequency of 10 Hz, and the amplitude of (+12/-1)~(+15/-1). 3 kinds of surface finishes Cu-OSP (Organic Solderability Preservative), ENIG (Electroless Nickel Immersion Gold), and ENEPIG (Electroless Nickel, Electroless Palladium, Immersion Gold) were used. Fracture surface showed that cracks were initiated and fractured along the intermetallic layer in the case of surface finishes of Cu-OSP and ENIG, while in the case of ENEPIG the cracks were initiated and propagated in the solder region.

Effect of Aging treatment and Epoxy on Bonding Strength of Sn-58Bi solder and OSP-finished PCB (Sn-58Bi Solder와 OSP 표면 처리된 PCB의 접합강도에 미치는 시효처리와 에폭시의 영향)

  • Kim, Jungsoo;Myung, Woo-Ram;Jung, Seung-Boo
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.21 no.4
    • /
    • pp.97-103
    • /
    • 2014
  • Among various lead-free solders, the Sn-58Bi solders have been considered as a highly promising lead-free solders because of its low melting temperature and high tensile strength. However, Sn-58Bi solder has the poor ductility. To enhance the mechanical property of Sn-58Bi solder, epoxy-enhanced Sn-58Bi solders have been studied. This study compared the microstructures and the mechanical properties of Sn-58Bi solder and Sn-58Bi epoxy solder with aging treatment. The solders ball were formed on the printed circuit board (PCB) with organic solderability preservative (OSP) surface finish, and then the joints were aged at 85, 95, 105 and $115^{\circ}C$ for up to 100, 300, 500 and 1000 hours. The shear test was conducted to evaluate the mechanical property of the solder joints. $Cu_6Sn_5$ intermetallic compound (IMC) layer grew with increasing aging time and temperature. The IMC layer for the Sn-58Bi epoxy solder was thicker than that for the Sn-58Bi solder. According to result of shear test, the shear strength of Sn-58Bi epoxy solder was higher than that of Sn-58Bi solder and the shear strength decreased with increasing aging time.

Effect of Zn content on Shear Strength of Sn-0.7Cu-xZn and OSP surface finished Joint with High Speed Shear Test (Sn-0.7Cu-xZn와 OSP 표면처리 된 기판의 솔더접합부의 고속 전단강도에 미치는 Zn의 영향)

  • Choi, Ji-Na;Bang, Jae-Oh;Jung, Seung-Boo
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.24 no.1
    • /
    • pp.45-50
    • /
    • 2017
  • We investigated effect of Zn content on shear strengh of Sn-0.7Cu-xZn and OSP surface finished solder joints. Five pastes of Sn-0.7Cu-xZn (x=0, 0.5, 1.0, 1.5, 2.0 wt.%) solders were fabricated by mixing of solder powder and flux using planatary mixer. $180{\mu}m$ diameter solder balls were formed on OSP surface finished Cu electrodes by screen print method, and the reflow process was performed. The shear strength was evaluated with two high shear speeds; 0.01 and 0.1 m/s. The thickness of the intermetallic compound(IMC) layer was decreased with increasing Zn content in Sn-0.7Cu-xZn solder. The highest shear strength was 3.47 N at the Zn content of 0.5 wt.%. As a whole, the shear strength at condition of 0.1 m/s was higher than that of 0.01 m/s because of impact stress. Fracture energies were calculated by F-x (Force-displacement) curve during high speed shear test and the tendency of fracture energy and that of shear strength were good agreement each other. Fracture took place within solder matrix at lower Zn content, and fracture occured near the interface of OSP surface finished Cu electrode and solder at higher Zn content.