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1.
Sn-Zn alloys have been considered for use as lead-free solders. Their poor wetting and oxidation resistance properties are
the main obstacles that prevent them from becoming commercially viable solders. The effects of alloying elements, such as
lanthanum, titanium, aluminum, and chromium, on oxidation resistance, wetting properties, and tensile properties of eutectic
Sn-Zn solder are described herein. Results show the addition of alloying Ti, Al, and Cr can improve the oxidation resistance
of Sn-9Zn solder. La, Ti, and Cr do not have much effect on the wetting properties, whereas Al worsens the wetting. Differential
scanning calorimetry investigations reveal the solidus temperature of these solders to be ∼200°C. Addition of Cr improves
ductility while maintaining tensile strength. 相似文献
2.
陶瓷添加剂MnO2,Fe2O3,Li2CO3的热分析 总被引:6,自引:0,他引:6
陶瓷添加剂能使陶瓷材料具有良好的烧结状态和最佳的压电性能。本文作者采用Dupont—2000型热分析仪对常用添加剂MnO2、Fe2O3、Li2CO3进行了DTA、TGA分析,研究了几种物质在烧结过程中的物理、化学变化。 相似文献
3.
Influence of Ag micro-particle additions on the microstructure, hardness and tensile properties of Sn-9Zn binary eutectic solder alloy 总被引:1,自引:0,他引:1
In this study, an addition of Ag micro-particles (8-10 μm) with a content in the range between 0 and 1.5 wt.% to Sn-9Zn eutectic solder, were examined in order to understand the effect of Ag additions as the particulate reinforcement on the microstructural and mechanical properties as well as the thermal behavior of the newly developed composite solders. Here, an approach to prepare a micro-composite solder alloy by mixing Ag micro-particles with a molten Sn-Zn solder alloy was developed. The composite solder was prepared by mechanically mixing Ag micro-particles into the Sn-9Zn alloy melt to ensure a homogeneous distribution of the reinforcing particles. The distribution of the Ag micro-particles in the matrix was found to be fairly uniform. The Ag particles reacted with the Zn and formed ε-AgZn3 intermetallic compounds (IMC) in the β-Sn matrix. It was found that the more Ag particles added to the Sn-9Zn solder, the more Ag-Zn compound formed. In the Sn-9Zn/XAg composite solder, the microstructure was composed of AgZn3 IMC and α-Zn phase in the β-Sn matrix. Interestingly, as the Ag particles in the composite solder increased, the α-Zn phase was found to be depleted from the matrix. The average tensile strength of the composite solders increased with the Ag micro-particles content up to a certain limit. Beyond this limit, the addition of Ag particles actually decreased the strength. 相似文献
4.
5.
采用脉冲激光沉积(PLD)法在Pt/Ti/SiO2/Si(001)基片上制备了Ba0.6Sr0.4TiO3(BST)薄膜,对Pt/BST/Pt电容器在空气中进行400℃快速退火(RTA)处理,研究了快速退火对Pt/BST/Pt电容器的结构和性能的影响。结果表明:快速退火虽然对BST薄膜的结晶质量影响较小,但却极大改善了Pt/BST/Pt电容器的电学性能。当测试频率为100kHz、直流偏压为0V时,介电损耗从快速退火前的0.07减小到0.03,介电常数和调谐率略有增加。快速退火后负向漏电流过大现象得到了明显抑制,正负向漏电流趋于对称,在300×103V/cm电场强度下,漏电流密度为4.83×10–5A/cm2。 相似文献
6.
Xiaoli Xu Richard T. Kuehn Mehmet C. Öztürk Jimmie J. Wortman Robert J. Nemanich Gari S. Harris Dennis M. Maher 《Journal of Electronic Materials》1993,22(3):335-339
Various silicon surface cleaning processes for rapid thermal in-situ polysilicon/ oxide/silicon stacked gate structures have
been evaluated. Metal-oxide-semiconductor capacitors were fabricated to assess the effects of cleaning on the quality of gate
oxide structures produced by both rapid thermal oxidation (RTO) and rapid thermal chemical vapor deposition (RTCVD). Excellent
electrical properties have been achieved for both RTO and RTCVD gate oxides formed on silicon wafers using either an ultraviole/zone
(UV/O3) treatment or a modified RCA clean. On the contrary, poor electrical properties have been observed for RTO and RTCVD gate
oxides formed on silicon wafers using a high temperature bake in Ar, H2, or high vacuum ambient. It has also been found that the electrical properties of the RTCVD gate oxides exhibit less dependence
upon cleaning conditions than those of RTO gate oxides. This work demonstrates that initial surface condition prior to gate
oxide formation plays an important role in determining the quality of RTO and RTCVD gate oxides. 相似文献
7.
8.
Thin films of Se87.5Te10Sn2.5 were prepared by vacuum thermal evaporation technique. Various optical constants were calculated for the studied composition. The mechanism of the optical absorption follows the rule of direct transition. It was found that the optical energy gap (Eg) decreases from 2.26 to 1.79 eV with increasing the annealing temperature from 340 to 450 K. This result can be interpreted by the Davis and Mott model. On the other hand, the maximum value of the refractive index (n) is shifted towards the long wavelength by increasing the annealing temperature. In addition, the high frequency dielectric constant (εL) increased from 31.26 to 48.11 whereas the ratio of the free carriers concentration to its effective of mass N/m⁎ decreased from 4.3 to 2.09 (×1057 (m−3 Kg−1)). The influence of annealed temperature on the structure was studied by using the X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD studies show that the as-deposited films are amorphous in nature, but the crystallinity improved with increasing the annealing temperature. Furthermore the particle size and crystallinity increased whereas the dislocation and strains decreased with increasing the annealing temperature. SEM examination showed that the annealing temperature induced changes in the morphology of the as-deposited film. 相似文献
9.
快速热退火温度对纳米晶氢-硅薄膜及其p-n结性能的影响 总被引:1,自引:1,他引:0
采用快速热退火(RTA)对热丝化学气相沉积HWCVD制 备的非晶氢-硅(a-Si:H)薄膜进行晶化处理,并在此基础上制备了 纳米晶氢-硅(nc-Si:H)薄膜p-n结。利用拉曼(Raman)光谱、X射线衍射(XRD)、 扫描电子显微镜(SEM)和分光光 度计研究了所制备(nc-Si:H)薄膜的结构、光学性能与退火温度的关系;同时, 研究了不同RTA条 件下制备p-n结的整流特性随温度变化的规律。研究发现,随RTA温度由700℃升高至 1100℃,薄膜的晶化率由46.3%提高到96%,拉曼峰半高宽(FWHM)由19.7cm-1降低至7. 1cm-1。当退火 温度为700℃时,薄膜的XRD谱中只有一个较弱的Si(111)峰;当退火 温度高于900 ℃时,薄膜 的XRD谱中除Si(111)峰外,还出现了Si(220)、Si(311)峰。同时,随退火温度的升高,薄膜 的禁 带宽度由1.68eV升高至2.05eV。由于禁带宽 度的增加,相应的p-n结最高工作温度也由180℃升高至300℃。 相似文献
10.
Sun Jung Kim Young Hun Seo Kee Suk Nahm Yun Bong Hahn Hyun Wook Shim Eun-Kyung Suh Kee Young Lim Hyung Jae Lee 《Journal of Electronic Materials》1999,28(8):970-974
The origin of the radiative recombination leading to yellow luminescence (YL) has been elucidated by the study of luminescence
properties of GaN films grown with two different gas feeding methods. GaN films were grown on a (0001) sapphire substrate
in a rapid thermal chemical vapor deposition (RTCVD) reactor. GaN films emitted two different luminescence energies, 2.2 and
3.47 eV, depending on the introducing position of hydrogen gas in the growth reactor. The distribution of the TMGa flow and
gas phase reactions in the reactor were investigated to understand the effect of the gas feeding methods on the optical properties
of GaN films. The results suggest that YL is related to Ga vacancies in the grown films. 相似文献
11.
Noboru Wade Tatsuo Akuzawa Seiji Yamada Daigo Sugiyama Ick-Soo Kim Kazuya Miyahara 《Journal of Electronic Materials》1999,28(11):1286-1289
The present research aims to improve the creep strength of Sn-Pb eutectic solder by the addition of small amount of effective
elements, such as Sb, Ag, Cu, and Ga, which are selected by preliminary experiments and analysis. Creep tests were conducted
at the stress and temperature range of 5 N/m to 15 N/m m2 and 313 K to 378 K, respectively. The microalloying treatment increased significantly the creep-rupture time by one order
at the same condition of creep stress and temperature, comparing with that of the regular Sn-Pb eutectic solder alloy. Microstructural
observation indicated that the excellent creep properties are obtained by the particles dispersion hardening due to the combined
addition of the microalloying elements. 相似文献
12.
Mulpuri V. Rao Sadanand M. Gulwadi Phillip E. Thompson Ayub Fathimulla Olaleye A. Aina 《Journal of Electronic Materials》1989,18(2):131-136
Halogen lamp rapid thermal annealing was used to activate 100 keV Si and 50 keV Be implants in In0.53Ga0.47As for doses ranging between 5 × 1012−4 × 1014 cm−2. Anneals were performed at different temperatures and time durations. Close to one hundred percent activation was obtained
for the 4.1 × 1013 cm−2 Si-implant, using an 850° C/5 s anneal. Si in-diffusion was not observed for the rapid thermal annealing temperatures and
times used in this study. For the 5 × 1013 cm−2 Be-implant, a maximum activation of 56% was measured. Be-implant depth profiles matched closely with gaussian profiles predicted
by LSS theory for the 800° C/5 s anneals. Peak carrier concentrations of 1.7 × 1019 and 4 × 1018 cm−3 were achieved for the 4 × 1014 cm−2 Si and Be implants, respectively. For comparison, furnace anneals were also performed for all doses. 相似文献
13.
Yoon Jeong-Won Kim Sang-Won Koo Ja-Myeong Kim Dae-Gon Jung Seung-Boo 《Journal of Electronic Materials》2004,33(10):1190-1199
The interfacial reactions between two Sn-Cu (Sn-0.7Cu and Sn-3Cu, wt.%) ball-grid-array (BGA) solders and the Au/Ni/Cu substrate
by solid-state isothermal aging were examined at temperatures between 70°C and 170°C for 0 to 100 days. For the Sn-0.7Cu solder,
a (Cu,Ni)6Sn5 layer was observed in the samples aged at 70–150°C. After isothermal aging at 170°C for 50 days, the solder/Ni interface
exhibited a duplex structure of (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4. For the Sn-3Cu solder, only the (Cu,Ni)6Sn5 layer was formed in all aged samples. Compared to these two Sn-Cu solders, the Cu content in the (Cu,Ni)6Sn5 layer formed at the interface increased with the Cu concentration in the Sn-xCu solders. And, the shear strength was measured
to evaluate the effect of the interfacial reactions on the mechanical reliability as a function of aging conditions. The shear
strength significantly decreased after aging for 1 day and then remained nearly unchanged by further prolonged aging. In all
the samples, the fracture always occurred in the bulk solder. Also, we studied the electrical property of Cu/Sn-3Cu/Cu BGA
packages with the number of reflows. The electrical resistivity increased with the number of reflows because of an increase
of intermetallic compound (IMC) thickness. 相似文献
14.
S. Venkataraman R. Singh V. Parihar K. F. Poole A. Rohatgi V. Yeludur A. Ebong 《Journal of Electronic Materials》1999,28(12):1394-1398
Minority carrier lifetime is an efficient indicator of defect levels present in the starting material as well as process and
equipment induced defects. By employing rapid thermal processing (RTP) and rapid photothermal processing (RPP) as the thermal
processing techniques, we have studied the effect of ultraviolet (UV) and vacuum ultraviolet (VUV) photons on the bulk minority
carrier lifetime of phosphorous doped and undoped single crystal silicon wafers. For both diffused and undiffused wafers,
we have observed an enhancement in the minority carrier lifetime when UV and VUV photons are used in conjunction with the
samples processed without the use of UV and VUV photons. The effect of ramp rates on the minority carrier lifetime and the
significance of optimized thermal cycles have also been studied in this paper. A possible explanation based on the dependence
of diffusion coefficient on the photo spectrum of light source is also given in this paper. 相似文献
15.
为了研究纳米CeO2颗粒对激光熔覆层的组织和性能的影响,在Q235钢基体上制备了加入不同量纳米CeO2的Ni基合金熔覆层,利用OLMPUS PME-3型光学显微镜,XD-3A型X射线衍射仪,HV-1000型显微硬度计,MM-200型环-块磨损试验机和扫描电镜等对激光熔覆层显微组织、相结构、显微硬度、磨损性能和磨损机理进行了研究。结果表明,在激光熔覆层中添加纳米CeO2能够细化组织,改变凝固组织的形态。当加入质量分数为1.5%的纳米CeO2时,熔覆层凝固组织形态为等轴树枝晶;生成了含Ce的新相Ce2Ni21B6,明显提高了熔覆层的显微硬度和耐磨性;熔覆层磨损由严重磨损转化为轻微磨损。但是加入过量的纳米CeO2,硬度反而降低。 相似文献
16.
将Si片经Secco腐蚀液腐蚀,用光学显微镜和原子力显微镜(AFM)对CZ-Si单晶中的流动图形缺陷(FPD)的形貌、分布及结构进行了研究,对Si片进行了湿氧化处理并采用较新的快速退火方法(RTA),在Ar气氛下对Si片进行热处理,研究了退火温度和退火时间对FPD缺陷密度的影响.结果表明,FPDs缺陷在1 100 ℃以下非常稳定;但是在1 100 ℃以上的温度,尤其在1 200℃对Si片进行RTA处理后,Si片中FPD的密度大大降低,而且随着的退火时间的延长,密度不断下降. 相似文献
17.
The effects of rapid thermal annealing (RTA) on CdTe/Si (100) heterostructures have been studied in order to improve the structural
quality of CdTe epilayers. Samples of CdTe (111) polycrystalline thin films grown by vapor phase epitaxy (VPE) on Si (100)
substrates have been investigated. The strained structures were rapidly thermally annealed at 400°C, 450°C, 500°C, 550°C,
and 600°C for 10 sec. The microstructural properties of the CdTe films were characterized by carrying out scanning electron
microscopy (SEM), x-ray diffraction (XRD), and atomic force microscopy (AFM). We have shown that the structural quality of
the CdTe epilayers improves significantly with increasing annealing temperature. The optimum annealing temperature resulting
in the highest film quality has been found to be 500°C. Additionally, we have shown that the surface nucleation characterized
by the island size distribution can be correlated with the crystalline quality of the film. 相似文献
18.
19.
The ball impact test was developed as a package-level measure for the board-level drop reliability of solder joints in the
sense that it leads to fracturing of solder joints around intermetallics, similar to that from a board-level drop test. We
investigated numerically the effects of constitutive relationships of solder alloy on transient structural responses of a
single package-level solder joint subjected to ball impact testing. This study focused on the characteristics of the ascending
part of the impact force profile. According to the piecewise linear stress-strain curve obtained for the Sn-4Ag-0.5Cu solder
alloy, parametric studies were performed by varying either segmental moduli or characteristic stresses of the curve at fixed
ratios, with regard to the lack of available rate-dependent material properties of solder alloys. 相似文献
20.
对比研究了夹层结构N i/P t/N i分别与掺杂p型多晶硅和n型单晶硅进行快速热退火形成的硅化物薄膜的电学特性。实验结果表明,在600~800°C范围内,掺P t的N iS i薄膜电阻率低且均匀,比具有低电阻率的镍硅化物的温度范围扩大了100~150°C。依据吉布斯自由能理论,对在N i(P t)S i薄膜中掺有2%和4%的P t样品进行了分析。结果表明,掺少量的P t可以推迟N iS i向N iS i2的转化温度,提高了镍硅化物的热稳定性。最后,制作了I-V特性良好的N i(P t)S i/S i肖特基势垒二极管,更进一步证明了掺少量的P t改善了N iS i肖特基二极管的稳定性。 相似文献