主要的微分析技术

不管电子器件还是半导体器件 ,在制造过程中都要用到微分析技术 ,以提高工艺水平和产品质量 ,微分析技术种类很多 ,我们将常用的微分析技术简要归结如下 :1.ＡＥＳ—俄歇电子能谱仪 ,电子束射到样品表面发射出俄歇电子 ,根据俄歇电子的能量和数量确定样品表面存在的元素种类及含量。灵敏度为 1% - 0 .1%或 10 18个原子 /ｃｍ2 ,检测深度为 1- 2 μｍ。2 .ＳＡＭ—扫描俄歇显微镜 ,利用细束斑电子束扫描激发样品 ,可实现元素的二维分析。具有亚微米量级的空间分辨率。3.ＥＳＣＡ ,ＸＰＳ—Ｘ射线光电子能谱仪 ,是一种有效的表面分析仪 ,能测…     

俄歇显微镜观察材料新世界

日本电子光学实验室已为美国能源部的艾姆斯实验室制造了一台俄歇电子谱学显微镜。俄歇显微镜是一种分析器 ,能让科学家了解表面层的组成和元素在材料中的分布。对于评估材料性质、故障、腐蚀和清洁的研究人员 ,这种能力非常重要。俄歇显微镜将一电子束聚焦在材料样品的表面 ,产生特别的电子 (俄歇电子 ) ,对于每种元素或原子上层的化合物这种俄歇电子的能量是唯一的。仪器分析电子数目 ,以及它们的动能 ,产生数据和图像以帮助科学家了解表面性质。由于离子枪能逐步剥离样品表面的材料 ,俄歇显微镜也能获得表面以下的材料组成信息。俄歇电子…     

p型GaN材料的表面物理特性

运用X射线光电子能谱(XPS)和俄歇电子能谱(AES)等表面分析手段对表面状态不同的p-GaN样品进行了分析.在样品表面制作了Ni/Au电极并进行了I-V特性测试.实验结果表明样品表面镓氮元素化学比(Ga/N)的减小以及C,O杂质含量的减少可以改善电极的欧姆接触性能.     

光电材料的俄歇电子谱分析

俄歇电子能谱(AES)是测定固体表面元素组分的分析技术。由于AES具有很高的空间分辨率和表面灵敏度,并可以通过离子束溅射刻蚀获得组分深度剖面分布,所以它在各种材料,特别是微电子材料、光电子材料和纳米薄膜材料的分析中应用广泛。文章详细地介绍了PHI595型多探针俄歇电子能谱仪及其在光电子材料分析中的应用。     

p型GaN材料的表面物理特性

运用X射线光电子能谱(XPS)和俄歇电子能谱(AES)等表面分析手段对表面状态不同的p- Ga N样品进行了分析.在样品表面制作了Ni/ Au电极并进行了I- V特性测试.实验结果表明样品表面镓氮元素化学比(Ga/ N)的减小以及C,O杂质含量的减少可以改善电极的欧姆接触性能.     

利用俄歇电子能谱仪研究Al焊垫表面的F腐蚀

Al焊垫的质量关系着半导体器件及封装的质量和可靠性.多项研究表明Al焊垫表面的沾污增强了Al焊垫腐蚀的可能性,特别是焊垫表面刻蚀后残留的F元素,极容易在焊垫表面引起各种类型得腐蚀.应用俄歇电子能谱仪,研究了两种发生在焊垫表面的腐蚀现象,结合其他失效分析手段,分析了Al焊垫表面的F腐蚀的成因.研究结果表明,被腐蚀的Al焊垫表面F元素的相对含量较高,腐蚀缺陷所在区域的氧化层大为加厚,将直接影响到后期封装过程中Al和相应封装材料的金属键合,造成潜在的芯片失效.     

用俄歇电子谱仪测量半导体

俄歇(Auger)电子谱仪是一种新型的综合性分析装置,利用它作半导体材料和器件的组分与表面的分析,是一个很有力的工具,也是一门新技术.本文将叙述采用俄歇电子谱仪,对光电子器件常用的化合物半导体镓铝砷(GA_(1-x)Al_xAs)、镓铝砷磷(Ga_(1-x)Al_xAs_(1-y)P_y)等多元化合物材料的组分,进行定性分析和定量测量,通过与标准样品作比较而推导出组分x、y值的计算公式,给出了实验方法与实验结果.一、概述俄歇电子谱仪是一种普遍适用于分析各种固体材料所含元素的新设备.它可以对半导体材料进行表面     

俄歇电子出现电势谱仪的研制及其应用

本文简要地介绍了俄歇电子出现电势谱仪的基本结构和它在钡钨阴极激活表面、吸气剂蒸散镜面、不锈钢材料表面以及阴极寿命过程中表面变化等表面分析中的初步应用.实践表明,本实验所采用的俄歇电子出现电势谱(AEAPS)分析管结构能够适应不同材料及不同场合中的各种表面分析,对俄歇电子出现电势谱的进一步推广应用具有实用价值.     

液相外延生长的Al_xGa_(1-x)As/GaAs异质结构的俄歇电子能谱

采用俄歇电子能谱仪(AES)对液相外延生长的GaAs-AlxGa_(1-x)As异质结构进行了研究.结果表明,在异质结界面处,有一过渡层,其组分由异质结的一边向另一边单调地变化,该层的厚度依赖于溶液的饱和度.还对样品表面的沾污情况进行了观测.     

用AES和XPS技术研究半绝缘多晶硅薄膜

本文用俄歇电子能谱仪(AES)和X射线光电子能谱仪(XPS)研究半绝缘多晶硅(SIPOS)薄膜中硅的化学价态.通过对Si LVV俄歇谱谱线形状和位移以及Si(2p)芯态峰位移的分析,揭示了SIPOS膜是由元素Si、SiO和SiO_2组成.经过1100℃高温退火的SIPOS 膜经历了一个再结构过程——SiO_2成份增强和SiO向Si_2O_3的转变.     

An investigation on the plasma treatment of integrated circuit bond pads

Integrated circuit (IC) bond pads play an important role in the wire bond reliability of the microelectronic devices. Being the device’s only electrical connection to the package and electronic systems, it is mandatory that the bond pads are free of contaminants and possess excellent bonding characteristics. Contaminants such as oxides and organic residues impair the bondability to a considerable extent and are very resistant to conventional wet cleaning methods. In this paper, we report the effects of an Ar/H₂ plasma treatment on the surface chemistry and morphology of IC bond pads. Surface and sub-surface chemical analyses have been conducted using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Results reveal that the oxygen level of the bond pad surface has decreased significantly after the plasma treatment. Although the treatment has successfully removed the surface crystallites on the bond pads on prolong etching; however, the aggressive process has also damaged the passivation layers that surround the pad areas.     

Increasing bondability and bonding strength of gold stud bumps onto copper pads with a deposited titanium barrier layer

A flip-chip assembly is an attractive scheme for use in high performance and miniaturized microelectronics packaging. Wafer bumping is essential before chips can be flip-bonded to a substrate. Wafer bumping can be used for mechanical-single point stud bump bonding (SBB), and is based on conventional thermosonic wire bonding. This work proposes depositing a titanium barrier layer between the copper film and the silver bonding layer to achieve perfect bondability and sufficiently strong thermosonic bonding between a stud bump and the copper pad.A titanium layer was deposited on the copper pads to prevent copper atoms from out-diffusing during thermosonic stud bump bonding. A silver film was then deposited on the surface of the titanium film as a bonding layer to increase the bondability and bonding strength for stud bumps onto copper pads. The integration of the silver bonding layer with a diffusion barrier layer of titanium on the copper pads yielded 100% bondability between the stud bump and pads. The strength of bonding between the gold bumps on the copper pads significantly exceeds the minimum average values in JEDEC specifications. The diffusion barrier layer of titanium effectively prevents copper atoms from out-diffusing to the silver bonding layer surface during thermosonic bonding, which fact can be interpreted with reference to the experimental results of energy dispersive spectrometry (EDS) and analyses of Auger depth profiles. This diffusion barrier layer of titanium efficiently provides perfect bondability and sufficiently strong bonding between a stud bump and copper pads with a silver bonding layer.     

Surface analytical techniques

This review briefly describes some of the techniques available for analysing surfaces and illustrates their usefulness with a few examples. In particular, Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS), sputter neutral mass spectroscopy (SNMS) and laser Raman spectroscopy are all described. In analysing a surface, AES and XPS would normally be considered first, with AES being applied where high spatial resolution is required and XPS where chemical state information is needed. SIMS and SNMS can be performed together and can detect smaller surface concentrations. Laser Raman spectroscopy is useful for determining molecular bonding. Techniques which give topographic information, such as scanning tunnelling microscopy (STM) and atomic force microscopy (AFM), have not been considered.     

Characterization of copper precipitates on aluminum copper bond pads formed after plasma clean and de-ionized water exposure

Semiconductor bond pads made from aluminum and small percentages of copper is susceptible to galvanic corrosion. In galvanic corrosion, the cathode (copper precipitate) is usually protected by the aluminum oxide that covers the surface of aluminum which acts as the anode. However, when the aluminum oxide thickness is reduced by plasma cleaning, the precipitates can be exposed. When exposed precipitates come in contact with de-ionized water, galvanic corrosion takes place. Therefore, though plasma cleaning in general is supposed to improve semiconductor bond pad surface in preparation for package level interconnection, adding the plasma clean step just before a process with de-ionized water can cause bond pad corrosion through the galvanic reaction between the exposed precipitate (cathode) and the surrounding aluminum (anode). This paper aims to investigate the mechanism of corrosion and characterize corroded bond pads by using wire bond ball shear method.     

Mechanical Strength and Interface Characteristics of Transmission Laser Bonding

A laser-based bonding technique, called transmission laser bonding (TLB), is studied for the purposes of device and wafer-level packaging. The TLB technique uses the specific characteristics of a laser to bond a transparent wafer on top of an opaque wafer. When a laser beam with a specific wavelength is passed through a transparent wafer, high-density laser energy is absorbed by the opaque wafer and melts a thin surface layer, resulting in the formation of strong chemical bonds across the two wafers. A Nd:YAG pulse laser has been used to bond a transparent glass wafer to a Si substrate. The associated bond strengths under various bonding conditions are examined by a microtensile tester to quantify the bonding quality. With a contact pressure higher than 0.5 MPa, the TLB strength can reach a stable value of 10.5 MPa, which is comparable to those obtained by other popular bonding processes currently used by the packaging industry. The wafer surface conditions are evaluated by atomic force microscopy (AFM) and profilometry, while Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) are used to study the characteristics of bonding interfaces. The AFM and profilometry results reveal that the wafer roughness and flatness required by TLB can be less stringent than those specified in the current industrial standards. The AES and XPS results are used to interpret the chemical and physical aspects of TLB formation and to provide the rationale for obtaining high-quality and high-strength TLB.     

硅片直接键合界面的存在对器件性能的影响

利用电子透射显微镜(TEM)和俄歇分析仪(AES)观察硅片直接键合界面结构,在界面存在一个小于2nm厚的非晶区-硅氧化物。此界面具有良好的吸杂效应,在同一退火温度下,退火时间愈长,吸杂现象愈明显。因此键合界面的存在改善了晶体管的性能。     

The effect of prebonding heat treatment on the separability of Auwire from Ag-plated Cu alloy substrate

The wire bonding technology that relies on subsequent wire separation of a connection has a possibility of becoming a key packaging technology in the environmentally friendly aspects of the recycling of mounting materials, such as the reworking of chip on board (COB) mounting and the application of the inter-poserless chip size package (CSP) in the manufacturing process. This study investigated how heat treatment before bonding affects separability at the ball bonding area. For the investigation, we used bonding pairs of Ag-plated Cu alloy substrate and An wire. Heating a board to 150°C before wire bonding degraded wire bondability but improved separability. An analysis of Ag plating by Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) revealed that the heat treatment caused the Cu on the board to diffuse into the Ag plating and to deposit concentrations of Cu in the form of Cu(OH)₂ and CuCl₂ on the Ag surface     

Monte Carlo方法计算定量俄歇电子能谱分析中的背散射因子

本文通过Monte Carlo方法模拟计算了定量俄歇电子能谱分析（如对Ni的LVV俄歇电子和Pt的M5N67N67俄歇电子）中的背散射因子。由于计算中结合了相关领域的各种最新进展．因此该新计算可以为定量俄歇电子能谱分析提供更为准确的参数。     

铍离子注入锑化铟快速热退火的背散射沟道分析

本文借助背散射沟道分析技术系统地研究了Be离子注入InSb快速热退火后的剩余损伤,采用俄歇电子能谱仪分析了InSb表层组分的化学配比,并对背散射分析的结果进行了详细的讨论。