HfSiON高K介质在HF基溶液中的湿法腐蚀特性研究

本文研究了HfSiON高K介质在HF基溶液中的湿法腐蚀特性。HF基溶液是最有希望实现HfSiON材料去除的湿法腐蚀溶液,而且通过在HF溶液中加入酸和/或无水乙醇可以提高HF基溶液的选择比。由于退火过程中引起的增密作用,与淀积后的HfSiON相比,经过900°C,30秒退火的HfSiON薄膜在HF基腐蚀溶液中的腐蚀速率显著降低。由于N扩散进入界面层或Si衬底形成在HF基溶液中很难溶解的Si-N键,采用HF基溶液完全去除HfSiON薄膜以后,存在一个不能被腐蚀干净的界面层且被腐蚀的表面未显示疏水特性。在新淀积的高K材料和Si衬底之间存在含有Si-N键的界面层可能因库伦散射而降低载流子迁移率。另外,对于很薄的HfSiON薄膜,在湿法腐蚀前采用N2等离子体处理对提高其湿法腐蚀速率并不是十分有效。     

量子阱红外探测器衬底完全去除技术研究

背面减薄技术对于提高量子阱红外焦平面探测器的性能有着重要的意义,通过衬底减薄能够缓解探测器芯片与读出电路的热膨胀失配,提高互连混成芯片可靠性,同时能够有效降低串扰。本文结合机械研磨、化学机械抛光和选择性湿法腐蚀技术,实现了量子阱探测器互连混成芯片的衬底完全去除。     

超薄芯片微波功率管制作成功

本人经过多次摸底试验,最后采用了先机械减薄后化学减薄的方法,制取了70～120μm的硅片,化学腐蚀液为HNO_3+HF+HAC的混合液。化学反应机理见化学方程式如下: 3Si+4HNO_3+18HF→3H_2SiF_6+4NO     

多层陶瓷电容器BaNd_2Ti_4O_(12)的化学腐蚀研究

以混合酸作为腐蚀液,研究了BaNd2Ti4O12多层陶瓷电容器的化学腐蚀的工艺条件。提高酸的浓度、时间和温度,都会加快腐蚀,其中温度的影响最大。硝酸替代氢氟酸,无法将BaNd2Ti4O12样品的晶界腐蚀出来。适宜的腐蚀条件为:40%氢氟酸3 mL、浓盐酸12 mL配制成100 mL溶液,加热温度60℃,时间30 s。     

多孔β-SiC薄膜的蓝光发射

通过射频溅射的方法在单晶硅衬底上沉积了β-SiC薄膜,用HF酸(40%)和C2H5OH(99%)的混合溶液对β-SiC薄膜进行了电化学腐蚀处理,形成了多孔β-SiC(PSC)薄膜.利用荧光分光光度计研究了样品的光致发光(PL)特性,用原子力显微镜(AFM)和扫描电子显微镜(SEM)观察了样品腐蚀前后的表面形貌.结果表明:多孔β-SiC薄膜具有较强的蓝光发射特性;通过改变腐蚀时间,可以改变蓝光发射的强度,也可以观察到蓝光-红光同时发射的现象;降低HF酸的浓度,蓝光发射峰明显变弱,并对多孔β-SiC薄膜的发光机理及其微观结构进行了讨论.     

多孔β-SiC薄膜的蓝光发射

通过射频溅射的方法在单晶硅衬底上沉积了βSiC薄膜,用HF酸(40 % )和C2 H5OH(99% )的混合溶液对βSiC薄膜进行了电化学腐蚀处理,形成了多孔βSiC(PSC)薄膜.利用荧光分光光度计研究了样品的光致发光(PL)特性,用原子力显微镜(AFM)和扫描电子显微镜(SEM )观察了样品腐蚀前后的表面形貌.结果表明:多孔βSiC薄膜具有较强的蓝光发射特性;通过改变腐蚀时间,可以改变蓝光发射的强度,也可以观察到蓝光红光同时发射的现象;降低HF酸的浓度,蓝光发射峰明显变弱,并对多孔βSiC薄膜的发光机理及其微观结构进行了讨论.     

选择性腐蚀Si1-xGex与Si制备绝缘体上超薄应变硅

基于应变硅以及绝缘体上超薄应变硅(SSOI)工艺,使用氢氟酸、硝酸和醋酸的混合溶液与质量分数为25%的四甲基氢氧化铵(TMAH)溶液选择性腐蚀Si1-xGex与Si以制备绝缘体上超薄应变硅。研究了质量分数为0.5%～5%的HF和Si1-xGex中Ge的含量对选择性腐蚀的腐蚀速度与选择比的影响,优化了选择性腐蚀工艺。采用氨水、过氧化氢和水的混合溶液处理选择性腐蚀后的Si1-xGex与Si表面,得到了高应变度、高晶体质量的超薄SSOI。采用原子力显微镜(AFM)测试腐蚀速度以及腐蚀后的表面粗糙度;使用喇曼光谱仪表征Si1-xGex以及应变硅的组分以及应变度;使用透射电子显微镜(TEM)对SSOI的晶体质量进行了表征。结果表明,超薄SSOI的表面粗糙度(RMS)为0.446 nm,顶层Si的应变度为0.91%,顶层应变硅层厚度为18 nm,且具有高的晶体质量。     

片式多层陶瓷电容器陶瓷晶粒酸腐蚀应用研究

以混合酸作为腐蚀液,腐蚀陶瓷介质层晶粒晶界,再使用扫描电子显微镜进行微观结构观察。试验结果表明,腐蚀液的种类、浓度、腐蚀时间及温度均对腐蚀效果影响较大。最终确定适宜的腐蚀条件为：氢氟酸-硝酸体系,氢氟酸2 mL,硝酸5 mL,配置成100 mL溶液,Class 2(BaTiO₃)陶瓷室温下腐蚀时间50 s, Class 1((Sr, Ca)(Zr, Ti)O₃陶瓷腐蚀15 s。     

碲镉汞焦平面器件背面减薄技术

采用机械抛光和机械化学抛光的方法进行碲镉汞焦平面器件的碲锌镉衬底背面减薄,最后利用专用腐蚀液腐蚀的方法将碲锌镉衬底全部去除,碲镉汞完全露出;器件测试结果表明减薄后的MW1280×1024器件经受高低温循环冲击的可靠性显著提高。     

多晶Si太阳电池表面酸腐蚀制绒的研究

研究了采用HF和HNO3非择优腐蚀多晶硅表面制备绒面的机理。通过实验分析了酸混合液的体积浓度配比、添加剂、温度和时间等因素对腐蚀速率和腐蚀后表面形貌的影响;总结出了多晶Si的酸腐蚀规律,得到了制备理想绒面的酸混合液体积配比(V(HF):V(HNO3):V(CH3COOH)=1∶12∶6)。在此基础上提出了优化设计方案:采用廉价的水代替醋酸作为缓蚀剂,腐蚀过程置于超声槽中进行,利用超声波的振动使反应生成的气泡快速脱离多晶Si片表面,同时使腐蚀液浓度分布更加均匀,从而制备出效果更佳的多晶Si绒面。     

Microstructure and corrosion resistance of room-temperature RF sputtered Ta2O5 thin films

The connection between the chemical corrosion resistance and the microstructure of the Ta₂O₅ thin films prepared at room temperature by a RF magnetron sputtering technique on Si substrates has been investigated. We find that the microstructure of the films changes with different RF sputtering power, and is responsible for the degradation of the corrosion resistance in HF solutions. The deposited films are amorphous and porous when the RF power is low. A preferred orientation toward (200) β-Ta₂O₅ can be observed when the RF power is increased to 150 W. In addition, the films deposited under this condition are dense and are consequently more resistant to the attack of chemicals. AT an RF power of 300 W the corrosion resistance of the films declines due to an increase of the exposed pore surface to the HF solution.     

多晶硅太阳电池酸腐表面织构的研究

采用酸腐多晶Si片的方法,获得了各向同性的表面织构.酸腐蚀液选取HF-HNO3混合溶液,并用H3PO4进行改良.分别利用扫描电镜(SEM)和光谱响应系统,分析了腐蚀后多晶Si片的表面形貌和反射率.结果表明,酸腐多晶Si表面分布均匀的蚯蚓状腐蚀坑,反射率很低,在等离子增强化学气相沉积(PECVD)Si3N4减反射膜后,反射率大大下降.     

膨胀石墨体积膨胀率对红外遮蔽性能的影响

膨胀石墨是一种具有潜在军事应用价值的新型光电无源干扰材料。依次以硝酸和磷酸、硝酸和乙酸的混酸为插层剂,高锰酸钾为氧化剂,采用分步插层法制备出了不同体积膨胀率的膨胀石墨;采用扫描电镜分析了膨胀石墨微观结构随膨胀体积的变化;采用静态测试方法测试了不同体积膨胀率膨胀石墨的红外遮蔽性能。结果表明:随膨胀体积的增大,膨胀石墨的孔隙率增大,石墨片层被充分打开;膨胀石墨对红外辐射的遮蔽性能随膨胀体积的增大而增大,当膨胀体积从233 mlg-1增大到450 mlg-1时,其红外遮蔽率从66.43%增大到90.77%。     

碎屑岩中长石蚀变形成次生孔隙的试验研究

次生孔隙发育带是深层寻找有利油气勘探目标区的基础,酸性地层水是含油气盆地内部物质迁移和能量交换的主要介质。利用含乙酸溶液,模拟地层水,对济阳坳陷的长石砂岩进行高温高压条件下溶蚀试验,使用扫描电镜、X-衍射分析设备对实验产物进行对比检测。实验证明：（1）高温高压条件下乙酸对长石矿物有很强的溶蚀作用。（2）斜长石比钾长石更容易遭到溶蚀。结合济阳坳陷深层勘探实际,认为深层长石溶蚀耗水作用导致岩石孔隙度变大,形成次生孔隙,从而改善深层储层物性。同时长石溶蚀耗水作用是油气运移成藏活动一种驱动力。     

A novel decapsulation technique for failure analysis of epoxy molded IC packages with Cu wire bonds

A cost-effective and simple technique involved in the decapsulation technique of different packages with various epoxy molding compounds (EMCs) attracted a large interest for use in failure analysis of reverse engineering. In this study, we reported that the epoxies molded IC packages with Cu wire bonds were decapsulated using a mixed acid controlled by a jet etcher with minimum degradation of Cu wires and bond interfaces. It was found that the nitric acid to sulfuric acid ratio of 2:1 was the optimum recipe for the preservation of Al pad and Cu wire. We also successfully developed a process both including laser and wet treatments to solve the over-etching and corrosion problems for critical package geometries of ball grid array packages. Additionally, the various physicochemical properties of the wet etching rates for EMCs were also studied using an atomic force micro microscopy, a Kelvin probe force microscopy, and thermo-gravimetrical analyses.     

Chemical spray pyrolysis deposited fluorine-doped zinc oxide thin films: Effect of acetic acid content in the starting solution on the physical properties

Fluorine-doped zinc oxide [ZnO:F] thin solid films have been deposited on soda lime glass substrates using the chemical spray technique. The effect of the acetic acid content in the starting solution on the composition, morphology, and photoluminescent properties of the ZnO:F thin films was studied. The fluorine content in the samples increases as the acetic acid content in the solutions increases. Morphology of the ZnO:F thin films changes drastically with the variation of acetic acid content. The photoluminescence spectra revealed the presence of high defect content in the films, nevertheless similar characteristic emissions, irrespective of the acetic acid content in the starting solution were presented.     

Analyzing lead information from SAR images

Leads are relatively linear features in the sea ice cover, which are composed of open water or new, thin ice. Because of their composition, leads impact the ocean/air heat exchange. Automated analysis of leads from sea ice imagery may provide a means of gathering important information about the sea ice cover and its climatic influence. This paper describes: (1) a method for extracting and analyzing leads from ERS-1 synthetic aperture radar (SAR) images classified by ice type and (2) the results of using this method on images of the Beaufort Sea. The methodology consists of identifying potential lead features in the image and measuring their characteristics both before and after using a thinning or skeletonization technique on the features. The measurements obtained using this method include lead area, average width, number of leads in an area, amount of branching, and linearity of the lead. These measurements were analyzed with respect to the time of year and the latitude of the images. Results indicate that the measurements produced by the methodology are consistent with lead measurement distributions that others have found. The results of the study suggest that the methodology is appropriate to study lead characteristics on a large scale     

耐强酸腐蚀超声波换能器

设计并制作了一种用于强酸性输液系统除垢的超声波换能器。利用聚丙烯管道组装的静态流体超声场强测试系统研究了影响超声传播的因素。结果表明,使用陶瓷超声发射头有利于超声能量向液相传输,随导波棒粗端与陶瓷发射头接触面积增大,超声波能量传输效率提高。结合有限元分析软件确定了换能器的振动节点,优化换能器结构设计。在硫酸、盐酸、硝酸和氢氟酸酸体系中测试了换能器陶瓷超声头的耐酸腐蚀性能。实验结果显示,主晶相w(Al2O3)>75%、碱金属和碱土金属氧化物总含量小于5%的氧化铝陶瓷超声发射头可以耐受酸度为1.0mol/L硫酸的腐蚀。w(Al2O3)>99%的刚玉陶瓷可用抵御0.5mol/L氢氟酸、或大于1mol/L硫酸的腐蚀。用主晶相w(Al2O3)>75%的氧化铝陶瓷超声发射头,在模拟某锌业公司的实际生产的酸性体系中测试3个月,超声发射头无明显腐蚀。