阳极氧化Al_2O_3膜/InP和自身氧化膜/InP的界面性质

研究了用阳极氧化法制备的Al_2O_3膜/InP和自身氧化膜/InP两种MIS结构的组分分布和电学性质,AES、I-V、C-V和DLTS等测试结果表明,Al_2O_3/InP结构的性能更为优越.用DLTS方法发现这两类样品都具有峰值能量为Ec-Es=0.5eV、俘获截面为～10~(-15)cm~2的连续分布的界面电子陷阱.认为该电子陷阱与磷空位缺陷有关.     

STUDY OF THE ANODIZATION OF Al FILM ON InP SUBSTRATE AND ITS PROPERTIES

The anodization of Al film on InP substrate and properties of anodic Al_2O_33/InPhave been investigated by AES,DLTS,I-V,C-V and ellipsometer.The results show that theanodic oxide Al_2O_3 has a permittivity of 11～12 and a resistivity of 1.3×10~(13) ohm-cm.Interfacestate density at Al_2O_3/InP is about 10~(11) cm~(-2)·eV~(-1).DLTS reveals that there is a continuouslydistributed interface electron traps at Al_2O_3/InP interface.Anodic Al_2O_3 exhibits good stabilityand electrical properties and could be used for passivation,diffusion mask and gate insulator,etc.     

GaAs、InP阳极氧化薄膜的光电子能谱、俄歇电子能谱分析

使用一种新的不含水的阳极氧化液生长出厚度均匀、重复性好的～10~2A GaAs、InP阳极氧化膜.XPS和 AES分析表明:GaAs 氧化膜表面和膜内组分均匀,Ga_2O_3/As_2O_3=1; InP一氧化物界面过渡区较窄,未见到富p现象.     

CVD法淀积Al_2O_3膜及其与InP、Si的界面性质

本文介绍了用CVD方法分别在Si和InP上淀积了Al_2O_3膜.并用椭偏仪、高频C-V,准静态C-V、DLTS对Al_2O_3膜的性质及其与Si和InP的界面性质进行了测试分析.     

Ga_(0.47)In_(0.53)As/SiO_2与Ga_(0.47)In_(0.53)As/Al_2O_3的界面性质

本文研究了GaInAs/SiO_2与GaInAs/Al_2O_3的界面性质.采用PECVD技术以TEOS为源以及采用MOCVD技术以Al(OC_3H_1)_3为源在n~+-InP衬底的n-Ga_(0.47) In_(0.33)As外延层上淀积了/SiO_2和Al_2O_3,制备成MIS结构.结果表明这些MIS结构具有良好的C-V特性,SiO_2/GaInAs界面在密度最低达 2.4×10~(11)cm~2·eV~(?),氧化物陷阱电荷密度达10~(?)～10~(10)cm~2,观察到GaInAs/SiO,结构中的深能级位置为E_c-E_T=0.39eV.GaInAs/Al_2O_3结构中的深能级位置为E_c=E_T=0.41eV.     

新的双层介质的InP MIS结构

本文提出了一种由真空蒸发法淀积的SiO薄膜和在P_2O_5气氛中进行InP的热氧化而形成的 InP本体氧化层(native oxide)所组成的新的双层介质 InP MIS结构.通过高频C-V特性的测量得到了较好的界面特性,其中最小界面态密度达8.5×10~(10)cm~(-2)eV~(-1).本文还通过俄歇电子能谱(AES)的测量探讨了上述InP的本体氧化层在改善InP MIS结构的界面特性方面所起的作用.     

Al/LB绝缘膜/Si结构界面态研究

I—V特性法表明单层LB聚酰亚胺膜(～0.5nm)MIS结构的界面态密度为10~(12)～10~(13)cm~(-2)eV~(-1)。对11和41层LB聚酰亚胺膜,DLTS测试得到的界面态密度分别为10~(12)～10~(13)和10~(11)～10~(12)cm~(-2)eV~(-1)。所有结果表明,在硅禁带中央附近具有较大的界面态密度。     

高介电常数Ta/Al_2O_3复合膜的制备及性能研究

首次在溴的丙酮溶液中,以钽为阳极,氧化铝为阴极,通过直流电沉积方法制备了Ta/Al_2O_3复合膜。借助LCR数字电桥、SEM、EDS等测试手段对Ta/Al_2O_3复合膜的介电性能及微观结构进行了分析与表征。研究表明:Ta/Al_2O_3复合氧化膜的表面沉积了质量分数为41.77%的钽。与普通铝阳极(Al_2O_3)氧化膜相比,复合氧化膜的电容提高了50%以上,这主要归因于介电常数较高的钽在复合氧化膜表面的沉积。     

阳极氧化制备硅基氧化铝薄膜MIM电容器

提出了一种在常温下通过简单的恒电流阳极氧化制备Al_2O_3薄膜构建金属-介质-金属(MIM)结构电容器的方法,通过控制阳极氧化时间制备出不同厚度Al_2O_3薄膜,避免了高成本且复杂的制备工艺。首先探究了不同Al_2O_3薄膜厚度对MIM电容器的电容特性的影响,发现厚度为25.1 nm的Al_2O_3薄膜层构成的电容器性能最佳。它的能量密度值最大,为3.55 J/cm~3;其电容密度较大,可达到5.05fF/μm~2;其漏电流性能好,在0.8 V时漏电流密度仅为9.36 nA/cm~2。此外,对该电容器电容变化率与施加电压时间的关系也进行了研究,当施加电压为2 V时,可预测工作十年后的电容变化率仅为1.82%。因此,通过阳极氧化制备介质层构建硅基MIM结构为制备低成本、可集成的储能电容器提供了一种新方案。     

磷化铟与氧化膜界面物理性质的研究

<正> 利用φ550型AES和ESCA与离子溅射相结合方法,研究了n型InP(100)晶面,浓度 10~(16)cm~(-3),迁移率约 2500cm~2/V·s的单晶片上低温淀积SiO_2热氧化膜和阳极氧化膜与本体InP界面区的光电子能谱随深度的变化,及其各种氧化物和俄歇信号的深度分布.在深度分析中Ar作溅射气体,离子枪工作电压为2keV,离子流密度为8μA,电子束电压为3keV,其束流为5μA.同时用椭圆偏振光测厚仪,测定了两种氧化膜的厚度和折射率及介电常数,并且还测定了它们的击穿电压,其结果列于表1.     

铝酸盐钡钨阴极中掺氧化钙和氧化钪的作用机理

各种铝酸盐钡钨阴极的发射物质中存在着2BaOCaOAl2O3和可利用氧化钡的共同成分。氧化钙的作用在于参予组成了2BaOCaOAl2O3相成分,稳定了可利用氧化钡。在掺氧化钪的发射物质5BaO3CaO2Al2O30.6Sc2O3中,氧化钪的作用则在于它和铝酸盐中的可利用氧化钡结合为2BaOSc2O3,成为电子发射源氧化钡或钡原子的载体,它起控制和补充发射源的作用。这个机理得到实验证实。     

BF+2注入的多晶硅薄膜快速热退火后氟行为的研究

本文报道BF_2~+注入的多晶硅薄膜经快速热退火后的物理和电学性质。发现造成氟异常分布的原因是由于快速热退火过程中氟的外扩散以及在多晶硅/二氧化硅界面处的聚集。在注入剂量为1×10~(15)和5×10~(15)cm~(-2)的样品中,经快速热退火后可以观察到氟泡。     

Plasma anodization of evaporated Al-InP systems

Aluminium oxide-InP structures were fabricated by plasma anodization of evaporated Al-InP systems with intention of fabricating InP MISFETS. It was found that the resistivity and break-down strength of the A1₂O₃ film were influenced by the selection of the end point of the anodization. At appropriate conditions the resistivity of 5 × 10¹⁰ − 10¹²Ω cm for the anodic Al₂O₃ and the minimum density of the interface trap states of 4 × 10¹¹ cm⁻² ev⁻¹ for Al₂ O₃ -InP systems were obtained.     

用深能级瞬态电容谱测定掺磷-Si:H的隙态密度

正 非晶硅的隙态密度在很大程度上决定了材料的电学和光学性质,因而对非晶硅隙态密度的研究具有重要的理论和实际意义。目前,对非晶硅隙态密度分布的认识,仍存在着争议。W.E.Spear.等人首先用场效应方法测定了非晶硅的隙态密度分布,并在相当一段时间为人们所接受。但由于场效应方法在实验数据处理上存在着很大误差。另外该方法的测量结果受界面态的影响很大。J.D.Cohen等人用深能级瞬态谱(DLTS)测     

Improved electrical properties on the anodic oxide/InP interface for MOS structures

The interface properties of the anodic oxide/n-type (111) InP metal oxide semiconductor (MOS) structures significantly improved while using the polishing agent HBr:K₂Cr₂O₇:H₂O (BCA). Annealing at 250°C dehydrates the grown oxides and has a strong effect on the surface potential. Composition of the oxides analyzed using x-ray photoelectron spectroscopy showed that the oxides are composed of In₂O₃, InPO₃, and InPO₄. MOS structures fabricated on BCA polished substrates show a lower surface state density of 6 × 10¹⁰ cm⁻² eV⁻¹ when compared to the substrates polished with bromine-methanol (8 × 10¹⁰ cm⁻² eV⁻¹).     

Formation of aluminum oxide films from aluminum hexafluoroacetylacetonate at 350–450° c

A study of the thermally activated decomposition of Al(hfa)₃ (aluminum hexafluoroacetylacetonate) from the gas phase to form Al₂O₃ on silicon substrates is reported. The decomposition process was carried out in an open tube atmospheric pressure reactor in either argon or oxygen/argon mixtures in the temperature range, 350–450° C. The chemical vapor deposition process resulted in the formation of aluminum oxide films in all instances. The dielectric strength of Al/Al₂O₃/Si capacitors which received a post-metal anneal, but did not receive a high temperature annealing treatment, with aluminum oxide films prepared from Al(hfa)₃ in argon, was found to be in the range 2–6 MV/cm. The difference between the flatband voltage of the MOS structures and the metal-silicon work function difference was positive, indicative of a net negative oxide charge with a density of approximately 3 × 10¹¹ – 3 × 10¹² cm^-2, assuming the charge is located at the oxide-silicon interface. Decomposition of Al(hfa)₃ was also carried out in oxygen/argon mixtures with the oxygen concentration in the range 10–60 vol %. This process led to the deposition of aluminum oxide films with breakdown fields in the range 8–9 MV/cm. However, the flatband voltages of the Al/Al₂O₃/Si capacitors were even more positive than those obtained with Al₂O₃ formed in pure argon. High temperature (800–1000° C) oxygen or nitrogen annealing treatments of alumina films deposited in either argon or oxygen/argon mixtures were evaluated from the point of view of their influence on the oxide film properties. In particular, an annealing process in oxygen at 1000° C for 15 min was found to result in a reduction of the net negative oxide charge, and an improvement of the dielectric strength of films deposited in argon. Films formed in oxygen/argon mixtures did not change appreciably following oxygen annealing, as far as breakdown fields are concerned, but the oxide net negative charge was reduced. As in an earlier study by the authors, of copper film deposition from Cu(hfa)₂, it was found that essentially carbon free films could be obtained under appropriate conditions.     

行波管夹持杆微波等离子体化学气相沉积金刚石厚膜改善散热性能研究

采用微波等离子体化学气相沉积法在行波管Al₂O₃夹持杆上沉积金刚石厚膜,取代传统有毒的氧化铍陶瓷杆,用于宽带大功率行波管改善其散热性能.经材料性能测试,慢波组件装配及性能测试,获得了较好的实验结果:导热率大于12W/cm.℃,介电常数为5.0~5.5,介质损耗为1×10^-3,体积电阻率大于10¹³Ω/cm; 慢波组件导热性能与同结构的BeO组件相比提高3.0倍.整管冷测参数全部合格;整管热测在C波段测得Po=95W,G=35db.     

砷化镓气相外延中Zn的行为和微光材料的制备

在Ga-AsCl_3-H_2系统中用金属Zn为掺杂剂,研究了气相外延GaAs时Zn的掺入和行为。GaAs中Zn的分配系数和空穴浓度分别为10和大于10~(20)cm~(-3),它们都比掺Cd的GaAs大2—3个数量级。这保证了用以制备光阴极材料所需的高空穴浓度的P-GaAs。结合掺Zn和掺s,已重复制得界面良好的P-n结构材料。