硅基底电子束蒸发铝膜阳极氧化特性

研究了硅衬底上电子束蒸发铝膜,在H2SO4水溶液中阳极氧化形成硅衬底多孔氧化铝复合结构的过程.硅衬底电子束蒸发铝膜的阳极氧化过程主要由多孔氧化铝的生长、氧化铝生长向氧化硅生长的过渡和氧化硅生长三个阶段构成.硅衬底多孔氧化铝复合结构的透射电子显微镜观察表明,在硅衬底上形成了垂直于硅表面的氧化铝纳米孔,而孔底可形成SiO2层.有序结构多孔氧化铝的形成不依赖于铝膜的结晶状态,而是由阳极氧化过程的自组织作用所决定的.实验表明将多孔氧化铝制备工艺移植到硅基衬底上直接形成硅基衬底多孔氧化铝复合结构是可行的,它也为硅基纳米材料的制备提供了一种新的自组织模板.     

用于制备SOI材料的基于硅片键合和双层多孔硅剥离的薄外延硅膜转移技术

采用在阳极化反应时改变电流强度的办法,在高掺杂的P型硅(111)衬底上制备了具有不同多孔度的双层结构多孔硅层.用超高真空电子束蒸发技术在多孔硅表面外延生长了一层高质量的单晶硅膜.在室温下,该外延硅片同另一生长有热二氧化硅的硅片键合在一起,在随后的热处理过程中,键合对可在多孔硅处裂开,从而使外延的单晶硅膜转移到具有二氧化硅的衬底上以形成SOI结构.扫描电镜、剖面投射电镜、扩展电阻和霍尔测试表明SOI样品具有较好的结构和电学性能.     

用于制备SOI材料的基于硅片键合和双层多孔硅剥离的薄外延硅膜转移技术

采用在阳极化反应时改变电流强度的办法 ,在高掺杂的 P型硅 (111)衬底上制备了具有不同多孔度的双层结构多孔硅层 .用超高真空电子束蒸发技术在多孔硅表面外延生长了一层高质量的单晶硅膜 .在室温下 ,该外延硅片同另一生长有热二氧化硅的硅片键合在一起 ,在随后的热处理过程中 ,键合对可在多孔硅处裂开 ,从而使外延的单晶硅膜转移到具有二氧化硅的衬底上以形成 SOI结构 .扫描电镜、剖面投射电镜、扩展电阻和霍尔测试表明 SOI样品具有较好的结构和电学性能     

用于硅衬底隔离的选择性多孔硅厚膜的制备

在硅衬底上形成高阻隔离层对于提高硅基射频电路的性能具有重要意义.采用多孔硅厚膜作为隔离层,能够极大地降低衬底高频损耗.本文对n 型硅衬底上选择性多孔硅厚膜的制备进行了研究.通过在阳极氧化反应中采用不同的HF溶液的浓度、电流密度和反应时间来控制多孔硅的膜厚、孔隙度等特性.有效地减少了多孔硅的龟裂失效,得到的多孔硅最大膜厚为72μm.并测量了多孔硅的生长速率与表面形貌.     

适用于高品质射频集成电感的多孔硅新型衬底制备技术

提出了背向选区腐蚀生长多孔硅的集成电感衬底结构.ASITIC模拟证明,该新型衬底结构的集成电感在高频下仍具有较高的品质因子.采用此工艺,在固定腐蚀液配比的条件下,变化电流密度和阳极氧化时间,制备出了高质量的厚膜多孔硅,并测量了多孔硅的生长厚度、孔径大小和表面形貌,得出了多孔硅生长速率随阳极氧化时间和电流密度的变化关系,为背向选区腐蚀工艺制备高品质硅基集成电感奠定了理论和实验基础.     

电化学制备亚微米氧化铝有序多孔膜方法研究

采用电化学阳极氧化法制备亚微米氧化铝有序多孔膜,研究了铝电极预处理过程、扩孔时间、阳极氧化时间和阳极氧化电压对亚微米氧化铝有序多孔膜孔径、孔密度以及孔排列有序性的影响规律,并且建立了一个理想模型来探讨亚微米氧化铝多孔膜的生长过程.     

玻璃基底上制备多孔氧化铝薄膜的研究

采用电子束蒸发和阳极氧化法,在B207光学玻璃基底上制备出了孔径大小可调、孔隙率可调的多孔氧化铝光学薄膜。用扫描电子显微镜(SEM)和分光光度计分别表征了薄膜的形貌和透射率。结果表明,电子束蒸发的铝膜表面质量比电抛光的铝箔表面质量差;与一次氧化法相比,二次氧化法可以显著提高膜的表面质量;与硫酸和草酸电解液相比,在磷酸电解液中制备的多孔氧化铝薄膜具有较大的孔径,更高的孔隙率;退火有利于多孔氧化铝薄膜透射率的提高。     

用于硅衬底隔离的选择性多孔硅厚膜的制备

在硅衬底上形成高阻隔离层对于提高硅基射频电路的性能具有重要意义。采用多孔硅厚膜作为隔离层 ,能够极大地降低衬底高频损耗。本文对n+型硅衬底上选择性多孔硅厚膜的制备进行了研究。通过在阳极氧化反应中采用不同的HF溶液的浓度、电流密度和反应时间来控制多孔硅的膜厚、孔隙度等特性。有效地减少了多孔硅的龟裂失效 ,得到的多孔硅最大膜厚为 72 μm。并测量了多孔硅的生长速率与表面形貌     

用于硅衬底隔离的选择性多孔硅厚膜的制备

在硅衬底上形成高阻隔离层对于提高硅基射频电路的性能具有重要意义。采用多孔硅厚膜作为隔离层，能够极大地降低衬底高频损耗。本文对n^ 型硅衬底上选择性多孔硅厚膜的制备进行了研究。通过在阳极氧化反应中采用不同的HF溶液的浓度、电流密度和反应时间来控制多孔硅的膜厚、孔隙度等特性。有效地减少了多孔硅的龟裂失效，得到的多孔硅最大膜厚为72μm。并测量了多孔硅的生长速率与表面形貌。     

电化学制备亚微米氧化铝有序多孔膜方法研究

采用电化学阳极氧化法制备亚微米氧化铝有序多孔膜 ,研究了铝电极预处理过程、扩孔时间、阳极氧化时间和阳极氧化电压对亚微米氧化铝有序多孔膜孔径、孔密度以及孔排列有序性的影响规律 ,并且建立了一个理想模型来探讨亚微米氧化铝多孔膜的生长过程     

一种硅基多孔氧化铝-荧光复合发光材料

制备了硅基多孔氧化铝 - 3-羟基 - 2 -萘甲酸钠复合发光材料 .PL谱表明 3-羟基 - 2 -萘甲酸钠进入氧化铝膜的纳米孔内以后 ,发光峰位相对于其在膜表面有明显蓝移 .FT- IR谱进一步确认了 3-羟基 - 2 -萘甲酸钠进入氧化铝膜孔内 .实验结果表明 ,以硅基多孔氧化铝膜为模板可以获得硅基纳米发光点     

Formation of Thick Porous Anodic Alumina Films and Nanowire Arrays on Silicon Wafers and Glass

A method for the fabrication of thick films of porous anodic alumina on rigid substrates is described. The anodic alumina film was generated by the anodization of an aluminum film evaporated on the substrate. The morphology of the barrier layer between the porous film and the substrate was different from that of anodic films grown on aluminum substrates. The removal of the barrier layer and the electrochemical growth of nanowires within the ordered pores were accomplished without the need to remove the anodic film from the substrate. We fabricated porous anodic alumina samples over large areas (up to 70 cm²), and deposited in them nanowire arrays of various materials. Long nanowires were obtained with lengths of at least 9 μm and aspect ratios as high as 300. Due to their mechanical robustness and the built‐in contact between the conducting substrate and the nanowires, the structures were useful for electrical transport measurements on the arrays. The method was also demonstrated on patterned and non‐planar substrates, further expanding the range of applications of these porous alumina and nanowire assemblies.     

Long-range-ordered Ag nanodot arrays grown on GaAs substrate using nanoporous alumina mask

With more and more attention given to the plasmonic nanostructures enhancing light trapping of solar cells, the fabrication of metal nanostructures becomes more and more important. In this work, we fabricated porous anodic alumina on SiO₂/GaAs substrate and obtained periodic Ag nanodots with hemispherical shape by electron beam evaporation. During the experiments, it was found that the properties of barrier layers of porous anodic alumina fabricated on SiO₂/GaAs and SiO₂/Si substrates after pore-widening are different. The through-hole porous anodic alumina film on SiO₂/GaAs substrate cannot be obtained after a long pore-widening process. The additional Ar ion bombardment against the samples was needed in our experiments to get the through-hole porous anodic alumina films on SiO₂/GaAs substrate.     

Nanostructured layers of anodic aluminum oxide on insulating substrates

A method for creation of porous alumina layers on insulating substrates is proposed. The anodic oxidation of thin aluminum films is performed in two stages: formation of a thin dense oxide layer and its local breakdown followed by the final oxidation of the film with a propagation of the oxidation front from a breakdown region to periphery. Aluminum oxide layers exhibit quasi-ordered structure with the pore diameter ranging from 10 to 100 nm and depending on conditions of electrochemical oxidation. The method provides the aluminum film oxidation right to the insulating substrate (i.e., the absence of residual metal phase inclusions on the interface) and can be used for the creation of matrix and composite structures for semiconductor microelectronics.     

Soft Imprinting: Creating Highly Ordered Porous Anodic Alumina Templates on Substrates for Nanofabrication

We demonstrate a “soft‐imprinting” method for the fabrication of highly ordered porous anodic alumina (HOPAA) templates on different substrates (such as Si, glass slides, and flexible polyimide films) over large areas (> 1.5 cm²). In this process, Ar plasma etching is employed to soft imprint an evaporated Al film on the substrates using a free‐standing HOPAA template as a mask, thus creating ordered nanoindentations on the Al surface. The ordered nanoindentations in turn guide the subsequent anodization of Al to generate HOPAA templates on the substrates (HOPAA–substrates), which inherit the pattern of the free‐standing HOPAA mask. This soft‐imprinting technique is also applicable to the fabrication of HOPAA on flexible polymer films. To demonstrate the potential uses of the HOPAA–substrates in nanofabrication, highly ordered Au nanowire arrays are fabricated on a Si substrate and TiO₂ nanotube arrays are prepared on a glass substrate via solution‐ and vapor‐based fabrication processes, respectively.     

纳米多孔铝的制备技术及应用

介绍了阳极氧化方法制备纳米多孔铝的技术。阳极氧化多孔铝由于孔径可以控制在纳米尺度,因而在半导体纳米线料的制备方面具有广泛的用途。     

铝阳极氧化基板制备过程对埋置型Ta-N薄膜电阻的影响

在铝阳极氧化多层基板内用RF反应溅射制备了埋置型Ta-N薄膜电阻,研究了铝阳极氧化过程对Ta-N薄膜电阻和显微结构的影响.实验结果表明:Ta-N薄膜受上层多孔氧化铝膜影响在表层形成了由Ta2O5和Ta-O-N组成的氧化物凸起绝缘层,氧化物凸起层厚度与氧化电压有关.底层Ta-N薄膜电阻率和电阻温度系数基本保持不变,表层氧化凸起使电阻稳定性增加.     

Organized porous alumina membranes for high density silicon nanowires growth

In this paper, we present results on the fabrication of porous alumina membranes on silicon substrates with a long-range order induced by nanoimprint lithography. Fabricated porous alumina matrices present a perfect triangular array of vertical cylindrical pores on areas of 500 × 500 μm² corresponding to the imprinted surfaces. Also, we demonstrate that it is possible to have a directed density multiplication during the pore formation, compared to the nanoimprint mold, by the initial indentation of only one third of the expected alumina pores. The gold catalyst, needed for nanowires growth, is deposited at the bottom of each pore by electrochemistry. The proposed process is scalable to wafer-scale areas, compatible with microelectronics fabrication standards and is not limited to non-fragile substrates like direct bulk aluminum nanoindentation.     

Characterization of thin textured tunnel oxide prepared by thermaloxidation of thin polysilicon film on silicon

In this paper, the characteristics of thin textured tunnel oxide prepared by thermal oxidation of thin polysilicon film on Si substrate (TOPS) are studied. Because of the rapid diffusion of oxygen through the grain boundaries of the thin polysilicon film into the Si substrate and the enhanced oxidation rate at the grain boundaries, the oxidation rate of the TOPS sample is close to that of a normal oxide grown on a (111) Si substrate. Also, a textured Si/SiO₂ interface is obtained. The textured Si/SiO₂ interface results in localized high fields and causes a much higher electron injection rate. The optimum TOPS sample can be obtained by properly oxidizing the stacked α-Si film, independent of the substrate doping level. Also, the optimum TOPS sample exhibits a smaller electron trapping rate and a lower interface state generation rate when compared to the sample from a standard tunnel oxide process. These differences are attributed to a lower bulk electric field and a smaller injection area in the TOPS samples