共查询到17条相似文献,搜索用时 140 毫秒
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多孔硅残余应力的研究 总被引:1,自引:0,他引:1
利用电化学腐蚀的方法在p型单晶硅(100)衬底上制备了多孔硅薄膜。利用微拉曼光谱法分别测量了处于湿化—干燥—再湿化3个阶段的多孔硅薄膜的拉曼频移,对多孔硅内应变引起的频移改变量和纳米硅晶粒因声子限制效应引起的频移改变量进行分离,找到多孔硅薄膜残余应力与拉曼频移之间的关系式。利用这一关系式,对不同孔隙率的多孔硅薄膜的残余应力进行了计算,获得了和声子模型拟合方法相一致的结果。研究中发现,多孔硅表面残余应力随孔隙率的增加而线性增大,其原因为随着孔隙率的增加,多孔硅晶格常数增大,且干燥过程中残液的蒸发产生的毛细应力使多孔硅薄膜与基体硅间晶格错配程度增大造成的。 相似文献
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TMAH腐蚀液制作硅微结构的研究 总被引:6,自引:2,他引:4
通过各向异性腐蚀硅微结构工艺,研究了四甲基氢氧化铵(TMAH)腐蚀液的特性,包括硅(100)晶面腐蚀速率与TAMH溶液浓度、温度、pH值以及过硫酸铵添加剂的关系,并采用原子力显微镜研究了不同腐蚀条件下硅的表面形貌,研究表明:随TMAH溶液的浓度的降低和腐蚀温度的提高,腐蚀速率提高,硅腔的表面粗糙度增大;过硫酸铵添加剂明显改善了硅微腔的表面平整度.本研究所确定的最佳腐蚀工艺条件为:溶液中TMAH浓度为25%,过硫酸铵添加剂浓度为3%,腐蚀温度80℃.在此工艺条件下腐蚀出了深度为230 μm、表面粗糙度小于50 nm的硅微腔. 相似文献
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针对多孔硅气敏传感器在室温下对NO2气体灵敏度较低、选择性不强的问题,采用双槽电化学腐蚀法制备多孔硅,然后在多孔硅顶部溅射沉积金属钨薄膜并经高温热处理氧化形成WO3纳米线,制备出WO3纳米线修饰多孔硅结构及其气敏传感器,对WO3纳米线/多孔硅材料进行了SEM和XRD分析,测试了传感器室温下对NO2的气敏特性。结果表明,制备WO3纳米线的最佳热处理条件是700℃,此温度下增加金属钨膜溅射时间可提升WO3纳米线的生长密度? 所制备的传感器对NO2气体表现出反型气敏响应,特别是溅射1min金属钨的样品显示出优异的NO2室温探测能力与选择性,对4×10-6NO的气敏灵敏度是单纯多孔硅样品的 5.8倍。 相似文献
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硅微机械结构的微电流型电化学气体传感器 总被引:2,自引:0,他引:2
探索研究了用于构制以硅为基体材料、具有特定三维微结构的微电流型电化学气体传感器的微加工工艺,提出了双面光刻、高硼掺杂腐蚀止停、化学各向异性刻蚀和硅表面多层膜剥离成形等既实用而又相容的硅微机械加工关键技术。如此构制的微电流型电化学气体传感器,在器件结构、检测灵敏度、电流响应的稳定重现性等方面,与用传统工艺制成的常规电流型气体传感器相比,具有独特的优点。 相似文献
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采用双槽电化学腐蚀法在p+单晶硅表面制备多孔硅层,然后在多孔硅表面沉积形成Pt薄膜电极,制备出多孔硅气敏元件样品.利用SEM技术分析多孔硅的表面形貌,研究了腐蚀条件对多孔硅的孔隙率、横向I-V特性及低浓度NO2气敏特性的影响.结果表明,多孔硅的横向I-V特性表现出非整流的欧姆接触;多孔硅的孔隙率及其对低浓度NO2的灵敏度均随腐蚀电流密度的增大而增加.当腐蚀电流密度为90 mA/cm2,腐蚀时间为30 min时,所得多孔硅气敏元件对体积分数为200×10-9的NO2的灵敏度可达到5.25,响应时间与恢复时间约分别为14 min与10 min. 相似文献
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采用双槽电化学腐蚀法在p+单晶硅表面制备多孔硅层,然后在多孔硅表面沉积形成Pt薄膜电极,制备出多孔硅气敏元件样品。利用SEM技术分析多孔硅的表面形貌,研究了腐蚀条件对多孔硅的孔隙率、横向Ⅰ-Ⅴ特性及低浓度NO2气敏特性的影响。结果表明,多孔硅的横向Ⅰ-Ⅴ特性表现出非整流的欧姆接触;多孔硅的孔隙率及其对低浓度NO2的灵敏度均随腐蚀电流密度的增大而增加。当腐蚀电流密度为90mA/cm^2,腐蚀时间为30min时.所得多孔硅气敏元件对体积分数为200×10^-9的NO2的灵敏度可达到5.25,响应时间与恢复时间约分别为14min与10min。 相似文献
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Cantilever transducers, which are recognized as a promising platform for the next generation of chemical and biological sensors, are currently under extensive research. Here we report composite porous silicon-crystalline silicon microcantilevers made of SOI wafers, where the porous silicon surface provides an excellent interface for immobilization of the biosensing layer. We start with crystalline silicon cantilevers fabricated from SOI wafers and we establish a surface layer of porous silicon on the cantilevers by vapor phase stain etching. The processed porous silicon does not introduce significant static bending of the cantilevers indicating that it does not introduce significant residual stress. It does provide an excellent biocompatible material for immobilization of a wide variety of chemical and biological materials, resulting in enhanced sensitivity as demonstrated on the covalently immobilized antibody binding its complementary antigen. 相似文献
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Bangtao Chen Jiashen Wei Francis E. H. Tay Yee Ting Wong Ciprian Iliescu 《Microsystem Technologies》2008,14(7):1015-1019
This paper presents the fabrication process, characterization results and basic functionality of silicon microneedle array
with biodegradable tips for transdermal drug delivery. In order to avoid the main problems related to silicon microneedles;
the breaking of the top part of the needles inside the skin, a simple solution can be the fabrication of microneedle array
with biodegradable tips. A silicon microneedle array was fabricated by deep reactive ion etching (RIE), using the photoresist
reflow effect and RIE notching effect. The biodegradable tips were successfully realized using the electrochemical anodization
process that selectively generated porous silicon only on the top part of the skin. The porous tips can be degraded within
a few weeks if some of them are broken inside the skin during the insertion and release process. The paper presents also the
results of in vitro release of calcein with animal skins using a microneedle array with biodegradable tips. Compared to the
transdermal drug delivery without microneedle enhancer, the microneedle array had presented significant enhancement of drug
release. 相似文献
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研究了《100》单晶硅在EPW腐蚀液中制作近似圆形硅膜,在EPW腐蚀液中因《100》单晶硅腐蚀速率各向异性,在圆形掩膜下很难实现圆形单晶硅膜.基于EPW腐蚀液中《100》单晶硅存在严重凸角削角,采用带锯齿(9个、20个、36个)结构的齿轮掩膜图形腐蚀制作近似圆形硅膜,通过采用SEM观察,随腐蚀时间增加,圆形掩膜EPW腐蚀后硅膜为近似方形,而带有36个锯齿结构的齿轮掩膜腐蚀后硅膜近似圆形.结果表明,利用掩膜锯齿结构在EPW腐蚀液中存在凸角削角现象,能够实现近似圆形硅膜的制作. 相似文献
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In this study, a simple method for the fabrication of high aspect ratio silicon nanoporous arrays is developed. A N-type silicon wafer is used as the substrate material. A micro-scale pattern of the desired porous array is transferred to the front surface of the silicon wafer by photolithography after which the wafer is placed in a home-made fixture to efficiently expel the etching generated air and promptly hold the back-side illumination light. A halogen lamp is used as the light source for backside illumination to enhance the electron–hole pair generation. An anodization process is then carried out using a new etchant consisting of hydrofluoric acid and mixed EtOH and EMSO surfactant to effectively polish the pore surfaces and sharpen the tips of the etched pores. A nanochannel array with a nano-tip of 61.4?nm is obtained. 相似文献
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Porous silicon (PS) was fabricated by laser-induced etching (LIE) process. The objective of this study is to investigate the selected LIE parameters to control size and shape of nanostructures,which are considered important factors in semiconductor device applications. Photoluminescence output intensity becomes stronger due to the increase in the number of emitted photons on the porous surface. There is a dramatic increase in photoluminescence intensity due to the increase of porosity as a function of laser... 相似文献