【作者】 陈亮；

【导师】 梁军生；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2018， 硕士

【摘要】 超高温薄膜应变计是应用于超高温环境,对试件进行应变测量的微型传感器,这种传感器在试件质量评估及改进方面起到至关重要的作用。NASA早在上世纪90年代就开始了超高温薄膜应变计方面的研究,而国内对这方面的研究仍然比较滞后。在超高温薄膜应变计的结构中,绝缘层和敏感层是最重要的两个功能层。本文采用微纳米制造技术,对超高温薄膜应变计的绝缘层和敏感层进行了相关的研究。（1）配制了稳定的氧化铝溶胶,并测试了溶胶的各项物理性质。为了避免溶胶制备的薄膜在热处理过程中开裂,向氧化铝溶胶中加入氧化铝纳米悬浮液,有效消除了裂纹。（2）探究了沉积高度和液体流速等电射流工艺参数对薄膜均匀性的影响,确定了最佳的电射流逐层沉积参数。以100硅片为基底,制备了均匀致密无裂纹的氧化铝绝缘薄膜。为了降低薄膜表面粗糙度,对薄膜表面进行了抛光处理,有效改善了薄膜表面质量。将制备的氧化铝薄膜在1000℃进行高温烧结,获得了高温稳定的α相氧化铝薄膜。在25-1200℃范围内测试了氧化铝薄膜的绝缘电阻。结果表明,在1000℃时氧化铝薄膜的绝缘电阻值在100KΩ左右,满足超高温薄膜应变传感器的测试要求。设计了氧化铝溶胶薄膜/氧化铝混合液薄膜和氮化硅薄膜/氧化铝混合液薄膜两种不同的复合绝缘结构。高温测试表明,在1200℃,两种复合结构的绝缘电阻值分别提高了34%和41%,证明了复合结构的有效性。（3）利用磁控反应溅射在硅基底上制备了氮化钽薄膜。在保持其他磁控溅射参数不变的情况下,通过调节氮分压,获得了不同成分的氮化钽薄膜。探究了氮分压对磁控溅射速率、薄膜表面粗糙度、物相结构及电阻率的影响。使用X射线衍射仪测试了氮化钽薄膜的物相结构,利用场发射扫描电子显微镜观测了薄膜的表面和断面形貌。结果表明:在2%氮分压下,薄膜的物相结构为TaN_0.1,在3%氮分压下,薄膜的物相结构为Ta₂N,而当氮分压在4-6%的情况下,薄膜的物相结构为TaN。对氮化钽薄膜进行高温热处理。结果表明,薄膜电阻率的范围从80-433μΩ.cm提升到了120-647μΩ.cm。在25-600℃范围内测试了3%氮分压下制备的氮化钽薄膜的电阻温度系数。结果表明,其电阻温度系数为-59ppm/℃。更多还原

【Abstract】 The ultrahigh temperature film strain gauge is a micro sensor used for strainmeasurement in ultrahigh temperature.This kind of sensor plays an important role in the quality evaluation and improvement of the specimen.NASA has been studying high-temperature thin-film strain gauges since the 1990 s,and domestic research is still lagging behind.In the structure of high temperature film sensor,insulation layer and sensitive layer are the two most important functional layers.In this paper,micro-nano fabrication technology is used to study the insulation layer and sensitive layer of high temperature thin film sensor.First,a stable alumina sol was prepared and physical properties of the sol were tested.In order to avoid the film cracking during heat treatment,alumina nano-particle suspension was added to alumina sol,which were effectively eliminated the cracks.Then,the influence of the deposition height and liquid velocity on the uniformity of the film was investigated,and the optimal deposition parameters of the film were determined.Uniform density crack-free alumina insulation film was prepared on the basis of 100 silicon wafers.In order to reduce the film surface roughness,the film surface was polished and the film surface quality was improved effectively.The high-temperature stable α alumina thin film was obtained by 1000 ℃ high temperature sintering.The insulation resistance was tested in the range of 25-1200℃.The results showed that the insulation resistance is 100KΩat 1000℃,which can meet the test requirements of ultrahigh temperature thin film strain sensor.Two different kinds of composite insulation structures were designed,such as alumina film/alumina mixture and silicon nitride/alumina mixture.High temperature tests show that compared with the insulation resistance of alumina mixture film at 1200℃,two the insulation resistance value of two kinds of composite structure increased by 34% and41%,respectively,which proved the effectiveness of the composite structure.Finally,tantalum nitride films were prepared by magnetron sputtering on silicon substrate.Under the condition that other magnetron sputtering parameters are invariable,differentcomponents of tantalum nitride film are obtained by adjusting the nitrogen partial pressure.The effects of nitrogen partial pressure on magnetron sputtering rate,film surface roughness,structure and resistivity were investigated.The phase structure of tantalum nitride film was tested by X-ray diffractometer,and the surface morphology and cross section of the film were observed by field emission scanning electron microscope(SEM).The results showed that: under the pressure of 2% nitrogen,the phase structure of the film was Ta N0.1,and the structure of the membrane was Ta2 N under the pressure of 3% nitrogen,while the structure of the film was Ta N when the nitrogen pressure was 4-6%.High temperature heat treatment of tantalum nitride was carried out by High temperature oven.The resistivity of the tantalum nitride film was measured using a semiconductor parameter test system and a 3d manual probe.The results show that the range of film resistivity is from 80 to 433μΩ.cm is increased to 120-647μΩ.cm.The resistance temperature coefficient of the nitride film prepared under 3% nitrogen pressure was tested within 25-600℃ range.The results showed that the resistance temperature coefficient was 59ppm/ ℃.更多还原