膜厚对多晶硅纳米薄膜压阻温度特性的影响

重掺杂多晶硅纳米薄膜具有良好的压阻温度特性,用它制作高温压阻式传感器灵敏度高、成本低,具有广阔的应用前景.为优化多晶硅纳米薄膜的压阻温度特性,本文采用低压化学气相淀积(LPCVD)技术制作了不同膜厚(30～250 nm)的多晶硅薄膜,分别测试了应变系数、薄膜电阻率与工作温度的关系.利用扫描电镜(SEM)和X射线衍射实验(XRD)对薄膜进行了表征,在此基础上结合隧道压阻模型分析了膜厚对多晶硅薄膜压阻温度特性的影响,结果表明,对于淀积温度620℃、掺杂浓度2.3×1020 cm-3的多晶硅纳米薄膜,膜厚的最佳值在80 nm厚左右.     

多晶硅纳米薄膜压阻和电学修正特性

本文制备了不同掺杂浓度的多晶硅纳米薄膜,研究了掺杂浓度对多晶硅纳米薄膜压阻和电学修正特性的影响。利用低压化学气相淀积法制备了不同掺杂浓度的多晶硅纳米薄膜,掺杂浓度分别为1.0*10^20cm-3、2.0*10^20cm-3、4.1*10^20cm-3和7.1*10^20cm-3。利用应变系数测量装置对不同掺杂浓度多晶硅纳米薄膜的应变系数进行了测量,利用恒流源和万用表测量 不同掺杂浓度多晶硅纳米薄膜的电学修正特性。实验结果表明:多晶硅纳米薄膜的应变系数与掺杂浓度有关,应变系数范围:33.38~38.41,利用电学方法能够修正多晶硅纳米薄膜的电阻,最大修正范围可达15.4%,多晶硅纳米薄膜具有较高的应变系数,适用于制作压阻式传感器,电学修正可用来调整多晶硅纳米薄膜的电阻,进而降低传感器的失调。     

不同淀积温度多晶硅纳米薄膜的压阻特性

重掺杂多晶硅纳米薄膜具有较大的应变系数和良好的温度特性,是制作力学量传感器的理想压阻材料.为优化多晶硅纳米薄膜的压阻特性,就淀积温度对低压化学气相淀积多晶硅纳米薄膜的压阻特性的影响进行了实验研究.在扫描电镜观测和X射线衍射实验基础上,利用隧道压阻模型分析了薄膜结构和压阻特性的关系.结果表明薄膜结构对应变系数的影响非常显著,但对应变系数的温度特性影响却很小.综合淀积温度对压阻特性和电导特性的影响,多晶硅纳米薄膜的最佳淀积温度在620℃左右.     

多晶硅纳米薄膜电学特性的实验研究

用低压化学气相淀积(LPCVD)法淀积了膜厚为60～250nm的多晶硅纳米薄膜,研究了膜厚和掺杂浓度对多晶硅纳米薄膜电学特性的影响。结合扫描电镜(SEM)图片,在电阻率与电阻率温度系数测试结果的基础上,分析了膜厚和掺杂浓度对薄膜电学特性的影响。结果表明:重掺杂多晶硅纳米薄膜具有良好的温度特性,电阻率温度系数可达到1×10-4～3×10-4/℃的水平。     

高性能多晶硅压力传感器的研制

本文介绍的高性能多晶硅压力传感器,以重掺杂的LPCVD多晶硅薄膜作应变敏感电阻,用二氧化硅层隔离单晶硅衬底,使其工作温度高达200℃以上,若用恒流源供应惠斯登电桥,即使在没有外电路补偿情况下,灵敏度系数(TDS)也仅1.32×10~(-6)FS/℃,可实现近乎理想的灵敏度温度补偿.     

LPCVD制备Si3N4薄膜工艺研究

本文简要介绍了Si3N4薄膜的制备方法,详细介绍了低压化学气相淀积(Low Pressure Chemical Vapor Deposition)LPCVD制备氮化硅的工艺.并对工艺的结果进行了适当的分析,为LPCVD制备高质量的Si3N4薄膜奠定了基础.     

多晶硅高温压力传感器

一、前言 现代航空、汽车发动机以及石油化工领域常常需要对200℃以上高温范围的压力进行检测。200℃以上温度工作的高温压力传感器一般可采用SOS或绝缘衬底上多晶硅结构制作,因为多晶硅薄膜压阻元件可淀积在各种低成本衬底上,而且工艺简     

衬底同步加热溅射BST薄膜的研究

介绍了一种衬底同步加热射频磁控溅射制备BST(BaxSr1-xTiO3)薄膜的新方法,讨论了BST薄膜的晶化效果对介电常数的影响,分析了薄膜的居里温度和εr-V铁电性能.XRD测试结果表明制备的BST薄膜具有完整的钙钛矿晶体结构,相对介电常数超过150,介质击穿强度大于1.3 MV/cm.使用这种方法不需要专门的退火工艺,就可以制备晶体结构完整的高介电常数BST薄膜.     

多晶硅敏感技术(连载四)

<正> 5 多晶硅薄膜的压阻效应 目前,多晶硅薄膜在传感器上的应用主要有压力传感器、加速度传感器、应变计、热电传感器及执行器等。对于前几种可归结为力学量传感器,其理论基础是依据于多晶硅的压阻效应。     

材锗薄膜的制备及特性研究

报导了用蒸发法制备半导体锗薄膜的工艺条件，薄膜的结晶特性，电学性质及其压阻应和热电效应。     

PN结型硅基TiO_2氧传感器的特性分析

采用薄膜技术研制了一种以硅PN结结构为基底材料的TiO2氧传感器,阐述了该传感器的工作原理、结构设计、工艺流程及其特性。给出了磁控溅射工艺制备银电极及TiO2薄膜的方法,利用X射线衍射(XRD)标定了TiO2薄膜的金红石相晶体结构,通过扫描电镜(SEM)分析了薄膜的表面形貌及晶粒结构,讨论了TiO2的氧敏感机理,测试薄膜的敏感特性及响应特性。实验结果表明:硅PN结基底TiO2氧传感器具有工作温度低、低功耗、体积小、线性化好的优点。     

NiCrAlY薄膜应变计的研制

采用射频磁控溅射法在Ni基高温合金拉伸件上制备NiCrAlY薄膜应变计。研究了热稳定处理对NiCrAlY薄膜结构、表面形貌的影响,并且测试了NiCrAlY薄膜应变计的电学与应变性能。结果表明：热稳定处理后 NiCrAlY 薄膜应变计由于在表面形成了一层 Al2 O3膜,具有抗高温氧化的特性,在室温～800℃范围内,应变计电阻同温度呈线性变化,电阻温度系数（ TCR）约为290×10－6/℃,室温下的应变计系数（ GF）为2.1。     

Tensile testing of microfabricated thin films

 Mechanical properties of titanium thin films of 0.5 μm thickness and aluminum thin films of 1.0 μm thickness, microfabricated by magnetron sputtering, were measured by using a novel tensile machine. These thin films are difficult to handle because they are fragile, so the thin film specimens were fabricated by using semiconductor manufacturing technology in a silicon frame to protect them. The test section of these specimens was 300 μm in width and 1400 μm in gauge length. By gripping the thin film specimen with a new device using a micrometer, it could be mounted on the tensile machine easily. The stress-strain diagrams of both thin films were measured continuously in the atmosphere at room temperature. The experimental results indicated that the titanium thin film and the aluminum thin film had a smaller breaking elongation although they had a larger tensile strength than bulk pure titanium and bulk pure aluminum, respectively. Received: 31.10.96/Accepted: 14.11.96     

硅基底和金刚石基底上沉积ZnO薄膜工艺研究

采用射频磁控溅射方法分别在硅基底和金刚石基底上制备ZnO薄膜,研究了硅和金刚石衬底的不同对ZnO薄膜生长机理的影响,同时分析了氩氧比和退火温度这两个工艺参数对薄膜的晶格取向和表面形貌的影响。利用XRD和AFM对ZnO压电薄膜的性能进行了测试。结果显示,金刚石基片上制备的薄膜表面状态远优于硅基片上的薄膜表面状态;在同类型基底上生长的ZnO薄膜,薄膜的晶格取向随着氩氧比的升高而增强;对于硅基底上生长的ZnO薄膜,适当的退火能够成倍地提高薄膜的c轴取向性。     

Smart ultrasonic sensors systems: potential of aluminum nitride thin films for the excitation of the ultrasound at high frequencies

We investigated the potential of the aluminum nitride films to excite ultrasonic waves at frequencies >50?MHz. The deposition process of the aluminum nitride thin film layers on silicon substrates was investigated and optimized regarding their piezoelectric behavior. Large single element transducers were deposited on silicon substrates with aluminum electrodes, under different parameters for the magnetron sputter process, like pressure and bias voltage. Special test setup and a measuring station were created to characterize the sensors. Acoustical measurements were carried out in pulse echo mode up to 500?MHz and the values of piezoelectric charge constant (d₃₃) were determined. As a result, two parameter sets were found for the sputtering process to obtain an excellent piezoelectric charge constant of about 7.2?pC/N maximum. Then the sputtering process with these parameters was used to deposit sensors on various substrate materials and with different electrode sizes.     

Effect of magnesium doping on the structural and piezoelectric properties of sputtered ZnO thin film

Structural and piezoelectric characteristics of magnesium-doped ZnO films were investigated. Magnesium-doped ZnO films with a c-axis preferred orientation were deposited on ST-cut quartz by radio frequency magnetron sputtering. The crystalline structure and surface morphology of films were studied by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The electromechanical coupling coefficient and temperature coefficient of frequency of the filters were then determined using a Love wave filter. A uniform crystalline structure and smooth surface of the ZnO films were obtained when magnesium dopant level was 1.5 mol%. The grain size of the ZnO film increased when magnesium doped. It has been found that the temperature coefficient of frequency declines to +0.44 ppm/°C at 1.5 mol% magnesium-doped ZnO film.     

Novel top‐gate zinc oxide thin‐film transistors (ZnO TFTs) for AMLCDs

Abstract— High‐performance top‐gate thin‐film transistors (TFTs) with a transparent zinc oxide (ZnO) channel have been developed. ZnO thin films used as active channels were deposited by rf magnetron sputtering. The electrical properties and thermal stability of the ZnO films are controlled by the deposition conditions. A gate insulator made of silicon nitride (SiN_x) was deposited on the ZnO films by conventional P‐CVD. A novel ZnO‐TFT process based on photolithography is proposed for AMLCDs. AMLCDs having an aperture ratio and pixel density comparable to those of a‐Si:H TFT‐LCDs are driven by ZnO TFTs using the same driving scheme of conventional AMLCDs.     

对靶磁控溅射制备VO_x薄膜及其退火研究

利用对靶磁控溅射法在玻璃基片上制备VOx薄膜,采用正交实验方法研究了镀膜条件对VOx薄膜电阻温度系数(TCR)的影响,得到优化的镀膜工艺参数,主要包括Ar∶O2为48∶0.4、工作压力恒定为2 Pa、基底的温度为室温27℃、溅射功率保持在180W,在此基础上,进行不同温度条件的真空退火,得到薄膜TCR在-2.5%~-4.5%范围。利用原子力显微镜(AFM)和X射线光电子能谱法(XPS)分析了退火对提高薄膜TCR的作用,并找出VOx薄膜阻值与TCR的优化组合。同时,还观察到薄膜表面形貌的变化以及退火后薄膜中VO2,V2O3,V2O5的比例变化情况,并对其机理进行解释。     

ZnO系薄膜对NOx气体的气敏光透射特性

用射频磁控溅射方法制备了纯氧化锌（ＺｎＯ）薄膜和掺Ａｇ、掺Ｐｔ与掺Ｐｄ的ＺｎＯ三种气敏光学薄膜。测量了这些薄膜在ＮＯｘ气体中的透射光谱,然后由透射光谱获得了灵敏度的变化规律,并用吸附平衡关系式解释了气敏光透射特性,最终优化得到一种对ＮＯｘ气体灵敏度高的掺Ａｇ氧化锌薄膜。     

MEMS结构氧传感器的研究

采用微加工技术研制了一种以硅为基底材料,具有MEMS结构的氧传感器.阐述了该传感器的工作原理、结构设计、工艺流程以及特性分析.给出了溅射制备TiO2薄膜的方法及锐钛矿型晶体结构能谱,讨论了二氧化钛的氧敏机理.研究表明与传统的气体传感器相比,此种传感器具有体积小、低功耗、可集成的特点.