共查询到20条相似文献,搜索用时 46 毫秒
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硅基微带天线损耗机理分析 总被引:1,自引:1,他引:0
硅基微带天线存在损耗大、效率低、增益不足等问题。其成因在于以下五种损耗:1.金属贴片及匹配微带线的导体损耗。2.介质的介电损耗。3.表面波损耗。4.半导体基底的电阻性损耗。5.由基底与绝缘层交界面上的载流子运动导致的界面损耗。在深入分析各种损耗的形成机理的基础上,研究了相应损耗的计算模型及其在总损耗中所占的地位,并提出了降低损耗的有效途径。实验结果显示,采用微机械(MEMS)工艺,在高阻硅与低介电常数介质的混合衬底上,生长一层多晶硅薄膜的方法,可有效降低损耗,使硅基微带天线单元的效率达到87%,增益达到8dB。 相似文献
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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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设计一种以黑硅这种对几乎所以可见光和部分红外光具有很高吸收率的新型材料作为表面吸收层的热电堆红外探测器,针对这一设计作出了大量关于黑硅对不同波长下的红外吸收率的研究。通过红外基本理论,结合MEMS工艺的兼容性,设计采用两种热电偶材料叠放的方式,并以氧化硅薄膜作为隔离的结构;另外,探测器采用氧化硅上制作的多晶硅作为新型衬底。在器件释放中被XeF2正面腐蚀的部分是多晶硅,这样的设计解决了硅释放的对准问题和SOI衬底陈本高的问题。这种材料可以提高探测器的性能同时减小成本。 相似文献
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介绍一种硅纳米线制作方法.在SOI顶层硅上制作硅纳米梁,通过离子注入形成pnp结构,利用新发现的没有特殊光照时BOE溶液腐蚀pn结n型区域现象,结合BOE溶液氧化硅腐蚀,实现硅纳米线制作.制作完全采用传统MEMS工艺,具有工艺简单,成本低,可控,可靠性好,可批量制作等优点.利用该方法制作出了厚50 nm,宽100 nm的单晶硅纳米线,制作的纳米线可用于一维纳米结构电学性能研究、谐振器研究等. 相似文献
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采用非光敏苯并环丁烯(BCB)进行MEMS压阻式加速度敏感芯片三层结构制作.BCB键合具有工艺温度低、键合表面要求低等特点,适用于芯片的圆片级封装.但是固化过程中BCB粘度随温度升高而下降,流动性变大,在毛细作用的影响下沿着微小间隙流淌,导致可动部件粘连,器件失效.通过控制BCB厚度、增加BCB阻挡槽解决了可动部件粘连问题,制作了三层硅结构的加速度敏感芯片.样品漏率小于1.0×10-10pa.m3/s,键合剪切强度大于20 MPa,能够满足航天、工业、消费电子等各领域的应用需求. 相似文献
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基于SOI的硅微谐振式压力传感器芯片制作 总被引:2,自引:0,他引:2
采用SOI硅片,基于MEMS技术,设计并加工了一种新型三明治结构的硅微谐振式压力传感器,根据传感器敏感单元的结构设计,制定了相应的制备工艺步骤,并且针对湿法深刻蚀过程中谐振子的刻蚀保护等问题,提出了一种基于氮化硅、氧化硅和氮化硅三层薄膜的保护工艺,实验表明,在采用三层薄膜保护工艺下进行湿法刻蚀10 h后,谐振子被完全释放,三层薄膜保护工艺对要求采用湿法刻蚀镂空释放可动结构具有较高的实用价值。最后对加工完成的谐振式压力传感器进行了初步的性能测试,结果表明,在标准大气压力下谐振子的固有频率为9.932 kHz,品质因数为34。 相似文献
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Frontiers of Information Technology & Electronic Engineering - Silicon photonics is a promising technology to address the demand for dense and integrated next-generation optical... 相似文献
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The fabrication process of a silicon condenser microphone and experimental results of the acoustic measurements are described. The microphone consists of two chips. One chip carries the 150 nm thick silicon nitride membrane, which has an area of 0.8 mm × 0.8 mm. The second chip contains the back electrode, the spacer and the contact pads of the microphone. In order to reduce the streaming resistances in the air gap, the back-electrode area is either structured with grooves by a plasma etching technique or with holes by an anisotropic etching technique. A frequency-independent sensitivity of 10 mV/Pa (open circuit, 1.8 mV/Pa measured) up to 30 kHz is obtained as a result of this structuring of the back-electrode area. Since the air-gap height is only 2 μm, the capacitance of the transducers ranges from 1 to 1.3 pF. The total size of the silicon microphone is 1.6 mm × 2 mm × 0.56 mm. 相似文献
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Micro-metalforming with silicon dies 总被引:1,自引:0,他引:1
The introduction of forming technology into MEMS manufacturing demands forming dies being characterized by a high strength
and hardness, a good microstructurability, a low surface roughness, and a high precision of the microgeometry to be molded.
Silicon structured by lithography and etching processes meeting these requirements especially concerning precision and surface
roughness. For micro-metalforming silicon dies with different structural dimensions (>1 μm) have been used. The microstructures
could be molded in different materials using cold and superplastic embossing. The precision and surface quality of the formed
parts correspond to the high quality of the microstructured die. Both the low surface roughness and the accurate edges of
the silicon structures are nearly represented in the molded structures. However, in particular during cold embossing die wear
or even die failure could be observed limiting the implementation of silicon for micro-metalforming. 相似文献
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Copper-encapsulated silicon micromachined structures 总被引:1,自引:0,他引:1
Yeh J.-L.A. Hongrui Jiang Neves H.P. Tien N.C. 《Journal of microelectromechanical systems》2000,9(3):281-287
Selective copper encapsulation on silicon has been used to fabricate micromachined devices such as inductors with quality factors over 30 at frequencies above 5 GHz. The devices are fabricated using either polysilicon surface micromachining, or integrated polysilicon and deep reactive ion etching bulk silicon micromachining. Their exposed silicon surfaces are selectively activated by palladium activation, which allows the subsequent copper deposition on the activated silicon surfaces only. This silicon encapsulated-with-copper technique takes advantage of both the excellent mechanical properties of silicon (to maintain structural integrity), and the high conductivity of copper (for electrical signal transmission). Furthermore, the process not only minimizes interfacial forces typical of physical metal deposition on silicon, but also balances the forces by metal encapsulation on all sides of the silicon structures 相似文献
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High precision vacuum grippers for optical fibre components are fabricated by silicon bulk micromachining. Anisotropic etching
of (100) and (110) silicon wafers offers high precision and lower fabrication costs than deep reactive ion etching (D-RIE)
processes. Two types of grippers are introduced: a vertical, narrow one for chips where space is limited and short fibre elements
have to be assembled. For longer fibres and high angular precision a horizontal gripper with multiple gripper ledges is presented. 相似文献
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In this paper a fully IC-compatible silicon wafer-to-wafer fusion-bonding process is described. Before the bonding, the silicon surfaces are treated by chemicals which do not attack the electronic circuits or aluminium patterns on the silicon. The prebonding of the two silicon wafers is performed at room temperature. after which bonding takes place through annealing at temperatures between 120 and 400°C without affecting the performance of the electronic circuitry. The bonding is sufficiently strong for microsensor applications. 相似文献
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Laser transmission bonding of silicon to silicon with metallic interlayers for wafer-level packaging
Anselm Wissinger Alexander Olowinsky Arnold Gillner Reinhart Poprawe 《Microsystem Technologies》2013,19(5):669-673
For packaging of silicon components with low thermal load and high spatial selectivity laser transmission bonding (LTB) of silicon–silicon compounds with intermediate layers using a cw-thulium fiber laser (wavelength 1,940 nm) is investigated. The intermediate layer combination titanium and gold is examined with respect to the bond characteristics and the achievable mechanical properties of the bonded specimens. The tensile strength is measured by using tensile test. Similar specimens bonded with corresponding standard bond process using the same bond geometry are also analyzed in order to compare the measurements. 相似文献
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Investigation of attractive forces between PECVD silicon nitride microstructures and an oxidized silicon substrate 总被引:4,自引:0,他引:4
P.R. Scheeper J.A. Voorthuyzen W. Olthuis P. Bergveld 《Sensors and actuators. A, Physical》1992,30(3):231-239
A troublesome phenomenon encountered during the realization of free-standing microstructures, for example, beams, diaphragms and micromotors, is that initially released structures afterwards stick to the substrate. This effect may occur during wafer drying after the etching process has been completed, as well as during normal operation as soon as released structures come into contact with the substrate. In this paper the most important types of attractive forces are discussed with respect to their possible influence on the performance of micromachined structures. It is concluded that the main reason for sticking of PECVD silicon nitride micromachined structures is adsorption of water molecules. The water molecules, adsorbed on both surfaces, attract each other as soon as the surfaces come into contact. It is shown that a chemical surface modification, in order to achieve hydrophobic surfaces, is an effective method for avoiding adsorption of water, and therefore reduces sticking. Sticking of micromachined structures during drying is reduced by rinsing with a non-polar liquid before wafer drying. 相似文献
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Three-axes monolithic silicon low-g accelerometer 总被引:3,自引:0,他引:3
In this paper, four different designs for a new three-axes monolithic low-g acceleration sensor are presented. The silicon spring mass system of the sensor is fabricated in a single step by anisotropic wet chemical etching in KOH using (111) planes as physical etch stop. The orientation of the supporting beams of the spring-mass systems allows the seismic mass to move in a direction orthogonal to the (111) planes. Four mass-spring systems, each one rotated by 90°, enables the detection of three components of the acceleration vector using capacitive readout. Two alignment structures are presented meeting the high requirements in terms of mask alignment, which are necessary when using the described etch technique. A new space saving compensation structure protecting the convex edges of the seismic masses during the etch process was realized and compared with standard solutions. The sensors performance was characterized and is demonstrated 相似文献