用于微波/射频集成电路的一种新型低损耗介质——多孔硅及氧化多孔硅厚膜

提出在单片微波集成电路(MMIC)中用多孔硅/氧化多孔硅厚膜作微波无源器件的低损耗介质膜.研究了厚度为70μm的多孔硅/氧化多孔硅厚膜在低阻硅衬底上的形成,这层厚膜增加了衬底的电阻率,减少了微波的有效介质损耗.通过测量在低阻硅衬底上形成的氧化多孔硅厚膜上的共平面波导的微波特性,证明了在低阻硅衬底上用厚膜氧化多孔硅可以提高共平面传输线(CPW)的微波特性.     

用于微波/射频集成电路的一种新型低损耗介质——多孔硅及氧化多孔硅厚膜

提出在单片微波集成电路(MMIC)中用多孔硅/氧化多孔硅厚膜作微波无源器件的低损耗介质膜.研究了厚度为70μm的多孔硅/氧化多孔硅厚膜在低阻硅衬底上的形成,这层厚膜增加了衬底的电阻率,减少了微波的有效介质损耗.通过测量在低阻硅衬底上形成的氧化多孔硅厚膜上的共平面波导的微波特性,证明了在低阻硅衬底上用厚膜氧化多孔硅可以提高共平面传输线(CPW)的微波特性.     

微波固体有源传感器研究

本文讨论微波固体源作为测量电量、非电量有源传感器的工作原理。指出频带反射高Q腔稳耿氏振荡器适于作为有源传感器,用它取样测量电容介质(ε_τ(?)2～3)薄膜的厚度,量程:200μm,分辨率≤±0.1μm,介质微扰稳频腔产生的振荡器频偏⊿f与其厚度d具有很好的线性关系。频偏的实验值与微扰方法计算值吻合良好。     

电介质膜增强的Goos-H(a)nchen位移的微波测量

如果在折射率较高的电介质基底上镀一层折射率较低的电介质薄膜(介质膜的另一侧为折射率更低的介质,如空气),并且恰当选择基底内光束的入射角,使得光束在基底-介质膜界面上折射到薄膜内、在薄膜-空气界面上全反射,那么反射光束的Goos-H(a)nchen(GH)位移在一定条件下会得到共振增强.采用微波技术直接地测量了这种Goos-H(a)nchen位移随电介质膜厚度的变化,测量结果与理论预言吻合得较好.     

电介质膜增强的Goos-Hnchen位移的微波测量

如果在折射率较高的电介质基底上镀一层折射率较低的电介质薄膜(介质膜的另一侧为折射率更低的介质,如空气),并且恰当选择基底内光束的入射角,使得光束在基底-介质膜界面上折射到薄膜内、在薄膜-空气界面上全反射,那么反射光束的Goos-Ha¨nchen(GH)位移在一定条件下会得到共振增强。采用微波技术直接地测量了这种Goos-Ha¨nchen位移随电介质膜厚度的变化,测量结果与理论预言吻合得较好。     

超薄硅基介质膜的制备技术与表征方法研究

在等离子体增强化学气相淀积(PECVD)系统中,采用等离子体氧化和等离子体氮化的方法,在单晶硅表面上成功制备厚度小于10nm的超薄硅基介质膜。通过X射线光电子谱(XPS)分析了超薄介质膜的化学结构,利用椭圆偏振仪测量了厚度以及折射率,同时对超薄介质膜进行了电容电压(C-V)和电流电压(I-V)特性的测量,研究其电学性质,探讨了C-V测量模式对超薄介质膜性质表征的影响,最后对两种介质膜的优缺点进行了比较。     

用SEM直接测定介质薄膜的厚度

本文主要介绍利用SEM对几种介质薄膜厚度的直接测定,并讨论了其应用的范围及测量精度,在集成电路的研制工艺中,需要研制多种同质和异质的介质膜,如氮化硅、二氧化硅,多晶和单晶硅、金属铝等。而通常用光学测量这些膜厚并相应地建立了直接或间接的多种方法,在此基础上我们利用SEM具有测量精度高、图象清晰等特点,建立了同时测量多种膜厚和非破坏的样品倾斜法,能谱特征峰比例法直接测定膜厚度,精度可达10％以内,方法简易、快速、精度高。尤其是可检测厚度的均匀性。实践表明,均能满足与符合工艺要求。     

同轴探头法测量片状介质材料的微波介电常数

提出了一种可用于测量片状介质材料微波复介电常数的同轴探头技术,该技术将同轴探头紧贴有导电衬底的片状介质,通过测量探头终端的矢量反射系数来确定介质的微波复介电常数。详细介绍了所采用的理论模型和测量系统。测量了一些常见介质材料的介电常数,测量值与理论值基本吻合。文章的同轴探头技术不仅可用于测量厚度较小的片状介质,而且可用测量样品量有限的液体。     

测量膜厚的装置

为测量膜厚,包括透明和半透明材料测量而设计的膜厚测量装置(TFTM),比类似的CCD系统更具有优势.由Spectra International公司提供的TFTM能够测量CCD传感器不能测量的更薄的薄膜.以2nm的膜厚分辨率,该系统在可±1%或0.4nm的内提高重复精度,并且可在现场使用(如在真空室内)或作为独立的装置使用.膜厚测量可以用来计算吸收和非吸收材料的折射率,并能同时测量多层膜.也可以用来测量未知厚度或不确定组分的薄膜.该系统能测量介质膜,如氮化物,氧化硅,聚合物涂层和薄膜吸收材料,例如,硅,多晶硅,非晶硅及其它半导体材料.该装置性能先进,在加工方面会有广范的应用,包括半导体芯片,太阳电池,平板显示器和光学镀膜等.(No.45     

PET复合衬底上梯度介质薄膜厚度的椭偏表征

为了监控3维玻璃上聚对苯二甲酸乙二醇酯(PET)复合衬底介质膜膜厚, 采用将PET复合衬底等效为单层基底材料的建模分析方法, 通过椭偏测量技术实现了复杂衬底上TiO₂梯度折射率材料薄膜厚度的检测。结果表明, 采用该方法测量的PET复合衬底上TiO₂梯度折射率薄膜厚度为212.48nm, 扫描电子显微镜的测量结果为211nm, 结果非常准确。以TiO₂为例验证了等效衬底方法, 该方法也同样适用于其它介质膜。等效衬底法可实现PET复合衬底上的TiO₂薄膜厚度的高精度测量表征, 对镀膜工艺过程监控具有重要意义。     

Circulating power, RF magnetic field, and RF current density ofshielded dielectric resonators for power handling analysis ofhigh-temperature superconducting thin films of arbitrary thickness

In the current quest for HTS films with negligible power effects at high RF power levels for wireless communications, accurate calculations of a maximum RF magnetic field H_max and of a maximum RF current density J_max flowing on the surface of superconducting films is necessary to allow for any sensible conclusions and comparisons. As the dielectric resonator method is used most frequently for investigation of HTS losses, the authors discuss in this paper a dependence of the circulating power and of a maximum RF magnetic field H_max on dielectric resonators' geometry as well as of the maximum RF current density J_max flowing on the surface of superconducting films on the films' thickness, for a general case of a resonator shielded in a metallic cavity. The authors' results demonstrate that under the same input power levels the same HTS films may be exposed to differing RF power level conditions, depending on the cavity to dielectric radius ratio and thickness of superconducting films. This means that there may be a significant discrepancy between calculated and real power handling capabilities of HTS films tested in different dielectric resonators unless correct formulas are used     

Quantum Size Effects on Dielectric Constants and Optical Absorption of Ultrathin Silicon Films

The size dependence of the dielectric constants and optical absorption for silicon nanostructured films are investigated using density-functional theory. A critical thickness of 4.3 nm is observed for Si (100)-oriented thin films. Within this critical thickness, the dielectric function and optical absorption show remarkable size dependence, and a large reduction of static dielectric constant (from 10.8 to 4.4) is observed. This is in contrast to the weak dependence of dielectric constant on film thickness in silicon dioxide thin films. The pronounced dependence and large critical thickness demonstrate a quantum-confinement effect on optical properties, which is of great importance to nanophotonics.      

内置介质板开孔腔体电磁屏蔽效能拓扑模型

文中针对现有内置介质板腔体屏蔽效能拓扑模型中介质板等效导纳模型的局限性,考虑介质板高度、厚度与位置对介质板等效导纳模型的影响,建立内置介质板腔体屏蔽效能(BLT)方程拓扑模型。将传输线法、BLT方程拓扑模型与仿真结果进行对比,验证BLT方程拓扑模型的准确性和有效性。以300 mm×300 mm×120 mm开孔腔体为研究对象,分别探究其在3种不同谐振主模式下,介质板高度、厚度和位置对腔体屏蔽效能的影响。结果表明,改变介质板高度,腔体的谐振主模式不变,仅影响腔体屏蔽效能大小;腔体内部安装介质板可增强腔体屏蔽能力,但是介质板厚度过大,在一定范围内会削弱腔体屏蔽能力;距腔体孔阵0 mm～58 mm处安装介质板会削弱腔体屏蔽能力,距腔体孔阵100 mm～150 mm处安装介质板会增强腔体屏蔽能力。该结论可为机箱电磁屏蔽设计提供有效参考。     

半导体激光器输出光功率的最佳值

本文分析了半导体激光器输出光功率与镜面反射率的关系,数值计算结果表明镀制介质腔控制正反镜面反射率可以得到最佳输出光功率.此外,分析表明减少腔内损耗,减薄有源层厚度和缩小条宽对输出功率都有显著的增加.     

Metrological Application of a Stationarity Property in Rectangular Cavities Containing a Dielectric Slab (Short Papers)

A stationarity property for the resonant frequency of a rectangular cavity as a function of the thickness of a low-loss dielectric slab inserted within is used for the accurate determination of the microwave permittivity of the sample. The accuracy estimated to a few promille in X band has been confirmed by experimentation on a standard material.     

高温超导微波电路衬底材料复介电常数的测量

本文讨论了在液氮温度下高温超导微波电路介质衬底材料复介电常数测试技术。利用TMono模高Q圆柱形谐振腔,对高温超导常用的几种单晶介质材料进行了测试。结果表明,该测试技术在不同温度下,可对低耗单晶和各向同性介质材料进行准确的测试,且测试简便、迅速、自动化程度高,具有测试介质材料某一方向复介电常数的优点。     

毫米波椭偏测量法的数值模拟研究

介绍了一种新型的毫米波椭偏法,可以用来测量介质材料的介电常数和厚度.通过分析入射波波长和入射角的不同取值对实验结果的影响,给出了入射波波长和入射角的取值范围,同时对介电常数、厚度与椭偏参数之间的关系进行了数值模拟研究.研究结果表明,由椭偏参数经数值计算反演出的介电常数、厚度通常会出现多值的情况.但对大多数的介质薄膜而言,却可以通过该方法求出唯一确定的介电常数与厚度,表明了毫米波椭偏法在介质参数测量上的可行性.     

Anticipation of nitrided oxides electrical thickness based on XPS measurement

Plasma nitridation of thermally grown oxide films has proven to be an excellent gate dielectric in meeting the electrical requirements of the 65 nm node. As the 65 nm device performance is very sensitive to both physical thickness and nitrogen dose of these dielectric films, it is highly desirable to predict the electrical properties of such films. We present a simple physical model to forecast the capacitance-equivalent thickness (CET) of nMOS devices for 65 nm technology. The model is based on the total nitrogen dose and the dielectric physical thickness, both given by in-line X-ray photoelectron spectroscopy (XPS) measurement of the plasma nitrided gate dielectric. This model uses an estimated gate oxide dielectric constant, the gate depletion capacitance and the inversion layer capacitance. A good correlation is obtained between calculated and measured CET for plasma nitrided oxides from 19 to 30 Å CET and for a large range of incorporated nitrogen doses.     

Epoxy/BaTiO/sub 3/ composite films and pastes for high dielectric constant and low-tolerance embedded capacitors fabrication in organic substrates

Epoxy/BaTiO/sub 3/ composite embedded capacitor films (ECFs) were newly designed for high dielectric constant and low-tolerance (less than /spl plusmn/5%) embedded capacitor fabrication for organic substrates. In terms of material formulation, ECFs are composed of a specially formulated epoxy resin and latent curing agent, and in terms of a coating process, a comma roll coating method is used for uniform film thickness in large area. The dielectric constant of ECF in high frequency range (0.5/spl sim/3 GHz) is measured using the cavity resonance method. In order to estimate dielectric constant, the reflection coefficient is measured with a network analyzer. The dielectric constant is calculated by observing the frequencies of the resonant cavity modes. Calculated dielectric constants in this frequency range are about 3/4 of the dielectric constants at 1 MHz. This difference is due to the decrease of the dielectric constant of the epoxy matrix. The dielectric relaxation of barium titanate (BaTiO/sub 3/: BT) powder is not observed within measured frequency. An alternative material for embedded capacitor fabrication is epoxy/BaTiO/sub 3/ composite embedded capacitor paste (ECP). It uses similar materials formulation like ECF and a screen printing method for film coating. The screen printing method has the advantage of forming a capacitor partially in the desired part. However, the screen printing makes surface irregularities during mask peel-off. Surface flatness is significantly improved by adding some additives and by applying pressure during curing. As a result, a dielectric layer with improved thickness uniformity is successfully demonstrated. Using epoxy/BaTiO/sub 3/ composite ECP, a dielectric constant of 63 and specific capacitance of 5.1 nF/cm/sup 2/ were achieved.     

膜电阻作为微波电路封装谐振模式抑制层

通常将微波电路置于金属封装之内.如果该封装波导谐振模恰好位于电路工作频率范围之内,电路与封装谐振模间的耦合将干扰电路的工作.在腔内放入覆有膜电阻的介质基片,可以有效地削弱封装谐振模,避免了放入吸波材料的传统方法给军用、宇航用毫米波电路带来的可靠性和机械加工难题.膜电阻的吸波性能取决于膜电阻方阻值和介质层厚度,使用数值方法计算得到应用该方法削弱后的最低阶封装谐振模的品质因数.