高基频高机电耦合系数晶体滤波器

采用离子刻蚀工艺对钽酸锂晶体材料进行刻蚀加工,得到了反台面结构晶片,其厚度约为31.3 μm,可用于制作高基频晶体谐振器。应用该晶体谐振器,在电路上采用差接桥型电路,设计了一种高频宽带晶体滤波器,其中心频率为63 MHz,3 dB带宽为780 kHz,阻带衰耗大于75 dB,工作温度为-55～+95 ℃。结果表明,采用离子刻蚀工艺能极大地提高晶体滤波器的工作频率上限。     

均匀周期极化化学计量比钽酸锂晶片的制备

采用添加助熔剂(K2O)的方法,成功制备了近化学计量比钽酸锂晶体,并基于1mol%MgO掺杂的化学计量比钽酸锂晶体周期性畴反转制备光参量振荡器(OPO)。通过在晶片表面形成占空比为60%的聚酰亚胺周期结构并利用液体电极施加极化电压,运用三步电压极化技术,制备出Z向切割1mm厚的均匀周期极化化学计量比钽酸锂晶片,晶片的畴反转占空比接近50%。     

小型化宽带钽酸锂晶体滤波器

介绍比较了钽酸锂(LiTaO3,简称LT)晶体和其他几种常用压电体波材料的物理特性,并从电路结构设计、寄生和谐波抑制及温度性能等方面详细介绍了单片钽酸锂晶体滤波器的设计方法并根据该方案设计了一种11.2 MHz单片式晶体滤波器.结果表明,钽酸锂晶体能方便地实现相对带宽0.8%～4.0%、频率温度稳定性好、体积小的宽带晶体滤波器,具有广泛的应用价值.     

基于超薄钽酸锂晶体材料高响应太赫兹探测器

太赫兹(Thz)探测器工作在室温条件下极大地促进了太赫兹科学与技术的应用。超薄(10μm)钽酸锂(LiTaO3)晶片被用作太赫兹探测器敏感元材料。基于钽酸锂晶片太赫兹探测器在2.52 THz激光辐射源照射下, 20Hz斩波频率时响应率可达到8.38×104V/W, 等效噪声功率NEP)可达到1.26×10-10W。这种加工超薄钽酸锂晶片的方法为制备高响应率太赫兹探测器提供了一个可行的方法。     

基于超薄钽酸锂晶体材料高响应太赫兹探测器（英文）

太赫兹(Thz)探测器工作在室温条件下极大地促进了太赫兹科学与技术的应用。超薄(10μm)钽酸锂(LiTaO_3)晶片被用作太赫兹探测器敏感元材料。基于钽酸锂晶片太赫兹探测器在2.52 THz激光辐射源照射下,20Hz斩波频率时响应率可达到8.38×10~4V/W,等效噪声功率NEP)可达到1.26×10~(-10)W。这种加工超薄钽酸锂晶片的方法为制备高响应率太赫兹探测器提供了一个可行的方法。     

基于周期性极化钽酸锂晶体的连续激光倍频技术研究

针对连续激光倍频的需求,对比分析了周期性极化钽酸锂晶体和铌酸锂晶体的非线性光学特性,从技术研究角度确定了周期性极化钽酸锂晶体更适合用于连续激光倍频。依据非线性转换效率和晶体结构安装尺寸,确定了基频激光压缩及倍频激光准直的参数,从保证工程应用的角度选择了81μm极化周期的钽酸锂晶体,设计并实现了双光路倍频,获得了超过5W的540nm连续倍频激光输出。     

钽酸锂薄膜红外探测器探测性能的模拟研究

建立了热释电钽酸锂薄膜红外探测器理论模型,用五层薄膜系统模拟了探测器结构,用钽酸锂晶体参数,模拟了探测器结构参数与探测率等性能指标之间的关系,研究了硅衬底厚度和钽酸锂薄膜厚度对探测器性能的影响。模拟结果显示,硅衬底彻底腐蚀形成悬空结构是减小探测器热传导损耗的最有效途径;热释电钽酸锂膜层越薄,器件探测率越高。探测器电压响应同时取决于钽酸锂膜层厚度和探测器外接电路参数。使探测器整体性能最佳的钽酸锂膜层厚度为1～2μm。     

钽酸锂晶体及其应用分析

钽酸锂作为一种优良的多功能晶体材料,具有良好的压电、电光和热释电等性能,已被广泛应用于通信、电子等行业。该文介绍了钽酸锂晶体的结构、缺陷及性能调控方式,总结了钽酸锂晶体的制备方法及优缺点,分析了钽酸锂晶体在各应用领域的国内外研究进展,并对钽酸锂晶体的发展进行了展望,以期对钽酸锂晶体的应用及研究提供帮助。     

42°Y钽酸锂晶体生长及性能研究

钽酸锂晶体具有优异的压电性能,是声表面波(SAW)滤波器广泛使用的衬底材料。该文采用自主研制的提拉单晶炉,成功生长出4英寸、42°Y方向、外观完整的钽酸锂晶体。经可见及近红外分光光度计测试,晶体透过率接近80%;经X线摇摆测试,其半高全峰宽(FWHM)为28.4″,单晶性较好;采用差热分析仪对生长的晶体头尾进行居里温度测试,居里温度偏差为4.4 ℃。声表面波性能测试结果表明,钽酸锂晶体的声表面波速度、机电耦合系数和频率温度系数等指标均满足SAW滤波器的使用要求。     

基于SOI的光子晶体波导的研究

给出了基于SOI晶片、带隙中心位于1550nm的光子带隙材料及光子晶体波导器件的设计方法。采用基于超原胞的平面波展开法和基于完美匹配层边界条件的三维时域有限差分法,对二维光子晶体平板的带隙结构及光波传输进行仿真。在大量计算和优化的基础上,设计了适于248nm深紫外曝光和0.18μm离子束刻蚀工艺的光子晶体带隙材料及波导器件,得到了初步的工艺实验结果和样品SEM测试结果。     

MEMS THz滤波器的制作工艺

基于MEMS技术制作了太赫兹(THz)滤波器样品,研究了制作滤波器的工艺流程方案,其关键工艺技术包括硅深槽刻蚀技术、深槽结构的表面金属化技术、阳极键合和金-硅共晶键合技术。采用4μm的热氧化硅层作刻蚀掩膜,成功完成了800μm的深槽硅干法刻蚀;采用基片倾斜放置、多次离子束溅射和电镀加厚的方法完成了深槽结构的表面金属化,内部金属层厚度为3~5μm;用硅-玻璃阳极键合技术和金-硅共晶键合技术实现了三层结构、四面封闭的波导滤波器样品加工。测试结果表明,研制的滤波器样品中心频率138GHz,带宽15GHz,插损小于3dB。     

掺镁铌酸锂晶体的ICP刻蚀性能

掺镁铌酸锂晶体(Mg:LiNbO3)是一种相对难刻蚀的晶体,Mg:LiNbO3的干法刻蚀速率和刻蚀形貌控制是铌酸锂光电子器件加工中的关键技术之一。采用牛津仪器公司的Plasmalab System 100以SF6/Ar为刻蚀气体,具体研究Mg:LiNbO3的刻蚀速率随着感应耦合等离子体(ICP)功率、反应离子刻蚀(RIE)功率、气室压强和气体流量配比等刻蚀参数的变化,同时研究发现SF6/(Ar+SF6)气体流量配比还会影响刻蚀表面的粗糙度。实验结果表明:在ICP功率为1000W,RIE功率为150W,标准状态(0℃,1个标准大气压)下气体总流量为52mL/min,压强为0.532Pa,SF6/(Ar+SF6)气体体积分数为0.077的条件下,刻蚀速率可达到152nm/min,刻蚀表面粗糙度为1.37nm,可获得刻蚀深度为2.5μm,侧壁角度为74.8°的表面平整脊形Mg:LiNbO3结构。     

Electron beam testing of VLSI circuits assisted by focused ion beam etching

Electron beam testing assisted by focused ion beam etching was examined. Before electron beam testing (EB testing), a small window was made in the passivation film by focused ion beam etching (FIB etching). EB testing was performed through this window. This method was useful because charge buildup on the passivation film is avoided during EB testing. The threshold voltage shift caused by FIB etching was permitted until the residual film thickness on the gate electrode became 0.5μm. This technique was applied to measure the internal voltage waveform of the 256K bit dynamic RAM and confirmed that it was effective for functional testing and failure analysis of VLSI circuits.     

Fabrication of an optical directional coupler of CdTe by electron beam lithography and ion etching

Various kinds of high resolution techniques such as ion etching, chemical etching, ion implantation, and electron beam lithography are studied for fabricating CdTe optical integrated circuits. It is found that the ion-etching rate of CdTe is high and has only a small dependence on crystal orientation. A special chemical etching solution for aluminum on CdTe that does not corrode CdTe and proton implanted CdTe is used for high resolution patterning of CdTe. The smooth patterns in PMMA resist produced by an electron beam exposure is replicated deep into 2.5 μm of CdTe face through the aluminum layer. Rib guides and a rib-type optical directional coupler are fabricated from planar guides by using proton implantation which makes refractive index change on CdTe face. The two-dimensional optical confinement is observed. A coupling coefficient ofk simeq 0.39mm^-1is observed in the rib-type optical directional coupler.     

Optical mode conversion using chirped gratings

A design is presented for a 3 dB TE0-TE1 optical waveguide mode convertor using a chirped grating. Devices were fabricated in Ti in-diffused lithium niobate by ion beam etching the grating pattern into the waveguide surface. TE0-TE1 mode coupling was observed experimentally with an insertion loss of 1.5 dB.     

离子束刻蚀双频光栅的实验研究

本文利用离子束在玻璃上刻蚀出双频光栅,研究了光栅掩模制作中曝光量和显影条件,离子束刻蚀工艺等因素对光栅衍射效率的影响,并给出一些实验结果。     

Fabrication and characteristics of ion beam etched cavity InP/InGaAsP BH lasers

A low temperature ion beam etching (IBE) process is successfully applied to facet mirror fabrication of 1.3 μm InGaAsP/InP buried heterostructure (BH) lasers. Ar ion beam etching characteristics of InP are studied and masking conditions are optimized for obtaining low-damage, vertical, and smooth etched facets. Lasers fabricated by this technique have threshold currents and quantum efficiencies comparable to those of lasers with conventionally cleaved mirrors. CW operation at room temperature has been achieved. Initial experimental results of preliminary aging tests are also presented.     

High-power 0.98-μm strained quantum-well lasers fabricated usingin situ monitored reactive ion beam etching

0.98-μm wavelength InGaAs-AlGaAs strained quantum-well buried ridge lasers were fabricated using in situ monitored reactive ion beam etching (RIBE). This technique allowed a very accurate ridge geometry, resulting in high single transverse-mode power more than 250 mW and high-fiber coupled power more than 150 mW     

2.1305GHz高频反台温补晶体振荡器的研制

介绍了一种应用离子束刻蚀技术制作的三次泛音355MHz高频反台晶体谐振器,制作2．1305GHz温补晶体振荡器（TCXO）的方法。经测试,该温补晶体振荡器性能优良,且体积和功耗都较小,适用于导弹、无人机、卫星等飞行器。     

Cross-Section Preparation for Solder Joints and MEMS Device Using Argon Ion Beam Milling

Mechanical cross-section polishing has traditionally been the method of choice for preparing samples to be examined by scanning electron microscopy (SEM). Although mechanical polishing, allied to selective chemical etching can reveal the most important characteristics of solder joint microstructure, subtle details may be lost. A relatively new cross section polishing method has been developed using an argon ion beam to prepare a flat surface with potentially less sample damage. In this study we compare these two methods of cross section polishing for solder-substrate couples, and for delicate MEMS type structures. Four solder samples were prepared, consisting of SAC (Sn-Ag-Cu) solder, SAC solder on copper substrate, SAC solder on nickel substrate and In-Sn solder on niobium substrate. SEM was used to examine the polished samples and it was found that features such as the internal structure of intermetallic compounds (IMCs) was more readily identified using the new technique. The ion beam milling technique was also found to be more suitable for simultaneous observation of multiple aspects of microstructure (e.g., identification of IMCs in relation to grain boundaries, substrate crystal structure or the eutectic solder structure). The MEMS device cross-sections could only be prepared by the ion beam method as mechanical polishing caused too much damage.