硅薄膜的短波红外光学特性和1.30μm带通滤光片

在短波红外区域(1～3μm),硅薄膜材料因其具有折射率高、透明性好、膜层应力易匹配等诸多优点而得到广泛应用。基于改进后的Sellmeier模型拟合出了制备的硅薄膜的短波红外光学特性,以此为基础,选用硅和二氧化硅两种材料,设计并制备出中心波长在1.30μm,相对带宽2.46%的带通滤光片。利用了硅薄膜在波长小于1.0μm波段的吸收特性较好地扩展了带外截止范围。测量结果表明,具有2个谐振腔的带通滤光片峰值透射率达到85.8%,半功率带宽控制在约32nm,带外截止范围覆盖了波长小于1.75μm的光谱区域。     

用于中红外甲烷检测的压强测量与补偿（英文）

利用一个波长为3.291μm的室温连续、带间级联激光器和一个有效光程长为54.6 m的多通池,研究了用于中红外甲烷检测的压强测量及补偿技术。通过对测得的甲烷直接吸收光谱信号进行洛伦兹吸收线型拟合,测量了吸收池内气体压强并补偿了压强变化对甲烷浓度的影响。利用浓度为2.1×10~(-6)的甲烷气体样品,在1.33×10~4~10.64×10~4 Pa的范围内进行了压强标定;对压强为9.31×10~4 Pa、浓度为2.1×10~(-6)甲烷气体样品的压强测量结果进行阿仑方差分析,结果表明,当积分时间为2.2s时,压强的测量精度约为219.5Pa。在1.33×104、3.99×10~4和6.65×10~4 Pa三种不同压强条件下,对浓度分别为1.0×10~(-6)、1.2×10~(-6)、1.4×10~(-6)、1.6×10~(-6)、2.1×10~(-6)甲烷气体样品的浓度和压强做了15组测量,验证了所给出的压强测量和补偿技术的可行性。     

α-SiN:H薄膜的光学声子与VO2基Mott相变场效应晶体管的红外吸收特性

从器件构成材料中α-SiN:H，VO₂，Al薄膜介电常数弥散特性的Lorentz多谐振模型出发，研究了器件在金属表面等离子体与VO₂，特别是α-SiN:H薄膜光学声子共同作用下的红外吸收特性；得到了在不同的光谱范围器件的红外吸收特性随着α-SiN: H钝化层几何厚度的变化关系，与中心工作波长10μm对应的且经过位相修正以后钝化层的几何厚度为λ/4n时的红外吸收光谱、以及VO₂的相变对吸收光谱的影响. 关键词： 红外吸收特性 Mott相变 场效应晶体管 二氧化钒     

吸收对垂直腔面发射激光器光学特性的影响

采用光学传输矩阵方法，详细分析了反射镜以及键合界面的吸收对垂直腔面发射激光器光学特性的影响. 结果表明，反射镜以及键合界面的吸收对反射镜和垂直腔面发射激光器的反射率和势透射率有较大影响，而对反射镜中心波长处的反射相移以及垂直腔面发射激光器模式的反射相移和模式位置影响很小. 随着反射镜以及键合界面的吸收增大，反射镜中心波长处的反射率逐渐减小，垂直腔面发射激光器的模式反射率变化则是先急剧减小，达到一个极小值，然后再逐渐增大，而反射镜中心波长处以及垂直腔面发射激光器模式处的势透射率则都是迅速降低的. 此外，将有吸收的键合界面离有源区的距离远一些，有利于提高垂直腔面发射激光器模式处的光输出效率.     

掺Yb3+石英玻璃中非桥氧空穴缺陷特性的研究

为了对存在于石英玻璃中的非桥氧空穴缺陷的特性进行研究,采用高频等离子体法对掺Yb³⁺石英玻璃进行了制备。首先介绍了玻璃样品的制备过程,然后对所制备的掺Yb³⁺石英玻璃样品的吸收特性、发射特性以及傅里叶变换红外吸收光谱进行了分析。结果表明,所制备的玻璃样品具有Yb³⁺离子典型的吸收特性。位于260 nm波长的吸收峰以及200 nm激发波长下产生的位于630 nm波长的发射峰都表明所制备的玻璃样品中存在非桥氧空穴缺陷。并且不同激发波长所产生的发射峰以及红外吸收光谱都说明玻璃样品中的非桥氧空穴缺陷是由≡Si－O↑和≡Si－O↑…H－O－Si≡两类空穴中心构成,Yb³⁺离子对合作发光与非桥氧空穴缺陷间存在能量转移过程。     

7×1中红外光纤合束器的设计、制备与性能

中红外光纤合束器可将多个低功率的中红外激光器进行合束，从而实现较高的功率输出。本工作研制了一种7×1硫系玻璃光纤合束器(未熔接输出光纤)，评估了其中红外传输特性。该光纤合束器由As₄₀S₆₀/As₃₈S₆₂光纤组束熔融拉锥而成，初始光纤的纤芯直径和包层直径分别为200μm和250μm，数值孔径为0.38～0.35(@2～6μm)，拉锥比例R为3和4，锥形过渡区长度为2 cm。测试结果表明：当R=3时，制备的光纤合束器在3μm和4.6μm波长的端口传输效率分别为>90%和>87%；当R=4时，制备的光纤合束器在3μm和4.6μm波长的端口传输效率分别为>88%和>85%；光纤合束器输出端的光纤单丝之间未发生明显串扰。     

工作压强对硅掺杂辉光放电聚合物结构和性能的影响

采用辉光放电聚合技术,在不同工作压强条件下制备了掺硅的辉光放电聚合物(Si-GDP)薄膜.并采用傅里叶变换红外吸收光谱和X射线光电子能谱(XPS)对Si-GDP薄膜进行了表征,分析了压强变化对其内部结构及成分的影响.利用紫外—可见光谱对Si-GDP薄膜的光学带隙进行了分析.结果表明:Si-GDP薄膜中Si元素主要以Si—C,Si—H,Si—O,Si—CH₃的键合形式存在;随着工作压强的增大,薄膜中Si—C键相对含量先减小后增加;从Si-GDP薄膜的XPS分析可以发现,C—C与C C含 关键词： 硅掺杂辉光放电聚合物薄膜 工作压强 傅里叶变换红外吸收光谱 X射线光电子能谱     

ZnSe-ZnS超晶格的通光蚀孔及列阵研究

用MOCVD方法在GaAs衬底上生长ZnSe-ZnS超晶格.用化学腐蚀方法在GaAs衬底上开一个通光窗口,使该窗口上仅剩有1～1.8μm厚的生长层.室温下测量了蚀孔后由于化学腐蚀造成生长层表面差异的ZnSe-ZnS超晶格的吸收光谱.研究了带有生长过渡层和无过渡层的超晶格质量对其吸收光谱性能的影响.发现过渡层的存在保护了超晶格激子吸收性能.在此基础上首次采用新工艺在3×3mm2面积上把GaAs衬底金部腐蚀掉,剩下均匀、光滑的ZnSe-ZnS超晶格层,在其上做出了300×300μm2的列阵,为在ZnSe-ZnS超晶格上实现光学双稳的集成化提供了必要条件.     

菱面片层氧化镁的制备及晶格畸变与反常红外特性

以低品位白云石为原料采用二次酸浸、EDTA-氨水沉淀法制备前驱体Mg(OH)2,经煅烧得到菱面片层状多空隙结构的纳米MgO晶体.通过X射线衍射(XRD)、高分辨率扫描电镜(HRSEM) 及傅立叶红外光谱(FT-IR)等测试手段对所得产物的物相和形貌等进行了表征.分析表明:氧化镁为结晶良好、立方晶系,厚度约10～20 nm,最大面积可达1μm2左右的菱形纳米片层结构;XRD数据表明纳米氧化镁的微结构存在晶格畸变并导致XRD相位差发生变化;红外光谱表明,Mg-O键伸缩特征吸收峰向高波数方向移动(蓝移)了约84.82 cm-1,而弯曲特征吸收峰向低波数方向移动(红移)了约31.88 cm-1,并导致红外吸收光谱的宽频化.结合XRD数据分析结果和界面效应等物理现象讨论了反常红外吸收机理.     

钛基纳米金刚石涂层场发射阴极

设计了一种新的金刚石场发射阴极工艺.用旋涂法在金属钛片上涂覆纳米金刚石涂层，经过适当条件的真空热处理，实现钛与金刚石之间的化学键合即欧姆接触，从而形成以金属钛为衬底，碳化钛键合层为过渡层，金刚石纳米颗粒为场发射体的场发射阴极.样品的阈值场强可达6.3V/μm，场发射电流密度在21 V/μm场强下可达到60.7 μA/cm2.提出了样品的结构模型,并分析了其电子输运方式.样品的Fowler-Nordheim曲线基本为一直线，根据经典场发射理论，可以证实其电子发射机制为场发射.观察到在获得稳定的场发射性能之前存在激发过程，并对其作了简单解释.     

Si layer transfer to InP substrate using low-temperature wafer bonding

Using a low-temperature wafer bonding process, InP substrates are bonded to silicon-on-insulator (SOI) substrates at 220 °C. A combination of oxygen plasma and chemical treatment results in a direct contact bonding at room temperature. After the bonding process at 220 °C for 45 min, removal of the Si handle substrate by sacrificial etching of the buried oxide layer in SOI, results in a thin membrane of Si robustly bonded to InP. The thin Si membrane bonded to InP shows uniformly bonded interface under high-resolution electron microscopy. Micro-Raman analysis has also been carried out to study the bonded interface. I-V characteristics of the bonded structures suggest that such bonding and layer transfer processes are suitable for device integration.     

Formation of interface bubbles in bonded silicon wafers: A thermodynamic model

A thermodynamic model of the formation of unbonded areas or bubbles generated at the interface of bonded silicon wafers in the temperature range of 200–800°C is presented. Within this model it is assumed that the desorption of hydrocarbon contamination at the silicon wafer surfaces leads to small hydrocarbon molecules which are mobile at the bonding interface. When the vapor pressure generated by these molecules overcomes the interface bonding strength, interface bubbles are nucleated. These bubbles grow by incorporating further hydrocarbon and also possible hydrogen molecules. The model semiquantitatively explains all the essential features of interface bubble formation observed experimentally.     

Effects of homogenous loading on silicon direct bonding

The effect of a homogenous loaded stress on the bonding quality of silicon wafer pairs was investigated by employing a Nano-Imprint System and a homogenous plane-stress applied over the entire surface area of pre-cleaned wafers. In addition, the effects of variations in the applied homogenous stress (1, 10, 100, 500 psi) on the interface energy of the bonded pairs were examined using a dynamic blade insertion (DBI) method. Infrared imaging was used to evaluate the quality of the bonded interface of each bonded pair immediately after the bonding process and after allowing the bonded pairs to rest at room temperature for 80 h after bonding. The results indicated that the homogenous loading with the Nano-Imprint System further improved the bonding condition of wafer pairs that had been pre-bonded using an anodic bonder. Furthermore, the bonded pairs exhibited almost identical interfacial energies of about 0.2 Jm⁻² when the homogenous stress was varied from 1 psi to 500 psi, which clearly indicates that the interfacial energy of bonded wafers is independent of the amount of stress applied by the homogenous loading process.     

Wafer bonding of gallium arsenide on sapphire

$1\overline{1} 02$ ) sapphire in a micro-cleanroom at room temperature under hydrophilic or hydrophobic surface conditions. Subsequent heating up to 500 °C increased the bond energy of the GaAs-on-sapphire (GOS) wafer pair close to the fracture energy of the bulk material. The bond energy was measured as a function of the temperature. Since the thermal expansion coefficients of GaAs and sapphire are close to each other, the bonded wafer pair is stable against thermal treatment and quenching in liquid nitrogen. During heating in different gas atmospheres, macroscopic interface bubbles and microscopic imperfections were formed within the bonding interface, which were analysed by transmission electron microscopy (TEM). These interface bubbles can be prevented by hydrophobic bonding in a hydrogen atmosphere. Received: 10 February 1997/Accepted: 17 February 1997     

(001) silicon surfacial grain boundaries obtained by direct wafer bonding process: accurate control of the structure before bonding

Ultra-thin (001) silicon films bonded onto (001) silicon wafers, which form ‘surfacial grain boundaries’, are analysed by transmission electron microscopy and X-ray diffraction. The aim of this study is to find a way of controlling precisely, before direct wafer bonding, the structure of the Si/Si (001) interface. Two kinds of dislocation networks are found at the bonded interface. A square array of screw dislocations accommodates the twist between the two crystals, whereas a linear network of mixed dislocations accommodates the tilt resulting from the residual vicinality of the initial surfaces. A theoretical study shows that knowing and choosing before bonding the characteristics of these interfacial dislocations depend on the control of the ‘twist’ angle during the hydrophobic molecular bonding process. Recently, a new bonding method allows us to obtain an accuracy of ±?0.005° for the ‘twist’ angle from patterned grooves without any crystallographic measurement. The precision of this technique is compared with three different measurement of the disorientation between the two grains taken after bonding. The first one is deduced from the periodicity of the dislocation networks located at the interface. The second one is calculated from large angle convergent beam electron diffraction patterns. The last one is obtained by synchrotron X-ray diffraction. The possibility of choosing precisely the characteristics of the Si (001) ‘surfacial grain boundaries’ before direct wafer bonding process is then discussed in light of an experimental study.     

超薄LiTaO3晶片的键合减薄技术

在制造红外热释电探测器阵列过程中，需要利用超薄钽酸锂(LiTaO₃)晶片作为红外热释电探测器件的敏感层。通常LiTaO₃晶片的厚度远厚于红外热释电探测器件要求的厚度，所以需要采用键合减薄技术对LiTaO₃晶片进行加工处理。键合减薄技术主要包括：苯并环丁烯（BCB）键合、铣磨、抛光、加热剥离、刻蚀BCB。加工后得到面积为10mm×10mm、厚度为25μm的超薄单晶LiTaO₃薄膜，晶片厚度、表面粗糙度和面形精度比较理想。测得了LT晶片减薄后的热释电系数为1.6×10^-4Cm^-2K^-1。得到的单晶LiTaO₃薄膜满足红外热释电探测器敏感层的要求。     

Effects of spacer layers on magnetic properties and exchange couplings of Nd-Fe-B/Nd-Ce-Fe-B multilayer films

The influences of the spacer-layer Ta on the structures and magnetic properties of Nd Fe B/Nd Ce Fe B multilayer films are investigated via DC sputtering under an Ar pressure of 1.2 Pa. An obvious(00l) texture of the hard phase is observed in each of the films, which indicates that the main phase of the film does not significantly change with Ta spacer-layer thickness. As a result, both the remanence and the saturation magnetization of the magnet first increase and then decrease,and the maximum values of 4πM_r and H_(cj) are 10.4 k Gs(1 Gs = 10_(-4)T) and 15.0 kOe(1 Oe = 79.5775 A·m_(-1)) for the film with a 2-nm-thick Ta spacer-layer, respectively, where the crystalline structures are columnar shape particles. The measured relationship between irreversible portion D(H) =-?M_(irr)/2 M_r and H indicates that the nucleation field of the film decreases with spacer layer thickness increasing, owing to slightly disordered grains near the interface between different magnetic layers.     

Molecular Dynamics Investigation of Bonded Twist Boundaries

Molecular dynamics simulations using empirical potentials have been performed to describe atomic interactions at interfaces created by macroscopic wafer bonding. Misalignment due to relative twist rotation of the wafers influences the bondability of larger areas. Depending on the twist angle the bond energy varies and different defect and atomic arrangements at the interfaces occur. In addition, if very thin wafers are being bonded the free surfaces are modified by the resulting interface relaxation.     

Low-temperature direct wafer bonding of GaAs/InP

An approach for low-temperature direct wafer bonding of GaAs/InP was presented. The bonding procedure was carried out at temperatures from 350 to 500 ^°C, and the bonded n-GaAs/n-InP specimens were obtained even at a temperature as low as 350 ^°C. The compositional profile on the GaAs/InP heterointerface was studied by X-ray photoelectron spectroscopy. The bonded interfacial properties were also characterized by current–voltage (I–V$I\text{–}V$) and bonding strength measurement. The experimental results revealed an InGaAsP (or/and InGaAs) interlayer formed at the bonded interface, which influences the electrical property as well as the bonding strength. For the specimen bonded at 350 ^°C, the transport of major carriers could be explained by a tunneling effect. But the carrier transport was described by the thermionic emission theory for the specimen bonded at 450 ^°C. Finally, the mechanism of GaAs/InP bonding was discussed.     

SOI大截面单模脊形X型分支波导的研制

报道了硅片直接键合（ＳＤＢ）ＳＯＩ大截面单模脊形互型分支波导的研制．对于波长为１．３μｍ的光，在θ＝２°小分支角时，这种分支波导的通道串音小于－２０ｄＢ，辐射损耗小于０．３ｄＢ．直通传输损耗小于０．８５ｄＢ／ｃｍ．