Si/InP材料的应力转化特性分析

InP材料被广泛的应用于光电子领域,但其材料脆、工艺不成熟、成本高,而Si基外延InP材料能良好的改善该技术瓶颈。论文中对不同介质、不同厚度的介质键合制备Si/InP材料进行了分析。其中以SiO2键合制备的Si/InP材料应力转化率最高,且SiO2制备工艺简单、亲水,材料键合强度大,机械特性好,是键合制备Si/InP材料的首选。而且,SiO2键合介质越薄,其应力转化率越高,材料对力学信号就越敏感,制备的Si/InP材料的机械性能越好。     

InP/Si键合技术研究进展

InP材料及其器件的研制是近年来研究热点之一,而键合技术又是光电子集成研究领域内一项新的制作工艺。利用键合技术结合离子注入技术可以InP薄膜及器件集成到Si衬底上,改善机械强度,降低成本,具有非常诱人的应用前景。概括地介绍了近年来InP在Si上的键合工艺及层转移技术研究进展,并对InP和Si的几种键合工艺进行了分析。降低InP和Si键合温度,进行低温键合是其发展趋势。比较几种键合技术,利用等离子活化辅助键合是降低键合温度的有效途径。     

Si-玻璃阳极键合失效机理研究

在采用Si-玻璃阳极键合技术制备微惯性传感器的过程中,实验发现键合圆片中心区域键合失效。通过对键合机理和工艺过程进行分析,认为湿法腐蚀工艺引入钾离子(K+)污染是造成键合失效的主要原因,也可以对键合失效现象给出合理的解释。改变工艺参数进行了键合对比实验,结果表明,未受K+污染的键合圆片没有发生键合失效现象。提出了解决键合失效问题的两种方案,并首次提出在Si片表面生长氧化层提高失效区键合强度的方法;从理论上分析了增加SiO2介质层的可行性。强度测试结果表明,在SiO2厚度为150nm时,键合剪切强度达到14MPa,验证了方案的可靠性。利用上述方法制备出微加速度传感器敏感结构。     

InP/Si键合界面热应力分析

从理论上分析了键合热应力产生的原因,在此基础上,采用双层条状金属热应力模型讨论InP/Si键合过程中应力的大小及分布情况.结果表明, 由剪切应力和晶片弯矩决定的界面正应力是晶片中心区域大面积键合失败的主要原因,同时InP/Si键合合适的退火温度应该在250～300 ℃.最后在300 ℃退火条件下很好地实现了InP/Si键合,界面几乎没有气泡,有效键合面积超过90%.     

界面热应力对InP/Si键合质量的影响

通过实验和理论计算,分析了InP/Si键合过程中,界面热应力的分布情况、影响键合结果的关键应力因素及退火温度的允许范围。分析结果表明,由剪切应力和晶片弯矩决定的界面正应力是晶片中心区域大面积键合失败的主要原因,为保证良好的键合质量,InP/Si键合退火温度应该在300～350℃范围内选取。具体实验验证表明,该理论计算值与实验结果相一致。最后,在300℃退火条件下,很好地实现了2inInP/Si晶片键合,红外图像显示,界面几乎没有空洞和裂隙存在,有效键合面积超过90%。     

硅应力缓冲衬底上GaAs薄层转移探索

本文研究晶格矢配较大的Ⅲ－Ⅴ族化合物向Si基底转移薄层的技术,为此制备了Si/SiO2/Si结构的应力缓冲衬底。利用智能切割（smart-cut）技术制备薄层GaAs并以低温SiO2层过渡与应力缓冲衬底相键合,达到GaAs向Si基底的转移目的。并对结果进行了分析和讨论,认为该技术是可行的。同时特别强调了低温淀积SiO2层的完美性对最终转移的GaAs薄层的完整性是重要的。     

多晶硅后热退火引起SiO2栅介质可靠性下降的原因分析及其抑制方法

实验研究表明,多晶硅后的高温退火明显引起热SiO2栅介质击穿电荷降低和FN应力下电子陷阱产生速率增加．采用N2O氮化则可完全消除这些退化效应,而且氮化栅介质性能随着退火时间增加反而提高．分析认为,高温退火促使多晶硅内H扩散到SiO2内同Si—O应力键反应形成Si—H是多晶硅后SiO2栅介质可靠性退化的主要原因;氮化抑制退化效应是由于N“缝合”了SiO2体内的Si—O应力键缺陷．     

Si/InP键合界面的研究

应用疏水处理方法成功实现了Si/InP的键合,然后通过对InP和Si的表面XPS能谱分析得到界面信息,从而了解键合机理.I-V曲线也反应了键合界面的性质,通过450、550℃退火样品的伏安特性可知道,对于InP/Si键合结构而言,退火温度与界面特性应该存在最佳值.     

GaAs/Si晶圆片键合偏差及影响因素研究

针对化合物半导体与Si基晶圆异质集成中的热失配问题,利用有限元分析方法开展GaAs半导体与Si晶片键合匹配偏差及影响因素研究,建立了101.6 mm(4英寸)GaAs/Si晶圆片键合匹配偏差评估的三维仿真模型,研究了不同键合结构和工艺对GaAs/Si晶圆级键合匹配的影响,系统分析了键合温度、键合压力、键合介质厚度及摩擦特性等因素对键合偏差影响的规律。结果表明,键合压力和键合层摩擦系数对键合偏差的影响极大,并通过对上述因素的优化,其匹配偏差可控制到3μm以内。     

平面型InGaAs红外探测器I-V特性研究

采用闭管扩散方式,利用SiO2及Si3N4扩散掩膜在NIN型InP/In0.53Ga0.47As/InP外延材料上制备了两种不同的平面型InGaAs红外探测器,研究了室温下不同扩散区面积的两种器件的正向I-V特性及反向暗电流密度与器件周长面积比的关系,结果表明,扩散区边缘的钝化是平面型InGaAs探测器的制备过程中非常重要的一环,而且Si3N4薄膜的钝化效果优于SiO2薄膜。室温下和-0.1V偏压下,采用Si3N4扩散掩膜的器件的暗电流密度约为20nA/cm2。     

Silicon raised strip waveguides based on silicon and silicon dioxide thermal bonding

Si raised strip waveguides on SiO/sub 2/ have been proposed and fabricated, which are based on silicon-on-insulator (SOI) material. In the waveguides, the SOI technique utilizes silicon and silicon dioxide thermal bonding and back-polishing. An anisotropic etchant is used to produce the trapezoidal Si raised strip waveguides by etching the Si film down to the SiO/sub 2/ etch-stop buried layer. The transmission losses of the Si waveguides are measured to be less than 0.2 dB/cm at the 1.3 /spl mu/m wavelength for the lowest mode TE-like mode.     

InP/InGaAs PIN红外探测器增透膜的研究

简单介绍了单层增透膜的基本工作原理,并理论计算了增透膜为SiO2和Si3N4时InP/InGaAs PIN探测器的透射率.计算结果表明Si3N4的增透效果要优于SiO2,通过测试淀积有Si3N4增透膜的探测器的响应度,并和理论计算的透射率进行比较,研究了不同的淀积工艺对响应度的影响和探测器在不同应用时膜厚的设计方法.     

直接键合四结GaAs太阳电池研究

晶圆直接键合技术由于能将表面洁净的两个晶圆集成到一起,从而可以用来制备晶格失配 III-V族多结太阳电池。为了制备GaInP/GaAs/InGaAsP/InGaAs四结太阳电池,需采用具有低电阻率的GaAs/InP键合界面,从而实现GaInP/GaAs和InGaAsP/InGaA上下两个子电池的电学导通。我们设计并研究了具有不同掺杂元素和掺杂浓度的三种键合界面,并采用IV曲线对其电学性质进行表征。此外,对影响键合界面质量的关键工艺过程进行了研究,主要包括表面清洗技术和键合参数优化,例如键合温度、键合压力和键合时间等。最终制备出的键合四结GaInP/GaAs/InGaAsP/InGaAs太阳电池在AM0条件下效率最高达33.2%。     

Layer Combination Effect on Band Gap Shift of InGaAsP／InP MQWs by Impurity-free Vacancy Disordering

InGaAsP/InP multiple quantum wells with quantum well intermixing have been prepared by impurity-free vacancy disordering. The luminescent characteristics were investigated using photoluminescence and photoreflectance, from which the band gap blue shift was observed, Si3N4, SiO2 and SOG were used for the dielectric layer to enhance intermixing from the outdiffusion of group Ⅲ atoms. All samples were annealed by rapid thermal annealing. The results indicate that the band gap blue shift varies with the dielectric layers and the annealing temperature, The SiO2 capping with an InGaAs cladding layer was successfully used to induce larger band tuning effect in the InGaAsP/InP MQWs than the Si3N4 capping with an InGaAs cladding layer, On the other hand, samples with the Si3 N4- InP cap layer combination also show larger energy shifts than that with SiO2-InP cap layer combination.     

Fabrication of 1.55 μm VCSELs on Si using metallic bonding

Using AuGeNiCr multilayered metals as the wafer bonding medium, long-wavelength GaInAsP/InP vertical cavity surface emitting lasers employing Al-oxide/Si as the upper and lower distributed Bragg reflectors were fabricated on Si substrate with the bonding interface formed outside the vertical cavity surface emitting laser cavity. Laser emission at 1.545 μm was measured under pulsed operations near room temperature. The low-temperature metallic bonding process demonstrates a great potential in device fabrication     

Surface and optical properties of silicon nitride deposited by inductively coupled plasma-chemical vapor deposition

The surface and optical properties of silicon nitride samples with different compositions were investigated.The samples were deposited on InP by inductively coupled plasma chemical vapor deposition using different NH3 flow rates.Atomic force microscopy measurements show that the surface roughness is increased for the samples with both low and high NH3 flow rates.By optimization,when the NH3 flow rate is 6 sccm,a smooth surface with RMS roughness of 0.74 nm over a 5 × 5μm2 area has been achieved.X-ray photoelectron spectroscopy measurements reveal the Si/N ratio of the samples as a function ofNH3 flow rate.It is found that amorphous silicon is dominant in the samples with low NH3 flow rates,which is also proved in Raman measurements.The bonding energies of the Si and N atoms have been extracted and analyzed.Results show that the bonding states of Si atoms transfer from Si0 to Si+4 as the NH3 flow rate increases.     

Atomic scale effects of zirconium and hafnium incorporation at amodel silicon/silicate interface by first principles calculations

First principles calculations aimed at quantifying the effects of zirconium and hafnium incorporation at a model silicon/silicate interface have been performed. The tetrahedral bonding character of silicates allows useful comparisons as well as important new distinctions to be drawn with the familiar Si/SiO₂ system. The calculated energy cost of forming (Zr,Hf)-Si bonds suggests that SiO ₂-like bonding is energetically favored over silicide-like bonding at the Si interface. The calculations also suggest that the volume strain associated with Zr or Hf incorporation may lead to increased stress, both in the bulk oxide and in the interfacial transition region     

硅基1.55μm共振腔增强型探测器

报道了一种利用硅乳胶作为键合介质的新型键合技术.高反射率的SiO2/Si反射镜预先用PECVD系统生长在硅片上,然后键合到InGaAs有源区上,键合温度为350℃,无需特殊表面处理,反射镜的反射率可以高达99.9%以上,制作工艺简单,价格便宜.并获得硅基峰值响应波长为1.54μm,量子效率达22.6%的窄带响应,峰值半高宽为27nm.本方法有望用于工业生产.