Resonant Cavity-enhanced Si Photodetectors with Distributed Bragg Reflector

采用电子束蒸发和键合技术,制作了具有高反射率的、表面为薄层单晶Si的分布Bragg反射器。用标准光刻工艺在单晶Si薄层上制作出窄带谐振腔增强型(RCE)金属-半导体-金属(MSM)光电探测器,响应峰值波长分别在836、900、965和1 030 nm处,其中在900 nm处峰值半高宽为18 nm。该器件具有波长选择特性,可有效抑制相邻频道间的串扰,而且容易制成集成面阵。Si distributed Bragg reflector with crystal Si thin film on the reflector was fabricated by electron beam evaporation and bonding techniques.Narrow band Si resonant-cavity-enhanced(RCE) metal-semiconductor-metal(MSM) photodetectors were fabricated by standard photolithography with responsivity peaks at 836 nm,900 nm,965 nm and 1 030 nm respectively.The full-width-at-half-maximum was about 18 nm at 900 nm.The wavelength selectivity of the device could eliminate crosstalk between channels,and the integrated array could be easily realized.福建省青年科技人才创新资助项目(2004J021

XPS Dissection of the Optical Transition Additive in Farm Film

报道了无保护气氛条件下,采用高温固相还原法合成适用于农用塑料地膜的光转换添加剂,共掺铜、铕激活剂的硫化钙(CaS)无机荧光材料,用X射线光电子能谱(XPS)方法对光转换添加剂中不同工艺下激活剂元素进行表征,再通过光致发光谱、透射光谱测量,探索材料中激活剂的能量传输特性,为高新农业的发展提供清洁能源。An optical transition additive used in farmfilmwas synthesized by doping the Cu and Eu activators into an inorganic fluorescent material,CaS with the high-temperature solid phase reduction method under unˉprotected atmosphere.The characteristics of the activators in the films prepared under different conditions were measured by X-ray photo-electron spectroscopy.The energy-transfer properties of the activators in the films were investigated by the photo-induced luminescence spectra and transmission spectra.It is useful for developing a clean energy source in agriculture.福建省自然科学基金资助项目(A0110006);; 厦门大学自选课题基金资助项目(Y07007

Schottky Barrier S /D Metal Oxide Semiconductor Field Effect Transistors with Ge /SiGe Heterostructure

制备了氧化铪(HfO2)高k介质栅SI基gE/SIgE异质结构肖特基源漏场效应晶体管(Sb-MOSfET)器件,研究了n型掺杂SI0.16gE0.84层对器件特性的影响,分析了n型掺杂SIgE层降低器件关态电流的机理。使用uHV CVd沉积系统,采用低温gE缓冲层技术进行了材料生长,首先在SI衬底上外延gE缓冲层,随后生长32 nM SI0.16gE0.84和12 nM gE,并生长1 nM SI作为钝化层。使用原子力显微镜和X射线衍射对材料形貌和晶体质量进行表征,在源漏区沉积nI薄膜并退火形成nIgE/gE肖特基结,制备的P型沟道肖特基源漏MOSfET,其未掺杂gE/SIgE异质结构MOSfET器件的空穴有效迁移率比相同工艺条件制备的硅器件的高1.5倍,比传统硅器件空穴有效迁移率提高了80%,掺杂器件的空穴有效迁移率与传统硅器件的相当。Si-based Ge /SiGe heterostructure Schottky barrier source and drain metal oxide semiconductor field effect transistors( SB-MOSFETs) with hafnium dioxide high-k gate were fabricated.The effect of the n-type doped Si 0.16 Ge 0.84 layer on the device performance was investigated,and the mechanism of the device off-state current reduction caused by the n type doping SiGe layer was analyzed.Firstly,Ge buffer was fabricated with low-temperature Ge buffer technique.Then a 32 nm Si 0.16 Ge 0.84 layer and a 12 nm Ge layer were grown on the Ge buffer in the same UHVCVD system.For comparative study, the 32 nm Si 0.16 Ge 0.84 layer was controlled undoped or n-type doped by P.For all samples,1 nm Si layer was grown to passivate the Ge surface.Atomic force microscopy and X-ray diffraction were used to characterize the surface morphology and crystal quality of the materials.NiGe / Ge Schottky junctions in source and drain were formed by nickel layer deposition and anneal.The fabricated Ge / SiGe heterosturctual MOSFET device without n-type doping shows 150% enhancement of the hole effective mobility over that of the control Si device and about 80% enhancement over the universal Si device.And the device with n-type doping shows a comparable hole effective mobility with the universal Si MOSFET device.国家自然科学基金资助项目(61036003;61176092); 国家重点基础研究发展计划(973计划)资助项目(2012CB933503;2013CB632103); 中央高校基本科研业务费资助项目(2010121056

Luminescence of Strain Compensated Si/Si_(0.62)Ge_(0.38) Quantum Well Grown on Si_(0.75)Ge_(0.25) Virtual Substrate

由于SI/SIgE异质结构的带阶差主要发生在价带,为实现高效率的发光,本文从理论上设计了在硅基SI1-XgEX虚衬底上外延应变补偿的SI/S1-ygEy(y>X)量子阱的能带结构,将量子阱对电子的限制势垒提高到100MEV以上。在实验上,采用300℃生长的gE量子点插入层,制备出薄的SIgE驰豫缓冲层(虚衬底),表面gE组份达到0.25,表面粗糙度小于2nM,驰豫度接近100%。在我们制备的SIgE缓冲层上外延了应变补偿SIgE/SI多量子阱结构,并初步研究了其发光特性。In this paper,band structures of strain compensated Si/S_(1-y)Ge_y(y>x) quantum well grown on Si_(1-x)Ge_x virtual substrate was design to enlarge the conduction band offset up to 100meV for improving luminescence.The fully strain-relaxed Si_(0.75)Ge_(0.25) virtual substrate was prepared by inserting a low-temperature Ge islands layer in ultra-high vacuum chemical deposition.The root-mean-square surface roughness of the virtual substrate is less than 2nm.The luminescence of the strain compensated Si/SiGe quantum well on the virtual substrate was investigated.国家重点基础研究发展计划资助项目2007CB613400;国家自然科学基金资助项目(60676027;50672079

Selective area growth of Ge film on Si

利用超高真空化学气相沉积系统,基于低温gE缓冲层和选区外延技术,在SI/SI O2图形衬底上选择性外延生长gE薄膜.采用X射线衍射、扫描电镜、原子力显微镜、拉曼散射光谱等表征了其晶体质量和应变等参数随图形尺寸的变化规律.测试结果显示,位错密度随着图形衬底外延窗口的尺寸减小而减少,gE层中的张应变随窗口尺寸的增大先增大而后趋于稳定.其原因是选区外延gE在图形边界形成了(113)面,减小了材料系统的应变能,而单位体积应变能随窗口尺寸的增加而减少;选区外延厚度为380 nM的gE薄膜X射线衍射曲线半高宽为678′′,表面粗糙度为0.2 nM,表明选区生长的gE材料具有良好的晶体质量,有望应用于SI基光电集成.According to low temperature Ge buffer layer and selective area epitaxy technology, we selectively grow Ge film on patterned Si/Si O2 substrate using ultra-high vacuum chemical vapor deposition.By using X-ray diffraction(XRD),scanning electron microscope, atomic force microscopy and Raman scattering spectrum, we obtain its crystal quality and the laws of stress and other parameters varying with shape size.The results show that threading dislocation density decreases with shape size decreasing.Moreover, the tensile strain of Ge layer first increases and then turns stable with the increase of shape size, which can be attributed to the formation of(113) facet during Ge selective area growth.The formation of(113) facet reduces the strain energy of epitaxial material system, and the reduction of strain energy per unit volume decreases with increasing the shape size.The root-mean-square surface roughness of the Ge epilayer with a thickness of 380 nm is about 0.2 nm, the full-width-at-half maximum of the Ge peak of the XRD profile is about 678′′.It is indicated that the selective area epitaxial Ge layer is of good quality and will be a promising material for Si-based optoelectronic integration.国家自然科学基金(批准号:61474094); 国家重点基础研究发展计划(批准号:2012CB933503)资助的课题~

带有Bragg反射镜的谐振腔增强型Si光电探测器

采用电子束蒸发和键合技术，制作了具有高反射率的、表面为薄层单晶Si的分布Bragg反射器。用标准光刻工艺在单晶Si薄层上制作出窄带谐振腔增强型（RCE）金属一半导体一金属（MSM）光电探测器，响应峰值波长分别在836、900、965和1030nm处，其中在900nm处峰值半高宽为18nm。该器件具有波长选择特性，可有效抑制相邻频道间的串扰，而且容易制成集成面阵

Ag纳米结构局域表面等离激元共振模拟与分析

金属纳米材料因其特有的局域表面等离激元共振(LSPR)特性而广泛应用于半导体材料发光、太阳能电池、表面增强拉曼散射探测、光电化学等领域。Ag由于其在特定波段极低的吸收损耗而被视为优秀的LSPR候选材料。以Ag纳米结构作为研究对象,利用时域有限差分法(FDTD)对圆柱形Ag纳米结构的近场局域增强和远场散射特性进行了系统的模拟与分析。结果表明Ag纳米结构的尺寸、间距及衬底折射率均会对LSPR效果产生显著影响,可以通过改变结构参数来调控Ag纳米结构的LSPR特性。闽南理工学院校级科研项目(16KJX02);;国家自然科学基金(61534005,61474081);;工业机器人测控与模具快速制造福建省高校重点实验室项目(闽教科[2017]8号

Study of Stratified Crystallization of Amorphous Silicon Induced by Aluminum

铝诱导晶化(AIC)法是一种低成本、低温制备高质量多晶硅薄膜的方法.采用磁控溅射和自然氧化法在石英衬底上生长铝/三氧化二铝/非晶硅结构的材料,然后进行低温(低于硅铝共熔温度577℃)退火处理.通过共焦显微镜、扫描电子显微镜(SEM)、拉曼光谱(rAMAn)和X射线衍射(Xrd)手段进行表征.结果表明,退火后薄膜分为两层,上层是铝、非晶硅和多晶硅的连续混合膜,随退火时间增加,上层晶化率快速增加;下层形成了完全晶化的大尺寸多晶硅晶粒,晶粒结晶质量接近单晶硅;增加退火时间,下层晶粒增长很缓慢;降低退火温度,下层晶粒尺寸明显增大;形成的多晶硅薄膜均具有高度(111)择优取向.并且,进一步地对上述退火过程中样品的变化行为作出分析.Aluminum induced crystallization(AIC)can be used to prepared polysilicon thin film at low temperature and low cost.The properties of polysilicon thin film induced by Al film were investigated in this paper.The stack of Al/Al2O3/a-Si was deposited by radio frequency magnetron sputtering on quartz(after deposition of Al film,the sample was exposed to air for 24 hto form a thin Al2O3film),and then annealed at temperature below 577℃.The morphology,crystal quality,and crystal orientation were characterized by confocal scanning laser microscopy,scanning electron microscope(SEM),raman scattering spectroscopy,and X-ray diffraction(XRD)analysis.It turned out that highly(111)oriented polysilicon thin film with bilayer structure was formed by annealing of the stack of quartz/Al/Al2O3/a-Si.The upper layer was continuous and crystallized partly after removing Al content.However,the lower layer was composed of large grains which were crystallized completely with high quality similar to silicon.Annealing time and temperature were important factors of AIC process.The crystallization rate of the upper layer increased rapidly with increasing annealing time,while the lower layer grain size is almost constant.The lower annealing temperature was,the larger grain size of the lower layer was.Then the upper layer and the lower layer behaviors on annealing were explained.国家自然科学基金(61176050;61036003;61176092); 福建省自然科学基金(2012H0038