富硅氧化硅微盘的制备研究

采用等离子体增强化学气相沉积(PECVD)及高温退火工艺制备了富硅氧化硅(SRSO)薄膜材料.喇曼光谱仪探测表明,该材料具有较高的光致发光(PL)效率,并在750 nm波长处达到发光峰值.采用电子束光刻(EBL)及电感耦合反应离子刻蚀(ICP)技术在Si衬底上制备了基于富硅氧化硅材料的光学微盘结构.为防止Si衬底的光吸收,在反应离子刻蚀(RIE)系统中研究出一种各向同性的刻蚀工艺,有效使微盘与Si衬底分离.扫描电镜(SEM)探测表明,该工艺具有良好的尺寸控制及高稳定性.利用该工艺,成功制备了直径为4μm的富硅氧化硅微盘器件.     

多晶硅微型电极阵列的研制

讨论了pn结对制作硅微电极阵列的局限性,提出了一种在沟道侧壁制作多晶硅电极阵列的设计和制作方法.实验结果表明,利用该方法研制的微电极阵列不仅克服了pn结的影响,能够为MEMS芯片器件提供所需的工作电压,而且也为一些小型化电极的设计及研制提供了新的思路和方法.     

Silicon Microrefrigerator

We fabricated a silicon microrefrigerator on a 500-$mu$m-thick substrate with the standard integrated circuit (IC) fabrication process. The cooler achieves a maximum cooling of 1$^circ$C below ambient at room temperature. Simulations show that the cooling power density for a$hbox40times hbox40 muhboxm^2$device exceeds 500$hboxW/cm^2$. The unique three-dimensional (3-D) geometry, current and heat spreading, different from conventional one-dimensional (1-D) thermoelectric device, contribute to this large cooling power density. A 3-D finite element electrothermal model is used to analyze non-ideal factors inside the device and predict its limits. The simulation results show that in the ideal situation, with low contact resistance, bulk silicon with 3-D geometry could cool$sim hbox20 , ^circhboxC$with a cooling power density of 1000$hboxW/cm^2$despite the low thermoelectric figure-of-merit (ZT) of the material. The large cooling power density is due to the geometry dependent heat and current spreading in the device. The non-uniformity of current and Joule heating inside the substrate also contributes to the maximum cooling of silicon microrefrigerator, exceeding 30% limit given in one–dimensional thermoelectric theory$DeltaT_max=hbox0.5hboxZT_c^2$, where$T_c$is the cold side temperature. These devices can be used to remove hot spots on a chip.     

Silicon optics

Arroyo Optics, a flexible wavelength management solution manufacturer, and Lightcross Inc, a manufacturer of integrated, silicon-based optical products for telecoms equipment have agreed to merge. Arroyo Optics, the resulting company, will comprise technologies and products developed with over $50m of combined R&D capital provided by private equity investors. Both companies focus on products targeting fibre optics infrastructure applications.Visit www.three-fives.com for the latest advanced semiconductor industry news     

单多晶太阳能硅片切割线痕问题研究

线痕是多线切割领域比较常见的问题之一,分类总结了各种线痕产生的原因,并提出了相应的解决方法。     

Integration of Germanium-on-Insulator and Silicon MOSFETs on a Silicon Substrate

The monolithic integration of germanium-on-insulator (GeOI) p-MOSFETs with silicon n-MOSFETs on a silicon substrate is demonstrated. The GeOI p-MOSFETs are fabricated on the oxide for silicon device isolation based on the newly developed rapid-melt-growth method. CMOS inverters consisting of the silicon n-MOSFET and GeOI p-MOSFET were obtained, and the measured results show that the processing of high-performance GeOI devices is compatible with bulk-silicon technology     

硅光敏管内量子效率与硅的能带结构

讨论了硅光管敏管内量子效率与硅的能带结构、硅的光吸收系数的关系，认为在硅光敏管PN结实现100％收集载流子的情况下，内量子效率曲线在一定程度上反映了硅的能带结构、能态密度。     

Self-aligned half-micrometer Silicon MASFET's with metallic amorphous Silicon gate

Ternary metallic amorphous silicon (a-Si-Ge-B), having a high barrier height feature with crystalline semiconductors is applied to the gate metal of Si MESFET's. A submicrometer gate length is successfully fabricated using a self-aligned technology and a conventional photolithography. A large transconductance above 130 mS/mm under the normally-OFF state and a small standard deviation of threshold voltage less than 11 mV are realized for a 0.5-µm gate-length device across a 4-in-diameter wafer. A minimum delay time of 114 ps/gate with an associated switching energy of 1.6 pJ and a minimum switching energy of 3.3 fJ with a delay time of 26 ns/gate are attained by a 21-stage ring oscillator with E/R direct-coupled FET logic circuits.     

Silicon Photonics

After dominating the electronics industry for decades, silicon is on the verge of becoming the material of choice for the photonics industry: the traditional stronghold of III-V semiconductors. Stimulated by a series of recent breakthroughs and propelled by increasing investments by governments and the private sector, silicon photonics is now the most active discipline within the field of integrated optics. This paper provides an overview of the state of the art in silicon photonics and outlines challenges that must be overcome before large-scale commercialization can occur. In particular, for realization of integration with CMOS very large scale integration (VLSI), silicon photonics must be compatible with the economics of silicon manufacturing and must operate within thermal constraints of VLSI chips. The impact of silicon photonics will reach beyond optical communication-its traditionally anticipated application. Silicon has excellent linear and nonlinear optical properties in the midwave infrared (IR) spectrum. These properties, along with silicon's excellent thermal conductivity and optical damage threshold, open up the possibility for a new class of mid-IR photonic devices     

Formation of Silicon Nanoclusters in Disproportionation of Silicon Monoxide

Semiconductors - The processes of the disproportionation of solid-phase silicon monoxide, accompanied by the formation of nanocrystalline silicon precipitates in the medium of amorphous suboxide...     

Low-Temperature Epitaxy of Compressively Strained Silicon Directly on Silicon Substrates

We report epitaxial growth of compressively strained silicon directly on (100) silicon substrates by plasma-enhanced chemical vapor deposition. The silicon epitaxy was performed in a silane and hydrogen gas mixture at temperatures as low as 150°C. We investigate the effect of hydrogen dilution during the silicon epitaxy on the strain level by high-resolution x-ray diffraction. Additionally, triple-axis x-ray reciprocal-space mapping of the samples indicates that (i) the epitaxial layers are fully strained and (ii) the strain is graded. Secondary-ion mass spectrometry depth profiling reveals the correlation between the strain gradient and the hydrogen concentration profile within the epitaxial layers. Furthermore, heavily phosphorus-doped layers with an electrically active doping concentration of ~2 × 10²⁰ cm⁻³ were obtained at such low growth temperatures.     

用微硅层析法制作的微型硅传感器

主要介绍1种用硅的微机械加工技术研制的硅电容式传感器，采用电容层析法(ECT)技术可检测尺寸为50μm左右的微小粒子。其中的主要技术有硅材料的微机械加工技术，特厚光刻胶的匀胶曝光技术，微集成电镀技术。     

Silicon Nanocrystals as an Enabling Material for Silicon Photonics

Silicon nanocrystals (Si-nc) is an enabling material for silicon photonics, which is no longer an emerging field of research but an available technology with the first commercial products available on the market. In this paper, properties and applications of Si-nc in silicon photonics are reviewed. After a brief history of silicon photonics, the limitations of silicon as a light emitter are discussed and the strategies to overcome them are briefly treated, with particular attention to the recent achievements. Emphasis is given to the visible optical gain properties of Si-nc and to its sensitization effect on Er ions to achieve infrared light amplification. The state of the art of Si-nc applied in a few photonic components is reviewed and discussed. The possibility to exploit Si-nc for solar cells is also presented. In addition, nonlinear optical effects, which enable fast all-optical switches, are described.     

非晶硅和非晶硅锗薄膜的金属诱导结晶

分析了金属Ni、Al诱导非晶Si及非晶SiGe薄膜结晶的条件、特点和机理.简要介绍了金属诱导结晶相对于其它一些结晶工艺的优势及其在薄膜晶体管中的应用.概述了影响诱导结晶速率和薄膜微结构的诸多因素,如热处理条件和外加电场等.对电场增强金属诱导横向结晶的相关问题进行了探讨,指出适当强度的电场可显著加快横向诱导结晶的速率,但更强电场则会降低该速率,基于电迁移效应对该现象进行了解释.     

硅芯硅棒自动清洗设备的研制

通过分析硅芯硅棒清洗方式的现状,提出其自动清洗设备研制的必要,介绍了全自动硅芯硅棒清洗机的技术参数和工艺流程,详细分析了设备的结构设计,包括工艺清洗系统、传动系统、电气控制系统、排风系统、管路系统和设备主体等。     

Motility of Metal Nanoparticles in Silicon and Induced Anisotropic Silicon Etching

The autonomous motion behavior of metal particles in Si, and the consequential anisotropic etching of silicon and production of Si nanostructures, in particular, Si nanowire arrays in oxidizing hydrofluoric acid solution, has been systematically investigated. It is found that the autonomous motion of metal particles (Ag and Au) in Si is highly uniform, yet directional and preferential along the [100] crystallographic orientation of Si, rather than always being normal to the silicon surface. An electrokinetic model has been formulated, which, for the first time, satisfactorily explains the microscopic dynamic origin of motility of metal particles in Si. According to this model, the power generated in the bipolar electrochemical reaction at a metal particle's surface can be directly converted into mechanical work to propel the tunneling motion of metal particles in Si. The mechanism of pore and wire formation and their dependence on the crystal orientation are discussed. These models not only provide fundamental interpretation of metal‐induced formation of pits, porous silicon, and silicon nanowires and nanopores, they also reveal that metal particles in the metal/Si system could work as a self‐propelled nanomotor. Significantly, it provides a facile approach to produce various Si nanostructures, especially ordered Si nanowire arrays from Si wafers of desired properties.     

硅纳米颗粒和多孔硅的荧光光谱研究

采用不同氧化电流密度制备多孔硅,利用超声波粉碎多孔硅层得到硅纳米颗粒,研究了多孔硅和硅纳米颗粒的荧光光谱性质。结果表明,随着氧化电流密度的增加．多孔硅的发光峰值波长向短波方向“蓝移”。硅纳米颗粒相对多孔硅发光强度提高,峰值波长也发生“蓝移”,观察到硅纳米颗粒极强的蓝紫光发射(≈400nm)现象。表明量子限制效应和表面态对多孔硅和硅纳米颗粒的PL性质有重要作用,并用量子限制效应发光中心模型对实验现象进行了解释。     

Synthesis of Silicon Nanoneedles

Nanoneedles are novel silicon nanostructures. With the use of silicon monoxide as the starting material, a small quantity of deionized water as the reaction medium, and argon as the protection gas, silicon nanoneedles were successfully synthesized. The growth conditions were controlled at 490°C with a pressure of 3.2–3.5 MPa. High-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED) and electron energy-dispersive spectroscopy (EDS) revealed that the as-grown nanoneedles had pyramidal tips with the diamond structure. The chemical composition at the pyramidal tip was silicon with a small amount of oxygen. Compared with single-crystal silicon, the Raman spectra of silicon nanoneedles were found to be downshifted because of their small size.     

Laser on Silicon

Silicon is not a natural for producing and manipulating light. Nevertheless, Intel and Luxtera each have been able to produce silicon versions of optoelectronic components by binding a light emitter made from indium phosphide to a silicon laser cavity. The key was in making a kind of glass glue, a thin layer of oxidized material, on both the indium-phosphide light emitter and the silicon laser and then bonding them together. Applying a voltage to the indium phosphide device produces light that passes through the glass into the silicon