重掺杂硅物理参数的低温特性分析

本文考虑了杂质重掺杂引起的禁带变窄效应，提出了新的电离率和有效多数载流子浓度的数学模型，并应用于由发射效率决定的硅双极晶体管电流增益的计算，所获得的计算结果与实验相符合，这为硅低温半导体器件的设计提出了理论基础。     

重掺杂N型硅中低温本征载流子浓度(英文)

<正> The intrinsic carrier concentration ni0 in the undoped and the lightly doped silicon has been studied from 77 to 300K[1]. Considering that there exists the bandgap narrowing △Eg in the heavily doping silicon, the effective intrinsic carrier concentration niE of the heavily doped silicon can be Written as:     

Temperature Coefficient of Electrical Resistivity in Individual Single-Crystal Bismuth Nanowires

The temperature dependence of electrical resistivity and the crystal orientation of single-crystal bismuth nanowires each encapsulated in a quartz template were studied. The electrical resistivities of four bismuth nanowires with diameter of 356 nm, 376 nm, 622 nm, and 633 nm were measured in the temperature range from 4.2 K to 300 K. The temperature coefficient of resistivity of 376-nm- and 633-nm-diameter nanowires was negative in the low-temperature region. On the other hand, a positive temperature coefficient appeared in 356-nm- and 622-nm-diameter nanowires. The positive temperature coefficient was not explained by carrier mean free path limitation. Thus, the crystal orientation of the bismuth nanowires was observed by x-ray diffraction measurements to study the relationship between electrical resistivity and crystal orientation. It was confirmed that the temperature dependence of electrical resistivity strongly depended on the crystal orientation of the bismuth nanowire.     

重掺杂P型Si1-xGex层中少数载流子浓度的低温特性

考虑了重掺杂引起的禁带变窄效应,建立起少数载流子室温和低温模型,并进行了定量的计算。研究发现,p-Si1-xGex中的少子浓度(电子)随x的增加而增加。在重掺杂条件下,常温时,少子浓度随杂质浓度的上升而下降;而低温时,少子浓度却随杂质浓度的上升而上升。     

正温度系数热敏电阻烧结气氛的研究

研究了不同烧结气氛对正温度系数热敏电阻（ＰＴＣＲ）性能的影响，在ＣＯ２气氛下烧结的ＰＴＣＲ室温电阻率（ρ０）比在空气中烧结的低将近５０％，而其他各种电性能几乎没有明显的变化，因而在ＣＯ２气氛下的烧结是获得低电阻率ＰＴＣＲ的一种有效的工艺途径。     

低温重掺杂硅爱因斯坦关系的修正

量化分析了低温杂质重掺杂条件下，采用非简并、简并近似和非抛物线能带结构对硅半导体中爱因斯坦关系的影响。主要分析结果表明：对于低温重掺杂硅中的爱因斯坦关系，有必要进行简并近似的修正，在甚高掺杂时，还有必要进行更为精确的非抛物线能带结构的修正；修正因子随温度的上升而下降，随掺杂浓度的上升而上升。具有很强的物理指导意义。     

重掺硅中氧的测定

研究了重掺硅中氧的测定,实验首先选用轻掺(ρ＞10Ω@cm)样品分别用气体熔化分析法(GFA法)和傅里叶变换红外法(FTIR法)测氧,而后用GFA法测定了重掺锑、砷、硼单晶的氧浓度.实验发现用GFA法和FTIR法测氧,二者的结果成很好的线性关系,为便于比较可将重掺硅在GFA法下的测定结果转换为FTIR法下的测定结果,还对影响GFA法测定结果的样品制取、样品处理、测试参数选择等方面进行了探讨.     

多品硅压力传感器灵敏温度系数自补偿技术研究

介绍了硅压力传感器的灵敏温度系数补偿原理 ,给出了一种在宽温度范围内采用二次补偿灵敏度温度系数的方法 ,实现了宽范围较高的补偿精度。具体方案是把压阻式惠斯登电桥与温度传感器、可微调多晶硅电阻集成在一个芯片上 ,通过优化多晶硅电阻的掺杂浓度和改变激励源的温度特性 ,从而实现对多晶硅压力传感器灵敏温度系数的二次补偿作用。经补偿 ,传感器的灵敏温度系数小于 - 1.5× 10 - 4/℃ ,该方法的补偿温度范围为 2 0℃～ +15 0℃ ,通用性强。     

重掺硅中氧的测定

研究了重掺硅中氧的测定 ,实验首先选用轻掺 (ρ>10Ω· cm)样品分别用气体熔化分析法 (GFA法 )和傅里叶变换红外法 (FTIR法 )测氧 ,而后用 GFA法测定了重掺锑、砷、硼单晶的氧浓度 .实验发现用 GFA法和 FTIR法测氧 ,二者的结果成很好的线性关系 ,为便于比较可将重掺硅在 GFA法下的测定结果转换为 FTIR法下的测定结果 ,还对影响 GFA法测定结果的样品制取、样品处理、测试参数选择等方面进行了探讨     

多晶硅压力传感器灵敏温度系数自补偿技术研究

介绍了硅压力传感器的灵敏温度系数补偿原理,给出了一种在宽温度范围内采用二次补偿灵敏度温度系数的方法,实现了宽范围较高的补偿精度.具体方案是把压阻式惠斯登电桥与温度传感器、可微调多晶硅电阻集成在一个芯片上,通过优化多晶硅电阻的掺杂浓度和改变激励源的温度特性,从而实现对多晶硅压力传感器灵敏温度系数的二次补偿作用.经补偿,传感器的灵敏温度系数小于-1.5×10-4/℃,该方法的补偿温度范围为20℃～ 150℃,通用性强.     

掺氧多晶硅(SIPOS)薄膜结晶学性质研究

本文用XRD,RHEED和SEM对LPCVD掺氧多晶硅的结晶学性质进行了研究.结果表明,对于含氧量为8～37at%预淀积SIPOS薄膜其结构呈无定形.当进行高温热退火(T_a≥900℃)时,薄膜经历了一个再结晶过程.晶粒度的大小与退火条件有关;而修氧多晶硅中的含氧量对再结晶过程具有抑制作用.     

Quasi-Classical Model of the Static Electrical Conductivity of Heavily Doped Degenerate Semiconductors at Low Temperatures

Germanium, silicon, gallium arsenide, and indium antimonide n-type crystals on the metal side of the insulator–metal transition (Mott transition) are considered. In the quasi-classical approximation, the static (direct current) electrical conductivity and the drift mobility of electrons of the c band, and electrostatic fluctuations of their potential energy and the mobility edge are calculated. It is considered that a single event of the elastic Coulomb scattering of a mobile electron occurs only in a spherical region of the crystal matrix with an impurity ion at the center. The results of calculations using the proposed formulas without using fitting parameters are numerically consistent with experimental data in a wide range of concentrations of hydrogenlike donors at their weak and moderate compensation by acceptors.     

用于激光热疗的激光抽运高掺杂光纤光热头研究

利用晶体光纤中高掺杂离子的非辐射跃迁机制,研制成功一种可用于激光热疗的高掺杂光纤光热转换头。在一个809nm半导体激光器抽运下,光热头在空气和蛋清样品中分别产生最高达465℃(抽运功率为1124mW)和98℃(抽运功率为933mW)的温度,已足够用于激光热疗。同时,光热头在温度稳定性、热响应时间、生物相容性、抗热冲击强度和化学稳定性等方面均能满足要求。     

X-Ray Study of the Superstructure in Heavily Doped Porous Indium Phosphide

An indium-phosphide InP sample subjected to the pore-generation procedure and then doped with S atoms is studied by the methods of X-ray diffraction analysis (XRD) and small-angle X-ray scattering (SAXS) (with CuK_α1-radiation). The XRD data demonstrate that the sample consists of (coherent) aligned homogeneous components. A point detector is used to obtain, in the anomalous transmission mode by Borrmann, a set of SAXS curves at sample positions varied by azimuthal rotations. The SAXS data are used to simulate a 2D SAXS pattern for the sample under study, which makes it possible to determine the long-distance translation symmetry and, consequently, the presence of a superstructure. The interplanar distances in the superstructure in the directions (110) and (1 0) of the InP lattice are found to be ~260 and 450 nm, respectively. The symmetry group of the superstructure is determined as C_2v in the (001) plane of the sample lattice.     

重掺杂直拉硅单晶氧沉淀及其诱生二次缺陷

研究了重掺杂直拉硅单晶中掺杂元素硼、磷、砷、锑对氧沉淀及其诱生二次缺陷行为的影响.实验结果表明:重掺p型(硼)硅片氧沉淀被促进,氧沉淀密度高但无诱生二次缺陷;重掺n型(磷、砷、锑)硅片氧沉淀受抑制,氧沉淀密度低却诱生出层错;不同掺杂元素及浓度对重掺n型硅片氧沉淀抑制程度不同,并对氧沉淀诱生层错的形态产生影响.讨论了重掺硅单晶中掺杂元素影响氧沉淀及其诱生二次缺陷的机理,并利用掺杂元素-本征点缺陷作用模型和原子半径效应模型对实验结果进行了解释.     

Emission Properties of Heavily Doped Epitaxial Indium-Nitride Layers

Semiconductors - The results of studies of the spontaneous photoluminescence and stimulated emission spectra of epitaxial n-InN layers with a concentration of free electrons of ~1019 cm–3 are...     

重掺杂直拉硅单晶氧沉淀及其诱生二次缺陷

研究了重掺杂直拉硅单晶中掺杂元素硼、磷、砷、锑对氧沉淀及其诱生二次缺陷行为的影响 .实验结果表明 :重掺p型 (硼 )硅片氧沉淀被促进 ,氧沉淀密度高但无诱生二次缺陷 ;重掺n型 (磷、砷、锑 )硅片氧沉淀受抑制 ,氧沉淀密度低却诱生出层错 ;不同掺杂元素及浓度对重掺n型硅片氧沉淀抑制程度不同 ,并对氧沉淀诱生层错的形态产生影响 .讨论了重掺硅单晶中掺杂元素影响氧沉淀及其诱生二次缺陷的机理 ,并利用掺杂元素 本征点缺陷作用模型和原子半径效应模型对实验结果进行了解释 .     

A Simple Model of DIGBL Effect for Polysilicon Films and Polysilicon Thin-Film Transistors

Based on charge conservation assumption, analytical models of the drain-induced grain barrier lowering effect are developed for polysilicon films by 1-D Poisson's equation and for polysilicon thin-film transistors (poly-Si TFTs) by quasi-2-D Poisson's equation. It is shown that the voltage drop at the lower barrier side is less than that at the higher barrier side for both poly-Si films and poly-Si TFTs when applying a lateral bias across the grain-boundary barrier.     

Physical Modeling of Temperature Coefficient of Resistance for Single- and Multi-Wall Carbon Nanotube Interconnects

Equivalent circuit models are presented for the resistance of single- and multi-wall carbon nanotubes (MWCNs) that capture various electron-phonon scattering mechanisms as well as changes in the number of conduction channels as a function of temperature. For single- and few-wall nanotubes, the temperature coefficient of resistance (TCR) is always positive and increases with length. It reaches 1/(T-200 K) for lengths much larger than the electron mean free path, where T is the temperature in kelvin. For MWCNs with large diameters (>20 nm), TCR varies from -1/T to +0.66/(T-200 K) as the length varies from zero to very large values     

多晶硅薄膜热膨胀系数的电测试结构

提出了一种新型多晶硅薄膜热膨胀系数的电测试结构,给出了热机电耦合模型和测试方法,并利用Coventor软件和ANSYS软件进行模拟和验证.分析表明模拟结果和理论结果基本一致,从而验证了该模型.该方法能够实现多晶硅薄膜热膨胀系数的在线提取,测量方便,独立性较高,以电学量形式输出,对于薄膜热膨胀系数的在线检测有一定参考价值.