注F短沟MOSFET的沟道热载流子效应

通过对短沟 NMOSFET的沟道热载流子效应研究 ,发现在短沟 NMOSFET栅介质中引入 F离子能明显抑制因沟道热载流子注入引起的阈电压正向漂移和跨导下降以及输出特性曲线的下移 .分析讨论了 F抑制沟道热载流子损伤的机理 . Si— F键释放了 Si/Si O2 界面应力 ,并部分替换了 Si— H弱键是抑制热载流子损伤的主要原因 .     

注F短沟MOSFET的沟道热载流子效应

通过对短沟NMOSFET的沟道热载流子效应研究,发现在短沟NMOSFET栅介质中引入F离子能明显抑制因沟道热载流子注入引起的阈电压正向漂移和跨导下降以及输出特性曲线的下移.分析讨论了F抑制沟道热载流子损伤的机理.Si—F键释放了Si/SiO2界面应力,并部分替换了Si—H弱键是抑制热载流子损伤的主要原因.     

不同沟道长度MOSFET的热载流子效应

对同一工艺制作的几种不同沟道长度的 MOSFET进行了沟道热载流子注入实验。研究了短沟 MOS器件的热载流子效应与沟道长度之间的关系。实验结果表明 ,沟道热载流子注入使 MOSFET的器件特性发生退变 ,退变的程度与器件的沟道长度之间有非常密切的关系。沟道长度越短器件的热载流子效应越明显 ,沟道长度较长的器件的热载流子效应很小。利用热载流子效应产生的机理分析和解释了这一现象     

Halo注入角度对热载流子效应的影响及优化

通过模拟和实验研究了不同的halo注入角度的NMOSFET,研究发现halo的注入角度越大,热载流子效应的退化越严重。考虑到由于热载流子的注入造成栅氧化层损伤,使器件可靠性变差,halo注入时应该采用小的倾角注入。     

动态应力下MOS器件热载流子效应研究

研究了 MOS器件中的热载流子效应 ,在分析了静态应力下 MOSFET寿命模型的基础上 ,提出了动态应力条件下 MOSFET的寿命模型。此外 ,还研究了沟道热载流子的产生和注入与器件偏置条件的关系 ,讨论了热载流子效应对电路性能的影响。通过对这些失效因素的研究和通过一定的再设计手段 ,可以减少热载流子效应导致的器件退化     

N-LDMOS热载流子注入效应的分析和优化

研究了一种N-LDMOS器件的热载流子注入效应,分析了热载流子效应产生的机理、对器件性能以及可靠性的影响,提出了改进方法.为了降低此器件的热载流子注入效应,我们利用华润上华公司提供的ISE软件对N-LDMOS高压工艺进行模拟,根据模拟结果调整了器件结构,通过增大器件的场板长度、漂移区长度以及增加N阱与有源区的交叠长度等措施,使得相同偏置条件下,表征热载流子注入强度的物理量——器件衬底电流降为改进前的1/10,显著改善了该器件的热载流子注入效应.     

MOSFET的热载流子损伤及其退火

对国内常规54HC工艺制作的PMOSFET进行了F-N热载流子注入损伤实验,研究了MOSFET跨导、阈电压等参数随热载流子注入的退化规律,特别是从微观氧化物电荷和界面态变化对阈电压影响角度,对国内外较少见报道的MOSFET热载流子损伤在室温和高温(100°C)下的退火特性进行了研究,并从该角度探讨了MOSFET热载流子注入产生氧化物电荷和界面态的特性。     

采用最佳横向变掺杂技术的LDMOS中热载流子效应的研究

本文提出了一个计算结果,分析了热载流子注入氧化层的机率与表面电场强度的关系,证实了一定条件下传统的采用最佳横向变掺杂技术的LDMOS结构会受热载流子注入氧化层的影响产生热载流子效应。进而提出了一种优化的可以削弱热载流子效应的结构,研究结果表明无需变动任何工艺,该结构就能将器件表面的电场强度从 268kV/cm 降至100kV/cm ,极大地阻抗了热载流子的发射.     

不同应力条件下亚微米MOSFET''s热载流子退变特性实验研究

本文对N沟道亚微米器件在不同应力条件下的热载流子退变特性进行了实验研究。实验结果表明:热空穴注入对器件的热载流子退变特性有重要影响。文章对不同应力条件下器件中的热空穴注入与热电子注入的相互作用进行了分析。     

MOS电容的热载流子损伤及其与电离辐射损伤的关系

通过对国产加固 N型 MOS电容进行衬底热电子高场注入 ( SHE)及 γ总剂量辐照实验 ,特别是进行总剂量辐射损伤后的热载流子损伤叠加实验 ,从微观氧化物电荷、界面态的感生变化及其界面态的能量分布变化等角度研究比较了 MOS结构热载流子损伤特性及与电离辐射损伤的关系。     

集成电路中多晶硅薄膜载流子迁移率的实验研究和理论模型

本文系统地研究了多晶硅薄膜载流子迁移率与掺杂浓度的关系,发现不仅如前人所指出的那样,多晶硅载流子迁移率在中等掺杂区有一极小值,而且同时在高掺杂区存在一个极大值.本文将前人提出的杂质分凝模型、晶粒间界陷阱模型和杂质散射机构结合起来,从理论上计算了极大值及其相应的掺杂浓度与晶粒大小、晶粒间界界面态密度的关系,并与实验结果进行了比较.理论模型较好地说明了实验结果.     

Predicting shapes of hysteresis loops on the output of tunableexternal-cavity semiconductor lasers

Studies have been made of the nonlinear characteristics of grating tuned external-cavity semiconductor lasers with the aid of the analytical expression of the threshold carrier density required for the laser to oscillate at different frequencies. After connecting refractive index with carrier density through the spectral broadening factor and choosing an appropriate reference carrier density, the key points defining hysteresis loops on the N-ν (carrier density-frequency) curves have been determined analytically. Consequently, different shapes of hysteresis loops on P-ν (power-frequency) curves have been predicted. The validity of the theory has been examined using the data provided by different papers     

Carrier Pulses at Microwave and Millimeter-Wave Frequencies

This paper discusses some recent experimental results obtained using special gallium arsenide point-contact diodes for the generation of phase-locked carrier pulses in the microwave and millimeter-wave bands. Several methods of generating such pulses are described. 11.2-Gc microwave phase-locked carrier pulses of about 1.0-nanosecond base duration have been generated at a 160-megabit/second rate. These microwave pulses, which are generated directly from a baseband signal, normally have peak power levels in excess of 0.5 mw. Millimeter-wave phase-locked carrier pulses have also been generated at 56 Gc. These very high frequency pulses have a base duration as short as 0.25 nanosecond and occur at a 160-megabit/second rate. Furthermore, phase-locked carrier pulses have been generated at frequencies as high as 89.6 Gc. A simple method of generating nonphase-locked 0.3-nanosecond millimeter-wave carrier pulses directly from 1.92 gigabit/second rate baseband pulses has also been investigated. The experimental arrangement used to demonstrate the "turn on" and "turn off" principle of transient carrier pulse generation is described.     

紧束缚带半导体中载流子浓度和费米能量解析近似研究

本文给出了紧束缚带半导体中载流子浓度和费米能量之间的解析近似表达式。借助贝塞尔函数我们获得载流子浓度的系列展开公式，该公式具有快速收敛性。采用高斯积分方法获得了简单和高精度的费米能量解析近似表达式。由解析公式计算的结果与精确数值解吻合得很好，精度为10^-5量级。该解析公式可以方便地用于计算微带超晶格的电子输运和超晶格器件模拟。     

Effects of lateral mode and carrier density profile on dynamic behaviors of semiconductor lasers

Dynamic behaviors of the semiconductor lasers have been investigated both theoretically and experimentally. A single-mode rate equation, which takes account of the lateral mode profile and the carrier density profile, has been solved numerically. Effects of the carrier and lateral mode confinement have been clarified. The lateral mode deformation in lasers without a built-in mode confinement structure greatly enhances the relaxation oscillations. In lasers whose stripe width is narrower thansim10 mum, the carrier diffusion is found to play an important role in suppressing the relaxation oscillations, especially for lasers without a lateral carrier confinement structure. On the other hand, the fraction of the spontaneous emission going into the lasing mode is significant for lasers with a lateral carrier confinement structure. The slow increase of the laser output at the transient is confirmed to be due to the carrier diffusion.     

Compact Channel Noise Models for Deep-Submicron MOSFETs

In this paper, compact channel noise models valid in all regions of operation for deep-submicron MOSFETs have been developed and experimentally verified. The physics-based expressions for thermal noise and flicker noise and corner frequency constitute compact channel noise models. The carrier heating, channel-length modulation, and mobility degradation due to the lateral electric field have been incorporated in the models. The effect of the mobility and carrier number fluctuations on the flicker noise, as well as the dependence of the mobility limited by Coulomb scattering on the inversion carrier density, have been considered in the flicker noise model. The measurement results validate the proposed models.      

解析式表示外腔半导体激光器的特征参量

用射线法研究了强反馈可调谐外腔式半导体激光器的阈值行为，导出了ＥＣＬＤ被财在不同波长振荡所需的阈值载流子数密度外腔长度及阈值电流的解析表达式，也得到了不同电流ＥＣＬＤ的调谐输出功率及载流子密度的表达式。     

Improvement in HgCdTe diode characteristics by low temperature post-implantation annealing

Hg_1−xCd_xTe diodes (x∼0.22) with different carrier concentrations in p type materials have been fabricated by employing an ion-implantation technique. The performances of the diodes, prior to and after low temperature postimplantation annealing, have been investigated in detail by model fitting, taking into account dark current mechanisms. Prior to the annealing process, dark currents for diodes with relatively low carrier concentrations are found to be limited by generation-recombination current and trap-assisted tunneling current, while dark currents for diodes with higher carrier concentrations are limited by band-to-band tunneling current. These dark currents in both diodes have been dramatically decreased by the low temperature annealing at 120∼150°C. From the model fitting analyses, it turned out that trap density and the density of the surface recombination center in the vicinity of the pn junction were reduced by one order of magnitude for a diode with lower carrier concentration and that the carrier concentration profile in a pn junction changed for a diode with higher carrier concentration. The improvements are explained by changes in both carrier concentration profile and pn junction position determined by interaction of interstitial Hg with Hg vacancy in the vicinity of the junction during the annealing process.     

静电感应晶闸管沟道载流子分布的物理效应

The physical effects of the carrier distribution in the channel on the dynamical performance of a static induction thyristor （SITH） have been studied numerically and experimentally. The analytical expressions of the minority carrier distribution in the channel of the SITH were also derived and the space charge distribution control- ling mechanism on the current of the SITH under high level injection have been analyzed deeply. The relationships among the minority carrier distribution, potential distribution, I-V characteristics and transient performances of the SITH are revealed.     

几周期啁啾高斯脉冲的时域特性研究

研究了带有线性啁啾的几周期高斯脉冲的主要时域特性 ,分析了载波相位对啁啾脉冲的影响。结果表明啁啾在很大程度上增大了载波相位发挥作用所对应的脉宽范围 ,并且相位对啁啾脉冲的作用比对无啁啾的情况更加显著。