MOS器件界面态与陷阱电荷分离方法研究

对MOS结构器件．要分离由辐射效应引起的界面态电荷与氧化层陷阱电荷的方法有根多种．如中电带压法、电荷泵法和双晶体管法就是目前比较常用、有效的方法,分析了这些方法的优点和局限性。     

对目前市内电话资费若干问题的探讨

文中对目前国内自动电话业务中市内电话的资费问题作了较详细的分析探讨 ,指出所存在的问题 ,并提出了新的解决方案。     

程控交换机计费系统的设计

本文采用计费系统的通用计算模型，提出了计费，分拣及月结一体化（也可分离）的程控交换机计费系统的设计思想，并给出了一种实际实现的计费系统。     

手机单双向收费利弊谈

通过手机单双向收费的起因、合理性、优缺点的比较,以及手机收费对其他相关业务的影响,提出双向收费仍是一种合理的收费方式。同时提出某些改进意见,以弥补双向收费的不足。     

共轭点电荷系在静电劈形问题中的应用

根据点-面情形电像解的规律提出共轭点电荷系概念,对不同类型的共轭点电荷系在半无限大导体平面上的感应电荷总量进行了计算,并应用到有一定对称性分布的静电劈形问题中。共轭点电荷系思想对π是夹角整数倍情形时的劈形角平分面上点电荷的电像解提供了一种新的解法和思路。     

一种新型低电荷共享电荷泵电路

采用GSMC0.18μm工艺设计了性能优良的电荷泵,与传统电荷泵相比,此电荷泵具有低失配(mismatch≤2%)、低功耗(≤0.15mw)、低电荷共享的特点,可广泛应用于电荷泵锁相环(CPPLL)中。     

利用改进的电荷泵法研究SONOS存储器陷阱电荷的分布特性

在silicon-oxide-nitride-oxide-silicon(SONOS)等电荷俘获型不挥发存储器中,编程操作后注入电荷的分布会对器件的读取、擦写以及可靠性带来影响.利用电荷泵方法可以有效而准确地测量出注入电荷沿沟道方向的分布.为了提高测试精度,在进行电荷泵测试时,采用固定低电平与固定高电平相结合的方法,分别对SONOS器件源端和漏端进行注入电荷分布的测试.通过测试,最终获得SONOS存储器在沟道热电子注入编程后的电子分布.电子分布的峰值区域在漏端附近,分布宽度在50nm左右.     

An Improved Charge Pumping Method to Study Distribution of Trapped Charges in SONOS Memory

In silicon-oxide-nitride-oxide-silicon (SONOS) memory and other charge trapping memories,the charge distribution after programming operation has great impact on the device’s characteristics,such as reading,programming/erasing,and reliability.The lateral distribution of injected charges can be measured precisely using the charge pumping method.To improve the precision of the actual measurement,a combination of a constant low voltage method and a constant high voltage method is introduced during the charge pumping testing of the drain side and the source side,respectively.Finally,the electron distribution after channel hot electron programming in SONOS memory is obtained,which is close to the drain side with a width of about 50nm.     

陷阱俘获存储器中电荷积累过程对保持特性的影响

本文通过数值模拟的方法对陷阱俘获存储器单元在多次擦写过程中的电荷积累过程进行了分析。由于多次擦写后陷阱电荷的积累,电荷之间的复合过程成为一个重要的问题。分析结果显示擦写过程中积累的空穴会对存储器的保持特性产生影响,同时在分析器件保持特性的时候电荷之间的复合机制必须加以考虑。     

A novel modified charge pumping method for trapped charge characterization in nanometer-scale devices

A new modified method based on the charge pumping technique is proposed and adopted to extract the lateral profiles of oxide charges in an advanced MOSFET.A 0.12μm SONOS device with 50 nm threshold voltage peak is designed and utilized to demonstrate the proposed method.The trapped charge distribution with a narrow peak can be precisely characterized with this method,which shows good consistency with the measured threshold voltage.     

Effect of trapped charge accumulation on the retention of charge trapping memory

The accumulation process of trapped charges in a TANOS cell during P/E cycling is investigated via numerical simulation.The recombination process between trapped charges is an important issue on the retention of charge trapping memory.Our results show that accumulated trapped holes during P/E cycling can have an influence on retention,and the recombination mechanism between trapped charges should be taken into account when evaluating the retention capability of TANOS.     

一种高效率的二相位CMOS高压发生器

随着电源电压的不断降低和芯片面积的不断减小，电荷泵的效率已成为MOS电荷泵电路设计过程中最为人们关心的问题之一，由于传统的Dickson MOS电荷泵在每个传输管上都有问值电压的损失，使得它的效率很低，为了解决这一问题，各种电荷泵电路在不断地出现，四相位MOS电荷泵电路自发明以来，得到了广泛的应用，但是它需要产生四个时钟，增大了面积；更为重要的是，由于四相位电荷泵要求在一个周期内提供四个互不重叠的高电平，从而限制了时钟频率的提高。本文在四相位电荷泵的基础上，提出了一种新型的二相位的电荷泵电路，解决了提高效率和增加芯片面积以及时钟频率提升的矛盾。     

一种采用PVT不敏感电荷传输电路的27mW 10位125MSPS 电荷域流水线模数转换器

A low power 10-bit 125-MSPS charge-domain(CD) pipelined analog-to-digital converter(ADC) based on MOS bucket-brigade devices(BBDs) is presented.A PVT insensitive boosted charge transfer(BCT) that is able to reject the charge error induced by PVT variations is proposed.With the proposed BCT,the common mode charge control circuit can be eliminated in the CD pipelined ADC and the system complexity is reduced remarkably.The prototype ADC based on the proposed BCT is realized in a 0.18μm CMOS process,with power consumption of only 27 mW at 1.8-V supply and active die area of 1.04 mm~2.The prototype ADC achieves a spurious free dynamic range(SFDR) of 67.7 dB,a signal-to-noise ratio(SNDR) of 57.3 dB,and an effective number of bits(ENOB) of 9.0 for a 3.79 MHz input at full sampling rate.The measured differential nonlinearity(DNL) and integral nonlinearity (INL) are +0.5/-0.3 LSB and +0.7/-0.55 LSB,respectively.     

三维圆柱形电荷俘获存储器件的继续微缩对其性能的影响

本文详细地研究了关键尺寸的继续微缩对三维圆柱形无结型电荷俘获存储器器件性能的影响。通过Sentaurus三维器件仿真器,我们对器件性能的主要评价指标进行了系统地研究,包括编程擦除速度和高温下的纵向电荷损失及横向电荷扩散。沟道半径的继续微缩有利于操作速度的提升,但使得纵向电荷损失, 尤其是通过阻挡层的纵向电荷损失,变得越来越严重。栅极长度的继续微缩在降低操作速度的同时将导致俘获电荷有更为严重的横向扩散。栅间长度的继续微缩对于邻近器件之间的相互干扰有决定性作用,对于特定的工作温度及条件其值需谨慎优化。此外,栅堆栈的形状也是影响电荷横向扩散特性的重要因素。研究结果为高密度及高可靠性三维集成优化提供了指导作用。     

一种新型计费系统建设方案的探讨

本文简要地介绍了现有计费方案,从实时计费的需求出发,说明了在线计费的必要性.然后结合目前计费系统的实际情况,提出了弹性计费系统的建设方案,并分析了该方案的优势.最后,指出弹性计费系统是一种优化的计费系统.     

可调压谐振充电脉冲激光电源频率变化范围分析

本文从理论上详细分析了可调压谐振充电脉冲激光电源的频率变化范围，及有关因素对频素的影响，并讨论了频率过快时将会出现的结果。     

SEU电荷收集模式的器件级仿真

文章通过计算机模拟仿真的方法对单粒子翻转(SEU)电荷收集的三种模式进行研究.模拟结果表明,在SEU的三种电荷收集模式中.浓度梯度引起的扩散电荷收集和漏斗区的漂移电荷收集对SEU影响很小.它们均只在短时间内对电荷收集有作用.所以对SEU的影响不大,随着集成电路的发展,由于漏斗电场的减弱,漏斗区的漂移作州越来越小,在SEU的产牛过程中,耗尽层的漂移对SEU的产生起主要作用.     

一个有利于消除电荷共享的新型电荷泵

为了消除电荷泵的电荷共享效应,通过在发生电荷共享的节点预置一个特定的电压,设计出了一个适用于频率合成器的新型电荷泵.在Chartered公司0.18 RF CMOS工艺条件下,HSPICE的仿真结果表明,这一新型电荷泵与传统的相比,很好地抑制了电荷共享效应,具有很低的输出纹波,在高性能频率合成器中具有良好的应用前景.     

一种新型锁相环电荷泵的分析与设计

在分析传统电荷泵的一些不理想因素的基础上,提出一种新型的电路结构,以解决电荷泵的电流失配、电荷共享、电荷注入现象。本设计电路结构简单,电流匹配好,输出电压稳定。基于65nm CMOS工艺仿真结果表明:电荷泵充放电电流大小基本相等,环路稳定后输出电压Vc最大起伏为20μV。     

Organic Field‐Effect Transistors: A 3D Kinetic Monte Carlo Simulation of the Current Characteristics in Micrometer‐Sized Devices

The electrical properties of organic field‐effect transistors (OFETs) are usually characterized by applying models initially developed for inorganic‐based devices, which often implies the use of approximations that might be inappropriate for organic semiconductors. These approximations have brought limitations to the understanding of the device physics associated with organic materials. A strategy to overcome this issue is to establish straightforward connections between the macroscopic current characteristics and microscopic charge transport in OFETs. Here, a 3D kinetic Monte Carlo model is developed that goes beyond both the conventional assumption of zero channel thickness and the gradual channel approximation to simulate carrier transport and current. Using parallel computing and a new algorithm that significantly improves the evaluation of electric potential within the device, this methodology allows the simulation of micrometer‐sized OFETs. The current characteristics of representative OFET devices are well reproduced, which provides insight into the validity of the gradual channel approximation in the case of OFETs, the impact of the channel thickness, and the nature of microscopic charge transport.