一种新型MOSFET静电场传感器

本文提出了一种非常有发展前途的低温漂固态电场传感器。此传感器是一种恒压惠斯顿电桥,它的电阻是由四个直接栅极SOI MOSFET器件。理论上证明这种传感器的输出信号电压与测量电场成正比,温度漂移等于零。实验结果表明,在300K温度下,传感器的分辨率为3.27 mV/KV/m,大气环境下的温度漂移相当于47V/m的电场,其远小于大气温度下相当于10,000V/m的电流漂移。     

液氮温区集成式数字温度传感器设计

温度传感器是制冷型红外焦平面探测器的重要组成部分,它用于测量探测器工作温度,其输出用于制冷机控制,从而控制探测器温度。探测器的工作温度将直接影响探测器的性能,如信噪比、探测率和盲元率等。针对传统PN结温度传感器需要模拟信号处理电路及易受电磁干扰的弊端,设计了一种基于CMOS工艺的集成式数字温度传感器,可以集成到红外焦平面探测器读出电路中,直接通过SPI接口输出数字测温值。设计的集成式数字温度传感器采用0.35 m CMOS工艺流片,芯片面积为380 m500 m（不包含PAD）,在电源电压2.5 V和采样频率6.1次/s条件下,功耗为300 W,分辨率0.061 6 K。在77 K温度下输出的RMS噪声为0.148 K。测试结果表明,集成式数字温度传感器可以应用于制冷型红外焦平面探测器温度测量。     

Effect of a transverse applied electric field on electron drift velocity in a GaAs quantum wire: A Monte Carlo simulation

A Monte Carlo simulation is run to study the electron transport in a thin undoped GaAs quantum wire under the influence of a transverse applied electric field. Phonon and surface-roughness scattering are included. Electron drift velocity is investigated as a function of roughness amplitude at a temperature of 77 or 300 K and a longitudinal electric field of 10⁴ or 10⁵ V/m. A transverse applied field is shown to provide a means of controlling drift velocity, affecting the scattering rate.     

SOI高压MOSFET的电流-电压特性模拟

在不同漂移区浓度分布下 ,通过二维数值模拟充分地研究了薄膜 SOI高压 MOSFET击穿电压的浓度相关性 ,指出了击穿优化对 MOSFET漂移区杂质浓度分布的要求。分析了MOSFET的电场电位分布随漏源电压的变化 ,提出寄生晶体管击穿有使 SOI MOSFET击穿降低的作用。     

一种低功耗低温度系数基准电压源的设计

基于0.35μm CMOS工艺,设计一种不带电阻的低功耗基准电压源,该基准源工作电压范围1.2 V~3.6 V.在3.6 V和室温时测量最大的电源电流为130 nA.在-20℃~100℃温度范围内,该基准电压温度系数为7.5×10-6/℃.在1.2 V~3.6 V电源电压范围内,线灵敏度为40×10-6/V,且在100 Hz时电源抑制比为-50 dB.该基准电压源适合在一些例如移动设备、植入式医疗设备和智能传感器网络等节能集成电路上应用.     

New High-Voltage ( $>$ 1200 V) MOSFET With the Charge Trenches on Partial SOI

A novel silicon-on-insulator (SOI) high-voltage MOSFET structure and its breakdown mechanism are presented in this paper. The structure is characterized by oxide trenches on the top interface of the buried oxide layer on partial SOI (TPSOI). Inversion charges located in the trenches enhance the electric field of the buried layer in the high-voltage blocking state, and a silicon window makes the depletion region spread into the substrate. Both of them modulate the electric field in the drift region; therefore, the breakdown voltage (BV) for a TPSOI LDMOS is greatly enhanced. Moreover, the Si window alleviates the self-heating effect. The influences of the structure parameters on device characteristics are analyzed for the proposed device structure. The TPSOI LDMOS with BV > 1200 V and the buried-layer electric field of E_I > 700 V/ mum is obtained by the simulation on a 2-mum-thick SOI layer over 2-mum-thick buried oxide layer, and its maximal temperature reduces by 19 and 8.7 K in comparison with the conventional SOI and partial SOI devices.     

Development and analysis of electric field sensor using LiNbO3 optical modulator

The sensitivity of an electromagnetic field sensor which uses a LiNbO₃ electrooptical crystal and an optical-fiber link is improved by using a Mach-Zehnder interferometer, whose half-wave voltage is about 4 V at 1.3-μm wavelength, and a YAG laser pumped by a laser diode whose output power is 25 mW. The resulting frequency response is about flat from 100 Hz to 300 MHz, and the minimum detectable electric field strengths are 0.22 mV/m at 50 MHz and 0.079 mV/m at 750 MHz. The variation of the sensitivity with the frequency and element length are analyzed using the moment method, and the calculated results agree with the measured results. The measurement of the cross-polarization of the sensor indicates that this property is similar to that of a dipole antenna. The improved sensor can measure an electromagnetic impulse whose peak value is larger than 10 V/m and whose width is wider than 5 ns     

9μm截止波长128×128 AlGaAs/GaAs量子阱红外焦平面探测器阵列

报道了128×128 AlGaAs/GaAs量子阱红外焦平面探测器阵列的设计和制作.采用金属有机化学气相淀积外延技术生长外延材料,并在GaAs集成电路工艺线上完成工艺制作.为得到器件参数,设计制作了台面尺寸为300μm×300μm的大面积测试器件;77K下2V偏压时暗电流密度为1.5×10-3A/cm2;80K工作温度下,器件峰值响应波长为8.4μm,截止波长为9μm,黑体探测率DB 为3.95×108(cm·Hz1/2)/W.将128×128元 AlGaAs/GaAs量子阱红外焦平面探测器阵列芯片与相关CMOS读出电路芯片倒装焊互连,在80K工作温度下实现了室温环境目标的红外热成像,盲元率小于1%.     

Short-channel-effect free 0.18 μm MOSFET bytemperature-dimension combination scaling theory: design and experiment

We have fabricated 77 K deep-submicron MOSFETs on the basis of the temperature-dimension combination scaling theory (CST). The 77 K MOSFETs with 1-V supply voltage are designed from a 300 K MOSFET with 4-V supply voltage. The fabricated 77 K 0.18 μm device has exhibited fully scaled characteristics. The subthreshold swing (S) and the threshold voltage (V_th) of the 77 K device are found to be 1/4≈77 K/300 K of those of the 300 K device. Furthermore, S and V_th are achieved to be 27 mV/dec and 0.21 V without short-channel effect degradation     

A novel trench gate floating islands power MOSFET (TG-FLIMOSFET): Two-dimensional simulation study

Novel trench gate floating islands MOSFET (TG-FLIMOSFET) designed using the concept of “Opposite Doped Buried Regions” (ODBR) and floating islands (FLI) along with trench gate technology is proposed and verified using two-dimensional simulations. The conventional FLIMOSFET experimentally demonstrated recently, although offers lowest on-resistance in the low voltage range, however, suffers from quasi-saturation effect like any other power MOSFETs. The proposed TG-FLIMOSFET demonstrated to obtain about 30% reduction in peak electric field in drift region of the proposed device. TG-FLIMOSFET also demonstrates quasi-saturation free forward and transconductance characteristics, improved synchronous rectifying characteristics, identical breakdown voltage, reduced on-resistance and increased transconductance ‘gm’ when compared with the conventional FLIMOSFET for various trench geometries. The proposed device breaks the limit set by the conventional FLIMOSFET approximately by a factor of 10. A possible process flow sequence to fabricate the proposed device commercially by integrating multi-epitaxial process with trench gate technology is also presented.     

Drift velocity and diffusivity of hot carriers in germanium: Model calculations

A simple analytical model with two adjustable parameters is employed in describing the drift velocity and longitudinal diffusion coefficient of charge carriers (electrons and holes) in purified germanium, over a wide range of electric field (10-10⁴ V/cm). The effects of the lattice temperature for the range 130–300 K are also considered, and a comparison with experimental data is made. The model may be used for the simulation of the behaviour of germanium devices.     

硅纳米晶粒基MOSFET存储器的荷电特征研究

本文研究了硅纳米晶粒MOSFET存储器的荷电特征.器件阈值电压偏移达1.8V以上,并随着沟道宽度的变窄而增加,而与沟道长度基本无关.同时,阈值涨落也随宽度的变窄而增大.在20~300K测量温度范围内,器件阈值偏移和电荷的存储特性几乎不随温度变化,说明荷电过程主要由直接隧穿决定.进一步,在最窄沟道器件中观察到单电荷的荷电过程.     

直接栅MOSFET静电场传感器温度漂移模型和模拟

推导出了直接栅MOSFET静电场传感器的温度漂移系数,并研究了温度漂移的主要原因。此研究工作对消除直接栅MOSFET静电场传感器的温度漂移有一定的帮助。首先,建立了直接栅MOSFET静电场传感器沟道中电荷随温度变化的模型。其次,根据直接栅MOSFET沟道载流子浓度和载流子迁移率都为温度的函数,将直接栅MOSFET静电场传感器的温度漂移定义为由沟道载流子迁移率随温度变化引起的温度漂移系数αμ和由沟道载流子浓度随温度变化引起的温度漂移系数αQ,并对它们与温度的关系作了推导和研究。最后,对沟道载流子迁移率随温度变化引起的温度漂移系数αμ和由沟道载流子浓度随温度变化引起的温度漂移系数αQ进行了模拟和比较。模拟结果表明,温度漂移系数αμ远小于温度漂移系数αQ。因此沟道载流子浓度随温度变化是直接栅MOSFET静电场传感器的温度漂移的主要原因。     

基于L波段气象雷达的空中三维电场探测系统

以往采用的大气电场探测方法需搭建独立的电场探测系统,并且主要实现空中矢量电场的一个或两个分量的探测。该文介绍了一种新型空中电场探测系统,基于气象部门现有L波段气象雷达探测系统,采用新型3维电场传感器,构建了新型空中电场探测平台,实现了空中3维电场、温度、湿度、气压等气象信息的同步实时探测。系统中电场传感器采用了独特的结构设计和信号处理电路,在30 kV/m的电场测量范围内,分辨力可达20 V/m,线性度优于1%,可以连续探测地面至15000 m高空的3维电场强度,为飞行器升空提供安全保障。     

Engineering model of inversion channel mobility for 60-300 K temperature range

Describes the first engineering MOSFET effective-mobility model covering the temperature range 60-300 K which is important for low-temperature CMOS applications. The experimental data obtained using the split C/V method clearly demonstrate the deviations from the universal dependence of the effective mobility mu on the effective vertical field E/sub eff/ at low temperatures. The model presented in this letter is verified by comparison with experimental device characteristics and shows explicitly how the universal mu (E/sub eff/) dependence emerges at the ambient temperature around 300 K.<>     

一种新型的CMOS亚阈值低功耗基准电压源

利用工作于亚阈值的NMOS器件,产生两个负温度系数的电压源,然后将两个电压源作差,产生稳定的基准电压输出.整体电路采用HJTCl80 nrn标准CM（）S工艺实现.仿真结果表明,基准源输出电压为220 mV,在一25℃到100℃的温度范围内的温度系数为68×10^-6/ C.电路的最小供电电压可低至O.7 V,在供电电压O.7～4V范围内的线性调整率为1.5 mV/V.无滤波电容时,1 kHz的电源抑制比为-56 dB室温下,1.O V电压供电时,电路总体功耗为3.7μW.版图设计后的芯片核心面积为O.02 mm².本文设计的电压源适用于低电压低功耗的条件.     

一种高电源抑制比带隙基准电压源的设计

设计了一种基于反馈电路的基准电压电路。通过正、负两路反馈使输出基准电压获得了高交流电源抑制比(PSRR),为后续电路提供了稳定的电压。采用NPN型三极管,有效消除了运放失调电压对带隙基准电压精度产生的影响,并对电路进行温度补偿,大大减小了温漂。整个电路采用0.35μm CMOS工艺实现,通过spectre仿真软件在室温27℃、工作电压为4 V的条件下进行仿真,带隙基准的输出电压为1.28 V,静态电流为2μA,在-20~80℃范围内其温度系数约为18.9×10-6/℃,交流PSRR约为-107 dB。     

Limits of temperature drift in noncompensated DC amplifiers

Temperature-stability limits of differential amplifiers consisting of two bipolar transistors mounted in tight thermal contact are discussed. No external temperature compensation or stabilization methods are provided. It is shown that the temperature drift of the input difference (offset) voltage is equal to about 3.3 to 3.9 /spl mu/V//spl deg/K per 1-mV difference (offset) voltage at room temperature (300/spl deg/K). This value seems to depend little on the transistor type used.     

Hot electron transport in wurtzite-GaN: effects of temperature and doping concentration

The hot electron transport in wurtzite phase gallium nitride (Wz-GaN) has been studied in this paper.An analytical expression of electron drift velocity under the condition of impact ionization has been developed by considering all major scattering mechanisms such as deformation potential acoustic phonon scattering,piezoelectric acoustic phonon scattering,optical phonon scattering,electron-electron scattering and ionizing scattering.Numerical calculations show that electron drift velocity in Wz-GaN saturates at 1.44 x 105 m/s at room temperature for the electron concentration of 1022 m-3.The effects of temperature and doping concentration on the hot electron drift velocity in Wz-GaN have also been studied.Results show that the saturation electron drift velocity varies from 1.91 × 105-0.77 × 105 m/s for the change in temperature within the range of 10--1000 K,for the electron concentration of 1022 m-3;whereas the same varies from 1.44 x 105-0.91 × 105 m/s at 300 K for the variation in the electron concentration within the range of 1022-1025 m-3.The numerically calculated results have been compared with the Monte Carlo simulated results and experimental data reported earlier,and those are found to be in good agreement.     

铌酸锂晶体结构对电场传感器灵敏度影响分析

铌酸锂晶体光学电场传感器为全介质结构,具有宽带宽、对被测电场干扰小的优点,但其灵敏度较低。因此,分析了晶体几何尺寸对传感器灵敏度的影响机理,得出通过增加沿外加电场方向的晶体尺寸同时减少晶体横截面上沿外加电场垂直方向的晶体尺寸来提高传感器的灵敏度。使用COMSOL仿真分析了铌酸锂晶体不同厚度、宽度、长度对晶体内部电场强度的影响,得出晶体厚度从15 mm减小到3 mm和宽度从3 mm增加到22 mm时,晶体内部电场强度分别提高约5.1倍和12.3倍;晶体长度从15 mm变化到55 mm时,晶体内部的电场强度变化仅约为5%。设计并研制出晶体尺寸分别为3 mm×3 mm×42.2 mm (x×y×z),3 mm×6 mm×42.2 mm (x×y×z),6 mm×6 mm×42.2 mm(x×y×z)的三只铌酸锂晶体电场传感器,并搭建工频电场测试平台,测试得出三只电场传感器的灵敏度分别为0.243 mV/(kV·m^-1)、0.758 mV/(kV·m^-1)、0.150 mV/(kV·m^-1)。当晶体厚度和长度一定且晶体宽度从3 ...