用于过流保护的薄膜电阻技术

电子电路中的电源意外可分成两大类:过流风险和过压风险。过流情况通常是由过载或短路引起的,而过压情况通常是由闪电或切换感性负载造成的快速瞬态电压引起的。     

低TCR高温薄膜电阻

PLTT精密低TCR高温薄膜电阻现可提供0805、1206、2010和2512外形尺寸,阻值范围扩大至250Ω～3MΩ,并可提供非标阻值。PLTT电阻的工作温度范围为膜电阻扩大了近100℃。器件±5×10^-6／℃的标准TCR,比传统薄具有低至容差低至±0．02％,噪声低于-35dB,     

Vishay公司MIL级薄膜片式电阻

Vishay Intercechnoloy公司发布其E／HMil级片式电阻，共有3种尺寸，紧凑型0402、0603和0502型，这为需要可靠性得到保证的设计师们在器件选择方面提供了更大自由度。Vishay薄膜电阻针对性能要求严格的军事应用，可满足Mil-PRF55342规范。采用标准封装尺寸，     

现代电阻薄膜

电阻薄膜是一种重要的电子薄膜。本文系统地论述了这种薄膜。     

热环境对微机械多晶硅薄膜电阻电特性的影响

将 CMOS工艺和微机械加工技术相结合 ,制作出悬空式微桥支撑、薄膜支撑以及无悬空结构的微机械多晶硅薄膜电阻。通过对样品的电阻温度系数 ( TCR)和电流 ( I) -电压 ( V)特性的测量 ,研究了热隔离程度、工作气压等热环境对多晶硅薄膜电阻电学特性的影响程度     

硅含量对真空熔炼电阻靶材和电阻薄膜性能的影响

采用真空熔炼方法研制新型溅射用高阻靶材,并试验靶材含硅量对溅射电阻薄膜性能的影响。     

薄膜电阻对微带均衡器的影响研究

为了使微带均衡器满足衰减特性与给定的误差曲线逐点拟和的要求,就必须使其频率可调、衰减可调、品质因数可调。因此,本文通过大量仿真和实验,研究了加载了薄膜电阻的微带谐振器及其在微带均衡器中的应用,研究分析了薄膜电阻对微带均衡器传输特性及驻波特性的影响。研究结果表明将薄膜电阻加载到微带谐振器上构造微带均衡器,可以通过改变谐振器的尺寸使其频率可调,通过改变电阻阻值及位置使其衰减可调、品质因数可调。大量HFSS仿真及实验证明这种方式很适合微带均衡器的设计制造。本文利用这种结构设计制作出了一个宽带微带均衡器,得到了很好的实验结果。     

Test Rig for High-Temperature Thermopower and Electrical Conductivity Measurements

A high-temperature test rig to simultaneously measure electrical conductivity and thermopower is described. The apparatus allows to perform measurements in a controlled atmosphere or vacuum to protect oxygen-sensitive materials. A spring-loaded mounting placed in the cold zone reduces the thermal contact resistance between the sample and two metallic blocks (the hot side and the heat sink) even at high temperatures. The hot-side metal block is periodically heated to obtain the thermopower from the slope of ΔV versus ΔT. Conductivity is measured before each thermopower measurement by a linear four-wire method. The automatic data acquisition and analysis are controlled by a LabView-based interface. Two interchangeable setups are possible. The first one uses silver blocks and K-type thermocouples and is suitable for temperatures from 300 K to about 1000 K. The second one uses W blocks and S-type thermocouples to allow higher-temperature measurements since all the hot-zone parts are made of Al₂O₃, Pt or W. The device was tested using PdAg alloy and Ni rods and, for the low-temperature range, the NIST standard reference material 3451 (bismuth telluride), strictly confirming the reference data.     

Advanced Amorphous Silicon Thin-Film Transistors for AM-OLEDs: Electrical Performance and Stability

We fabricated and characterized the advanced amorphous silicon thin-film transistors with a bilayer structure for both the active and gate dielectric films. The electrical field across the gate insulator has a significant influence on the device threshold voltage electrical stability. We show that high thin-film transistor stability can be achieved even under the presence of a high channel current. Its electrical and high-temperature stability improves up to a factor of five when the TFT biasing condition changes from the linear to the saturation region of operation.     

Electrical Stress Degradation of Small-Grain Polysilicon Thin-Film Transistors

This paper is focused on the stability of n-channel laser-crystallized polysilicon thin-film transistors (TFTs) submitted to a hydrogenation process during the fabrication and with small grains dimension. With the aid of numerical simulations, we investigate the effects of static stress using two types of procedures: the on stress and the hot carrier stress. Results show that the variations of trap state density into the whole polysilicon layer and not only near the drain junction are responsible for the degradation of TFTs performances in both the two types of stress and that the interface trap states play a negligible role compared to the bulk trap states     

High-Temperature Measurement of Seebeck Coefficient and Electrical Conductivity

We have developed a system for simultaneous measurement of the electrical conductivity and Seebeck coefficient for thermoelectric samples in the temperature region of 300 K to 1000 K. The system features flexibility in sample dimensions and easy sample exchange. To verify the accuracy of the setup we have referenced our system against the NIST standard reference material 3451 and other setups and can show good agreement. The developed system has been used in the search for a possible high-temperature Seebeck standard material. FeSi₂ emerges as a possible candidate, as this material combines properties typical of thermoelectric materials with large-scale fabrication, good spatial homogeneity, and thermal stability up to 1000 K.     

Electrical Instability of RF Sputter Amorphous In-Ga-Zn-O Thin-Film Transistors

Bias-temperature-stress (BTS) induced electrical instability of the RF sputter amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) was investigated. Both positive and negative BTS were applied and found to primarily cause a positive and negative voltage shift in transfer $(I _{rm DS} -V _{rm GS})$ characteristics, respectively. The time evolution of bulk-state density $(N _{rm BS})$ and characteristic temperature of the conduction-band-tail-states $(T _{G})$ are extracted. Since both values showed only minor changes after BTS, the results imply that observed shift in TFT $I _{rm DS} -V _{rm GS}$ curves were primarily due to channel charge injection/trapping rather than defect states creation. We also demonstrated the validity of using stretch-exponential equation to model both positive and negative BTS induced threshold voltage shift $(Delta V _{rm th})$ of the a-IGZO TFTs. Stress voltage and temperature dependence of $Delta V _{rm th}$ evolution are described.      

SRVCC增强技术分析

SRVCC技术用于EPS网络部署的初期阶段,在LTE接入热点覆盖的情况下,利用现有电路域网络实现语音业务的全覆盖。本文介绍了SRVCC的技术特点,分析了SRVCC技术的增强方案,对SRVCC技术的最新进展进行了描述。     

The Electrical Properties of Unidirectional Metal-Induced Lateral Crystallized Polycrystalline-Silicon Thin-Film Transistors

It has been known that adjacent Pd enhances the crystallization rate in Ni metal-induced lateral crystallization (Ni-MILC) and this knowledge has been used to fabricate the unidirectional MILC thin-film transistors (TFTs), which eliminate the boundary formed at the center of TFT channel in a normal MILC TFTs. It is discovered that the MILC/MILC boundary (MMB) is responsible for the high leakage current and low field- effect mobility. The electrical properties of unidirectional MILC TFTs (Width/Length = 10/10 mum) improved considerably comparing to those of MILC TFTs containing the MMB. The leakage current and field-effect mobility, which have been regarded as obstacles for industrialization of the MILC process, measure to be 2.1 X 10-11 A and 83 cm²/ V ldr s, respectively.     

Electrical Behavior and Technology Optimization of Si/SiGeC HBTs on Thin-Film SOI

A growing interest has been focused on silicon on insulator (SOI) technologies over the past years. Yet, few studies were carried out regarding the integration of vertical SiGe heterojunction bipolar transistors (HBTs) using such substrates. This paper deals both with the integration of a SiGeC HBT on thin-film CMOS-compatible SOI, and a comprehensive study of its electrical behavior based on physical simulation and electrical characterization. Various aspects of the optimization of device performances are described, considering process or layout improvements.     

绝缘层/有源层界面修饰及对有机薄膜晶体管性能的影响

制备了具有修饰层的有机薄膜场效应晶体管,采用高掺杂Si作为栅极,传统的无机绝缘材料SiO2作为栅绝缘层,有机绝缘材料PMMA或OTS作为修饰层,CuPc作为有源层,Au作为源、漏极.测试结果表明,采用经过修饰的栅绝缘层SiO2/OTS和SiO2/PMMA的两种器件的开关电流比最高可达8×104,迁移率最高为1.22×10-3cm2/(V·s),而漏电流仅为10-10A,总体性能优于单层SiO2器件.