半导体保护器件阴极短路区的设计

为改善半导体保护器件的主要特性参数，通过对半导体保护器件基本原理的简单论述，深入研究了阴极短路结构的相关理论，分析了阴极短路区结构和工艺对半导体保护器件主要特性参数的影响，提出了优化半导体保护器件主要特性参数的一些方法。     

南宝EC-142彩电故障检修

故障现象：开机两分钟后，图像消失，出现全红色光栅，满屏横亮线，伴音正常。分析与检修：这种现象为红阴极电压降低所致。测红视放管BG506集电极电压为50V（正常时为125V），基极、发射极电压正常。因为发射极电位正常，说明该管不存在击穿损坏的可能性，故障原因在与集电极相关的电路和显像管本身。查R591，阻值正常，断开R901，BG506集电极电压恢复正常。查红阴极对地的放电间隙无脏物。据此，说明显像管极间短路，因为是开机两分钟后出现故障，为热态短路，断电后用万用表测不出短路点，为证实红阴极是与灯丝相碰，还是与栅极相碰…     

阴极修饰对染料敏化TiO_2太阳能电池性能的改进

通过对染料敏化TiO2纳米晶太阳能电池中阴极进行修饰来提高电池的光电性能。结果表明:在阴极表面镀上具有催化性能的白金、镍或石墨均可提高电池的光电转化效率(IPCE)、短路电流、开路电压和填充因子等性能。其中白金修饰阴极后,电池的性能较好,IPCE从7.59%升至48.32%,短路电流从0.91 mA升至7.23 mA,开路电压从478 mV升至571 mV以及填充因子从0.09升至0.47。并给出用UV—3100型紫外可见分光光度计测定染料RuL2(SCN)2溶液的吸收光谱。     

显象管灯丝阴极短路故障维修几例

显象管是电视机中最贵重的元件。如果显象管灯丝和阴极短路,某些灯丝接地的电视机会使亮度失去控制,视频信号被短路,显象管最亮有回扫线而无图象。某些灯丝不接地的机器会使视频信号的中高频成分被电源变压器灯丝绕组与地之间的分布电容短路,使进入显象管     

提高晶闸管结温的途径

探讨了在半导体晶闸管(SCR)制造过程中,采用合理的工艺手段,选用最低电阻率的单晶、偏长的基区、阴极加短路环、短路点,使小电流a2为零,经过严格的斜边清洗与钝化,使SCR最高工作结温尽量达到理论值.     

维修园地

▲阴极和灯丝碰极显象管的有效复活方法有的电视机使用一段时间后,突然出现图象水平拖尾,清晰度下降,严重时无法收看。用万用表测量阴极与灯丝间的电阻只有几欧姆,这是阴极和灯丝绝缘不良或短路所致。由于加给显象管阴极的图象信号高频分量被电源变压器灯丝绕组和初级绕组以及铁心问分布电容旁路到地,图象失去高频分量,故变得模糊不清。我把图象信号原来从阴极输入改为从栅极输入,同时在视放前加了一级倒相后,上述故障消除,     

可控硅的简易检测

可控硅元件使用前均需进行简易的检测,以确定其质量好坏。简易的检测方法如下: 1.检测阳、阴极间的正、反向电阻。可用万用表R×1k电阻档测试阳、阴极间的正、反向电阻,都应很大(指针基本不动),否则元件内部有短路或性能不良。     

具有阴极短路点结构的快速软恢复整流管的研制

分析了具有阴极短路点结构的快速软恢复整流管的反向恢复过程，讨论了ｎ区中设置ｐ＾＋短路点使反向恢复时间明显缩短物理过程，指出重金属铂在ｎ区中的优化分布使反向恢复电流呈现软特性，实现通态下的低压降，小的反向漏电流和快速软恢复特性。     

解决电子管漏电的方法

使用钍钨阴极或钡钨阴极的电子管,在老练、测试过程中,极间绝缘电阻明显下降,严重时,甚至引起两极之间的短路。为了查明原因,我们解剖了一些管子,发现某些电极上蒸发物很多、很脏。经分析:是阴极的蒸发物,它包括二部分:一、阴极的早期蒸发物,是主要的;二、阴极使用过程中的蒸发物,是次要的。为此,我们采用如下方法: (一)阴极的预蒸发——解决阴极的早期蒸发问题。把阴极部件装在玻璃管内,接上排气台,当系统真空度等于或高于1×10~(-5)托时,灯丝电压由零逐渐增加,一直到灯丝电压值(或灯丝电流值)高于其额定值的20％为止,而每     

红外热成像技术在铜电解电流分布测量中的应用

针对铜电解槽中阴极棒电流值无法实时测量的问题,应用红外热成像技术采集电解槽阴极棒的红外图像。对原始图像进行处理与分析的基础上,获取阴极棒的表面温度值。其次,通过理论分析与数据验证,结合COMSOL仿真软件数据建立了温度与电流之间的函数关系模型,进而求出电流值。对比实测电流值与模型电流值,结果表明:电解槽的总电流误差均在±5%以内,各阴极棒的电流误差基本在±12%以内,仅个别阴极棒电流误差偏大。该方法不仅实现了对阴极棒电流值的在线监测,而且对极间短路故障的检测提供了依据。     

Effect of circuit load on the phase of bias tuning in transferred-electron devices

The phase (sign) of the bias tuning of a transferred-electron device is found to be affected by the circuit load. A high-nl device tends to show positive tuning and a low-nl device tends to show negative tuning. The frequency of operation also affects the voltage at which the device starts to change its tuning phase from positive to negative.     

A new photo-sensitive voltage-controlled differential negative resistance device—The lambda bipolar photo-transistor

A new photo-sensitive voltage-controlled differential negative resistance device called the LAMBDA bipolar photo-transistor is presented. The basic structure of the Lambda bipolar photo-transistor consists of the simultaneous integration of a bipolar junction transistor and a merged metal-oxide-semiconductor field effect transistor. The IV characteristic of this new device will exhibit a voltage-controlled differential negative resistance when the device is exposed to light. The operational principle of this new device will be described and the characteristics of the fabricated device are discussed.     

Noise in two-port devices with a negative input or output conductance

The noise figures of a two-port device with negative input conductance and of a two-port device with negative output conductance are calculated. It is shown that such devices, if developed, might open up interesting possibilities.     

High gain millimetric negative resistance low noise amplifiers

The limited gain available from GaAs FETs and HEMTs at millimetric frequencies can be overcome by using the devices in a negative resistance amplifier configuration. The advantage of the solid-state negative resistance amplifier over the transmission amplifier is that the gain available is not limited by the active device used. It has been shown that, over a narrow bandwidth, significantly higher gain can be obtained from a negative resistance amplifier, when compared to a transmission amplifier using the same device, while maintaining the same overall noise performance. This has been demonstrated experimentally using a 0.25 mu m HEMT device.<>     

SOI铁电负电容晶体管亚阈值特性研究

随着微电子技术进入纳米领域,功耗成为制约技术发展的主要因素,因此,低功耗器件成为半导体器件领域的研究热点。负电容场效应晶体管基于铁电材料的负电容效应可有效地降低器件的亚阈值摆幅,从而降低器件的功耗。该文设计了一种基于绝缘体上硅(SOI)结构的铁电负电容场效应晶体管,利用TCAD Sentaurus仿真工具对负电容晶体管进行仿真研究,得到了亚阈值摆幅为30.931 mV/dec的负电容场效应晶体管的器件结构和参数。最后仿真研究了铁电层厚度、等效栅氧化层厚度对负电容场效应晶体管亚阈值特性的影响。     

Bistable gated bipolar device

We report a semiconductor device that exhibits a negative differential resistance characteristic. The device has the same structure as metal-oxide-semiconductor (MOS) transistors currently used in integrated circuits. Biasing the structure in the subthreshold regime and sweeping the bulk bias results in the negative differential resistance characteristic. The device exhibits a peak valley current ratio of approximately 52 at room temperature while drawing ten nanoampers of current which is of sufficiently low power for ultra-large scale integration (ULSI) applications.     

一种新型硅三端负阻器件

提出并研制成一种新型硅三端负阻器件。该器件由一n沟耗尽型MOS管、一横向pnp双极晶体管和一个电阻集成而得。它具有“双负阻”特性和正阻区阻值易于控制等特点。由理论计算出的器件I_c—V_(CB)特性和负阻参数与实验结果符合良好。     

“GAMBIT: GAte Modulated BIpolar Transistor”

A planar, interdigitated, integrated device structure is described whose characteristics show a voltage controlled negative resistance between two of its terminals. This negative resistance can be controlled by the applied bias to a third terminal. Devices have been fabricated with this structure to achieve negative resistance values ranging from a few hundred thousand ohms down to less than a hundred ohms. The physical mechanisms that give rise to this negative resistance are described and a dc analysis of its behavior is presented. The analysis shows excellent agreement with the observed device characteristics.     

电阻栅结构负阻异质结双极晶体管

设计并研制成功了具有电阻栅结构的n-InGaP/p-GaAs/n-GaAs负阻异质结双极晶体管．研制出的器件I-V特性优于相关文献的报导；得到了恒定电压和恒定电流两种模式的负阻特性曲线；对两种模式负阻特性产生的物理机制进行了解释；最后对此器件的应用前景进行了预测．     

Negative refraction device with electrically controllable permittivity and negative permeability

A controllable negative refraction device operated between 7 and 16 GHz is presented. This compact device, which is composed of split-ring resonators and metallic wires including pin diodes, presents a controllable permittivity and a fixed permeability. The switching of the electromagnetic state is demonstrated from transmission measurements between 7 and 16 GHz. The negative refraction of the material is verified from measurements at oblique incidence.