双极晶体管和肖特基二极管改进技术

设计进步以及封装技术的改进使得开发优化的分立半导体器件成为可能，例如低饱和电压晶体管以及超低正向压降肖特基整流二极管。此类新器件可满足当今电子产品在散热、效率、空间占用和成本方面的高要求。对于便携式电池供电设备(如笔记本电脑、数字相机)以及汽车中的负载切换和电源系统，此类新器件是首选的解决方案。     

超高速半导体器件 肖特基二极管

肖特基势垒二极管SBD(Schottky Barrier Diode，简称肖特基二极管)是上世纪问世的低功耗、大电流、超高速半导体器件。其反向恢复时间极短(可以小到几纳秒)，正向导通压降仅0．4V左右，而整流电流却可达到几千安培。这些优良特性是快恢复二极管所无法比拟的。中、小功率肖特基整流二极管大多采用塑封形武。     

肖特基二极管与快恢复整流二极管之比较

本文对肖特基二级管与快恢复整流二极管在同样作为有效开关方面简要作一下比较。     

安森美半导体推出新微封装的晶体管和二极管

安森美半导体(ON Semiconductor)扩充分立器件封装系列,推出新微封装的晶体管和二极管.新增加的封装拓展了公司的微封装晶体管和二极管系列,配合当今空间受限型便携应用的严峻设计需求.     

飞利浦最新PMEG系列肖特基二极管

皇家飞利浦电子集团推出PMEG系列肖特基二极管。该PMEG系列内在的低正向电压降和高速开关能力使这些新的肖特基二极管非常适用于高效率DC/DC转换器，在提高整体电效率的同时，使手机，数码相机等设备更加小型化。通过将正向电阻降至目前市场上同类二极管的一半以下，PMEG超低正向电压降肖特基整流器二极管系列能达到的功效水平仅为BAT54等业界标准型号的一半。     

采用SiGe双极技术的晶体管

ＮＥＣ电子器件公司研制成噪声系数为 0 9ｄＢ的晶体管 ,型号为 2ＳＣ5 76 1,样品已开始销售。主要用途为Ｗ -ＣＤＭＡ等第三代移动通信机 ,蓝牙接收部分的低噪声放大器等。在 2ＳＣ5 76 1器件中已采用制作 ,最高振荡频率为 6 0ＧＨｚ晶体管的ＳｉＧｅ双极技术。工作频率为2ＧＨｚ ,收集极———发射极间施加 + 2Ｖ下 ,最小ＮＦ时的增益为 + 16ｄＢ(收集极电流为 5ｍＡ时 )。在相同条件下的功率增益为 14 5ｄＢ ,比该公司用Ｓｉ双极技术制作的晶体管提高 1 6倍。直流电流放大系数为 30 0 ,为此前该公司的产品 3倍以上。接合部到管壳间的热…     

科锐推出封装型1,700V碳化硅肖特基二极管

科锐公司日前宣布推出全新系列封装型二极管,在现有碳化硅肖特基二极管技术条件下,该系列二极管可提供业界最高的阻断电压。科锐1,700V Z-Rec肖特基二极管从根本上消除了硅PiN二极管替代品中存在的反向恢复损耗,     

4H-SiC TSOB结势垒肖特基二极管的结构优化设计

室温下,沟槽底部有氧化物间隔的结势垒肖特基二极管的击穿电压达到2 009V,正向导通压降为2.5V,在正向偏压为5V时,正向电流密度为300A/cm2。在P型多晶硅掺杂的有源区生成双层SiO2间隔,以优化漂移区电场分布,正向导通压降为2.5V,击穿电压达到2 230V,耐压值提高11%。反向电压为1 000V时,反向漏电流密度比普通结构降低90%,有效地降低了器件的漏电功耗。普通结构的开/关电流比为2.56×103(1~500V),而改进结构的开/关电流比为3.59×104(1~500V)。     

High-temperature point-contact transistors and Schottky diodes formed on synthetic boron-doped diamond

Point-contact transistors and Schottky diodes have been formed on synthetic boron-doped diamond. This is the first report of diamond transistors that have power gain. Further, the transistors exhibited power gain at 510°C and the Schottky diodes were operational at 700°C.     

Improved circuit-device interface for microwave bipolar power transistors

Several improvements in the mounting and interconnection of bipolar microwave power transistors are described. A plated heat sink applied to thinned transistor pellets decreases the junction temperature for a given dissipation level by approximately a factor of 2. A new, low-parasitic-BeO carrier provides improved power sharing between cells and better high-frequency performance as illustrated by a CW power output of 4 W at 5 GHz with 6-dB gain. Finally, a new etched-line interconnection system is discussed that promises to become a highly reproducible, low-cost replacement for the widely used, but troublesome, multiple wire bonds.     

Improved second breakdown of integrated bipolar power transistors

This paper presents two new power bipolar transistor structures With greatly increased forward Second breakdown values without saturation voltage degradation. These structures, labeledS1 andS2, were obtained with slight modification of the output stages of an IC power amplifier and without complicating the standard IC process. The design concepts developed in this paper were applied to power transistors fabricated using two different processes already in production: processA(V_{CEO(sus)} gt 50V) and processB(V_{CEO(sus)} gt 80V). Measurements have Shown that an improvement of three times for dc conditions and four times or more for single pulses duration of less than 1 ms can be obtained for structureS1 while structureS2 is able to achieve the proportionality between power silicon area and power levels. Experimental temperature distributions over emitter area and some theoretical calculations for the steady-state condition are given.     

GaSb Schottky diodes for infrared detectors

GaSb Schottky barrier photodiodes are shown to have quantum efficiency higher than 35 percent over a broad band of infra-red light wavelength shorter than 1.6 µm. Theoretical calculations of current voltage characteristics including tunneling current are compared with the experiment and it is suggested that surface leakage current, tunneling current, and avalanche breakdown, respectively, dominate the reverse characteristics with increasing voltage. Epitaxial growth of an n-type layer with carrier density 10¹⁵cm^-3and suitable surface passivation are key technologies for the application of this material to infra-red detectors.     

Parameter extraction for bipolar transistors

Different methods of extracting the DC Gummel-Poon bipolar transistor model parameters are reviewed. First the shortcomings of the classical extraction schemes for the intrinsic model are presented together with some improved procedures. Finally the extraction of the series resistances is addressed.     

Improved ESD protection by combining InGaN-GaN MQW LEDs with GaN Schottky diodes

GaN Schottky diodes were built internally inside the GaN green LEDs by using etching and redeposition techniques. By properly selecting the etching areas underneath the bonding pads, one can minimize the optical loss due to the etching process. Although the reverse current and the forward turn-on voltage were both higher for the GaN LED with a Schottky diode, it was found that the internal Schottky diode could significantly increase the electrostatic discharge threshold from 450 to 1300 V.     

Collector models for bipolar transistors

Using Ryder's formula for drift velocity vs. electric field, the d.c. field and carrier densities in the collector of a bipolar transistor are calculated analytically for all possible bias conditions. This is accomplished by modeling the majority carrier distribution. The results are compared with computer calculations and fairly close agreement is found. The analytic calculations are used to make a detailed division of the (J_c, V_cb) plane into injection, depletion and scattering-limited drift velocity (SLDV) areas. It turns out that the doping level N_d and the collector width W determine the nature of this division of the (J_c, V_cb) plane.     

Design considerations for planar Schottky barrier diodes

The cut-off frequency of the simplest planar Schottky diode on a uniformly doped n-layer of GaAs is derived. The theoretical results are given as functions of doping concentration and layer thickness with the specific contact resistance as parameter. An improved planar diode structure is presented with several short Schottky contact fingers connected in parallel. Experimental values ranging from 100 to 300 GHz agree with the calculated values when parasitic capacitances are taken into account.     

GaAs Schottky diodes for THz mixing applications

The operation of GaAs Schottky barrier diodes, the critical mixer element used in heterodyne receivers for a variety of scientific applications in the terahertz frequency range, is reviewed. The constraints that the receiver system places on the diodes are considered, and the fundamental guidelines for device optimization are presented. The status of ongoing research, both experimental and theoretical, is examined. Emphasis is placed on investigations of the various effects that can limit diode performance at these high frequencies. Investigations of planar diode technology are summarized, and the potential replacement of whisker-contacted devices with planar structures is considered