一种具有高电流增益的平面集成SiGe HBT

研制了一种平面集成多晶发射极SiGe HBT。经测量,在室温下电流增益β大于1 500,最大达到2 800,其Vceo为5 V,厄利(Early)电压VA大于10 V,βVA乘积达到15 000以上。这种器件对多晶硅发射极砷杂质浓度分布十分敏感。     

一种高电流增益的SiGe HBT的研制

研制了一种平面集成多晶发射极SiGe HBT。经测量,在室温下电流增益β大于1500,最大达到2800,其Vceo为5V,厄利（Early）电压VA大于10V,βVh乘积达到15000以上。这种器件对多晶硅发射极砷杂质浓度分布十分敏感。     

多晶发射极双台面微波功率SiGe HBT

研制成功了可商业化的75mm单片超高真空化学气相淀积锗硅外延设备SGE500,并生长了器件级SiGe HBT材料.研制了具有优良小电流特性的多晶发射极双台面微波功率SiGe HBT器件,其性能为:β=60@VCE/IC=9V/300μA,β=100@5V/50mA,BVCBO=22V,ft/fmax=5.4GHz/7.7GHz@10指,3V/10mA.多晶发射极可进一步提供直流和射频性能的折衷,该工艺总共只有6步光刻,与CMOS工艺兼容且(因多晶发射极)无需发射极外延层的生长,这些优点使其适合于商业化生产.利用60指和120指的SiGe HBT制作了微波锗硅功率放大器.60指功放在900MHz和3.5V/0.2A偏置时在1dB压缩点给出P1dB/Gp/PAE＝22dBm/11dB/26.1%.120指功放900MHz工作时给出了Pout/Gp/PAE＝33.3dBm (2.1W)/10.3dB/33.9%@11V/0.52A.     

改善不同环境温度下SiGe HBT热稳定性的技术

提出了发射极非均匀指间距技术以增强多发射极指SiGe HBT在不同环境温度下的热稳定性。通过建立热电反馈模型对采用发射极非均匀指间距技术的SiGe HBT进行热稳定性分析,得到多发射极指上的温度分布。结果表明,与传统的均匀发射极指间距SiGe HBT相比,在相同的环境温度及耗散功率下,采用发射极非均匀指间距技术的SiGe HBT,其最高结温明显降低,热阻显著减小,温度分布更加均匀,有效地提高了多发射极指功率SiGe HBT在不同环境温度下的热稳定性。     

SiGe BiCMOS工艺中HBT的关键制造工艺研究

研究了0.18μm SiGe BiCMOS中的核心器件SiGe HBT的关键制造工艺,包括集电极的形成、SiGe基区的淀积、发射极窗口的形成、发射极多晶的淀积、深孔刻蚀等,指出了这些制造工艺的难点和问题,提出了解决办法,并报导了解决相关难题的实验结果。     

一种新型双多晶自对准结构的高压功率SiGe HBT

为了改善高压功率SiGe HBT的综合性能,应用图形外延SiGe工艺,研制出了一种新型的双多晶自对准SiGe HBT器件.相对于双台面结构的SiGe HBT而言,该结构的SiGe HBT在发射极总周长不变的情况下,其发射结面积减少超过50%,集电结面积减少近70%,BVCBO也提高了近28%.经测试,器件的结漏电和直流增益等参数均符合设计要求.     

SiGe HBT基区结构的优化对欧拉电压的影响

欧拉电压是SiGe HBT一项重要的直流参数,受到基区结构(如Ge组分)的影响。研究发现,高温过程会导致硼的外扩散,从而影响异质结的位置,使欧拉电压受到影响。实验发现,通过优化基区结构,加厚CB结处i-SiGe厚度,可获得VA=520 V,βVA=164,320 V的SiGe HBT。     

TiSi2在微波低噪声SiGe HBT中的应用

通过在SiGe HBT外基区和多晶发射极上制作TiSi2,从而使器件的高频噪声系数得到进一步降低.以PD=200mW的SiGe HBT为例,采用TiSi2工艺的噪声系数典型值为F=1.6dB@1.1GHz,明显低于无TiSi2工艺SiGe HBT的2.0dB@1.1GHz,且频率越高,二者差别越大.     

辐照对SiGe HBT增益的影响

比较了电子和γ射线辐照后SiGe HBT和Si BJT直流增益β的变化.在Vbe≤0.5V时,较高剂量辐照时SiGe HBT的放大倍数辐照损伤因子d(β)为负;在Vbe≥0.5V时,SiGe HBT的d(β)远比Si BJT的小.SiGe HBT有更好的抗辐照性能.针对测得的一些电子陷阱对辐照致性能变化的影响进行了讨论.     

辐照对SiGe HBT增益的影响

比较了电子和γ射线辐照后SiGe HBT和Si BJT直流增益β的变化.在Vbe≤0.5V时,较高剂量辐照时SiGe HBT的放大倍数辐照损伤因子d(β)为负;在Vbe≥0.5V时,SiGe HBT的d(β)远比Si BJT的小.SiGe HBT有更好的抗辐照性能.针对测得的一些电子陷阱对辐照致性能变化的影响进行了讨论.     

多晶发射极结构三极管抗总剂量能力研究

文章通过分析总剂量辐照机理和三极管结构总剂量辐照的瓶颈部位,比较普通和多晶发射极VNPN晶体管结构上的区别,指出多晶发射极结构具有更强的总剂量辐照能力。多晶发射极结构总剂量辐照能力增强是由于该结构EB之间存在多晶+薄氧化层的结构,该结构中多晶屏蔽了顶部厚氧化层辐照效应的影响,而普通结构EB之间则是厚氧化层结构,总剂量辐照能力弱。在对多晶发射极结构总剂量辐照关键部位的分析过程中,对多晶发射极三极管局部结构进行了进一步优化设计,最后给出了多晶发射极结构三极管的辐照实验结果,并对实验结果进行了分析。     

Device characteristics of the GaAs/InGaAsN/GaAs p-n-p doubleheterojunction bipolar transistor

We have demonstrated the dc and rf characteristics of a novel p-n-p GaAs/InGaAsN/GaAs double heterojunction bipolar transistor. This device has near ideal current-voltage (I-V) characteristics with a current gain greater than 45. The smaller bandgap energy of the InGaAsN base has led to a device turn-on voltage that is 0.27 V lower than in a comparable p-n-p AlGaAs/GaAs heterojunction bipolar transistor. This device has shown f_T and f_MAX values of 12 GHz. In addition, the aluminum-free emitter structure eliminates issues typically associated with AlGaAs     

Double heterojunction NpN GaAlAs/GaAs bipolar transistor

Double heterojunction NpN Ga0.7Al0.3As/GaAsAs/Ga0.7Al0.3-As bipolar transistors have been developed and tested. Besides a wide-gap emitter a wide-gap collector was added to form the NpN double heterojunction structure, which can be operated as a bipolar transistor in bidirection. I/V measurements show that the turn-on voltage of about 0.2 V, which is the normal case in Npn wide-gap emitter GaAsAs/Ga0.7Al0.3As transistors (common emitter), is eliminated. As compared with the Npn GaAs transistor the storage time ts of the NpN GaAs transistor is reduced by a factor of about 2.     

A novel vertical SCR for ESD protection in 40 V HV bipolar process

A vertical Silicon Controlled Rectifier (VSCR) realized in a high-voltage (HV) 40 V bipolar process is proposed for electrostatic discharge (ESD) protection applications. In addition, a new method is proposed to alter the layout of the emitter regions of the parasitic vertical PNP (VPNP) bipolar transistor in the VSCR to optimize the trigger voltage and the area of the VSCR. The transmission line pulsing (TLP) measurement results show that the VSCR possesses enhanced ESD robustness compared to the conventional vertical PNP (VPNP) bipolar transistor. The new VSCR can adjust trigger voltage, holding voltage and failure current with changing the number of emitter regions. Compare to VPNP bipolar transistor, the VSCR is more suitable for 40 V bipolar process.     

用氧化镉(CdO)为发射区的InGaAsP/InP双异质结晶体管

本文提出和研制了一个新型的InGaAsP/InP双极型晶体管.在单片集成电路中它能与1.55μmInGaAsP/InP双异质结激光器共容而组成一个晶体管-激光器器件.该晶体管的主要特点是采用氧化镉(CdO)薄层作为器件发射区,由InP组成收集区而形成NpN双异质结晶体管.测量结果表明晶体管能双向工作,测得的正向共发射极电流增益为40(V_(CE)=5V,Ic=1mA),反向增益为8(V_(CE)=1.5V,Ic=100μA).文中还给出了h_(fe)—I_c特性和晶体管CdO-InGaAsP发射结的伏安特性.     

Super-gain silicon MIS heterojunction emitter transistors

Silicon bipolar transistors are described with common emitter current gains approaching 25 000, believed to be the highest ever reported for a bipolar device. A heterojunction emitter structure based on a tunneling metal-thin insulator-semiconductor (MIS) contact in conjunction with a shallow implanted base region is responsible for this improved performance. The significance of this result lies in the fact that it demonstrates advantages in both the injection efficiency of the emitter and the control of base properties which may lead to improved silicon bipolar transistor performance over a range of applications.     

4H-SiC npn双极型晶体管的研制

采用国产的4H-SiC外延材料和自行开发的SiC双极晶体管的工艺技术,实现了4H-SiC npn双极晶体管特性。为避免二次外延或高温离子p+注入等操作,外延形成n+/p+/p/n-结构材料,然后根据版图设计进行相应的刻蚀,形成双台面结构。为保证p型基区能实现良好的欧姆接触,外延时在n+层和p层中间插入适当高掺杂的p+层外延,但也使双极晶体管发射效率降低,电流放大系数降低。为提高器件的击穿电压,在尽量实现低损伤刻蚀时,采用牺牲氧化等技术减少表面损伤及粗糙度,避免表面态及尖端电场集中,并利用SiC能形成稳定氧化层的优势来形成钝化保护。器件的集电结反向击穿电压达200 V,集电结在100 V下的反向截止漏电流小于0.05 mA,共发射极电流放大系数约为3。     

Comparison of hot electron and related amplifiers

It is proposed that novel amplifiers be compared with each other and with existing amplifiers on the basis of as many figures of merit as are calculable. The bipolar transistor; field-effect transistor; Schottky-emitter, space-charge-limited-emitter, and tunnel-emitter, metal-base, hot-electron amplifiers are compared with respect to frequency cutoff and maximum frequency of oscillation. Using reasonable ground rules for the comparison, the amplifiers rank (with respect to frequency cutoff) in the order: Schottky emitter, bipolar transistor, space-charge-limited emitter, and tunnel emitter. With respect to maximum frequency, the amplifiers rank in the order: Schottky emitter; space-charge-limited emitter; tunnel emitter and bipolar transistor equivalent; and field-effect transistor.     

AlGaN/GaN heterojunction bipolar transistor

We demonstrate the first GaN bipolar transistor. An AlGaN/GaN HBT structure was grown by MOCVD on c-plane sapphire substrate. The emitter was grown with an Al_0.1Ga_0.9N barrier to increase the emitter injection efficiency. Cl₂ RIE was used to pattern the emitter mesa, and selectively regrown base contact pads were implemented to reduce a contact barrier associated with RIE etch damage to the base surface. The current gain of the devices was measured to be as high as three with a base width of 200 nm. DC transistor characteristics were measured to 30 V V_CE in the common emitter configuration, with an offset voltage of 5 V. A gummel plot and base contact characteristics are also presented     

New method to measure emitter resistance of heterojunction bipolar transistors

The in third-order intermodulation as a function of emitter current in a bipolar transistor is exploited to find emitter Ohmic resistance. The measurement can be carried out using only low-cost equipment and a scalar receiver. Results for an heterojunction bipolar transistor (HBT) are compared with those found using a vector network analyzer and a sophisticated extraction algorithm. The method is extended to simultaneously determine thermal resistance, R/sub TH/, and to obtain a most precise estimate of emitter resistance.