SiGe/Si异质结双极晶体管工艺技术研究

介绍了多晶硅发射极双台面SiGe/Si异质结双极晶体管制作工艺流程。通过对LPCVD在n型Si衬底上外延生长SiGe合金层作为异质结双极晶体管基区、自中止腐蚀工艺制作发射区台面、多晶硅n型杂质掺杂工艺制作发射极、PtSi金属硅化物制作器件欧姆接触等工艺技术进行研究,探索出关键工艺的控制方法,并对采用以上工艺技术制作的多晶硅发射极双台面SiGe/Si异质结双极晶体管进行了I-V特性及频率特性测试。结果显示该器件饱和压降小,欧姆接触良好,直流电流放大倍数β随Ic变化不大,截止频率最高达到11.2 GHz。     

美国IBM公司研制成75GHz的SiGe合金晶体管

<正>据日本《电子材料》1990年第6期报道,美国IBM公司已研制成最高工作频率为75GHz硅和锗合金的双极晶体管,其速度比通常硅双极晶体管快两倍.异质结双极晶体管(HBT)采用IBM公司发明SiGe合金的 UHV(Ultra-High-Vacuum)CVD法中沉积工艺来制作.该工艺比现在的生长工艺温度低.据IBM公司报道,SiGe HBT的功能早在1987年已确定.1989年SiGe晶体管的工作频率为40GHz.     

UHV/CVD生长本征硅外延层的研究

在微波双极型晶体管中,收集区的厚度是影响其截止频率的一个重要因素。普通的常压外延难以生长出杂质浓度变化陡峭的薄外延层。文章利用自行研制的超高真空化学气相淀积(UHV/CVD)系统SGE500,在N型(掺As)重掺杂衬底上进行了薄本征硅外延层生长规律的研究;并采用扩展电阻(SPR)、原子力显微镜(AFM)、双晶衍射(DCXRD)等方法,对外延层的质量进行了评价。采用该外延材料制作的锗硅异质结双极型晶体管(SiGe HBT)器件击穿特性良好。     

SiGe HBT的Mextram 504模型温度参数提取与模型改进

针对IMEC 0.13μm准自对准SiGe BiCMOS工艺制成的基区Ge组分二阶分布结构SiGe异质结双极晶体管,在25～125℃温度范围内,对其进行了包括Early电压,Gummel图形等在内的完整双极晶体管特性曲线测量,提取了该器件在25～125℃范围内的温度可变Mextram 504模型参数.在此基础上,为Mextram 504模型对0.13μm基区Ge组分二阶分布SiGe异质结双极晶体管探索了完整的模型提取方案.提出了对Mextram 504模型温度参数提取方法的改进,优化了提取流程.对SiGe异质结双极晶体管雪崩电流受温度影响的特性进行了讨论,为Mextram模型提出了雪崩外延层的有效厚度的温度变化经验公式和新的雪崩电流温度变化参数,提高了Mextram模型对不同温度下SiGe双极型晶体管进行模拟仿真的精确度.     

SiGe HBT的Mextram 504模型温度参数提取与模型改进

针对IMEC0．13μm准自对准SiGe BiCMOS工艺制成的基区Ge组分二阶分布结构SiGe异质结双极晶体管,在25～125℃温度范围内,对其进行了包括Early电压,Gummel图形等在内的完整双极晶体管特性曲线测量,提取了该器件在25～125℃范围内的温度可变Mextram 504模型参数．在此基础上,为Mextram 504模型对0．13μm基区Ge组分二阶分布SiGe异质结双极晶体管探索了完整的模型提取方案．提出了对Mextram 504模型温度参数提取方法的改进,优化了提取流程．对SiGe异质结双极晶体管雪崩电流受温度影响的特性进行了讨论,为Mextram模型提出了雪崩外延层的有效厚度的温度变化经验公式和新的雪崩电流温度变化参数,提高了Mextram模型对不同温度下SiGe双极型晶体管进行模拟仿真的精确度．     

采用高真空／快速热处理／化学气相淀积外延SiGe HBT结构

采用新近研制的高真空／快速热处理／化学气相淀积（HV／RTP／CVD）系统生长了应变SiGe材料．通过仔细设计的处理过程可以得到器件质量的材料．Ge组分可以变化至0.25,可以得到控制良好的n型和p型掺杂层,适用于异质结双极型晶体管(HBT)的制作．研究了SiGe HBT的n-Si／i-p＋-i SiGe／n-Si结构．所制作出的微波HBT性能良好,证明了设备和工艺的水平．     

一种低噪声SiGe微波单片放大电路

介绍了一种利用SiGe技术制作的低噪声SiGe微波单片放大电路(MMIC)。该电路以达林顿结构的形式级联,由两个异质结双极型晶体管(HBT)和4个电阻组成;HBT采用准自对准结构,其SiGe基区为非选择性外延。在1 GHz频率下,电路噪声为1.59 dB,功率增益为14.3 dB,输入驻波比为1.6,输出驻波比为2.0。     

SiGe晶体管工作频率达500GHz

来自IBM和佐治亚理工大学(Georgia Institute of Technology)的研究人员近日宣布,他们研发的基于SiGe工艺的晶体管工作频率达到500GHz,比现有的手机中所用的晶体管的工作频率快250倍。到目前为止,只有采用昂贵的-族混合半导体材料的IC才能达到这种性能。SiGe异质结双极晶体管工     

微波大功率SiGe HBT的研究进展及其应用

文章论述了SiGe异质结双极晶体管(HBT)在微波功率领域应用的优势,详细介绍了微波功率SiGe HBT的结构设计方法,以及主要影响器件性能的材料和结构因素,评述了其最新进展及今后发展方向.     

C掺杂SiGe HBT

硼的瞬时增强扩散(TED)所造成的外扩散将对双极晶体管的性能产生不利影响。在HBT的SiGe区加入C(<1020cm-3),能够抑制掺杂硼的外扩散。文章讨论了C掺杂的SiGe∶CHBT在性能和工艺上的优势。SiGe∶C HBT的静态参数优于普通SiGe HBT。同时,由于SiGe∶C HBT允许高浓度的硼存在于很薄的SiGe基区层,甚至在外延后经注入和退火仍可保持很高浓度的硼掺杂,所以,SiGe∶C HBT的高频特性有很大的提高。     

硅—锗异质合金及其在异质结双极晶体管中的应用

八十年代后期发展起来的硅-锗异质结构材料,得益于成熟的硅技术,正在取得令人鼓舞的成果。采用应变层外延技术,已经获得高质量的Ge_xSi_(1-x)/Si异质膜。这些材料已被应用于各种半导体器件的研究之中。异质结双极晶体管是硅-锗异质结构材料的一个典型应用领域。近期研究结果显示出硅-锗异质结双极晶体管(HBT)巨大的潜在优势和在超高频、超高速及低温应用领域的美好前景。本文考察了这种被称为第二代硅的新材料的生长技术及其在异质结双极晶体管中的应用,并简要介绍了国外在硅锗HBT研究方面的一些成果,展望了这种新型器件的发展前景。     

A base transport model for ultra-thin-base SiGe HBT

The characteristics of parameters such as carrier temperature and diffusion coefficient in ultra-thin-base SiGe heterojunction bipolar transistors (HBTs) are analysed according to the solution of the Boltzmann equation; a new model of base transport in SiGe HBTs, different from traditional ones is described.     

On the high-temperature (to 300/spl deg/C) characteristics of SiGe HBTs

A comprehensive investigation of the high-temperature characteristics of advanced SiGe heterojunction bipolar transistors (HBTs) is presented, and demonstrates that, contrary to popular opinion, SiGe HBTs are potentially well-suited for many electronics applications operating at temperatures as high as 300/spl deg/C.     

Determination of bandgap narrowing and parasitic energy barriers inSiGe HBT's integrated in a bipolar technology

This paper describes a method for characterizing the bandgap narrowing and parasitic energy barrier in SiGe heterojunction bipolar transistors (HBTs), fabricated using a single-polysilicon self-aligned bipolar process. From a comprehensive study of the temperature dependence of the collector current, the bandgap narrowing in the base due to germanium has been dissociated from that due to the heavy dopant concentration. The same approach has been used to characterize the height and width of parasitic energy barriers which appear when boron out-diffusion from the SiGe base is present. The method has been applied to SiGe heterojunction bipolar transistors fabricated using a single polysilicon, self-aligned, bipolar process, as well as mesa transistors. The experimental results show that small geometry transistors have degraded collector currents due to boron out-diffusion around the perimeter of the emitter. This behavior has been explained by accelerated boron diffusion due to point defects generated during the extrinsic base implant. The values of undoped SiGe spacer thickness needed to suppress the parasitic energy barrier are described. Finally, high-frequency results are reported, which correlate the frequency transition to these parasitic energy barriers     

Materials and technology issues for SiGe heterojunction bipolar transistors

This paper reviews progress in SiGe heterojunction bipolar technology, with particular emphasis on the influence of materials issues on the technology performance. Low-temperature epitaxy and transient enhanced diffusion are identified as the main materials issues. Three epitaxy approaches are described, namely differential epitaxy, selective epitaxy, and combined selective and non-selective epitaxy. Differential epitaxy has the advantage of a simple growth process, selective epitaxy the advantage that an extrinsic base implant is not needed, and combined expitaxy the advantage that the Si collector and SiGe base can be grown in a single step. Transient enhanced diffusion of the boron in the base is shown to be a constraint on transistor performance, and the incorporation of a carbon concentration of ≈1×10²⁰ cm⁻³ in the base is shown to ease this constraint. Preliminary results on SiGe HBTs on wafer bonded SOI substrates are reported. The SOI transistors have characteristics comparable to those of bulk transistors, but the advantage of a gain that is a factor of approximately two higher.     

Voltage stress-induced hot carrier effects on SiGe HBT VCO

This paper presents the hot carrier (HC) induced performance degradation in a 10 GHz voltage controlled oscillator (VCO) with SiGe heterojunction bipolar transistors (HBTs). SiGe device characteristics due to HC stress are examined experimentally. The vertical bipolar inter-company (VBIC) model parameters extracted from measured data are used in Cadence SpectreRF simulation to verify the HC effect on the VCO. The VCO shows significant vulnerability to hot carriers.     

Neutral base recombination and its influence on the temperaturedependence of Early voltage and current gain-Early voltage product inUHV/CVD SiGe heterojunction bipolar transistors

We present the first comprehensive investigation of neutral base recombination (NBR) in ultra-high vacuum/chemical vapor deposited (UHV/CVD) SiGe heterojunction bipolar transistors (HBT's), and its influence on the temperature characteristics of Early voltage (V_A ) and current gain-Early voltage product (βV_A). We show that a direct consequence of NBR in SiGe HBT's is the degradation of V_A when transistors are operated with constant-current input (forced-I_B) as opposed to a constant-voltage input (forced-V_BE). In addition, experimental and theoretical evidence indicates that with cooling, V_A in SiGe HBT's degrades faster than in Si bipolar junction transistors (BJT's) for forced-I_B mode of operation. Under the forced-V_BE mode of operation, however, SiGe HBT's exhibit a thermally-activated behavior for both V_A and βV_A, in agreement with the first-order theory. The differences in V_A as a function of the input bias and temperature for SiGe HBT's are accurately modeled using a modified version of SPICE. The performance of various practical SiGe HBT circuits as a function of temperature, in the presence of NBR, is analyzed using this calibrated SPICE model     

Combined effect of bias and annealing in gamma and neutron radiation assurance tests of SiGe bipolar transistors for HEP applications

SiGe BiCMOS technologies are one of the proposed options for the front-end readout electronics of the detectors in the middle region of the ATLAS-Upgrade. The radiation hardness of the SiGe bipolar transistors is being assessed for this application through irradiations with different particles. Biasing conditions during irradiation experiments of bipolar transistors or circuits have an influence on the damage and there is a risk of erroneous results. We have performed several irradiation experiments of SiGe devices in different bias conditions. We have observed a systematic trend in gamma irradiations, showing a smaller damage in transistors irradiated biased compared to those irradiated with shorted or floating terminals. These effects have not been observed in neutron irradiations.     

高性能双极型集成电路晶体管

本文讨论作为集成电路元件的高性能双极型晶体管的现状和有关的工艺问题。