掺硼金刚石薄膜热敏电阻器性能

用微波等离子体ＣＶＤ方法制作了掺硼金刚石薄膜热敏电阻器。该器件的结构由Ｓｉ３Ｎ４基底和２μｍ厚的掺硼金刚石薄膜组成，并采用了经退火处理的钛／金双金属层制作欧姆接触，结果在室温到６００℃范围内获得了欧姆接触，温度响应以及电阻温度系数优良的热敏电阻器。     

SiGe microsystems: world's first merchant SiGe epiwafer supplier

Merchant epiwafer companies are a classic example of spotting an unfulfilled need and then setting about satisfying it. Such companies are peculiar to III-Vs but as far as I am aware have no precedent in mainstream silicon. However, a new Canadian company called SiGe Microsystems looks set to change that. As the name suggests, this start-up is offering custom SiGe epiwafers and it is growing them on the revolutionary Leybold UHV-CVD system which was initially developed for IBM. I spoke to one of the founding members of the company, Derek Houghton, someone well-known for his contributions to both III-Vs and Si with some unique perspectives on the future of SiGe and GaAs.     

Anodic passivation of SiGe

We have investigated the oxide composition and the electronic behavior of the interface of anodically and thermally oxidized SiGe single crystals and epitaxial layers. X-ray photoelectron spectroscopies show the existence of SiO₂, GeO₂ and possibly mixed oxide compounds such as SiOGe only in the anodic oxide, whereas the thermally grown oxide layers on SiGe samples consist of pure SiO₂. In addition, the Ge enrichment at the interface and relaxation phenomena of the strained SiGe lattice of epitaxial layers, which occurs during thermal treatments, are completely reduced using the anodic treatment. Further, the defect concentration at the interface is reduced after the anodic oxidation as obtained from capacitance–voltage and photoluminescence measurements.     

Germanium-Rich SiGe Nanowires Formed Through Oxidation of Patterned SiGe FINs on Insulator

In this study, the authors report on the fabrication of Ge-rich SiGe nanowires (SGNWs) by oxidation of SiGe fins on insulator. Nanowires of different shapes and size are obtained by varying the initial fin shape, Ge content, oxidation process temperature, and oxidation time. Transmission electron microscopy observations revealed nanowires with rectangular, square, elliptical, circular, octagonal, and hexagonal cross-sections, with different Ge content. The elliptical, octagonal, and hexagonal facets are unique shapes formed with low-index faces belonging to (110) groups. These possess very high Ge content up to 95%, and were obtained in the samples oxidized from 850°C to 875°C. In␣addition, the in-plane strain in the fabricated SGNWs is evaluated using micro-Raman spectroscopy. The possible mechanism behind the formation and transformation of different nanowire shapes is discussed.     

微波功率SiGe HBT研究进展

Si的热导率比大部分化合物半导体(如GaAs)的热导率高,SiGe HBT在一个较宽的温度范围内稳定,SiGe HBT的发射结电压VBE的温度系数dVBE/dT比Si的小,双异质结SiGe HBT本身具有热-电耦合自调能力,所加镇流电阻可以较小,所有这些使SiGe HBT比GaAs HBT和SiBJT在功率处理能力上占一定优势。文章对微波功率SiGe HBT一些重要方面的国内外研究进展进行评述,希望对从事微波功率SiGe HBT的研究者有所帮助。     

Parasitic energy barriers in SiGe HBTs

Parasitic energy barriers can easily be introduced during processing. Measurements and calculations of experimental n-p-n HBTs (heterojunction bipolar transistors) are presented, showing that a parasitic conduction-band barrier at the base-collector junction reduces the collector current and the cutoff frequency. A simple analytical model explains the f_T degradation, caused by the reduction of the collector current and a pileup of minority carriers in the base. With the model the effective height and width of the barrier can also be derived from the measured collector current enhancement factor I_C(SiGe)/I_C(Si)     

165-GHz Transceiver in SiGe Technology

Two D-band transceivers, with and without amplifiers and static frequency divider, transmitting simultaneously in the 80-GHz and 160-GHz bands, are fabricated in SiGe HBT technology. The transceivers feature an 80-GHz quadrature Colpitts oscillator with differential outputs at 160 GHz, a double-balanced Gilbert-cell mixer, 170-GHz amplifiers and broadband 70-GHz to 180-GHz vertically stacked transformers for single-ended to differential conversion. For the transceiver with amplifiers and static frequency divider, which marks the highest level of integration above 100 GHz in silicon, the peak differential down-conversion gain is -3 dB for RF inputs at 165 GHz. The single-ended, 165-GHz transmitter output generates -3.5 dBm, while the 82.5-GHz differential output power is +2.5 dBm. This transceiver occupies 840 mum times 1365 mum, is biased from 3.3 V, and consumes 0.9 W. Two stand-alone 5-stage amplifiers, centered at 140 GHz and 170 GHz, were also fabricated showing 17 dB and 15 dB gain at 140 GHz and 170 GHz, respectively. The saturated output power of the amplifiers is +1 dBm at 130 GHz and 0 dBm at 165 GHz. All circuits were characterized over temperature up to 125degC. These results demonstrate for the first time the feasibility of SiGe BiCMOS technology for circuits in the 100-180-GHz range.     

调制掺杂层在SiGe PMOSFET中的应用

在普通Si器件性能模拟的基础上，详细研完了长沟应变SiGe器件的模拟，并进一步探讨了调制掺杂层的引入对器件性能(主要是跨导)的影响。在器件模拟过程中，采用隐含的SiGe材料和Si材料模型会得到与实际情况差别较大的结果。根据前人的材料研完工作，引入了插值所得的近似因子，以修正Silvaco中隐含的SiGe能带模型和迁移率参数。然后，依据修正后的模型对SiGe PMOS进行了更为精确的二维模拟，并验证了调制掺杂层的作用。     

Ultra-wideband SiGe low-noise amplifier

A low-noise amplifier (LNA) for ultra-wideband (UWB) is presented. The LNA, consisting of two gain stages in multiple feedback loops, achieves a flat power gain of a nominal 20 dB and a noise figure of 2.8-4.7 dB over the 3.1-10.6 GHz UWB band. Implemented in a 0.25 /spl mu/m SiGe BiCMOS process, the amplifier occupies 0.34 mm/sup 2/ and draws 11 mA from a 2.7 V supply.     

SiGe HBT技术进展

首先论述了 Si Ge技术的优势、发展历史和应用领域 ,并介绍了 Si Ge工艺和器件的进展 ,最后详细描述了 Si Ge IC的进展     

SiGe新技术及其应用前景

本文简单的介绍了SiGe技术的优异，应用潜力几发展概况，并预期了其今后的发展趋势和产业前景     

Half-terahertz operation of SiGe HBTs

This letter presents the first demonstration of a silicon-germanium heterojunction bipolar transistor (SiGe HBT) capable of operation above the one-half terahertz (500 GHz) frequency. An extracted peak unity gain cutoff frequency (f/sub T/) of 510 GHz at 4.5 K was measured for a 0.12/spl times/1.0 /spl mu/m/sup 2/ SiGe HBT (352 GHz at 300 K) at a breakdown voltage BV/sub CEO/ of 1.36 V (1.47 V at 300 K), yielding an f/sub T//spl times/BV/sub CEO/ product of 693.6 GHz-V at 4.5 K (517.4 GHz-V at 300 K).     

SiGe器件及其在蓝牙系统中的应用

SiGe是目前RF半导体领域中一项非常引人关注的半 导体生产工艺。继IBM公司之后,TI公司、ST公司和Conexant Systems公司等主要的芯片供应商纷纷加入了使 用者的行列。与此同时,随着蓝牙技术在个人无线设备（尤 其是手机、头戴式耳机、笔记本个人电脑和PDA等）领域 中应用的迅猛发展,迫切需要开发包含无线及基带电路的 超低功耗芯片组。SiGe技术不仅可满足这种低功耗要求,而且还能满足 蓝牙技术应用的诸多其他要求,本文将对有关情况做简要     

高电子迁移率Si/SiGe异质结构:缓解性SiGe缓冲层的影响

在不同类型的部分缓解性SiGe缓冲层上生长了n型调制掺杂Si/SiGe异质结构,采用这一材料系统是为了得到足够大的导带突变。对样品进行了各种测试分析,如二次离子质谱,x光摆动像分析,透射电子显微镜分析,卢瑟福背散射分析和变温霍尔测量。在750℃生长的厚的线性渐变SiGe缓冲层样品中得到了最高的霍尔迁移率为1.5K下173000cm~2V~(-1)s~(-1)。这一层序达到的室温迁移率约为1800cm~2V~(-1)s~(-1)。发现不管是用没有Ge组分渐变的一般缓冲层,还是直接用有源层是调制掺杂SiGe势垒开始以缓解应变了的Si阱层,主要是在低温下霍尔迁移率严重地下降。     

Applications and processing of SiGe and SiGe:C for high-speed HBT devices

The continued growth of high-speed-digital data transmission and wireless communications technology has motivated increased integration levels for ICs serving these markets. Further, the increasing use of portable wireless communications tools requiring long battery lifetimes necessitates low power consumption by the semiconductor devices within these tools. The SiGe and SiGe:C materials systems provide solutions to both of these market needs in that they are fully monolithically integratible with Si BiCMOS technology. Also, the use of SiGe or SiGe:C HBTs for the high-frequency bipolar elements in the BiCMOS circuits results in greatly decreased power consumption when compared to Si BJT devices.Either a DFT (graded Ge content across the base) or a true HBT (constant Ge content across the base) bipolar transistor can be fabricated using SiGe or SiGe:C. Historically, the graded profile has been favored in the industry since the average Ge content in the pseudomorphic base is less than that of a true HBT and, therefore, the DFT is tolerant of higher thermal budget processing after deposition of the base. The inclusion of small amounts of C (e.g. <0.5%) in SiGe is effective in suppressing the diffusion of B such that very narrow extremely heavily doped base regions can be built. Thus the f_T and f_max of a SiGe:C HBT/DFT are capable of being much higher than that of a SiGe HBT/DFT.The growth of the base region can be accomplished by either nonselective mixed deposition or by selective epitaxy. The nonselective process has the advantage of reduced complexity, higher deposition rate and, therefore, higher productivity than the selective epitaxy process. The selective epi process, however, requires fewer changes to an existing fabrication sequence in order to accommodate SiGe or SiGe:C HBT/DFT devices into the BiCMOS circuit.     

Influence of the oxygen content in SiGe on the parameters of Si/SiGe heterojunction bipolar transistors

We demonstrate peak f_T and f_max of 50 GHz for heterojunction bipolar transistors (HBTs) with an oxygen concentration in the epitaxial SiGe base layer of about 10²⁰ cm⁻³. These f_T/f_max values are over 10 GHz higher than for identically processed HBTs with an O content of only 10¹⁸ cm⁻³. This is due to reduced transient enhanced diffusion of boron in the O-rich layers. However, the base carrier lifetimes are reduced by the high oxygen content. We show that ideal base current characteristics and a low 1/fnoise level can be obtained despite this effect by localizing the emitter-base space-charge region outside the O-rich layer.     

SiGe半导体技术新进展

综述了 Si Ge材料的性质、主要研究方向以及最新的发展情况 ,并介绍了国外 Si Ge的研究情况。     

Surface treatment effects on atomic diffusion in Si explained without self interstitials

Many recent discussions of surface treatment effects on atomic diffusion in Si have explained these largely in terms of effects attributed to Si self interstitials. However, we have shown by our straight forward Monte Carlo (VIDSIM) simulation of diffusion of Au into Si according to the “kick-out” mechanism of Seeger that this mechanism is in fact completely incapable of explaining the two-sided, “U shaped” profile of substitutional Au which results from a one sided in-diffusion of Au. We have shown that if Auinterstitials can displace Si at any appreciable rate, then the Au substitutional profile must decrease monotonically from source side to far side. We noted that this is strong evidence that Si self interstitials play no role in thermal processes in Si. Here we show that the surface treatment effects often attributed to Si self interstitials can be naturally explained without them. Supported in part by U.S. AFOSR-89-0309.