一种InGaAs/InP复合沟道高电子迁移率晶体管模拟的新方法

采用一种新方法对InGaAs/InP复合沟道高电子迁移率晶体管进行了模拟.该方法通过流体力学模型和密度梯度模型的联合求解,得到了沟道内的电子密度分布.与一些传统方法相比,该方法收敛性更好,速度更快,且同样适用于其他类型高电子迁移率晶体管器件的模拟.利用仿真对InGaAs/InP复合沟道高电子迁移率晶体管进行了深入研究.     

0.25μm GaAs基MHEMT器件

采用普通接触曝光研制成栅长为0.25μm的GaAs基InAlAs/InGaAs变组分高电子迁移率晶体管(MHEMT),测得其跨导为522mS/mm,沟道电流密度达490mA/mm,截止频率为75GHz,比同样工艺条件下GaAs基InGaP/InGaAs PHEMT的性能有很大的提高.对该器件工艺及结果进行了分析,提取了器件的交流小信号等效电路模型参数,并提出了进一步得到高稳定性、高性能器件的方法.     

MBE生长高2-DEG面密度InP基PHEMT外延材料

利用MBE技术生长了InP基InAlAs/InGaAs PHEMT结构,使用原子力显微镜(AFM)、霍耳测试系统研究了影响二维电子气(2-DEG)面密度和电子迁移率的因素,着重分析了隔离层厚度、沟道层In组分的影响.在保持较高迁移率的基础上,生长出了高μn×ns的InP PHEMT外延材料.     

印制电路与集成电路

Y2002-63306-618 03094923英寸 InP 衬底上的0.1μm InGaAs/InAlAs/Inp 高电子迁移率晶体管毫米波集成电路可靠性=High relia-bility of 0.1μm InGaAs/InAlAs/InP HEMT MMICs on3-inch InP substrates[会,英]/Chou,Y.C.& Leung,D.//2001 IEEE International Confefence on IndiumPhosphjde and Related Materials.—618～621(E)     

InGaAs/InP SAGCM-APD的器件模型及其数值模拟

基于泊松方程和载流子连续性方程,导出了InGaAs/InP SAGCM-APD(吸收、渐变、电荷、倍增层分离结构雪崩光电二极管)特性的数学模型,利用数值计算工具对其进行了数值模拟,得到了APD内部电场分布、增益特性、暗电流特性、过剩噪声和增益带宽特性等的数值结果.模拟结果与实际器件特性测量结果相符合,表明运用该模型与数值模拟方法可对不同结构参数的InGaAs/InP SAGCM-APD进行结构设计、工艺改进和特性分析.     

最大振荡频率640 GHz的70 nm栅长InAs PHEMTs器件

由于高的电子迁移率和二维电子气浓度,InP基赝配高电子迁移率晶体管（PHEMTs）器件成为制作太赫兹器件最有前途的三端器件之一。为提高器件的工作频率,采用InAs复合沟道,使得二维电子气的电子迁移率达到13000 cm2/（Vs）。成功研制出70 nm栅长的InP基赝配高电子迁移率晶体管,器件采用双指,总栅宽为30 m,源漏间距为2 m。为降低器件的寄生电容,设计T型栅的栅根高度达到210 nm。器件的最大漏端电流为1440 mA/mm （VGS=0.4 V）,最大峰值跨导为2230 mS/mm。截止频率fT和最大振荡频率fmax分别为280 GHz和640 GHz。这些性能显示该器件适于毫米波和太赫兹波应用。     

带有复合掺杂层集电区的InP/InGaAs/InP DHBT直流特性分析

设计了一种新结构InP/InGaAs/InP双异质结双极晶体管(DHBT),在集电区与基区之间插入n+-InP层,以降低集电结的导带势垒尖峰,克服电流阻挡效应.采用基于热场发射和连续性方程的发射透射模型,计算了n+-InP插入层掺杂浓度和厚度对InP/InGaAs/InP DHBT集电结导带有效势垒高度和I-V特性的影响.结果表明,当n+-InP插入层掺杂浓度为3×1019cm-3、厚度为3nm时,可以获得较好的器件特性.采用气态源分子束外延(GSMBE)技术成功地生长出InP/InGaAs/InP DHBT结构材料.器件研制结果表明,所设计的DHBT材料结构能有效降低集电结的导带势垒尖峰,显著改善器件的输出特性.     

InP/InGaAs/InP双异质结双极晶体管技术研究

介绍了InP/InGaAs/InP双异质结双极晶体管(DHBT)材料生长、器件结构与设计、制作工艺和性能测试以及在振荡器中的应用等方面的研究.采用发射极-基极自对准工艺制作了InP/InGaAs/InP DHBT器件,发射极尺寸为1.5μm×10μm的器件小电流直流增益β约25,集电极-发射极击穿电压BVCEO≥10V,截止频率,ft和最高振荡频率,fmax分别为50和55GHz;     

InP/InGaAs/InP双异质结双极晶体管技术研究

介绍了InP/InGaAs/InP双异质结双极晶体管(DHBT)材料生长、器件结构与设计、制作工艺和性能测试以及在振荡器中的应用等方面的研究.采用发射极-基极自对准工艺制作了InP/InGaAs/InP DHBT器件,发射极尺寸为1.5μm×10μm的器件小电流直流增益β约25,集电极-发射极击穿电压BVCEO≥10V,截止频率,ft和最高振荡频率,fmax分别为50和55GHz;     

一种改进了碰撞电离的超高速InP基SHBT SDD模型

从物理机制上分析了超高速InP/InGaAs SHBT碰撞电离与温度的关系,通过加入表示温度的参数和简化电场计算,得到一种改进的碰撞电离模型. 同时针对自有工艺和器件特性,采用SDD (symbolically defined device）技术建立了一个包括碰撞电离和自热效应的InP/InGaAs SHBT的直流模型. 模型内嵌入HP-ADS中仿真并与测试结果进行比较,准确地拟合了InP/InGaAs SHBT的器件特性.     

Design and characteristics of InGaAs/InP composite-channel HFET's

A design for composite-channel structures consisting of an InGaAs channel and an InP subchannel for use as heterostructure field-effect transistors is presented for the first time. This novel channel structure takes advantage of both the high drift velocity and low impact ionization of InP at high electric fields as well as the high electron mobility of InGaAs at low electric fields. It is shown that the doping density of the InP subchannel is the key parameter to realize the advantages of the composite channel. A very high transconductance of 1.29 S/mm and a current gain cutoff frequency of 68.7 GHz are achieved with 0.6 and 0.7 /spl mu/m gates, respectively. The average velocity of electrons in the composite channel is 2.9/spl times/10/sup 7/ cm/s. The devices have no kink phenomena in their I-V characteristics possibly due to low impact ionization in the InP subchannel.<>     

Investigation of Impact Ionization in InAs-Channel HEMT for High-Speed and Low-Power Applications

An 80-nm InP high electron mobility transistor (HEMT) with InAs channel and InGaAs subchannels has been fabricated. The high current gain cutoff frequency (f_t) of 310 GHz and the maximum oscillation frequency (f_max) of 330 GHz were obtained at V_DS = 0.7 V due to the high electron mobility in the InAs channel. Performance degradation was observed on the cutoff frequency (f_t) and the corresponding gate delay time caused by impact ionization due to a low energy bandgap in the InAs channel. DC and RF characterizations on the device have been performed to determine the proper bias conditions in avoidance of performance degradations due to the impact ionization. With the design of InGaAs/InAs/InGaAs composite channel, the impact ionization was not observed until the drain bias reached 0.7 V, and at this bias, the device demonstrated very low gate delay time of 0.63 ps. The high performance of the InAs/InGaAs HEMTs demonstrated in this letter shows great potential for high-speed and very low-power logic applications.     

带有复合掺杂层集电区的InP/InGaAs/InP DHBT直流特性分析

设计了一种新结构InP/InGaAs/InP双异质结双极晶体管(DHBT),在集电区与基区之间插入n -InP层,以降低集电结的导带势垒尖峰,克服电流阻挡效应.采用基于热场发射和连续性方程的发射透射模型,计算了n -InP插入层掺杂浓度和厚度对InP/InGaAs/InP DHBT集电结导带有效势垒高度和I-V特性的影响.结果表明,当n -InP插入层掺杂浓度为3×1019cm-3、厚度为3nm时,可以获得较好的器件特性.采用气态源分子束外延(GSMBE)技术成功地生长出InP/InGaAs/InP DHBT结构材料.器件研制结果表明,所设计的DHBT材料结构能有效降低集电结的导带势垒尖峰,显著改善器件的输出特性.     

0.1-μm T-gate Al-free InP/InGaAs/InP pHEMTs for W-bandapplications using a nitrogen carrier for LP-MOCVD growth

We report on the DC and RF performance of HEMTs based on the Al-free material system InP/InGaAs/InP. These structures were grown by LP-MOCVD using a nitrogen carrier. The influence of gate length and channel composition on the performance of these devices is investigated. We demonstrate that optimum DC and RF performance using highly strained channels can be obtained only if additional composite channels are grown. The cutoff frequencies f_T=160 GHz and f_max=260 GHz for a 0.1-μm T-gate device indicate the suitability of our devices for W-band applications     

22 nm In0.75Ga0.25As channel-based HEMTs on InP/GaAs substrates for future THz applications

In this work, the performance of L_g=22 nm In_0.75Ga_0.25As channel-based high electron mobility transistor (HEMT) on InP substrate is compared with metamorphic high electron mobility transistor (MHEMT) on GaAs substrate. The devices features heavily doped In_0.6Ga_0.4As source/drain (S/D) regions, Si double δ-doping planar sheets on either side of the In_0.75Ga_0.25As channel layer to enhance the transconductance, and buried Pt metal gate technology for reducing short channel effects. The TCAD simulation results show that the InP HEMT performance is superior to GaAs MHEMT in terms of f_T, f_max and transconductance (g_{m_max}). The 22 nm InP HEMT shows an f_T of 733 GHz and an f_max of 1340 GHz where as in GaAs MHEMT it is 644 GHz and 924 GHz, respectively. InGaAs channel-based HEMTs on InP/GaAs substrates are suitable for future sub-millimeter and millimeter wave applications.     

Analysis of hot carrier transport in AlGaAs/InGaAs pseudomorphicHEMTs by means of electroluminescence

The carrier transport phenomena occurring in pseudomorphic AlGaAs/InGaAs HEMTs biased in the on-state impact-ionization regime is analyzed in this paper. We confirm the presence, in the electroluminescence spectra of pseudomorphic HEMTs, of a dominant contribution due to electron-hole recombination and we identify a composite peak due to recombination of cold carriers. We analyze the recombination peak using a high-resolution monochromator, which reveals the fine structure due to transitions between electron and hole subbands in the channel quantum well, thus providing useful data concerning the properties of the InGaAs HEMT channel. We also demonstrate that recombination between nonenergetic electrons and holes occurs in the gate-source region, as already observed in InAlAs/InGaAs HEMT's on InP. This recombination emission is superimposed to a less intense contribution mostly coming from the gate drain region. This contribution has a nearly Maxwellian distribution which extends to fairly high energies (>3 eV) and has equivalent temperatures in the 1000-3000 K range. Finally we show evidence of recombination in the AlGaAs layers (observed at high electric field), which demonstrates, in these devices, real space transfer of both electrons and holes     

Avalanche multiplication in InP/InGaAs double heterojunctionbipolar transistors with composite collectors

The experimental and theoretical studies of electron multiplication in InP/InGaAs double heterojunction bipolar transistors (DHBT's) with an InGaAs/InP composite collector are carried out. Both local electric field model and energy model are used to investigate the electron impact ionization in the composite collector. The analysis reveals that the nonlocal effect of the electron impact ionization in the composite collector is responsible for the suppression of the contribution of electron multiplication in the InGaAs layer. Experimental results for the fabricated devices were compared with the theoretical calculations, indicating that the conventional impact ionization models based on the local electric field significantly overestimate the electron multiplication for the composite collector. The energy model which takes into account the nonlocal effect is found to provide a more accurate prediction of electron multiplication for the DHBT's     

Temperature dependence of avalanche multiplication in InP-based HBTs with InGaAs/InP composite collector: device characterization and physics model

Recent efforts are being focused on improving the breakdown of InP-based heterojunction bipolar transistors (HBTs) towards high-power applications. A fundamental understanding of the temperature dependence of breakdown and its physics mechanism in these devices is important. In this work, a detailed characterization of temperature-dependent collector breakdown behavior in InP DHBTs (DHBTs) with an InGaAs/InP composite collector is carried out. A physics model for the prediction of temperature-dependent breakdown in lnP/InGaAs composite collector is developed. We found that, although the variation of impact ionization coefficient due to the change of temperature may affect the device breakdown, the temperature-dependence of breakdown in the lnGaAs/InP composite collector could be significantly affected by the carrier transport in the InGaAs region. As temperature is increased, the increase in the contribution of InGaAs layer to the junction breakdown due to the reduction of electron energy relaxation length could be the root cause of the reduction of junction breakdown voltage. Good agreement between the physics model and experimental data demonstrate the validities of the proposed physics model to predict the temperature dependent breakdown characteristics for InP DHBTs.     

Current-gain cutoff frequency comparison of InGaAs HEMTs

The current-gain cutoff frequency performance of pseudomorphic InGaAs/AlGaAs (20% InAs composition) high-electron-mobility transistors (HEMTs) on GaAs is compared to that of lattice-matched InGaAs/InAlAs HEMTs on InP. The current-gain cutoff frequency (f_t) characteristics as a function of gate length (L_g) indicate that the f_t-L_g product of ~26 GHz-μm in InGaAs/InAlAs HEMTs is 23% higher than that of ~21 GHz-μm in InGaAs/AlGaAs HEMTs. The performance of InGaAs/AlGaAs HEMTs is also 46% higher than that of conventional GaAs/AlGaAs HEMTs (~18 GHz-μm). These data are very useful in improving the device performance of HEMTs for a given gate length