基于锗硅工艺的40-Gb/s分接器

采用0.35μmSiGeBiCMOS工艺设计了一个1∶2分接器,核心电路单元采用经过改进的电路结构实现。由于传统的发射极耦合逻辑结构(ECL)电路的工作速度不能达到要求,对此加以了改进,在发射极耦合逻辑结构中增加一级射极跟随器,形成发射极-发射极耦合逻辑(E2CL)结构,从而提高电路的工作速度。测试结果显示,所设计分接器的工作速度可以达到40Gb/s。整个电路采用单电源5V供电,功耗为510mW。     

采用输入信号适配技术的BiCMOS运放

为了满足高性能开关电源中集成运放的应用需要,设计了一种结构简单且具有轨对轨输出的运算放大器.该运放基于0.5μm BiCMOS 工艺,采用浮动输出的输入信号适配器(ISAFO),将输入信号放大至差分输入级的工作区域,从而实现了轨对轨的运行.对所设计的运放进行了仿真分析,结果表明在工作电源电压为±0.75 V、外接100 kΩ电阻的条件下,该运放的直流开环增益达到了102 dB,单位增益-带宽为6.35 MHz,相位裕度为62.5°,而功耗仅约为150 μW.所设计的运放具有很宽的共模输入范围及较高的增益,所以特别适用于开关电源的误差放大器、过流、过压和过热保护模块中.     

一种多模多频无线收发器前端SiGe BiCMOS低噪声放大器

基于IBM 0.18μm SiGe BiCMOS工艺,提出了一种应用于2.4～2.5GHz 802.11b/g频段的低噪声放大器(LNA).电路采用全差分发射极电感负反馈共射共基(Cascode)结构,对称电感有效地降低了芯片面积,优化了电路性能.仿真结果表明:该电路在2.4 GHz到2.5 GHz频率范围内,增益(S21)达到25 dB,噪声系数(NF)小于1.5 dB,大幅度提高了收发机系统的性能.此外,输入和输出匹配(S11,S22)分别达到-15 dB,1 dB压缩点大于-25 dBm.电源电压为2.5 V时电路总电流为3 mA.     

一种新型热关断电路的设计

提出了一种新型BiCMOS过热关断电路.该电路结构简单、功耗较低、迟滞温度范围基本保持不变,可集成在电源管理芯片中作为过热保护模块使用.采用0.6,um BiCMOS工艺,对电路进行HSPICE仿真,结果表明:该电路对电源电压有很强的抑制比,可用于2～12 V电源电压.     

Electron spin resonance of the two-dimensional metallic state and the quantum Hall state in a Si/SiGe quantum well

We report electrically detected electron spin resonance (ESR) measurements of a high mobility two-dimensional (2D) electron system formed in a Si/SiGe quantum well, with millimeter wave in a high magnetic field . The negative ESR signal observed under an in-plane magnetic field gives direct evidence that the spin polarization leads to a resistance increase in the 2D metallic state. Suppression of spin decoherence was observed in the quantum Hall state at the Landau level filling factor ν=2. Strength of the nuclear magnetic field in the resonance is evaluated to be less than , much smaller than that reported for GaAs/AlGaAs heterostructures.     

SiGe共振腔增强型探测器的制备

利用SOI材料的埋层二氧化硅的自停止特性,成功制作了具有高反射底镜的共振腔增强型SiGe探测器.底镜沉积于EPW腐蚀液腐蚀形成的背孔内,在1.2～1.5μm范围内,反射率高达99%.探测器的共振峰在1.344μm,光响应为1.2mA/W.与普通结构的探测器相比,文中所报道的探测器光响应有8倍的增强.     

基于IBM SiGe BiCMOS工艺5PAe的2GHz功率放大器设计

采用IBM公司刚刚推出试用的0.35μm SiGe BiCMOS开发性工艺5PAe设计并实现了一个2GHz功率放大器. 该放大器采用两级单端结构,除集电极扼流电感外,其余元件全部片上实现,具有集成度高、结构简单的特点. 通过在管子基极和匹配电感中串联电阻,实现了全频段稳定. 键合测试表明,在所有电源电压下电路均能稳定工作. 在VC=3.5V, VB=6V, f=2.0GHz时,小信号增益为20.8dB,输入输出反射系数分别小于-17和-16dB, Pout-2dB约为24dBm. 而在输出功率为25.1dBm时,功率附加效率达到21.5%,二次和三次谐波分别小于-45和-52dBc,因而具有较好的线性度.     

Investigation of Laser-Assisted Microcrystalline SiGe Films Deposited at Low Temperature

SiGe films deposited by conventional plasma-enhanced chemical vapor deposition (PECVD) were compared with microcrystalline SiGe (μc-SiGe) films deposited at a low temperature using a laser-assisted plasma-enhanced chemical vapor deposition (LAPECVD). In the LAPECVD system, a CO₂ laser was used to assist the pyrolytic decomposition of SiH₄ and GeH₄ reactant gases. The μc-SiGe structure was identified using electron diffraction patterns from high-resolution transmission electron microscopy images. Microcrystalline SiGe films were analyzed using various measurements.     

二十四所半导体工艺技术发展历程与展望

回顾了中电科技集团公司第二十四研究所自建所以来的半导体集成电路工艺发展历程.晶圆尺寸从1.5吋(40 mm) 到6吋(150 mm),特征线宽从10 μm到0.5 μm,器件特征频率从低频到射频,工作电压从5 V到800 V,包括射频和高压大功率的各种器件.从研制成功全国第一块大规模集成电路至今,二十四所作为全国唯一的模拟集成电路专业研究所,在各个领域均取得了突出的成就,见证了中国半导体集成电路事业的发展历程.最后,展望了二十四所模拟及专用集成电路工艺技术的发展前景.     

Effect of Ge profile design on the performance of an n-p-n SiGe HBT-based analog circuit

Two new germanium profiles, graded double box (GDB) and graded step box (GSB), are considered in the base region for an n-p-n silicon-germanium heterojunctions bipolar transistors (SiGe HBTs). Their effects on the performance of the HBT-based common emitter amplifier circuit are investigated so as to predict the behavior of analog circuits in the high-frequency region. An analytical model of an n-p-n SiGe HBT with uniform impurity doping in the base is described, and used to extract SPICE parameters for the devices based on GDB and GSB as well as other two accepted profiles i.e. box and triangular profiles. The frequency response, current gain roll-off and gain-bandwidth product of HBT-based common emitter amplifier circuit for all the four profiles have been compared and contrasted.