【作者】 曹阳；

【导师】 张为；

【作者基本信息】 天津大学 ， 微电子学与固体电子学， 2020， 博士

【摘要】 CMOS技术的不断发展和新应用的迫切需求,结合低成本、低功耗以及高集成度等优势使其成为微波集成电路的重要选择。CMOS技术在微波集成电路以及系统中的应用与器件的准确建模和参数提取密切相关。同时,CMOS工艺特征尺寸的不断缩小为集成半导体器件集约模型的研究与开发带来了巨大挑战。目前普遍应用的MOSFET器件模型在微波频段内存在表征不全面、模型精度不够高等缺点,而且模型参数提取的准确性依然存在不足。基于上述问题,本文主要针对深亚微米CMOS工艺展开器件S参数在片测试、建模和参数提取等相关技术研究。主要工作如下:首先,设计不同尺寸的MOSFET及带有地屏蔽的共面波导等传输线结构,并流片测试。为了获取准确的建模数据,评估了简化的分布式四端口网络去嵌入方法,并与开路-短路法进行了比较。创新提出了一种电磁仿真辅助去嵌入技术,为微波无源器件提供建模参考。同时,验证了开路-短路去嵌入法的频率适用范围,为后续建模提参打下良好的基础。第二,建立了完整的微波MOSFET小信号等效电路模型。通过增加一个串联RC电路分支,更好地模拟了栅极和漏极间的高频耦合寄生效应。为了提高多参数优化效率,开发了一种新的遗传算法可对MOSFET模型中所有参数进行同步优化,缩短了处理时间,并且对进一步改进参数的提取方法具有指导意义。第三,基于器件的物理机理,提出了一种针对关态MOSFET小信号模型的多参数扫描参数提取方法,无需高频或低频近似,通过单个或多个参数扫描结合线性回归技术可准确提取关键寄生参数。此外,研究了一种将有理函数非线性拟合应用于上述关态MOSFET小信号模型的参数提取方法,践行了一种具有一般性的宽频带参数直接提取策略。这两种参数提取技术弥补了目前等效电路中因物理参数近似提取所产生的不足,并相互验证、互相补充。通过对上海华力微电子有限公司射频CMOS工艺一系列不同尺寸和偏置条件的NMOS晶体管进行测试与实验验证,证明了模型与参数提取方法的准确性和有效性。总之,本论文针对CMOS工艺微波器件建模和参数提取提出的去嵌入方法、模型及参数的直接提取技术,有效解决了目前微波器件片上测试去嵌入问题,改善了微波MOSFET模型的完整性,突破了现有参数提取技术中存在的近似和优化效率较低的局限性,可广泛适用于建立微波MOSFET集约模型,对深亚微米CMOS工艺的改进和微波集成电路设计优化具有重要的实际意义。更多还原

【Abstract】 The continued development of CMOS technology and the emergence of new applications make the CMOS technology an important choice for microwave integrated circuits for its low cost,low power consumption and high integration.The applications of the CMOS technology in microwave integrated circuits and systems are strongly linked to the accurate modeling and parameter extraction of devices.Simultaneously,the continued scaling of CMOS process poses great challenges for the research and development of compact models of integrated semiconductor devices.The widely used MOSFET compact models have disadvantages in microwave yet,such as incomplete characterization,insufficient model precision,and the accuracy of model parameter extraction is still insufficient.Based on the above issues,this thesis will carry out the technology research of S-parameter on-chip measurement,modeling and parameter extraction of the deep sub-micron CMOS process devices.The main tasks can be summarized as follows:Firstly,a set of MOSFET test structures and grounded coplanar waveguides(GCPWs)are designed,fabricated and measured.To get accurate modeling data,we evaluate the advantages of simplified distributed four-port de-embedding methods in comparison with the open-short de-embedding technique.An electromagnetic simulation aided de-embedding(EMSAD)technique is proposed innovatively.The de-embedded results of the proposed technique are used as reference for modeling of passive components at microwave frequencies.At the same time,the applicability of the open-short de-embedding method is verified,which laid a good foundation for subsequent research work of modeling and parameter extraction.Secondly,we propose a complete MOSFET small-signal equivalent circuit model.A RC branch is added to model the coupling effects arising from non-ideality parasitics in high frequency region between gate and drain.To improve the efficiency of multi-parameter optimization,a new genetic algorithm(GA)optimization technique is developed to optimize all of the MOSFET model parameters simultaneously,thus reducing the processing time,and the optimized parameters can guide us to improve the direct parameter extraction method in further research.Thirdly,based on the device physical mechanisms,a novel multi-parameter scanning(MPS)parameter extraction technique for the off-state MOSFET small-signal equivalent circuit is proposed.The MPS technique is used to accurately extract crucial parasitic parameters by single or multiple parameter scans and linear regression without using any high frequency or low frequency approximations.In addition,a nonlinear fitting extraction technique of rational function is researched of the above small-signal equivalent circuit.It implements a general direct extraction strategy for broadband application.These two parameter extraction techniques make up for the shortcomings caused by approximate extraction of physical parameters in equivalent circuits,with the two methods verifying and complementing each other.A set of NMOS transistor test structures fabricated on Shanghai Huali Microelectronics Corporation(HLMC)RF CMOS process with different device sizes and bias conditions are measured and investigated,thus demonstrating the accuracy and effectiveness of the model and parameter extraction.In summary,a series of the de-embedding methods,models and parameter direct extraction techniques for microwave MOSFET modeling proposed in this thesis,solve the problem of on-chip de-embedding for microwave devices and improve the modeling integrity of the microwave MOSFET,break through limitations of inaccurate or inefficient modeling extraction and low optimization efficiency in the existing parameter extraction methodologies.The proposed methods can be widely used in RF MOSFET compact modeling extraction,and therefore are of important practical significance in the improvement and microwave integrated circuit design and optimization of the deep sub-micron CMOS process technologies.更多还原