单轴应变Si NMOSFET模型及模拟技术研究
发布时间：2019-07-08 09:53
【摘要】：为了进一步提高半导体器件的性能,除了改进器件结构外,各种新材料与新技术被不断地应用到器件的设计制造中。由于应变Si材料载流子迁移率高、带隙可调,且应变Si技术与传统的Si工艺兼容等优点,其已成为高速高性能器件与电路研究与应用的重要技术之一。在应变Si技术中,相对于双轴应变,单轴应变更适用于CMOS集成电路制造,在高速高性能集成电路领域具有广阔的发展空间和应用前景。然而,单轴应变Si技术的引入使得器件性能获得提升的同时,其I-V特性、C-V特性、亚阈区特性、栅电流特性等与传统的Si器件相比呈现了新的变化,如果仅通过修改已有的Si器件模型参数值的方法难以描述出现的所有新特性,并且描述出的电学特性总有一些不自洽存在,相应的SPICE仿真精度也难以达到应用要求。因此,必须开发基于应变Si技术机理的器件模型来描述新的电学特性,提高模型精度,同时控制模型复杂度,从而更好地应用于应变Si集成电路的SPICE仿真。为此,本文从单轴应变Si技术提升器件性能的机理出发,基于基本的器件物理方程,对单轴应变Si器件的直流特性、瞬态特性、交流特性模型,以及亚阈区特性模型、栅电流特性模型进行了系统、深入的研究,同时对新建的模型通过仿真器外挂实现仿真的方法进行了研究,开展的主要研究工作和所取得的主要成果为:1、对单轴应变Si NMOSFET基本器件结构及应变Si技术性能提升机理进行了深入研究,在分析了单轴应力对有效质量和散射几率影响的基础上,建立了能准确反映器件物理本质的单轴应变Si NMOSFET载流子迁移率模型。同时给出了阈值电压与应力强度的关系,以及短沟道效应、漏致势垒降低效应、窄沟道效应以及衬偏效应等对阈值电压的影响,最终建立了完整的阈值电压模型。2、在建立了迁移率模型和阈值电压模型的基础上,基于器件不同的工作区域,从基本的漂移扩散方程出发,分别推导求解了沟道电流方程。其中对于亚阈区电流模型,基于常规采用有效沟道厚度近似方法建立的亚阈区电流模型存在精度不能满足要求的问题,提出并采用求解亚阈区反型电荷方法建立了亚阈区电流模型。同时将所建模型的仿真结果与实验结果进行了比较,验证了模型的可行性。所建模型可以准确地模拟单轴应变Si NMOSFET电学特性,适用于单轴应变Si NMOSFET的集成电路设计与仿真。3、针对当前主流SPICE电荷模型尚未考虑应力因素,提出并分别建立了基于应力的单轴应变Si NMOSFET积累区、耗尽区、亚阈区及反型区的电荷模型,同时通过平滑函数,最终获得了具有连续性的单轴应变Si NMOSFET的16个微分电容模型。模型揭示了应力对相关电容的作用与影响,并将微分电容的仿真结果与实验结果进行了比较,验证了所建模型的正确性。同时对相关电容与应力强度、偏置电压、沟道长度、栅极掺杂浓度等的关系进行了分析研究。并且建立了寄生元件模型、衬底结电荷与电容模型以及模型参数的温度依赖效应模型。4、为了解决主流SPICE栅电流模型仅通过公式拟合的方法应用于单轴应变Si NMOSFET而导致机制缺失及影响精度的问题,本章在深入分析热载流子栅电流及栅隧穿电流产生的微观物理机制基础上,提出并分别建立了包含应力作用的单轴应变Si NMOSFET热载流子栅电流及栅隧穿电流模型。模型考虑了热载流子面密度、注入效率、溢出几率、隧穿几率等影响,同时对栅电流与应力强度、沟道掺杂浓度、栅源电压、漏源电压等的关系,以及TDDB(经时击穿)寿命与栅源电压的关系进行了分析研究。5、在建立直流特性、瞬态特性、交流特性模型,以及亚阈区特性模型、栅电流特性模型的过程中,引入了应力强度参数,使得所建立的模型能直观地反映出电学特性与应力强度、应力类型等的关系,并且模型物理意义明确,有利于应变Si NMOSFET器件的分析和设计。6、基于单轴应变Si NMOSFET等效电路、器件参数、器件方程,采用verilogA语言实现了可以被SPICE仿真器外挂的器件模型文件,实现了与SPICE资源共享的单轴应变Si器件和电路的仿真。该方法开发灵活,利于模型的进一步改进和升级。利用课题组同步开发的参数提取软件ParaPlus++提取了模型参数,通过仿真结果与器件测试结果比较,验证了所建模型的正确性,实现了主流仿真器精确进行单轴应变Si器件和电路仿真的问题。
文内图片：
图片说明：MOSFET沟道长度等比例缩小趋势图
[Abstract]:In order to further improve the performance of the semiconductor device, various new materials and new technologies are constantly applied to the design and manufacture of the device in addition to the improved device structure. Because of the high carrier mobility and the tunable band gap of the strained Si material, and the strain Si technology is compatible with the traditional Si process, it has become one of the important technologies of high-speed high-performance device and circuit research and application. In that strain-Si technology, the uniaxial strain is adapt to the manufacture of a CMOS integrated circuit with respect to the biaxial strain, and has wide development space and application prospect in the field of high-speed high-performance integrated circuits. However, the introduction of the uniaxial strain Si technology makes the performance of the device improved, and the I-V characteristic, the C-V characteristic, the sub-threshold region characteristic, the gate current characteristic, and the like exhibit a new change compared to the conventional Si device, If only the method of modifying the existing Si device model parameter values is difficult to describe all the new characteristics that appear, and the electrical characteristics described are always self-consistent, the corresponding SPICE simulation accuracy is difficult to meet the application requirements. Therefore, a device model based on the mechanism of strain-Si technology must be developed to describe the new electrical characteristics, to improve the accuracy of the model, and to control the complexity of the model, so as to better apply to the SPICE simulation of the strained Si integrated circuit. In this paper, based on the basic device physical equation, the DC characteristic, the transient characteristic, the AC characteristic model, the sub-threshold region characteristic model and the grid current characteristic model of the single-axis strained Si device are studied based on the basic device physical equation. In this paper, a deep research is carried out, and the simulation method of the new model is studied. The main research work and the main results are as follows:1. The basic device structure of the single-axis strained Si NMOSFET and the mechanism of the strain-Si technology are studied deeply. Based on the analysis of the effect of uniaxial stress on the effective mass and the scattering probability, a single-axis strained Si NMOSFET carrier mobility model which can accurately reflect the physical essence of the device is established. The relationship between the threshold voltage and the stress intensity, the effect of the short channel effect, the leakage-induced potential barrier, the narrow channel effect and the bias effect on the threshold voltage are also given, and a complete threshold voltage model is finally established. Based on the establishment of the mobility model and the threshold voltage model, the channel current equation is derived from the basic drift diffusion equation based on different working regions of the device. In the sub-threshold region current model, the sub-threshold region current model is established based on the problem that the accuracy of the sub-threshold region current model which is established by using the effective channel thickness approximation method does not meet the requirements. The simulation results of the model are compared with the experimental results, and the feasibility of the model is verified. The model can accurately simulate the electrical characteristics of the single-axis strained Si NMOSFET, and is suitable for the integrated circuit design and simulation of the single-axis strained Si NMOSFET. The charge model of the subthreshold region and the inversion region is obtained, and the 16 differential capacitance models of the single-axis strained Si NMOSFET with continuity are finally obtained through the smoothing function. The effect and effect of the stress on the relevant capacitance are revealed, and the simulation results of the differential capacitance are compared with the experimental results, and the correctness of the model is verified. The relationship between the relative capacitance and the stress intensity, the bias voltage, the channel length, the gate doping concentration and so on is analyzed. And the temperature dependence effect model of the parasitic element model, the substrate junction charge and the capacitance model and the model parameters is established. On the basis of in-depth analysis of the micro-physical mechanism of the hot carrier gate current and the gate tunneling current, the thermal carrier gate current and the gate tunneling current model of the single-axis strained Si NMOSFET with stress are proposed and established, respectively. the model considers the influence of the hot carrier surface density, the injection efficiency, the overflow probability, the tunneling probability and the like, and at the same time, the relationship between the gate current and the stress intensity, the channel doping concentration, the gate source voltage, the drain source voltage and the like is taken into consideration, and the relationship between the life of the TDDB (with time breakdown) and the grid source voltage is analyzed and studied. In the process of establishing the DC characteristic, the transient characteristic, the AC characteristic model and the sub-threshold region characteristic model and the grid current characteristic model, the stress intensity parameter is introduced, so that the established model can intuitively reflect the relationship between the electrical characteristics and the stress intensity, the stress type, and the like, and the physical significance of the model is clear, the analysis and the design of the strained Si NMOSFET device are facilitated, and 6, based on the equivalent circuit of the single-axis strained Si NMOSFET, the device parameters and the device equation, The device model file which can be externally hung by the SPICE simulator is realized by using veriloA language, and the simulation of the single-axis strained Si device and the circuit with the SPICE resource sharing is realized. The method has flexible development and is beneficial to further improvement and upgrading of the model. The model parameters are extracted by using the parameter extraction software ParasPlus + + developed by the research group, and the correctness of the model is verified by comparing the simulation results with the device test results, and the problem of accurate single-axis strain Si device and circuit simulation of the main flow simulator is realized.
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN386
本文编号：2511506
文内图片：
图片说明：MOSFET沟道长度等比例缩小趋势图
[Abstract]:In order to further improve the performance of the semiconductor device, various new materials and new technologies are constantly applied to the design and manufacture of the device in addition to the improved device structure. Because of the high carrier mobility and the tunable band gap of the strained Si material, and the strain Si technology is compatible with the traditional Si process, it has become one of the important technologies of high-speed high-performance device and circuit research and application. In that strain-Si technology, the uniaxial strain is adapt to the manufacture of a CMOS integrated circuit with respect to the biaxial strain, and has wide development space and application prospect in the field of high-speed high-performance integrated circuits. However, the introduction of the uniaxial strain Si technology makes the performance of the device improved, and the I-V characteristic, the C-V characteristic, the sub-threshold region characteristic, the gate current characteristic, and the like exhibit a new change compared to the conventional Si device, If only the method of modifying the existing Si device model parameter values is difficult to describe all the new characteristics that appear, and the electrical characteristics described are always self-consistent, the corresponding SPICE simulation accuracy is difficult to meet the application requirements. Therefore, a device model based on the mechanism of strain-Si technology must be developed to describe the new electrical characteristics, to improve the accuracy of the model, and to control the complexity of the model, so as to better apply to the SPICE simulation of the strained Si integrated circuit. In this paper, based on the basic device physical equation, the DC characteristic, the transient characteristic, the AC characteristic model, the sub-threshold region characteristic model and the grid current characteristic model of the single-axis strained Si device are studied based on the basic device physical equation. In this paper, a deep research is carried out, and the simulation method of the new model is studied. The main research work and the main results are as follows:1. The basic device structure of the single-axis strained Si NMOSFET and the mechanism of the strain-Si technology are studied deeply. Based on the analysis of the effect of uniaxial stress on the effective mass and the scattering probability, a single-axis strained Si NMOSFET carrier mobility model which can accurately reflect the physical essence of the device is established. The relationship between the threshold voltage and the stress intensity, the effect of the short channel effect, the leakage-induced potential barrier, the narrow channel effect and the bias effect on the threshold voltage are also given, and a complete threshold voltage model is finally established. Based on the establishment of the mobility model and the threshold voltage model, the channel current equation is derived from the basic drift diffusion equation based on different working regions of the device. In the sub-threshold region current model, the sub-threshold region current model is established based on the problem that the accuracy of the sub-threshold region current model which is established by using the effective channel thickness approximation method does not meet the requirements. The simulation results of the model are compared with the experimental results, and the feasibility of the model is verified. The model can accurately simulate the electrical characteristics of the single-axis strained Si NMOSFET, and is suitable for the integrated circuit design and simulation of the single-axis strained Si NMOSFET. The charge model of the subthreshold region and the inversion region is obtained, and the 16 differential capacitance models of the single-axis strained Si NMOSFET with continuity are finally obtained through the smoothing function. The effect and effect of the stress on the relevant capacitance are revealed, and the simulation results of the differential capacitance are compared with the experimental results, and the correctness of the model is verified. The relationship between the relative capacitance and the stress intensity, the bias voltage, the channel length, the gate doping concentration and so on is analyzed. And the temperature dependence effect model of the parasitic element model, the substrate junction charge and the capacitance model and the model parameters is established. On the basis of in-depth analysis of the micro-physical mechanism of the hot carrier gate current and the gate tunneling current, the thermal carrier gate current and the gate tunneling current model of the single-axis strained Si NMOSFET with stress are proposed and established, respectively. the model considers the influence of the hot carrier surface density, the injection efficiency, the overflow probability, the tunneling probability and the like, and at the same time, the relationship between the gate current and the stress intensity, the channel doping concentration, the gate source voltage, the drain source voltage and the like is taken into consideration, and the relationship between the life of the TDDB (with time breakdown) and the grid source voltage is analyzed and studied. In the process of establishing the DC characteristic, the transient characteristic, the AC characteristic model and the sub-threshold region characteristic model and the grid current characteristic model, the stress intensity parameter is introduced, so that the established model can intuitively reflect the relationship between the electrical characteristics and the stress intensity, the stress type, and the like, and the physical significance of the model is clear, the analysis and the design of the strained Si NMOSFET device are facilitated, and 6, based on the equivalent circuit of the single-axis strained Si NMOSFET, the device parameters and the device equation, The device model file which can be externally hung by the SPICE simulator is realized by using veriloA language, and the simulation of the single-axis strained Si device and the circuit with the SPICE resource sharing is realized. The method has flexible development and is beneficial to further improvement and upgrading of the model. The model parameters are extracted by using the parameter extraction software ParasPlus + + developed by the research group, and the correctness of the model is verified by comparing the simulation results with the device test results, and the problem of accurate single-axis strain Si device and circuit simulation of the main flow simulator is realized.
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN386
【相似文献】
相关期刊论文 前2条
1 戴显英;王琳;杨程;郑若川;张鹤鸣;郝跃;;机械致单轴应变SOI晶圆的制备[J];西安电子科技大学学报;2012年03期
2 ;[J];;年期
相关博士学位论文 前2条
1 吕懿;单轴应变Si NMOSFET模型及模拟技术研究[D];西安电子科技大学;2015年
2 马建立;单轴应变硅能带结构及载流子迁移率研究[D];西安电子科技大学;2012年
相关硕士学位论文 前1条
1 王琳;机械致单轴应变SOI研究[D];西安电子科技大学;2012年
，本文编号：2511506
本文链接：https://www.wllwen.com/kejilunwen/dianzigongchenglunwen/2511506.html
