SPICE compatible analytical electron mobility model for biaxial strained-Si-MOSFETs

This paper describes an analytical model for bulk electron mobility in strained-Si layers as a function of strain.Phonon scattering,columbic scattering and surface roughness scattering are included to analyze the full mobility model.Analytical explicit calculations of all of the parameters to accurately estimate the electron mobility have been made.The results predict an increase in the electron mobility with the application of biaxial strain as also predicted from the basic theory of strain physics of metal oxide semiconductor(MOS) devices.The results have also been compared with numerically reported results and show good agreement.     

Two-dimensional threshold voltage analytical modes of DMG strained-silicon-on-insulator MOSFETs

For the first time, a simple and accurate two-dimensional analytical model for the surface potential variation along the channel in fully depleted dual-material gate strained-Si-on-insulator (DMG SSOI) MOSFETs is developed. We investigate the improved short channel effect (SCE), hot carrier effect (HCE), drain-induced barrier-lowering (DIBL) and carrier transport efficiency for the novel structure MOSFET. The analytical model takes into account the effects of different metal gate lengths, work functions, the drain bias and Ge mole fraction in the relaxed SiGe buffer. The surface potential in the channel region exhibits a step potential, which can suppress SCE, HCE and DIBL. Also, strained-Si and SOI structure can improve the carrier transport efficiency, with strained-Si being particularly effective. Further,the threshold voltage model correctly predicts a "rollup" in threshold voltage with decreasing channel length ratios or Ge mole fraction in the relaxed SiGe buffer. The validity of the two-dimensional analytical model is verified using numerical simulations.     

对称三材料双栅应变硅MOSFET亚阈值电流与亚阈值斜率解析模型

基于泊松方程和边界条件,推导了对称三材料双栅应变硅金属氧化物半导体场效应晶体管（MOSFET：metal oxide semiconductor field effect transistor）的表面势解析解.利用扩散-漂移理论,在亚阈值区电流密度方程的基础上,提出了亚阈值电流与亚阈值斜率二维解析模型.分析了沟道长度、功函数差、弛豫SiGe层的Ge组份、栅介质层的介电常数、应变硅沟道层厚度、栅介质高k层厚度和沟道掺杂浓度等参数对亚阈值性能的影响,并对亚阈值性能改进进行了分析研究.研究结果为优化器件参数提供了有意义的指导.模型解析结果与DESSIS仿真结果吻合较好.     

非对称异质双栅应变硅MOSFETs 二维模型研究

基于对二维泊松方程的精确求解,本文对全耗尽型非对称异质双栅应变硅MOSFET的二维表面势,表面电场,阈值电压进行了研究。模型结果和二维数值模拟器的结果很吻合。此外并对该器件的物理作了深入的研究。该模型对设计全耗尽型非对称异质双栅应变硅MOSFET器件有着重要的指导作用.     

A two-dimensional analytical model of fully depleted asymmetrical dual material gate double-gate strained-Si MOSFETs

On the basis of the exact resultant solution of two dimensional Poisson’s equations,a new accurate two-dimensional analytical model comprising surface channel potentials,a surface channel electric field and a threshold voltage for fully depleted asymmetrical dual material gate double-gate strained-Si MOSFETs is successfully developed. The model shows its validity by good agreement with the simulated results from a two-dimensional numerical simulator.Besides offering a physical insight into device physics,the model provides basic design guidance for fully depleted asymmetrical dual material gate double-gate strained-Si MOSFETs.     

单轴应变Si导带色散关系解析模型

本文基于k·p 理论框架, 分析了单轴应力对导带能带结构的影响, 详细讨论了剪切应力作用下布里渊区边界X点处Δ₁和Δ_2′ 能带之间的耦合作用及其对导带能谷极小值的改变, 由此进一步给出了能谷极值点附近的色散关系. 最后通过不同能谷之间的坐标变换, 得到了任意单轴应力作用下每个能谷的色散关系. 本文的研究可以为单轴应变Si材料物理性质的理解以及对反型层能带结构、电学特性的相关研究提供一定的理论参考.     

薄虚拟SiGe衬底上的应变Si pMOSFETs

成功地试制出薄虚拟SiGe衬底上的应变Si pMOSFETs.利用分子束外延技术在100nm低温Si(LT-Si)缓冲层上生长的弛豫虚拟Si0.8Ge0.2衬底可减薄至240nm.低温Si缓冲层用于释放虚拟SiGe衬底的应力,使其应变弛豫.X射线双晶衍射和原子力显微镜测试表明:虚拟SiGe衬底的应变弛豫度为85%,表面平均粗糙度仅为1.02nm.在室温下,应变Si pMOSFETs的最大迁移率达到140cm2/(V·s).器件性能略优于采用几微米厚虚拟SiGe衬底的器件.     

应变硅MOSFET沟道应变的有限元研究

本文报道了利用有限元计算和动力学大角度会聚束电子衍射模拟的方法研究了应变硅场效应晶体管沟道中的应变分布.沟道压应变是利用预非晶化源漏区锗离子注入应变诱导工艺技术引入的.有限元计算结果显示,器件的源漏区很低的锗注入剂量在沟道区的顶层造成了很大的压应变,而且在沟道和硅衬底中间形成一个应变过渡层.大角度会聚束电子衍射的动力学模拟结果与有限元计算结果符合很好.     

薄膜全耗尽应变Si SOI MOSFET特性模拟与优化分析

研究了应变Si沟道引入对薄膜全耗尽SOI MOSHET器件特性的影响,并分析了器件特性改进的物理机理.与传统的SOI MOSFET结构相比,器件的驱动电流和峰值跨导都有明显提高,对n-FET分别为21%和16.3%,对p-FET为14.3%和10%.应变si沟道的引入还降低了器件的阈值电压,这有益于集成电路中供电电压的降低和电路功耗的减小.另外,本文还对新结构中的Ge含量进行了优化分析,认为当Ge含量为30%时,器件有较好的电特性,而且不会增加器件制作的工艺成本.     

亚100 nm应变Si/SiGe nMOSFET阈值电压二维解析模型

本文基于二维泊松方程,建立了适用于亚100 nm应变Si/SiGe nMOSFET的阈值电压理论模型.为了保证该模型的准确性,同时考虑了器件尺寸减小所导致的物理效应,如短沟道效应,量子化效应等.通过将模型的计算结果与二维器件模拟器ISE的仿真结果进行对比分析,证明了本文提出的模型的正确性.最后,还讨论了亚100 nm器件中常规工艺对阈值电压的影响.该模型为亚100 nm小尺寸应变Si器件的分析设计提供了一定的参考. 关键词： 亚100nm 应变Si/SiGe nMOSFET 二维表面势 阈值电压