硅基超薄柔性芯片的力学和电学特性研究进展

Research Progress on Mechanical and Electrical Properties of Silicon-Based Ultrathin Flexible Chips

全面综述了硅基超薄柔性芯片在单轴弯曲应力下的力学和电学特性研究进展,包括弯曲形变的测试方法及应力计算公式,弯曲应力对器件及单元电路响应特性的影响,以及考虑应力效应的器件建模方法。弯曲应力会导致MOSFET的迁移率、阈值电压、漏极电流等关键电参数发生变化,且变化率与所施加的应力大小和方向均密切相关。将器件电学参数随应力变化的数学关系与常规的器件模型相结合,可得到适用于柔性可弯曲器件的紧凑模型,从而使下一代计算机辅助设计工具能够满足未来高性能柔性芯片的设计需求。

This paper comprehensively reviews the research progress on mechanical and electrical properties of silicon-based ultrathin flexible chips under uniaxial bending stress,including the bending test methods and the formulas for stress calculation,the bending stress induced effects on the responses of devices and cell circuits,as well as the device modelling strategies in considering bending stress effects.Bending stress can induce variations in critical electrical parameters such as mobility,threshold voltage and drain current of MOSFET,and the variation rate is closely related to the magnitude and direction of the applied stress.By combining the mathematical relations of varied electrical parameters and stress with the conventional device models,the new compact models suitable for flexible and bendable devices can be obtained,which enable the next generation computer-aided-design tools to meet the design needs of high-performance flexible chips in the future.