基片曲率法在多孔硅薄膜残余应力检测中的应用

Residual stress measurement of porous silicon thin film by substrate curvature method

通过基底曲率法设计和制作了一种测量薄膜应力的装置,它具有全场性、非接触性、高分辨率、无破坏、数据获取速度快等特点.使用该装置测量了电化学腐蚀法制作的多孔硅薄膜的残余应力,并研究了孔隙率和基底掺杂浓度对残余应力的影响,结果表明随着孔隙率的增加和硼离子掺杂浓度的提高,多孔硅表面的拉伸应力逐渐加大,由此表明多孔硅薄膜的微观结构与残余应力的大小有着密切的联系.

An optical apparatus based on substrate curvature method was developed for stress measurement of thin films, which offeres such advantages as overall field, non-contact, high precision, nondestructive, easy operation and quick response. Using the apparatus, the residual stress in porous silicon （PS） layers prepared by electrochemical etching using a solution of HF/ethanol with composition ratio of 1 ： 1 on heavily or gently doped （100） silicon as a function of the electric current density were obtained. It is found that the residual tensile stress tends to increase with the porosity increasing and the doping concentration of the silicon wafer increasing. The results show that there is a deep connection between the micro-structure PS and the residual stress distribution.