摘要
多孔硅薄膜 硅基底结构是微机电系统 (micro electro mechanicalsystem ,MEMS)中的一个基本组元 ,其厚度为微米量级。由于薄膜与基底材料之间存在着晶格错配 ,在薄膜 基底间的界面上会出现残余应力 ,严重时会导致裂纹出现而发生断裂。微拉曼光谱法 (micro Ramanspectroscopy ,MRS)是近些年来在化学、物理、材料和力学等学科领域迅速发展的光学测量方法。文中对这一方法进行介绍 ,并且用来测量化学腐蚀多孔硅薄膜结构的残余应力 ,发现随着孔隙率的增加 ,多孔硅表面的拉伸应力逐渐增大。特别对某一样品出现裂纹区的拉曼测量表明 ,在裂纹区的残余应力急剧上升 ,达到了 0 .92GPa。使用金相显微镜观察不同孔隙率的多孔硅薄膜表面的微观形貌 ,这种不同程度的微观孔穴结构与残余应力的分布存在着紧密的联系。
Porous Silicon film with μm level and Silicon bulk substrate is a basic structure of MEMS (micro-electro-mechanical systems). Porous Silicon keeps the same crystal structure of bulk Silicon, but with a larger lattice parameter. The lattice mismatch with the substrate is expected to introduce a stress on the porous film, and cause cracking of the interface. MRS (micro-Raman spectroscopy) was introduced and practical information is given for the application of this technique to stress measurements in porous Silicon films, which were obtained with chemical etching technique. Tensile stress increases with porosity. Especially, Raman study on a crack of one sample reveals that higher residual stresses (0.92*!GPa) appear in the cracking area and however, fall rapidly out of the cracking area. On the other hand, using metallographic microscopy to investigate surface appearance of porous Silicon film, micro-cavity structure is expected to have a relation with the distributions of residual stress.
出处
《机械强度》
CAS
CSCD
北大核心
2004年第4期389-392,共4页
Journal of Mechanical Strength
基金
国家自然科学基金资助项目 (1 0 2 32 0 30和 1 0 2 0 2 0 1 7)
教育部留学回国人员科研启动基金资助项目~~
关键词
残余应力
拉曼光谱法
孔隙率
裂纹
多孔硅
Residual stress
Raman spectroscopy
Porosity
Crack
Porous Silicon
