【摘要】 以电化学方法制备了多孔硅材料并通过表面轮廓测试仪、原子力显微镜、显微拉曼光谱仪等设备对制备多孔硅的孔隙率、厚度、表面形貌、以及热导率进行了表征。结果发现,本实验制备的多孔硅属于介孔硅(15~20nm),其孔隙率随腐蚀时间和腐蚀电流的变化有先增大后减小的趋势。增加多孔硅的厚度和孔隙率,可以使得多孔硅的热导率显著降低(最低可低至0.62W/m.K)。更多还原

【Abstract】 Porous silicon(PS) was used as a new thermal insulating material in MEMS during last five years due to its low thermal conductivity (T_c).In this paper,porous silicon were prepared by electrochemical method and different structures and morphologies of porous silicon were prepared in double cell.Morphologies of porous silicon were observed by AFM.A simple and nondestructive method,micro-Raman technique,was applied to study the T_c of PS samples with different porosity and thickness prepared by electrochemical method.Within all the samples,it is found that PS with a porosity of 75% and thickness of 65μm presents the lowest T_c value which is 0.62W/m·K.Then,the T_c of porous silicon increases rapidly with decreasing porosity and thickness(when the thickness and porosity decrease to 9μm and 40%,the T_c increase to 25.32W/m·K).更多还原