微结构参数对多孔硅层热绝缘性能的影响

研究了多孔硅层厚度,孔隙率以及多孔硅中微晶粒尺寸三个微结构参数对其热绝缘性的影响机制.实验选用p ,p-两种掺杂浓度的硅片基底,采用电化学腐蚀法,通过改变腐蚀时间和腐蚀电流密度获得不同微结构参数的多孔硅层.分别采用显微拉曼光谱法及测量显微镜聚焦法测量了样品的热导率和厚度.研究发现,多孔硅层厚度影响热量传输路径,而孔隙率和微晶粒尺寸通过降低热导率从而使多孔硅的绝热性增强.

Thermal Insulation of Porous Silicon under the Influence of the Micro Structural Parameter

The thick of porous silicon (PS), porosity and micro crystal size were measured in order to study their effect to thermal insulation. Porous silicon, which was formed on p~+ type and p~- type silicon, was fabricated by electrochemical approach, and different etching time and electric current density were used for preparing porous silicon with different micro-structural parameters. Its layer thick, thermal conductivity were scaled by metrical-microscope and micro Raman spectrum respectively. The results shows that the layer thick related to the path of thermal conduct while the porosity of PS and micro crystal size could enhance the thermal insulation by reduce thermal conductivity.