非制冷红外探测器多孔硅绝热层的研究

以多孔硅作为绝热层材料,采用超高真空对靶磁控溅射镀膜法,在多孔硅样品表面和硅基底表面沉积氧化钒薄膜。实验采用电化学腐蚀法制备多孔硅,利用场致发射扫描电子显微镜观测了孔隙率为50%,60%,70%三个多孔硅样品的微观形貌。利用显微喇曼光谱法测量其热导率,分别为8.16,7.28和0.624W/mK;利用纳米压入仪测量氧化钒薄膜的显微硬度和杨氏模量,测得沉积在孔隙率为50%,60%,70%的多孔硅基底上氧化钒薄膜的显微硬度分别为1.917,0.928和0.13GPa,杨氏模量分别为31.087,16.921和2.285GPa,而沉积在单晶硅基底的氧化钒薄膜的显微硬度和杨氏模量分别为10.919GPa和193.792GPa,并分析了微观结构差异对多孔硅绝热性能和机械性能的影响,为非制冷红外探测器的工艺制作过程提供一定的热学力学参数。

Study on Porous Silicon Isolation Layer in Uncooled Infrared Bolometer

Vanadium oxide thin films was deposited on silicon surface and porous silicon(PS) used as isolation material by facing targets direct current reactive sputtering in super high vacuum method.PS was prepared by electrochemistry etching method,the microstructures of PS samples with porosity of 50%,60%,70% were observed by field emission scanning electron microscope(FESEM),and the thermal conductivity was measured by micro-Raman spectrum method,which were 8.16,7.28 and 0.624 W/mK;nano-indentation instrument was used to measure the hardness and Young's modulus,the hardness of vanadium oxide thin films on PS with porosity of 50%,60%,70% were 1.917,0.928 and 0.13 GPa,and Young's modulus were 31.087,16.921 and 2.285 GPa,respectively;while its hardness and Young's modulus on silicon substrate were 10.919 GPa and 193.792 GPa.The dependence of PS's thermal isolation and mechanical performance on its microstructure was analyzed.It affords a certain thermal and mechanical parameters for the manufacture of uncooled infrared bolometer.