硅基超薄多孔氧化铝膜的制备

将二次阳极氧化法应用于硅基铝膜的制备, 在草酸溶液中得到了厚度可控的硅基超薄多孔氧化铝膜(PAM), 厚度小于100 nm. 实验中记录了氧化电流随时间的实时变化曲线, 发现硅衬底的氧化电流在大幅下降前有一小幅波动. 对应于Al/Si界面的氧化过程中, 孔洞底部之间的残留铝岛被优先氧化, 可将此作为终止铝氧化的标志. 扫描电镜(SEM)观察表明, 二次氧化提高了孔洞分布的均匀性, 使得孔在一定的区域内呈现有序六角分布.这种模板可进一步用于硅基纳米器件和纳米结构的制备.

Fabrication of Ultra Thin Porous Alumina Membrane on Silicon Substrate

Details of the fabrication of an ultra thin porous alumina membrane (PAM) on silicon substrate with controllable height (thinner than 100 nm) by a two-step anodization of the aluminum deposited on the silicon substrate in oxalic acid solution were revealed. A formation mechanism of preferential anodizing of the remaining aluminum islands in the Al/Si interface was firstly proposed on the basis of the current-time curve. FE-SEM top view and cross section micrographs showed that the non-ordered surface layer formed in the first anodizing process was etched away, and in the second process the hexagonal ordered arrangement of pores existed in the local domain, suggesting that the ultra thin porous alumina membrane can be used as template for further fabricating nano-devices and nano-structures on silicon substrate.