采用超临界CO_2流体清除硅芯片上的纳米粒子  

Removal of Nanoparticles on Silica Wafer by Supercritical Fluid Carbon Dioxide

作　　者：戴剑锋[1,2] 孙毅彬[1,2] 张超[1,2] 李扬[1,2] 王青[1,2] 李维学[1,2] 

机构地区：[1]兰州理工大学物理系,兰州730050 [2]兰州理工大学有色金属新材料国家重点实验室,兰州730050

出　　处：《纳米技术与精密工程》2009年第1期20-24,共5页Nanotechnology and Precision Engineering

基　　金：国家自然科学基金资助项目(50873047);国家留学基金资助项目(200321G030)

摘　　要：分析了Cu和Au纳米粒子在硅芯片表面的各种黏结机理,表明金属及其氧化物纳米粒子与硅芯片表面的主要黏结力为范德瓦耳斯力、静电双层吸引力和毛细吸附力.建立了高速流体清除纳米粒子的动力学模型,表明超临界CO2流体清除纳米粒子的机制是以滚动清除为主.与高压CO2气体相比,超临界CO2流体的密度高,有效增加了作用在纳米粒子上的拖拉力,同时消除了毛细吸附力,所以可以显著提高纳米粒子的清除效率.当超临界CO2流体的速度达到10.4m/s时,即可将直径为30nm的金属铜污染粒子清除掉;随着流体速度的增加,可清除更加微小的粒子.The adhesion mechanism of Cu and Au nanoparticles on silicon wafer was studied in this paper. The calculated results show that the dominant adhesion forces between metal/oxide particles and silicon wafer are London-Van de Waals force, capillary force and electrostatic double-layer force. The dynamics model of the removal of nanoparticles on the Si substrate using high speed fluid was established, which indicated that the main removal mechanism of Cu and Au nanoparticles by supercritical fluid CO2 was rolling. Compared with high pressure CO2 gas, supercritical fluid CO2 could greatly enhance the removal efficiency of metal/oxide nanoparticles owing to its high density and could eliminate the capillary force naturally. The Cu nanoparticles in diameter of 30 nm could be eliminated providing the velocity of supercritical fluid CO2 reached 10.4 m/s, and the minimum diameter of eliminable nanparticles could be smaller with the increase of the velocity of supercritical fluid CO2.

关 键 词：黏结 清除 纳米粒子 超临界CO2流体 

分 类 号：TN407[电子电信—微电子学与固体电子学]