深槽刻蚀侧壁平坦化技术  

Planarization Technology for DRIE Trench Sidewall

作　　者：於广军 杨彦涛[1] 闻永祥 李志栓[1] 方佼 马志坚[1] 

机构地区：[1]杭州士兰集成电路有限公司

出　　处：《半导体技术》2016年第5期390-393,共4页Semiconductor Technology

基　　金：国家科技重大专项资助项目(2013ZX02310)

摘　　要：介绍了一种博世(Bosch)工艺深槽刻蚀后的侧壁平坦化技术。优化深槽刻蚀工艺参数使侧壁扇贝褶皱的尺寸降低至约52 nm,然后在1 100℃炉管中热氧化生长100 nm牺牲氧化层,再用HF酸漂洗工艺去除牺牲氧化层得到完全光滑的侧壁形貌。研究表明,扇贝褶皱的底部沿<100>晶向氧化,而顶部沿<110>晶向氧化的矢量叠加方向。当热氧生长厚度较薄时,氧化行为倾向于线性氧化,由于线性氧化的速率常数强烈依赖晶向取向,因此氧化一定时间后,顶部的氧化深度与底部的氧化深度达到一致。基于上述氧化机制,Si/Si O2界面变得平滑陡直。A sidewall planarization technology for deep trench etched by Bosch process was introduced. Dimension of sidewall scallop reduced to about 52 nm by optimizing the parameters of deep trench ion etching process. A 100 nm sacrificial oxide layer was grew in furnace tube at 1 100 ℃. And then,HF acid rinsing process was utilized to remove sacrificial oxide layer,the smooth sidewall was got.The researches show that,the thermal oxidation is along 100 crystal orientation at the bottom of sidewall scallop. However,it changes to be along vector superposition direction of 110 crystal orientation on the top. The oxidation behavior belongs to linear oxidation when thermal oxide thickness is thin. The rate constant of linear oxidation strongly depends on the crystal orientation,which makes it possible for the top and bottom of scallop to reach the same depth after a certain time. Based on the above oxidation mechanism,the interface between Si and Si O2 becomes smooth and steep.

关 键 词：深槽刻蚀(DRIE) 扇贝褶皱 博世工艺 线性氧化 光滑侧壁 

分 类 号：TN405.98[电子电信—微电子学与固体电子学]