非晶熔石英表面等离子体刻蚀过程中的表面晶化研究

摘要

本工作采用电子回旋共振（ECR）低压等离子体刻蚀技术,刻蚀非晶熔石英表面.Ar/CF_4为反应气体刻蚀后再经O等离子体钝化,非晶熔石英表面出现晶化现象.晶化层约几百纳米厚.Ar/CF_4在ECR的电磁场作用下产生F离子与C离子,F离子使熔石英表面的Si-O共价键断裂,并释放出O离子.C离了与O离子迅速键合生成CO_2,而被断键的Si原子与四个F原子键合生成气态SiF4.熔石英原始表面被去除的同时,在新的表面留下大量不饱和Si原子.不饱和Si原子在高温条件下被O等离子钝化,形成结晶态α方石英.%After low pressure fluorine plasma ecthing and oxygen ion passivation,a crystallized layer composed of SiO_2 nano-crystal grains is observed in an amorphous fused silica surface.The depth of crystallized layer is at least several hundreds nanometers.Fluorine and carbon ion are generated from Ar/CF_4 by the method of electron cyclotron resonance（ECR）.F ion breaks Si-O band of initial silica surface layer and releases O ion.Carbon ion combines with oxygen ion,and turns into CO_2,and SiF_4 is generated from fluorine and silicon.After initial surface layer is removed,unsaturated Si atom remains.Si dangling bond recombines with new O ion and then creates crystallizedα-cristobalite nano-crystal grains under a high temperature.