通过实验对适用于90nm多晶硅栅刻蚀工艺中过刻蚀阶段等离子体的性质进行了研究分析.实验采用满足200mm硅晶片刻蚀的电感耦合多晶硅刻蚀设备,借助等离子体分析仪器(朗缪尔探针)进行实验数据测定,得到了等离子体性质与功率、气体流量等外部参数的关系.实验表明在射频功率增加的过程中,能量耦合系数处于一个相对稳定的常值;当等离子体处于局部加热状态时,绝大部分的电子处于附着状态,维持等离子体的电子数目相对减少.等离子体中的射频能量耦合空间随着射频功率的增加,分布状态会变得更加一致化.
The relations between the parameters of plasma and those of RF power and gas flow were analyzed under the conditions of over etch step in semiconductor plasma etching, by Langmuir probe. The results show that as the RF power was increasing,the RF couple coefficient was comparatively stable. When in a local heating state,most of the electrons were in an adhesive status. The distribution of power couple space in the chamber can be improved as the RF power increases. These results can help to develop plasma dry etching.