Sensitive End-Point Detection for Dielectric Etch
Sensitive End-Point Detection for Dielectric Etch
复制标题
电介质蚀刻的灵敏终点检测
DOI：
10.1149/1.1350675
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
F. C. Dassapa
中科院分区：
文献类型：
--
作者：
E. Hudson;F. C. Dassapa
描述了一种用于检测图案化介电膜下面的停止层的初始曝光的方法。来自陶瓷静电卡盘的电源的偏置补偿信号显示出当蚀刻前沿到达底层时的阶跃增加。端点信号强度在0.01%至1%的范围内基本上与暴露的氧化物面积无关。当底层暴露时检测到终点，明显早于光发射终点。偏置补偿终点信号的建议起源是晶片衬底和等离子体之间的电阻的变化，因为孔被蚀刻通过介电膜。该模型正确地预测了哪些蚀刻应用将产生终点信号，包括标准通孔蚀刻和接触蚀刻。显然，由于在蚀刻期间氮化硅停止层的电阻降低，双金属过孔蚀刻也产生有用的终点信号。本文介绍了偏置补偿终点在一个商业化的硅片生产设备中的应用。
A method is described for detecting the initial exposure of the stop layer underlying a patterned dielectric film. The bias compensation signal from the power supply of the ceramic electrostatic chuck displays a step increase when the etch front reaches the underlayer The end-point signal strength is essentially independent of exposed oxide area over the range ∼0.01 to 1%. End point is detected just as the underlayer is exposed, significantly earlier than that for optical emission end point. The proposed origin of the bias compensation end-point signal is the change in resistance between wafer substrate and plasma as holes are etched through the dielectric film. This model correctly predicts which etch applications will produce an end-point signal, including standard via etch and contact etch. Dual damascene via etch also produces a useful end-point signal, apparently due to lowered resistance of the silicon nitride stop layer during etch. The use of bias compensation end point in a commercial wafer production facility is described.