ACLV degradation: root cause analysis and effective monitoring strategy
ACLV degradation: root cause analysis and effective monitoring strategy
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ACLV 退化：根本原因分析和有效的监测策略
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
E. Foca
中科院分区：
文献类型：
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作者：
A. Tchikoulaeva;A. Holfeld;M. Arend;E. Foca
跨场线变化(ACLV)的稳定性在先进半导体制造中是至关重要的。退化的签名会导致晶体管参数的恶化和成品率损失。在遏制了雾霾问题之后，IC行业现在面临着一种新的网线退化机制。据报道，靶向能量随着暴露次数的增加而变化，随后观察到ACLV的快速增加。虽然已经采用了有效的监测和纠正方法，但这种类型的掩模退化的根本原因还没有完全阐明。我们对掩模版的AIMSTM、扫描电子显微镜和光学CD测量结果与晶片CD测量结果一致，并清楚地表明晶片上的图案失真源自掩模版的正面。结果表明，传输损耗逐渐分布在掩模表面上，导致了CD的变化。在最严重的情况下，可以通过掩模检查工具检测到中心区域的变化。观察到降解率依赖于掩模和掩模类型上的净场百分比。最后，使用各种分析技术，包括AFM、离子和气相色谱、TOF-SIMS、俄歇和透射电子显微镜，我们已经能够确定这个问题的根本原因。我们的实验结果确实表明，吸收膜的结构退化是导致Cd变化的主要原因。讨论了这种效应背后的可能机制。
Stability of across field line variation (ACLV) is crucial in advanced semiconductor manufacturing. Degraded signatures cause deterioration of transistor parameters and yield loss. After having contained haze issues, the IC industry is now confronting a new reticle degradation mechanism. It has been reported, that targeting energy is changing with the number of exposures and later on a rapid increase of ACLV is observed. Although effective monitoring and correction methods have been introduced, the root cause of this type of reticle degradation has not been fully elucidated. Our AIMSTM, SEM and optical CD measurements on reticle demonstrated consistency with wafer CD measurements and clearly show that pattern distortions on wafers originate from the front side of the reticle. The results indicate the transmission loss to be gradually distributed over the reticle surface causing CD variations. In the most acute case, changes in the center area could be detected by the reticle inspection tool. Dependency of degradation rate on percentage of the clear field on the reticle and reticle type was observed. Finally, using a variety of analytical techniques including AFM, ion and gas chromatography, TOF-SIMS, Auger and TEM we have been able to identify the root cause of this problem. Our experimental results do show that the structural degradation of the absorber film is the primary cause for CD change. Possible mechanisms behind this effect are discussed.