Functional IC analysis through chip backside with nano scale resolution - E-beam probing in FIB trenches to STI level
Functional IC analysis through chip backside with nano scale resolution - E-beam probing in FIB trenches to STI level
复制标题
通过具有纳米级分辨率的芯片背面进行功能 IC 分析 - FIB 沟槽中至 STI 级别的电子束探测
DOI：
10.1109/ipfa.2007.4378053
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
B. Kruger
中科院分区：
文献类型：
--
作者：
R. Schlangen;R. Leihkauf;U. Kerst;C. Boit;B. Kruger
成功的测量，应用EBP的背面减薄电路，使用测试结构和商业芯片已被证明。除了众所周知的CCVC之外，还检测到一种名为空间电荷耦合电压对比度（SCCVC）的新对比度机制，其强烈地增加了直接在晶体管源极或漏极区域上测量的EBP信号。因此，测量是可能的，只要电子束可以放置在晶体管阱区，这是大于下金属线的3倍。在其中一个测试结构上，电压信号已正确产生，噪声容限为100 mV，并且由于沟槽底部与硅表面的共面性非常好，因此当工艺正确校准时，任何DUT都可以预期具有相同的精度。结果表明，该方法是非常有前途的，因为EBP系统的横向分辨率潜力仅受低能电子束直径的限制。近年来，该领域的改进尚未用于增强EBP，但即使使用目前的系统，在亚50 nm技术上的测量似乎也是可能的。此外，光学方法正在努力解决其分辨率限制，因此背面EBP在不久的将来可能成为一种非常强大的方法。
Successful measurements, applying the EBP to the backside of thinned circuitry, using test structures and commercial chips have been demonstrated. In addition to the well known CCVC a new contrast mechanism named space charge coupled voltage contrast (SCCVC) was detected, which strongly increased the EBP signal measured directly on the transistor source or drain regions. Therefore, measurements are possible as long as the electron beam can be placed on a transistor well area, which is larger than the lower metal lines by a factor of 3. The voltage signal has been produced correctly with 100mV noise margin on one of the test structures and since the coplanarity of the trench bottom to silicon surface is excellent, the same accuracy can be expected for any DUT when the process is properly calibrated. As a result, the presented method is very promising since the lateral resolution potential of an EBP system is only limited by the low energy E-beam diameter. Improvements in this field have not been used to enhance EBP in recent years but even with the present systems, measurements on sub-50nm technology seem to be possible. Furthermore, optical methods are struggling with their resolution limits and therefore backside EBP can become a very powerful method in the near future.