EBIRCH
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Technical Concept |
EBIRCH is short for Electron Beam Induced Resistance Change, and it must be operated in the SEM chamber. The principle behind it is similar to that of OBIRCH. Two nano-probes are used on a PAD or metal/via to form a current loop and provide a constant DC voltage. Under electron beam irradiation, materials and operating elements are subject to temperature changes caused by electron beam heating, which then result in changes in resistance. The current too will change accordingly. EBIRCH effectively locates failure points by detecting the positions of such current changes.
Because it operates in an SEM environment, the resolution of this technique is better than that of the OBIRCH optical system. It is able to target specific Metal and Poly/Contact layers inside the IC, detect current changes, and locate short or high impedance failure locations.
Figure 1. The figures above and below are the schematic diagrams of the principle architectures of EBAC and EBIRCH respectively
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Advantages |
- When it comes to the appearance of abnormal bright spots, EBIRCH generated highlights are more concentrated and thus more effective for accurately locating abnormal positions with bright spots of less than 100nm2. Bright spots generated by OBIRCH are more divergent, with sizes greater than 750nm2.
- EBAC can only address open interconnection problems with a detection resistance greater than 1Mohm. If you encounter high impedance or direct short issues, you will need to use EBIRCH. As processes shrink, we are seeing an increase in impedance-related performance issues. As such, under the premise that the problematic lines can be determined, EBIRCH is a very powerful tool.
Figure 2. Effectively locate short positions using EBIRCH
By Brett A. Buchea, Christopher S. Butler, H. J. Ryu, Wen-hsien Chuang, Martin von Haartman, Tom Tong [Intel], ISTFA 2015: Conference Proceedings from the 41st International Symposium for Testing and Failure Analysis, November 1–5,
Figure 3. The range of resistance values detectable by EBIRCH and EBAC; The EBIRCH detection range is 10ohm to 50Mohm, which means it can detect short to high resistance
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Contact |
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