Non-volatile memory is the most important memory device in IC chips. As a memory, embedded non-volatile memory (NVM) is a fundamental structure in many kinds of semiconductor devices. It is commonly used in the modern electrical appliance as a code or data memory. For different applications, there are different memory designs or IP, like ROM, OTP, Flash, MRAM, PCRAM etc. The physical mechanism of these NVMs are different, some are electron based, some are resistance based and fuse or anti-fused based. The experiment described in this paper is performed on an electron charge storage based NVM. That means a medium is employed to store electron charge to differentiate two statuses “0” and “1”. Floating Poly gate is this medium used as electron charge storage in this NVM. Since the storage medium is in floating condition, it cannot be accessed externally. The methods of performing direct analysis are limited for this kind of device, especially in the case of subtle defects or soft fail. As semiconductor devices scale, the defects become smaller and more subtle. Nanoprobing is usually the only way to find the defect location electrically before any further physical analysis. In this experiment, the single bit NVM fail was analyzed. Different PFA methods used during the analysis, failed to find the defect. Nanoprobing was employed to precisely isolate the defect. Key word: nanoprobing, NVM, subtle defect, Poly-crystalline, floating gate

Reliability tests, such as Time-Dependent Dielectric Breakdown (TDDB), High-Temperature Operating Life (HTOL), Hot Carrier Injection (HCI), etc., is required for the lifetime prediction of an integrated circuit (IC) product. Those reliability tests are more stringent and complex especially for automotive Complementary Metal–Oxide–Semiconductor (CMOS) devices, this because it involves human lives and safety. In foundries failure analysis (FA), Transmission Electron Microscopy (TEM) analysis often required in order to provide insights into the defect mechanisms and the root cause of the reliability tests. In this paper, application of high resolution Nano-probing Electron Beam Absorbance Current (EBAC), Nano-probing active passive voltage contrast (APVC), and TEM with Energy Dispersive X-Ray Spectroscopy (EDX) to identify the failing root cause of Inter- Poly Oxide (IPO) TDDB failure on an automotive grade Non- Volatile Memory (NVM) device was investigated. We have successfully demonstrated that TEM analysis after Nanoprobing EBAC/APVC fault isolation is an effective technique to reveal the failure root cause of IPO breakdown after reliability stresses.

New process will introduce new failure mechanisms during microelectronic device manufacturing. Even if the same defect, its root causes can be different for different processes. For aluminum(Al)-tungsten(W) metallization, the root cause of metal bridging is quite simple and mostly it is blocked etch or under-etch. But, for copper damascene process, the root causes of metal bridging are complicated. This paper has discussed the various root causes of metal bridging for copper damascene process, such as those related to litho-etch issue, copper CMP issue, copper corrosion issue and so on.