Digital Block Defect Localization using in-depth Circuit Analysis for Electrical Verification and Fault Isolation Correlation

As semiconductor technology keeps scaling down, failure analysis and device characterizations become more and more challenging. Global fault isolation without detailed circuit information comprises the majority of foundry EFA cases. Certain suspected areas can be isolated, but further narrow-down of transistor and device performance is very important with regards to process monitoring and failure analysis. A nanoprobing methodology is widely applied in advanced failure analysis, especially during device level electrical characterization. It is useful to verify device performance and to prove the problematic structure electrically, especially for implantation related problems [1] [2]. Implantation related defects, or invisible defects, are the most challenging defect types for the application of fault isolation in all of the failure analysis jobs. The key challenge for these kinds of analyses is to make the defect visible. Sometimes, it is difficult or even impossible to visualize the defective point. Then, sufficient electrical evidence and theory analysis are important to bring the issue to resolution. For these kinds of analyses, a nanoprobing system is a necessary tool to conduct the detailed analysis. Combined with the device physics and electrical theory analysis, nanoprobing can bring out the perfect failure mechanism and problematic process step. There are two popular nanoprobing systems in our lab, one is SEM based and the other is AFM based. Both systems have their advantages and disadvantages in the electrical characterization and fault isolation field. In this paper, an implantation related issue was analyzed. Gross leakage was observed on the failed units as compared with good units. Global fault isolation, TIVA and EMMI failed to find the exclusive hotspot. With the GDS and process analysis, the nanoprobing was employed to the performance check on some of the suspected structures. Finally, the defective location was successfully isolated by nanoprobing. Combined with device physics and electrical analysis, the problematic process was successfully isolated.

It is a common perception that electrical fault isolation (EFI) is the heart of a successful integrated circuit failure analysis workflow. Much effort to enhance EFI approaches is vested on improving optical resolution and system signal-to-noise in order to meet performance demands of advanced technologies. In fact, pre- and post-EFI data processing procedures are equally important and capable to influence the success of fault localization significantly. We describe three different analytical workflows applied on actual SOC memory failures to demonstrate this importance.

The focused ion beam system has been widely used as a critical failure analysis tool as microprocessor technology advances at a ramping speed. It has become an essential step in failure analysis to reveal physical defects after electrical fault isolation. In the highly competitive and challenging environment prevalent at present, failure analysis throughput time is of utmost important. Therefore, a quick, efficient and reliable physical failure analysis technique is needed. This paper discusses the applications of FIB as a defect localization and root cause determination tool through the passive charge contrast technique and pattern FIB analysis.

Optoelectronic imaging of integrated-circuits has revolutionized device design debug, failure analysis and electrical fault isolation; however modern probing techniques like laser-assisted device alteration (LADA) have failed to keep pace with the semiconductor industry's aggressive device scaling, meaning that previously satisfactory techniques no longer exhibit a sufficient ability to localize electrical faults, instead casting suspicion upon dozens of potential root-cause transistors. Here, we introduce a new high-resolution probing technique, two-photon laser-assisted device alteration (2pLADA), which exploits two-photon absorption (TPA) to provide precise three-dimensional localization of the photo-carriers injected by the TPA process, enabling us to implicate individual transistors separated by 100 nm. Furthermore, we illustrate the technique's capability to reveal speed-limiting transistor switching evolution with an unprecedented timing resolution approaching <10 ps. Together, the exceptional spatial and temporal resolutions demonstrated here now make it possible to extend optical fault localization to sub-14 nm technology nodes.

&lt;p&gt;Electric fault is the main challenge in the process of providing continues electric supply. Fault can occur at anytime and anywhere. Due to the fault causes are mainly based on natural disaster or accident. Most fault occurrence hardly predicted nor avoided. Therefore, a quick response fault detection is necessary to ensure that the fault area is maintained to ensure a continuous power supply system. Hence, a system is required to detect and locate the position of the fault in the power system especially in the transmission line and distribution line. This paper will review the type of fault that possibly occurs in an electric power system, the type of fault detection and location technique that are available together with the protection device that can be utilized in the power system to protect the equipment from electric fault.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Getting accurate fault isolation during failure analysis is mandatory for success of Physical Failure Analysis (PFA) in critical applications. Unfortunately, achieving such accuracy is becoming more and more difficult with today’s diagnosis tools and actual process node such as BCD9 and FinFET 7 nm, compromising the success of subsequent PFA done on defective SoCs. Electrical simulation is used to reproduce emission microscopy, in our previous work and, in this paper, we demonstrate the possibility of using fault simulation tools with the results of electrical test and fault isolation techniques to provide diagnosis with accurate candidates for physical analysis. The experimental results of the presented flow, from several cases of application, show the validity of this approach.

This chapter briefly lays out the challenges associated with electrical fault isolation (EFI) brought on by continued transistor scaling and increasing package complexity. It also identifies high-priority issues and areas of technology that must be addressed for EFI tools and techniques to remain effective.

Failure analysis (FA) could provide timely feedback to process optimization and solution paths for system failures; thus, it is critical for the development of advanced driver assistance systems (ADAS). In this chapter, failure analysis flows starting from systems or boards until components or packages and dice are introduced. Electrical fault isolation (FI) techniques designed to locate subtle defects inside complicated semiconductor devices are reviewed. Physical failure analysis approaches adopted to provide artifact free nanometer scale analysis are discussed. Material analysis methods assisting in thorough root cause investigation are presented. Non-destructive and high-resolution imaging tools with the potential of significantly shortening failure analysis through put time are demonstrated. Case studies are used to illustrate strategies and methodologies in ADAS failure analysis.

We report on a new non-destructive electrical fault isolation (EFI) technique to localize interconnection failures in through-silicon via (TSV) structures for three-dimensional (3-D) integration. The scanning optical microscopy (SOM) technique is based on light-induced capacitance alteration (LICA) and uses localized photon probing of TSV interconnect capacitance to localize interruptions of electrical connectivity. The technique is applicable to passivated devices and allows rapid, efficient, and non-destructive fault isolation at wafer level. We describe the physics behind signal generation of the technique and demonstrate the TSV photocapacitance effect. We further demonstrate the LICA technique on open failed TSV daisy chain structures and confirm our results with microprobing and voltage contrast measurements in a scanning electron microscope (SEM).

We report on the use of Fresnel lenses in the failure analysis (FA) of actual failures. The design parameters affecting the performance of Fresnel lenses in terms of resolution, magnification, and field of view have been analyzed. It is demonstrated that the magnification depends linearly on the change in focus distance caused by the lens, normalized by the silicon thickness. The focus distance shift that can be obtained with the Fresnel lens is observed to saturate, whose root-cause remains to be investigated. The field of view is shown to increase with the silicon thickness and, to a lesser extent, with the number of lens rings. It has also been shown that these lenses are robust against patterning distortions. The OBIRCh responses of actual device failures before and after lens placement have been compared, demonstrating clearly the increase in magnification, resolution, and the ability to focus light which all translate into a better electrical fault isolation. All in all, this study proves the usefulness of Fresnel lenses for FA purposes and offers clear guidelines that will facilitate proper lens design.

Focused ion beam system has been widely used as a critical failure analysis tool as microprocessor technology advances at a ramping speed. It has become an essential step in failure analysis to reveal physical defects post electrical fault isolation. In this highly competitive and challenging environment prevalent today, failure analysis throughput time is of utmost important. Therefore quick, efficient and reliable physical failure analysis technique is needed to avoid potential issues from becoming bigger. This paper will discuss the applications of FIB as a defect localization and root cause determination tool through the passive charge contrast technique and pattern FIB analysis.

Embed SRAM IDDOFF fail root cause identification by combination of device analysis and localized circuit analysis

The advances on IC technology have made defect localization extremely challenging. “Soft” failures (resistive vias and contacts) are typically difficult to localize using commonly available failure analysis (FA) techniques such as emission microscopy (EMMI) and scanning optical microscopy (SOM), and often cannot be observed by two-dimensional inspections using layer by layer removal. The article describes the Resistive Contrast Imaging (RCI) defect localization technique (also known as Electron Beam Absorbed Current (EBAC), instrumentations, and case studies on test structures or process control monitors especially designed to detect “soft” open failures on advanced (28nm and below) technology devices. It also lists the key SEM parameters critical for effective FA using the RCI nano-probing system.

Fault in the propulsion system of UAVs is one of the main causes for incidents and loss of the aircraft. In electric propulsion systems typical faults are ball-bearing degradation leading to increased friction and losses, as well as propeller icing when operating in cold conditions. In this paper we propose a fault detection and isolation (FDI) framework that uses model-based estimators of the various faults, implemented with multiple Kalman and Bayes filters. The method is tested and shown to be effective in a simulation setup using a fixed-wing UAV simulator.

During all the system design phase of an SPC switching system, a considerable effort is devoted to maintenance, both from a hardware and software point of view. The maintenance phases include fault detection, fault analysis (e.g., identification of the faulty security block within the switching system), fault isolation, fault reporting, fault localization, fault clearance, and restoration to service with the eventual requalification and reinitialization of the repaired security block. The paper mainly discusses fault detection and fault analysis strategies with specific reference to PCM digital switching systems. Different means leading to fault detection are presented with reference to central control, network access devices (scanners, drivers, markers), and digital switching network (duplicated or not duplicated). These means include automatic on-line tests (monitoring and routining), on-demand on-line tests, and alarm handling. Fault analysis can be accomplished by means of a deductive or a statistical method. As the latter seems more attractive, three basic methods of statistical fault analysis are presented. They use, respectively, two counters (operation and fault counter) per security block; one fault counter per security block; one "historical" fault stack, in which all the identities of security blocks involved in faulty operations are stored. The above fault analysis strategies are compared mainly in terms of core memory occupancy, processor time, and software complexity.