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Voltage transfer characteristics for the CMOS inverter. Note that both transistors are only in saturation during the narrow switching region. This is when the most intense switching photon emission occurs.
Source publication
Photon Emission Microscopy (PEM) has been used
for fault isolation in Integrated Circuits (ICs) for well
over a decade and a half now.1 Even as ICs continue
to relentlessly follow Moore’s law – it is estimated
that the number of transistors per IC has increased
over 500× (during that time span – PEM continues
to be one of the most useful failure an...
Contexts in source publication
Context 1
... current (DC) operating points for the inverter where the current through both the PMOS and the NMOS devices is equal. Note that these operating points are located at either high or low output voltage values. Thus, the inverter exhibits a very narrow switching region, as shown in the voltage transfer characteristic for the static CMOS inverter (Fig. 4). 13 Now, note that the PMOS and the NMOS transistors are both "on" only during the narrow switching region of the voltage transfer curve (Fig. 4). It is during this region, where both transistors are "on," that current can effectively go from the supply voltage (V DD ) to ground (GND) as the capacitive load charges or discharges (Fig. ...
Context 2
... points are located at either high or low output voltage values. Thus, the inverter exhibits a very narrow switching region, as shown in the voltage transfer characteristic for the static CMOS inverter (Fig. 4). 13 Now, note that the PMOS and the NMOS transistors are both "on" only during the narrow switching region of the voltage transfer curve (Fig. 4). It is during this region, where both transistors are "on," that current can effectively go from the supply voltage (V DD ) to ground (GND) as the capacitive load charges or discharges (Fig. 5). The current must pass through the drain where a high electric field exists within the pinch-off region. 4 This high electric field imparts ...
Context 3
... is when the most intense switching photon emission occurs. engineered to a low value, the 'off' transistors within a CMOS gate halted in a known state may not truly be 'off' due to subthreshold leakage. 13 In other words, even though the transistors are not switching and one transistor is supposed to be 'off' while the other is in 'linear mode' (Fig. 4), some crowbar current will occur since the "off" transistor is not really completely "off." There is still a current path from V DD to GND and photon emission results. These devices may function; however, they often exhibit excessive static supply current (I DD ) and poor "off" drain current (I doff ) transistor characteristics as ...
Citations
... Hardware-based techniques use electrical failure analysis. They typically use photon emission [3] and laser [4]. Software-based diagnosis is preferred as mainstream due to its faster turnaround time and accuracy. ...
... Yeoh et al. [50] presented photon emission microscopy (PEM) based analysis to debug memory failures. PEM technique can detect defects caused by leakage or shorts [3]. These defects emit photons and create hotspots. ...
Nanometer memories are highly prone to defects due to dense structure, necessitating memory built-in self-repair as a must-have feature to improve yield. Today’s system-on-chips contain memories occupying an area as high as 90% of the chip area. Shrinking technology uses stricter design rules for memories, making them more prone to manufacturing defects. Further, using 3D-stacked memories makes the system vulnerable to newer defects such as those coming from through-silicon-vias (TSV) and micro bumps. The increased memory size is also resulting in an increase in soft errors during system operation. Multiple memory repair techniques based on redundancy and correction codes have been presented to recover from such defects and prevent system failures. This paper reviews recently published memory repair methodologies, including various built-in self-repair (BISR) architectures, repair analysis algorithms, in-system repair, and soft repair handling using error correcting codes (ECC). It provides a classification of these techniques based on method and usage. Finally, it reviews evaluation methods used to determine the effectiveness of the repair algorithms. The paper aims to present a survey of these methodologies and prepare a platform for developing repair methods for upcoming-generation memories.
... Finally, failure modeling is also a big problem for testing PST architectures because there are many different devices such as ADBs and PDs. It is very difficult to find a good failure model for the PST architecture [1][2][3][4][5][6][7][8][9][10][11]. ...
The scaling of CMOS technology faces challenges as the demand rises, but FinFETs emerging as a vital alternative for 22nm technology node and lower. Otherwise, FinFETs tend to have multiple PVT variations, making static timing analysis (STA) more flexible and suitable to analyze the timing delay of the logic generation. Device simulation and statistical temporal analysis are used to derive PVT variation models for FinFET-based standard cell designs. Mixing different FinFET design styles shows promise in optimizing delays and leakage, as FinFETs offer better control of short-channel effects and processing scalability. Furthermore, lowering clock skew is also a prime design aspect to consider. However, as technology scales to smaller devices, process, voltage, and temperature (PVT) variations make minimizing clock distortion very difficult. To mitigate the effects of PVT variations, many previous works proposed a Post Silicon Tuning (PST) architecture to dynamically balance the skew of the clock tree. In this paper, we will disclose the details of clock tree synthesis optimizations and FinFET logic developments minimizing PVT variations.
... Typical photon emitting defects such as oxide leakage, metal narrowing, inter metal/poly shorts have been summarized as an overview [1]. This work was extended with OBIRCH by introducing layout study and microprobe to better narrow down the defect location respectively [2][3]. ...
Metal defect has become one of the major failure mechanisms of integrated circuit, whose localization might need skillful techniques in failure analysis, especially within function issues. Popular failure analysis method has been suggested for about two decades, such as PEM and laser stimulation microscopy. Most of the reported works are based on CMOS silicon substrate ICs, and mostly for frontside analysis by dynamic method. Since Gallium Arsenide (GaAs) based integrated circuit is developing very fast, the failures are also bringing challenges. Conventional dynamic method should be implemented in accordance with GaAs features.
... The timing failures could be caused by circuit marginality, resistive interconnects, or process variations. While the physical fault isolation techniques that capture static silicon images or use static stimulation technologies, for example EMMI [1] [2], OBIRCH [3], LIVA and TIVA [4], et al., are still important in identifying static defects and leakage issues, they may not be able to capture the critical timing information of a dynamic failure. ...
In this paper, we describe a silicon debug flow that uses debug-friendly scan test patterns to improve the efficiency of physical fault isolation of timing failures using time-resolved emission (TRE) system. Several techniques have been developed to generate the debug-friendly test patterns. We further show a silicon debug case of a 90nm design based on the proposed debug flow.
... This can be very helpful in spatially identifying where a failing circuit might be. Passive techniques include emission microscopy (EMMI) [7] and time resolved emission (TRE), also known as picosecond imaging circuit analysis (PICA) [8][9]. Both techniques make use of the fact that CMOS transistors in saturation emit infrared photons. ...
Silicon debug begins with the arrival of design prototypes and can continue well after a product has gone into production. It is perhaps the most exciting and challenging stage of the integrated circuit development process. This paper gives an overview of silicon debug, and describes tools and methods used during the debug process
... Scanning photon emission microscopy is a well established tool for monitoring sites within modern silicon integrated devices [15,16]. Electrons, as injected highly into the conduction band when being accelerated due to high local electrical fields within operated devices, relax locally within the conduction band by emitting the energy difference between the electron's energy when injected and the lower band edge of the conduction band. ...
With the ongoing reduction of structures sizes within electronic devices inspection tools have to be used allowing a resolution of below 50nm. This is not only necessary for a mere topological evaluation of materials or devices under test, but even more important for the nanoscopic determination of material parameters and device properties. When using waves as probes for this purpose, near-field techniques are quite often the only means for overcoming limitations in spatial resolution as due to Rayleigh's criterion, independently of the nature of the wave type used. In this manner acoustic and thermal waves can be applied for very high resolution testing as well as the well known scanning near-field optical microscope. Moreover, such techniques are not limited to simple systems in which the probing wave and the resulting interaction product are of same nature, but more complicated systems may be suitable to gain the information needed. In this manner near-field optical microscopy can be used for optical induced current measurements as well as for nanoscopic cathodoluminescence experiments. To achieve a comprehensive information on the sample, results gained with one special technique can be compared with others, such as scanning thermal or acoustic microscopy. These allow determination of mechanical and thermal properties with appropriate spatial resolution to be compared with , for instance, optoelectronic structures. The necessary instrumentation is described for such experiments with emphasis on the scanning near-field optical microscope. Examples for the application of near-field microscopies will be given for silicon technology, compound semiconductors, and ferroelectric ceramics.
Electronic Device Failure Analysis Technology Roadmap examines the trends shaping the future of semiconductor technology as well as the tools and techniques that will be required to detect, analyze, and remediate failures. The information is organized into ten chapters, seven of which assess the capabilities, limitations, and future needs of fault isolation technology in light of continued transistor scaling, increasing package complexity, and emerging IC architectures. Other chapters assess the tools and techniques used in die-level post-isolation failure analysis and the opportunities and challenges related to 3D packaging technology. The book also includes a chapter summarizing the technology gaps identified in previous chapters.
Electronic Device Failure Analysis Technology Roadmap examines the trends shaping the future of semiconductor technology as well as the tools and techniques that will be required to detect, analyze, and remediate failures. The information is organized into ten chapters, seven of which assess the capabilities, limitations, and future needs of fault isolation technology in light of continued transistor scaling, increasing package complexity, and emerging IC architectures. Other chapters assess the tools and techniques used in die-level post-isolation failure analysis and the opportunities and challenges related to 3D packaging technology. The book also includes a chapter summarizing the technology gaps identified in previous chapters.
Delayed failure due to stress voiding is a concern with some aging microelectronics, as these voids can grow large enough to cause an open circuit. Local measurements of stress in the metallic layers are crucial to understanding and predicting this failure, but such measurements are complicated by the fact that exposing the aluminum conducting lines will relieve most of their stress. In this study, we instead mechanically thin the device substrate and measure distortions on the thinned surface using high resolution electron backscatter diffraction (HREBSD). These measurements are then related to the stresses in the metallic layers through elastic simulations. This study found that in legacy components that had no obvious voids, the stresses were comparable to the theoretical stresses at the time of manufacture (≈300 MPa). Distortion fields in the substrate were also determined around known voids, which may be directly compared to stress voiding models. The technique presented here for stress determination, HREBSD coupled with finite element analysis to infer subsurface stresses, is a valuable tool for assessing failure in layered microelectronics devices.
