bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inductive Operating Life Stress Metal Breakdown Mechanism
Authors: Gillette Bruce 
Published: December 2020

Abstract
Experimental devices in a deteriorated state were encountered after 168 hours of inductive operating life stress, (IOL) testing. A metal grain boundary breakdown mechanism was found during the analysis of the device, which was creating a low resistance current path between terminals. The AlSiCu top metal was breaking down along the grain boundaries. In addition there was alloying of the Aluminum into the underlying silicon. This alloying was creating a short to the gate, source, and drain. Several variations in the metal stack, testing conditions, number, and dimensions of bond wires die size and mold compound were evaluated to better understand the cause of the inability to withstand IOL stress and to provide a process solution. The prevention of the AlSiCu front metal grain boundary breakdown during inductive life stress testing required a die size, bond wire dimension, and testing condition change to meet the performance specification. This change resulted in a reduced grain boundary breakdown and consequently prevented Al grain boundary breakdown, TiW barrier breakdown, and Al alloy spiking. The die change and modified testing conditions resulted in a successful pass through the IOL stress testing.
Coupling C-AFM with Nanoprobing Technique for Further Junction Leakage Analysis
Authors: Shen Cha-Ming , Chuang Tsan-Chen , Huang Chen-May , Lin Shi-Chen , Chang Jie-Fei 
Published: December 2020

Abstract
With the evolution of advanced process technology, failure analysis has become more and more difficult because more defects are of the non-visual type (very tiny or even invisible defects) from new failure mechanisms. In this article, a novel and effective methodology which couples the conductive atomic force microscope (C-AFM) with nano-probing technique is proposed to reveal some particular failure modes which were not observable and difficult to identify with traditional physical failure analysis techniques. The capability of coupling C-AFM with nano-probing technique is used to distinguish cases which suffer general junction leakage or gate leakage from those that form the fake junction leakage or gate leakage cases. C-AFM can detect the abnormal contacts quickly, and nano-probing could provide the precise electrical characteristic further. Then, combining these variant measuring results, the favorable tactics can be adopted to deal with different states.
Laser Based Defect Localization for the Failure Analysis of Advanced Product
Authors: Cheng W.Y. , Chiu T.Y. , Lee Jon C. , Chiou J.Y. 
Published: December 2020

Abstract
Emission microscopy have been used for failure analysis (FA) defect isolation. But for advanced products, the working voltage of chip is getting smaller, thus many emission spots from normal transistors will be observed, which indeed affects the judgment on the emission spots from killer defects and increases the FA difficulty. Laser scanning microscope (LSM)-based techniques have been powerful defect isolation methods for many years. In this study, Checkpoint Infrascan 200TD, a laser-based tool, is used to perform defect localization. Here, thermally induced voltage alteration and optical beam induced resistance change are used to get defect locations. The study demonstrates three FA cases with 80nm/90nm technologies; metal direct short, poly leakage, and contact high resistance are also found in these cases. It is concluded that, by the selection of control parameters, Infrascan 200TD provides several capabilities of failure site localization and can be applied to different failure modes.
Enhanced Detection Sensitivity with Pulsed Laser Digital Signal Integration Algorithm
Authors: Quah A.C.T. , Phang J.C.H. , Koh L.S. , Tan S.H. , Chua C.M. 
Published: December 2020

Abstract
This paper describes a pulsed laser induced digital signal integration algorithm for pulsed laser operation that is compatible with existing ac-coupled and dc-coupled detection systems for fault localization. This algorithm enhances laser induced detection sensitivity without a lock-in amplifier. The best detection sensitivity is achieved at a pulsing frequency range between 500 Hz to 1.5 kHz. Within this frequency range, the algorithm is capable of achieving more than 9 times enhancement in detection sensitivity.
Nondestructive Method for Detecting Solder Defects at the Second Level Interconnect Using 3D X-Ray Tomography (uCT)
Authors: Toth Frank , Shade Gary F. 
Published: December 2020

Abstract
Today's printed circuit assemblies comprise of several layers with components populated on both sides of the PCBs. This presents challenges to conventional 2D nondestructive X-ray techniques due to shadowing and absorption of the x-ray energy. Tilting of the samples while imaging helps to get around this problem, however, often it might not always be adequate. This article proposes a non-destructive method for detecting solder defects at the second level interconnect using 3D X-ray tomography. A total of 6084 solder joints of 0.8mm and 0.5mm pitch BGAs were analyzed. Correlation between dye stain and package pull analysis and 3D-uCT X-ray revealed a 100% correlation. Virtual cross sections obtained using 3D x-ray tomography methods showed that it is possible to evaluate non-destructively the solder joint failure mode "H" known as "head-pillow or snowman" at the second level interconnect.
Development of the Polishing Technique for the Observation of the Intermetallic Compound at Solder Joint
Authors: Kongsubto Prong , Kongwudthiti Sirarat , Santipruksawong Nuannapa , Tippayamontri Jinusda , Promket Tewarit , Singsa Yaowalux 
Published: December 2020

Abstract
The monitoring of intermetallic compound (IMC) at solder joints has become more important recently because it is understood that IMC thickness and composition are the factors which determine the quality and reliability of solder joints. Normally it is quite difficult to view IMC optically due to its small (nanometer scale) thickness so scanning electron microscope (SEM) imaging is required to perform the observation. However, the most important factor for successful observation is the sample preparation, the grinding, polishing, and etching process in particular. Therefore, in this work we will discuss our experiments to develop an effective sample preparation technique to facilitate the observation of the IMC at the solder joint. Proper sample preparation will provide a good contrast between the IMC and surrounding metals under the SEM. We used the following 2 sample preparation techniques for ease of IMC observation: Fine polishing process: Polishing the sample with diamond compound followed by silica. Acid etching process: Etching the sample in HNO3 solution. This process is relatively simple and takes less time than polishing but acid etching will damage the solder so that this method is not suitable if analysis of the solder ball is also needed.
Translating Yield Learning Into Manufacturable Designs
Authors: Chowdhury Vijay , Rahim Irfan , Yu Ada , Venkitachalam Girish 
Published: December 2020

Abstract
Improving semiconductor yield is a multi-dimensional process that must include design, fabrication, and test aspects. Incorporating design-for-manufacturability (DFM) concepts needs to include prior and ongoing learning and experience on what worked and what did not. As feature sizes shrink beyond 130nm, it is possible to identify another class of failures that is more systematic and related not to manufacturing defects but to DFM marginalities related to layout. In this article, it is shown that DFM can also help reduce design sensitivity to process variations. Examples of these failure modes and the lessons learnt are listed: relaxed design rules for repeated patterns, relaxing design rules to reduce yield loss, and special considerations for analog circuit layout.
Soft Defect Localization Technique for Design and Debug on DRAM Devices
Authors: Versen Martin , Diaconescu Dorina , Touzel Jerome 
Published: December 2020

Abstract
A functional fail of a DRAM is analyzed by using an analog output of the device as an input signal of a microscope. Local heating by an IR laser changes the pass/fail behavior and thus the analog output of the DRAM. Although the observed spots do not belong to the physical defect, they give a starting point for further electrical analysis leading to the root cause of the failure. The paper will present a case study on a state-of-the art DRAM device failing with a timing problem. Especially the test aspects as well as the setup for the temperature dependent localization will be described. Finally an interpretation of the results will be proposed.
Three-Dimensional Nanometric Sub-Surface Imaging of a Silicon Flip-Chip Using the Two-Photon Optical Beam Induced Current Method
Authors: Ramsay E. , Serrels K. A. , Thomson M. J. , Waddie A. J. , Warburton R. J. , Taghizadeh M. R. , Reid D.T. 
Published: December 2020

Abstract
By implementing two-photon optical-beam-induced current microscopy using a solid-immersion lens, imaging inside a silicon flip chip is reported with 166nm lateral resolution and an axial resolution capable of resolving features only 100nm in height.
Effect of Inter-Die Adhesive Profile on the Integrity of Die Surface in Die Stacking Package
Authors: Flores Christopher C. , Aspera France B. 
Published: December 2020

Abstract
As the number of dice stacked within a microelectronic package increases, the need to maintain die surface integrity also increases. In this paper, one assembly packaging-related rootcause mechanism about passivation-metal damage (PMD) will be featured. The profile of inter-die adhesive was found to play an important role to maintain the integrity of die surface as more dice are stacked in a microelectronic package. Recommended solution to prevent this type of failure will be discussed.
A Novel Technique for Determining the Location of a Hermetic Leak in a ‘Metal Can’ (TO-x) Package
Authors: Nail Carl 
Published: December 2020

Abstract
Root-cause analysis of hermetic leak failures is complicated by the difficulty in isolating the leak location. Standard dye penetrant inspection is not consistently successful. The addition of pressure to the dye penetrant, followed by metallographic mounting and preparation, and subsequently followed by vacuum storage, greatly enhances the visibility of the dye and more effectively decorates the leak location.
Gradient Thermal Analysis by Induced Stimulus
Authors: Colvin Jim 
Published: December 2020

Abstract
In the field of failure analysis of integrated circuits, diagnosing functional failures is a requirement. Traditional beam-based analysis techniques use a scanning laser or ebeam to induce a parametric shift, which is monitored through changes in current or voltage driven to the device. Deep submicron technologies frustrate these analytical methods due to the nearly immeasurable parametric shifts externally caused by a small signal leakage path internally. These internal failures can be identified functionally by timing, temperature or voltage dependencies but the exact location of the fault is difficult to isolate. SIFT (Stimulus Induced Fault Test), RIL (Resistive Interconnect Localization) and SDL (Soft Defect Localization) can identify anomalies functionally using induced thermal gradients to the metal but does not address how to analyze embedded temperature sensitive defects inaccessible to the laser. 1,2,3,4 Stacked die and similar 3 dimensional (3D) devices complicate the analysis requiring destruction/removal of one or more die. This paper will show how to create quantifiable thermal gradients to a defect and triangulate the location of the defect in 1, 2, and 3 dimensions as follows: 1. Apply a differential temperature gradient across the device in each of the X,Y, and Z-axes. The defect is localized based on its measured response in the gradient as the gradient sweeps across. 2. Induce a gradient with a laser and use the measurement of DC power required to relate the distance to the defect from various locations in relation to a heat sink. 3. Measure the time of flight of the thermal propagation to a defect from known laser positions to triangulate the location of the defect.
Software Enhanced Time Resolved Laser Assisted Device Alteration with a Non-Pulsed Laser Source
Authors: Erington Kent , Asquith John , Bodoh Dan 
Published: December 2020

Abstract
We describe a technique that is used to obtain timing information from laser assisted device alteration (LADA). The technique uses a non-pulsed laser scanning microscope to obtain timing information with a temporal resolution on the order of microseconds. Custom software is used to extract the timing information from the LADA images.
Near-Infrared Microscopy in Semiconductor Failure Analysis Applications
Authors: Davis Thomas B. , Reagan Robert , Sun Yangyang , Jiang Tom 
Published: December 2020

Abstract
There has been ample discussion concerning the use of near infrared microscopy (NIR) in fields such as medical, materials science, and more recently in applications aimed toward micro-electro-mechanical systems (MEMS); however, little attention has been paid to the application of NIR microscopy in the verification and failure analysis of semiconductor memory devices. This paper will present a discussion of NIR and laser scanning confocal near-infrared microscopy, sample preparation for NIR microscopy, and emphasize examples of laser scanning confocal NIR microscopy in the measurement and failure analysis of silicon samples typical to the semiconductor industry.
Case Study: Failure Analysis of Functional Shmoo Hole with Laser Voltage Probing
Authors: Lee S.H. , Lee Y.W. , Lee K.T. , Choi C.Y. , Shin H.W. , Ng Yin S. , Lundquist T.R. 
Published: December 2020

Abstract
Innovations in semiconductor fabrication processes have driven process shrinks partly to fulfill the need for low power, system-on-chip (SOC) devices. As the process is innovated, it influences the related design debug and failure analysis which have gone through many changes. Historically for signal probing, engineers analyzed signals from metal layers by using e-beam probing methods [1]. But due to the increased number of metal layers and the introduction of flip chip packages, new signal probing systems were developed which used time resolved photon emission (TRE) to measure signals through the backside. However, as the fabrication process technology continues to shrink, the operating voltage drops as well. When the operating voltage drops below 1.0V, signal probing systems using TRE find it harder to detect the signals [2]. Fortunately, Laser Voltage Probing (LVP) technology [3] is capable of probing beyond this limitation of TRE. In this paper, we used an LVP system to analyze and identify a functional shmoo hole failure. We also proposed the design change to prevent its reoccurrence.
The Method for Retaining an Intermittent Electrical Failure Signature during the Interconnect Immobilization Process throughout Failure Analysis
Authors: Schuchman Julie , Willis Julie 
Published: December 2020

Abstract
This paper deals primarily with the difficulties and solutions to scanning transmission electron microscope (STEM) sample preparation by dual beam focused ion beam. Approximately twenty major challenges were encountered spanning hardware, software, and material sample preparation. The main focus is upon the variety of challenges which are encountered in trying to implement automated STEM and TEM sample fabrication with minimal operator input and the engineering solutions implemented to overcome these challenges. The automated STEM script has evolved significantly from the first generation attempt and is described in more detail in this paper. The mechanical, software, and materials challenges encountered are also presented. The paper highlights a mechanical issue with the ion aperture motor mechanism, which required extensive troubleshooting to fully diagnose and correct. A long standing software routine had to be modified to fully enable script automation by extending the beam dwell time of the automatic brightness contrast routine.
Magnetic Microscopy for 3D Structures: Use of the Simulation Approach for the Precise Localization of Deep Buried Weak Currents
Authors: Infante Fulvio , Gomes Rodolphe , Perdu Philippe , Battistella Fabien , Annereau Sebastien , Lewis Dean 
Published: December 2020

Abstract
With the innovations in packaging technologies which have taken place over the last decade, new assemblies often include an increasing number of dies inside a single package. This is exactly what was predicted by the More than Moore’s paradigm: as the integration of ICs increases, the heterogeneity of the devices found in a single package increases. As a result, the number of potential failures which can appear at assembly level has increased exponentially. At present, no technique has been able to precisely localize defects which are deep inside a complex package. For this reason, a new technique for failure localization for three-dimensional structures is needed. In this paper the technique proposed, based on the coupling of magnetic measurements and simulations, is applied to a three-dimensional structure to precisely localize the current path which is buried deep inside it. A new method, based on parameters fittings of magnetic simulations, is then applied in order to accurately evaluate the distance between the current and the sensor.
Process Induced Defects in the Silicon Substrate: Approaches for Successful Failure Analysis
Authors: van Hassel J.G. , Zhang Xiao-Mei 
Published: December 2020

Abstract
Failures induced in the silicon substrate by process marginalities or process mistakes need continuous attention in new as well as established technologies. Several case studies showing implant related defects and dislocations in silicon will be discussed. Depending on the electrical characteristics of the failure the localization method has to be chosen. The emphasis of the discussion will be on the importance of the right choice for further physical de-processing to reveal the defect. This paper focuses on the localization method, the de- processing technique and the use of Wright etch for subsequent TEM preparation.
Activation Energy Analysis of Dark and Laser Illuminated I-V Characteristics of Thin-Film Poly Silicon Solar Cells
Authors: Boostandoost M. , Kerst U. , Boit C. 
Published: December 2020

Abstract
The temperature dependence of photocurrent of polycrystalline Si (poly-Si) thin-film solar cells on glass with interdigitated mesa structure has been locally investigated using Infrared Light Beam Induced Current (IR-LBIC) in the temperature range of -25 to +70 °C. The temperature dependence of electrical characteristics of poly-Si thin-film solar cells in reverse bias has been also analysed and compared with the monocrystalline thin-film solar cells. The poly-Si solar cell shows a temperature coefficient (TC) for the photocurrent of around +0.8 and +0.6 %/°C in the grain interior and grain boundary, respectively. The activation energy of the reverse current and also the photocurrent due to the IR laser stimulation has been evaluated, which provide information about traps and their energy levels in the absorber layer of the poly-Si thin-film solar cell. The obtained average value of the activation energy associated with the photocurrent of the poly-Si cell suggests the existence of a shallow acceptor level at around 0.045 eV in the grain boundary and 0.062 eV in the grain interior of the absorber layer of the poly-Si thin-film solar cell. The activation energies of the reverse current for poly-Si and monocrystalline cells have been calculated when the device is biased at -1 and -2 V and the results compared with the activation energy of the saturation current obtained from extrapolation of the I-V curve in the SRH (Shockley-Read-Hall) regime. The results show strong voltage dependence. In both cases the activation energy of the reverse current decreases in the reverse bias voltage, approaching the values obtained from the photocurrent.
Improvement of Optical Resolution through Chip Backside Using FIB Trenches
Authors: Glowacki Arkadiusz , Helfmeier Clemens , Kerst Uwe , Boit Christian , Perdu Philippe 
Published: December 2020

Abstract
Optical spatial resolution improvement using local focused ion beam (FIB) assisted silicon material removal was investigated. Two types of test structures were chosen for imaging-resolution characterization to be able to use two ways of measuring resolution. Samples of various remaining bulk silicon thicknesses were prepared and characterized in terms of image quality and spatial resolution. The resulting remaining bulk Si thickness was measured using reflectance spectrometry. Images were acquired using halogen-lamp illumination and reflected light detection using a cooled Si-CCD detector. To investigate the image quality at various wavelengths, a set of interference band-pass filters was applied.
Energy-Dispersive X-ray Spectrometry Performance on Multiple Transmission Electron Microscope Platforms
Authors: Demarest James , Deeb Chris , Murray Thomas , Zhai Hong-Ying 
Published: December 2020

Abstract
Energy-dispersive X-ray spectrometry (EDS) is a key analytical tool aiding root cause determination in the failure analysis (FA) process. This paper looks at a number of analytical TEM microscopes currently in use in various facilities: microscope A, a STEM operated at 200kV; microscope B, a 300kV TEM; and microscopes C and D, both 200kV TEMs. EDS counts per unit time from multiple microscope platforms were examined. Microscope D demonstrated two orders of magnitude higher counts per unit time than the other three microscopes. Microscope D represents the state-of-the-art EDS analytical TEM configuration and has achieved this through a novel windowless EDS configuration which significantly increases the detector area (by about a factor of three) that receives X-rays generated from the sample.
Systematic Defect Identification through Layout Snippet Clustering
Authors: Tam Wing Chiu , Poku Osei , (Shawn) Blanton R. D. 
Published: December 2020

Abstract
Systematic defects due to design-process interactions are a dominant component of integrated circuit (IC) yield loss in nano-scaled technologies. Test structures do not adequately represent the product in terms of feature diversity and feature volume, and therefore are unable to identify all the systematic defects that affect the product. This paper describes a method that uses diagnosis to identify layout features that do not yield as expected. Specifically, clustering techniques are applied to layout snippets of diagnosis-implicated regions from (ideally) a statistically-significant number of IC failures for identifying feature commonalties. Experiments involving an industrial chip demonstrate the identification of possible systematic yield loss due to lithographic hotspots.
Novel Circuit Edit Solution for Bulk Copper Milling
Authors: Malik Tahir , Jain Rajesh , Meijer Ferdi , Velthof Tim 
Published: December 2020

Abstract
Focused Ion Beam (FIB) circuit edit (CE) has been playing a pivotal role in providing insight to ramp-up yield. Numerous IC fabrication processes inherently pose unique challenges to FIB circuit edit approaches. Copper (Cu) has been the material of choice for interconnects as technology features shrink to the 180 nm node and below. Thick copper planes are used for multiple reasons that are mentioned later. Milling through thick copper planes has been tremendously challenging and time consuming during FIB circuit edits. Proposed is a methodology to enhance the bulk Cu removal process at astounding etching rates while maintaining planarity.