Search Results for spatial resolution

This article reviews the basic physics behind active photon injection for local photocurrent generation in silicon and thermal laser stimulation along with standard scanning optical microscopy failure analysis tools. The discussion includes several models for understanding the local thermal effects on metallic lines, junctions, and complete devices. The article also provides a description and case study examples of multiple photocurrent and thermal injection techniques. The photocurrent examples are based on Optical Beam-Induced Current and Light-Induced Voltage Alteration. The thermal stimulus examples are Optical Beam-Induced Resistance Change/Thermally-Induced Voltage Alteration and Seebeck Effect Imaging. Lastly, the article discusses the application of solid immersion lenses to improve spatial resolution.

This chapter assesses the benefits of using a solid immersion lens (SIL) to detect faults in ICs via optical imaging and laser-stimulation techniques. It discusses the advantages and limitations of different types of SILs and their effect on spatial resolution, spot size, focus depth, and collection efficiency. It also provides a brief overview of technical challenges at the die level.

This chapter assesses the capabilities and limitations of electric fault isolation (EFI) technology, the measurement challenges associated with new device architectures, and the pathways for improvement in emission microscopy, laser stimulation, and optical probing. It also assesses the factors that influence signal strength, spatial and timing resolution, and alignment accuracy between signal response images and the physical layout of the IC.

Many defects generate excessive heat during operation; this is due to the power dissipation associated with the excess current flow at the defect site. There are several thermal detection techniques for failure analysis and this article focuses on infrared thermography with lock-in detection, which detects an object's temperature from its infrared emission based on blackbody radiation physics. The basic principles and the interpretation of the results are reviewed. Some typical results and a series of examples illustrating the application of this technique are also shown. Brief sections are devoted to the discussion on liquid-crystal imaging and fluorescent microthermal imaging technique for thermal detection.

Post-mortem analysis of photovoltaic modules that have degraded performance is essential for improving the long term durability of solar energy. This article focuses on a general procedure for analyzing a failed module. The procedure includes electrical characterization followed by thermal imaging such as forward bias, reverse bias, and lock-in, and emission imaging such as electroluminescence and photoluminescence imaging.

This article provides an overview of the most common micro-analytical technique in the failure analysis laboratory: energy dispersive X-ray spectroscopy (EDS). It discusses the general characteristics, advantages, and disadvantages of some of the X-ray detectors attached to the scanning electron microscope chamber including the lithium-drifted EDS detector, silicon drift detector (SDD), and wavelength dispersive X-ray detector. The article then provides information on qualitative and quantitative X-ray analysis programs followed by a discussion on EDS elemental mapping. The discussion includes a comparison of scanning transmission electron microscope-EDS elemental mapping and mapping with an SDD. A brief section is devoted to the discussion on the artifacts that occur during X-ray mapping.

X-ray imaging systems have long played a critical role in failure analysis laboratories. This article begins by listing several favorable traits that make X-rays uniquely well suited for non-destructive evaluation and testing. It then provides information on X-ray equipment and X-ray microscopy and its application in failure analysis of integrated circuit (IC) packaging and IC boards. The final section is devoted to the discussion on nanoscale 3D X-ray microscopy and its applications.

Laser Voltage Probing (LVP) is a key enabling technology that has matured into a well-established and essential analytical optical technique that is crucial for observing and evaluating internal circuit activity. This article begins by providing an overview on LVP history and LVP theory, providing information on electro-optical effects and free-carrier effects. It then focuses on commercially available continuous wave LVP systems. Alternative optoelectronic imaging and probing technologies for fault isolation, namely frequency mapping and laser voltage tracing, are also discussed. The subsequent section provides information on the use of Visible Laser Probing. The article closes with some common LVP observations/considerations and limitations and future work concerning LVP.

The overall chemical composition of metals and alloys is most commonly determined by x-ray fluorescence (XRF) and optical emission spectroscopy (OES). High-temperature combustion and inert gas fusion methods are typically used to analyze dissolved gases (oxygen, nitrogen, and hydrogen) and, in some cases, carbon and sulfur in metals. This chapter discusses the operating principles of XRF, OES, combustion and inert gas fusion analysis, surface analysis, and scanning auger microprobe analysis. The details of equipment set-up used for chemical composition analysis as well as the capabilities of related techniques of these methods are also covered.

An architectural shift to buried power rails (BPRs) with backside power delivery (BPD) is on the horizon as CMOS technology approaches the 2 nm node. The obstruction created by the presence of BPD networks obsoletes many of the electrical fault isolation (EFI) techniques that have been used for the past few decades and severely degrades the performance of others. This chapter provides an overview of EFI methods that are still applicable to ICs with BPD networks, including e-beam and atomic force probing, x-ray and magnetic field imaging, and lock-in thermography. It assesses the technical challenges of each method as well as the potential for improvement.

This chapter describes three approaches for 3D hot-spot localization of thermally active defects by lock-in thermography (LIT). In the first section, phase-shift analysis for analyzing stacked die packages is performed. The second example employs defocusing sequences for the localization of resistive electrical shorts in 3D architectures, and the third operates in cross sectional LIT mode to investigate defects in the insulation liner of Through Silicon Vias. All three approaches allow for a precise localization of thermally active defects in all three spatial dimensions to guide subsequent high-resolution physical analyses.

The first step in die-level failure analysis is to narrow the search to a specific circuit or transistor group. Then begins the post-isolation process which entails further localizing the defect, determining its electrical, physical, and chemical properties, and examining its microstructure in order to identify the root cause of failure. This chapter assesses the tools and techniques used for those purposes and the challenges brought on by continued transistor scaling, advanced 3D packages, and new IC architectures. The areas covered include sample preparation, nanoprobing, microscopy, FIB circuit edit, and scanning probe microscopy.

As semiconductor feature sizes have shrunk, the technology needed to encapsulate modern integrated circuits has expanded. Due to the various industry changes, package failure analyses are becoming much more challenging; a systematic approach is therefore critical. This article proposes a package failure analysis flow for analyzing open and short failures. The flow begins with a review of data on how the device failed and how it was processed. Next, non-destructive techniques are performed to document the condition of the as-received units. The techniques discussed are external optical inspection, X-ray inspection, scanning acoustic microscopy, infrared (IR) microscopy, and electrical verification. The article discusses various fault isolation techniques to tackle the wide array of failure signatures, namely IR lock-in thermography, magnetic current imaging, time domain reflectometry, and electro-optical terahertz pulse reflectometry. The final step is the step-by-step inspection and deprocessing stage that begins once the defect has been imaged.

Recent trends in electronic packaging, including the growing use of 3D designs and heterogeneous integration, are greatly adding to the complexity of isolating faults in semiconductor products. This chapter reviews the latest IC packaging and integration solutions and assesses the readiness level of fault isolation tools and techniques. It examines the capabilities, limitations, and optimization potential of x-ray tomography and magnetic field imaging, describes various approaches for optical fault isolation, and compares and contrasts pre-OFI sample preparation methods. The chapter also explains how time-domain and electro-optical terahertz pulse reflectometry are used to find shorts and opens in ICs and how challenges related to heterogenous integration may be met through design for testability (DFT) and built-in self-test (BIST) accommodations and the use of passive interposers.