Scanning microwave impedance microscopy is a nearfield technique using microwaves to probe the electrical properties of materials with nanoscale lateral resolution.

This article demonstrates the value of atomic force microscopes, particularly the different electrical modes, for characterizing complex microelectronic structures. It presents experimental results obtained from deep trench isolation (DTI) structures using SCM and SSRM analysis with emphasis on the voltage applied by the AFM. From these measurements, a failure analysis workflow is proposed that facilitates AFM voltage optimization to reveal the structure of cross-sectioned samples, make comparisons, and determine the underlying cause of failures.

Sample preparation is a critical step for dopant profiling of FinFET devices, especially when targeting individual fins. This article describes a sample-preparation technique based on low-energy, shallow-angle ion milling and shows how it minimizes surface amorphization and improves scanning capacitance microscopy (SCM) signals representative of local active dopant concentration.

This article describes the basic measurement physics of scanning nitrogen vacancy (NV) microscopy and the various ways it can be used in semiconductor device failure analysis. Scanning NV microscopy can measure topography as well as magnetic fields, local current density, ac noise, and local temperature variations.

Scanning nonlinear dielectric microscopy (SNDM) is a scanning probe technique that measures changes in oscillation frequency between the probe tip and a voltage-biased sample. As the probe moves across the surface of a semiconductor device, the oscillation frequency changes in response to variations in dielectric properties, charge and carrier density, dopant concentration, interface states, or any number of other variables that affect local capacitance. Over the past few years, researchers at Tohoku University have made several improvements in dielectric microscopy, the latest of which is a digital version called time-resolved SNDM (tr-SNDM). Here they describe their new technique and present an application in which it is used to acquire CV, d C /d V-V , and DLTS data from SiO 2 /SiC interface samples.

Scanning capacitance microscopy (SCM) and nanoprobing are key tools for isolating and understanding transistor level fails. In this case study, SCM and nanoprobing are used to determine the electrical characteristics of cluster-type failures in 14 nm SOI FinFET SRAM after standard FIB cross-section imaging failed to reveal any visible defects.

Scanning probe microscopy (SPM) is widely used for fault isolation as well as diagnosing leakage current, detecting open circuits, and characterizing doping related defects. In this article, the author presents two SPM applications that are fairly uncommon but no less important in the scope of failure analysis. The first case involves the discovery of nano-steps on the surface of high-voltage NFETs, a phenomenon associated with stress-induced crystalline shift along the (111) silicon plane. In the second case, the author uses an AFM probe in the conductive mode to correlate tunneling current distribution with hot spots in high-k gate oxide films, which is shown to be a better indicator of oxide quality than rms surface roughness.

Magnetic current imaging provides electrical fault isolation for shorts, leakage currents, resistive opens, and complete opens. In addition, it can be performed nondestructively from either side a die, wafer, packaged IC, or PCB. This article reviews the basic theory and attributes of MCI, describes the types of sensors used, and discusses general measurement procedures. It also presents application examples demonstrating recent advancements and improvements in MCI.

Failure analysis labs are fairly well equipped for dealing with shorts and leakages in stacked-die packages, but are at a disadvantage when it comes to opens, particularly those at the die or die interconnect level. This article presents a new FA technique that has the potential to make up for this shortcoming. The new method, called space domain reflectometry (SDR), is based on radio-frequency magnetic current imaging, and as the authors show, is capable of accurately locating a dead open in a double-stacked BGA package, even when the full stack is encapsulated in molding compound.

Magnetic microscopy is a defect localization technique that has several advantages. It is nondestructive, noninvasive, and contactless. In many cases, it can be used even before component depackaging. This article describes the basic setup of a magnetic current imaging (MCI) microscope and explains how it reveals 3D current paths at the package and die level. It also presents application examples showing how MCI has helped failure analysts isolate a wide range of electrical defects, including shorts, resistive opens, and full opens.

The Electronic Device Failure Analysis (EDFA) magazine celebrates its 10th anniversary with this issue. This significant milestone provides an opportunity to recall the transition of the Electronic Device Failure Analysis News (EDFAN) newsletter to EDFA magazine. When Chuck Hawkins, then the Editor of EDFAN, proposed converting from a newsletter to a magazine, EDFAS was only a few years into existence, and there was apprehension about such an early transition.

Magnetic current imaging is a proven fault-isolation technique. Its unsurpassed sensitivity and resolution coupled with the fact that magnetic fields are unaffected by packaging and die materials make it a valuable FA tool for a wide variety of ICs and devices. This article reviews the basic measurement physics of magnetic current imaging, describes the general implementation, and presents several practical examples of its use.

Probing in the sub-100 nm realm requires new tools and techniques that are relatively easy to learn if users follow the advice of the authors of this article. The authors present a probing method based on scanning probe technology and demonstrate its use on a 90-nm transistor failure due to a poly-silicon gate short. They also address challenges associated with sample preparation, probe tip contamination and wear, and the effects of vibration and drift.

Recent improvements in giant magnetoresistance sensors have increased the achievable spatial resolution of magnetic current imaging on packaged devices without a significant compromise in magnetic field sensitivity. Front and backside current imaging examples show the utility of these new sensors for die-level failure analysis.

Magnetic field imaging is proving to be a valuable tool for semiconductor failure analysts and test engineers. One of its main advantages is that it does not require sample preparation or deprocessing because magnetic fields pass through most materials used in ICs and device packages. This article discusses the theory and practical limitations of magnetic field imaging and demonstrates its use in mapping current density and determining the location and depth of current-carrying conductors.

With the growing complexity of new processes and the introduction of new materials, the need for product yield management and process control is placing unprecedented demands on failure analysis laboratories in the semiconductor industry. These demands are calling for faster and superior analytical capabilities to determine root-cause failure mechanisms in semiconductor devices fabricated using deep submicron processes. This article presents a new automated sample preparation technique that facilitates direct electrical contact to the area of interest, with a surface quality sufficient for scanning probe microscope analysis.

Scanning capacitance spectroscopy (SCS) is a new way to use a scanning capacitance microscope (SCM) to delineate pn junctions in silicon devices. SCS produces two-dimensional pn junction maps with features as small as 10 nm. It can also estimate the pn junction depletion width and hence doping levels near the junction. This article explains how SCS and SCMs allow a whole new regime of doping-related phenomena to be explored in Si devices and ICs.

Scanning probe microscopy (SPM) refers to a suite of techniques that measure the interaction between a fine probe or tip and a sample in contact or close proximity. These interaction measurements allow the study of properties such as topology, magnetic and electric fields, capacitance, temperature, work function, and friction. The information obtained from SPM plays an important role in IC failure analysis.