Scanning microwave impedance microscopy (sMIM) is a relatively new method for making electrical measurements on test samples in AFMs. This article presents examples in which sMIM technology is used to measure dielectric coefficients, doping concentrations, and nanoscale C-V curves for different semiconductor and dielectric materials. It also explains how measured results compare with theoretical models, confirming the validity of each approach.

Dopant profiles in submicron silicon devices are typically measured using scanning probe techniques. A new SEM-based method has recently emerged, however, that could prove to be a more powerful tool for quantitative dopant imaging. This article discusses the measurement physics of secondary electron potential contrast imaging and assesses its capabilities based on the analysis of SiC power transistors, vertical cavity surface emitting lasers, and quantum well devices.

This article presents and evaluates a calibration method that significantly improves the spectral information that can be extracted from photon emission signals obtained from semiconductor devices. Step-by-step instructions are given for calibrating photon emission microscopes for specific measurements such as device parameters and material band gap. The article also discusses the types of errors that can occur during calibration. Although the procedure presented is used on InGaAs sensors, it applies to all common photon emission detectors.

This article discusses the basic principles of SEM-based cathodoluminescence (CL) spectroscopy and demonstrates its usefulness in process development, statistical process control, and failure analysis. The technologies where the benefits of CL spectroscopy are most evident are compound semiconductor optoelectronics and high electron mobility transistors as reflected in the application examples.

Differential Hall effect metrology (DHEM) provides depth profiles of all critical electrical parameters through semiconductor layers at nanometer-level depth resolution. This article describes the relatively new method and shows how it is used to measure mobility and carrier concentration profiles in different materials and structures.

This article discusses the use of scanning-beam techniques such as EBIC, IBIC, and OBIC to optimize the design of edge-termination structures in vertical GaN and AlGaN power diodes.

This article reviews recent work aimed at characterizing soft-error effects in SRAM circuits fabricated with bulk silicon FinFETs. Accelerated tests were conducted on 6T planar and FinFET-based SRAM cells by exposing them to high-energy neutrons and alpha particles. Based on test results and simulations, the authors show that soft-error rates are much lower in FinFET devices because the geometry of the fins limits charge collection.

Nanoprobing of transistors and resistors is increasing in importance for both design debug and electrical fault isolation. It is thus necessary to understand the impact of scanning a resistor or transistor with an electron beam in order to draw valid conclusions from nanoprobe measurements. In this article, the authors show that exposing samples to electron beams with energies above 4 keV can change the value of diffusion resistors by as much as 30% and that changes can occur at even lower voltages in areas of the sample covered with less material. The article also sheds light on why the changes occur.

Scanning microwave impedance microscopy (sMIM) is an electrical measurement technique that can be used to determine dopant profiles in semiconductor devices. This article describes the basic setup and implementation of the method and demonstrates its use in the cross-sectional analysis of NMOS power transistors.

This article describes the physical characteristics, operating principles, and key failure modes of light-emitting diodes (LEDs), focusing on phosphor-converted blue LEDs because of their relative importance. The explanations throughout the article are supported by graphics that reveal microscale features of interest as well as defects.

Scanning capacitance microscopy (SCM) has proven to be an effective tool for investigating doping-related failure mechanism in ICs. The examples in this article show how the author used SCM to solve various problems including premature breakdown due to pattern misalignment, threshold voltage variations caused by poly gate doping anomalies, and source-drain leakage due to channeling effects.

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 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.

Off-axis electron holography is a TEM-based imaging technique that reveals dopant anomalies and junction profiles in semiconductor devices. This article explains how the method works and how it is being used to visualize transistor source-drain regions, diffusion-related defects, and other features of interest in TEM samples. It also discusses related challenges and compares off-axis electron holography with other profiling techniques, particularly junction staining.

Silicon pipeline defects are a growing concern in semiconductor manufacturing with no proposed methodology on how to effectively analyze them and separate the underlying causes. In light of this need, a study was conducted using complementary FA techniques to examine these unusual silicon crystal defects and gain a better understanding of their signature characteristics and their effect on device failure. This article, authored by the lead investigator, describes the tests that were performed and presents relevant findings and theories on the factors that contribute to "pipeline" and how they can be controlled. It also presents guidelines for distinguishing between pipeline and dislocation defects and explains how they are related.

STEM-EBIC imaging, a nano-characterization technique, has been used in the study of electrically active defects, minority carrier diffusion length, surface recombination velocity, and inhomogeneities in Si pn junctions. In this article, the authors explain how they developed and built a STEM-EBIC system, which they then used to determine the junction location of an InGaN quantum well LED. They also developed a novel FIB-based sample preparation method and a custom sample holder, facilitating the simultaneous collection of Z-contrast, EBIC, and energy dispersive spectroscopy images. The relative position of the pn junction with respect to the quantum well was found to be 19 ± 3 nm from the center of well.

This article discusses the basic principles of dark current spectroscopy (DCS), a measurement technique that can detect and identify low levels of metal contaminants in CMOS image sensors. An example is given in which DCS is used to determine the concentration of tungsten and gold contaminants in an image sensor and estimate the dark current generated by a single atom of each metal.

This article explains how oxide traps and mobile ions can lead to timing and function failures in ICs and provides insights and advice on how to identify and deal with potential problems.

Secondary ion mass spectrometry (SIMS) works by bombarding the surface of a solid sample with ions, freeing charged atomic and molecular species which are then collected and analyzed. This article explains that SIMS has the ability to detect all elements in the periodic table in addition to inherent depth profiling capabilities, making it an indispensable tool for the characterization and analysis of semiconductor components and materials. It also presents several application examples.

Microcalorimeter-based energy-dispersive spectroscopy is a breakthrough in semiconductor material analysis. With an energy resolution of less than 10 eV, it allows the unambiguous identification of elements in the low-energy range (<3 kV) which, until now, required wavelength-dispersive techniques.