Four-dimensional scanning transmission electron microscopy (4D-STEM) is a spatially resolved electron diffraction technique that records the electron scattering distribution at each point of the electron beam raster, thereby producing a four-dimensional dataset. The final article in this series covers ptychography, a form of computational imaging that recovers the phase information imparted to an electron beam as it interacts with a specimen.

Four-dimensional scanning transmission electron microscopy (4D-STEM) is a spatially resolved electron diffraction technique that records the electron scattering distribution at each point of the electron beam raster, thereby producing a four-dimensional dataset. This second installment of this series presents applications of 4D-STEM, including measurements of crystal orientation and phase, short- and medium-range order, and internal electromagnetic fields.

Four-dimensional scanning transmission electron microscopy (4D-STEM) is a spatially resolved electron diffraction technique that records the electron scattering distribution at each sampling point. 4D-STEM provides researchers with information that can be analyzed in a multitude of ways to characterize a sample’s structure, including imaging, strain measurement, and defect analysis. This article introduces the basics of the technique and some areas of application with an emphasis on semiconductor materials.

This article discusses sample preparation challenges that have impeded progress in producing bias-enabled TEM samples from electronic components, as well as strategies to mitigate these issues.

This article discusses the tradeoffs associated with minimizing beam dose in a scanning transmission electron microscope (STEM) and explains how to reduce beam exposure through subsampling and inpainting, a signal reconstruction technique that optimizes image quality and resolution. Although the method is described in the context of STEM imaging, it applies to any scanned imaging system.

This article provides a brief overview of STEM-in-SEM, discussing the pros and cons, recent advancements in detector technology, and the emergence of 4D STEM-in-SEM, a relatively new method that uses diffraction patterns recorded at different raster positions to enhance images offline in selected regions of interest.

The ability to discern the composition and placement of atoms in a sample makes TEM one of the most powerful characterization tools for microelectronic components. For many devices, however, the dynamics underlying normal operation do not displace atoms. Device function is, instead, mediated by electronic and thermal processes that have little effect on physical structure, necessitating additional tools to determine the causes of failure. In this article, the author presents results indicating that STEM EBIC, with the new SEEBIC mode, can provide electronic contrast that complements the physical-based contrast of STEM imaging. By identifying device features at higher risk of failure, the two methods may open a path to predictive failure analysis.

This article describes an ebook titled STEM-in-SEM: Introduction to Scanning Transmission Electron Microscopy for Microelectronics Failure Analysis , intended as an introductory tutorial for those with little or no transmission imaging experience and as a source of ideas for SEM users looking to expand the imaging and diffraction capabilities of their equipment.

Ex-situ lift out (EXLO) techniques rely on van der Waals forces to transfer FIB milled specimens to various types of carriers using a glass probe micromanipulator. This article describes some of the latest EXLO techniques for site specific scanning transmission electron microscopy, including the use slotted half-grids and vacuum-assisted lift out for plan-view analysis.

Recent developments in automated image acquisition and metrology using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) have significantly improved the speed, precision, and usability of these techniques for controlling advanced semiconductor device manufacturing processes. As device dimensions have continued to shrink, these techniques may be needed to replace scanning electron microscopy (SEM) for the smallest critical dimension (CD) measurements. This article describes the use of automated S/TEM in a high-throughput CD-metrology workflow to support process development and control and explains how automated sample-preparation, data-acquisition, and metrology tools increase both throughput and data quality.

Localizing defects in one-of-a-kind failures can take days, weeks, or even months, after which a detailed physical analysis is conducted to determine the root cause. TEM and STEM play complimentary roles in this process; TEM because of its superior spatial resolution and STEM because it produces images that are easier to interpret and is less susceptible to chromatic aberrations that can occur in thicker samples. In the past, the use of STEM in FA has been limited due to the time required to switch between imaging modes, but with the emergence of TEM/STEM microscopes with computer controlled lenses, the use of STEM is increasing. This article provides an overview of STEM techniques and present examples showing how it is used to characterize subtle and complex defects in ICs.

This article describes two innovative methods that can significantly improve the resolution of SEM imaging: scanning transmission electron microscopy in a scanning electron microscope (STEM-in-SEM) and forward-scattered electron imaging (FSEI). Both methods can be implemented in any SEM using special sample holders. No other modifications are required. Test results presented in the article show that 1 to 2 nm resolution is possible in thin sections, uncoated polysilicon gates, and photoresist.