Abstract This study shows that a high-volume TEM workflow can be achieved for inline defect characterization by adding a defect marking step using commercially available tools. A simple user-assisted defect marking procedure added to a conventional automated ex-situ lift-out TEM workflow increased throughput by a factor of nearly three and reduced man-hours by an order of magnitude, a significant improvement over conventional TEM workflows.

Abstract The automation of TEM imaging and lamella preparation using focused ion beam (FIB) technology has gained significant momentum, particularly in the development of microprocessors. A key requirement of automating TEM sample preparation is ensuring consistent thickness control and accurate targeting of features of interest in the ultra-thin lamella. This work examines the factors that impact both metrics. It explains how FIB pattern calibration requires milling to be divided into steps to minimize the effects of drift, how the height of the protective cap on the ion-beam tip influences sample thickness, and how FIB aperture erosion has little impact on lamella thickness until it reaches a certain point where the lamella profile cannot be reliably maintained. It was also found that the tail of the ion beam remains invariant during aperture degradation in the operable range and that it plays a prominent role in determining the cross-sectional thickness of the TEM lamella.

Abstract This paper describes an accurate and controllable delayering process to target defects in new materials and device structures. The workflow is a three-step process consisting of bulk device delayering by broad Ar ion beam milling, followed by plan view specimen preparation using a focused ion beam, then site-specific delayering via concentrated Ar ion beam milling. The end result is a precisely delayered device without sample preparation-induced artifacts suitable for identifying defects during physical failure analysis.

Abstract This paper evaluates the use of plasma etching for preparing TEM specimens to analyze high aspect ratio 3D NAND integrated circuits. By controlling plasma etching parameters, a relatively high material removal rate could be obtained. Moreover, through the control of etch time, the top region of the test specimens could be completely removed down through the expected number of layers, making it possible to resolve details throughout the entire sample, particularly in the middle region of the 3D NAND, using TEM cross-section analysis.

Abstract This paper evaluates the use of nanomilling and STEM imaging to analyze failure mechanisms in sub-50 nm InP HEMTS. The devices were life tested at elevated temperatures and biases and their electrical characteristics were measured at each stress interval. Devices that were damaged were investigated further to assess the underlying failure mechanism. Advanced microscopy with sub-nm resolution was employed to examine the physical characteristics of the failed HEMT devices at the atomic scale. As the paper explains, the examination was conducted using a focused ion beam/scanning electron microscope (FIB/SEM), an Ar gas ion nanomill, and STEM imaging.

Abstract This paper explains how to localize metal-to-metal short failures in DRAM using mechanical grinding, plasma FIB delayering, and electron beam induced resistance change (EBIRCH) analysis. Experiments show that the slope created during grinding is compensated by PFIB delayering, producing a high-quality planar surface in the target layer and site. Target layers can thus be prepared at any location (site-free), likewise, defective areas can be delayered to any depth without damage (layer-free). After delayering, exposed surfaces are generally flat enough to allow an electron beam to evenly penetrate the device for precise EBIRCH analysis. With the use of more advanced device preparation methods, EBIRCH analysis has a higher chance of successfully localizing metal line/via shorts even in large regions that include the aluminum layer.