The EDFAS Education Subcommittee strives for the development and delivery of educational products to the EDFAS membership. Keeping with its strategic focus on reaching a broader audience, including facilitating Q&A and educational exchanges on the ASM Connect platform, the Subcommittee presents short format presentations on selected FA topics. These presentations are available on ASM Connect and highlighted in EDFA Magazine.
We present the tutorial:
Sample Preparation for Scanning Electron Microscopy Characterization and Failure Analysis of Advanced Semiconductor Devices
Dr. Pawel Nowakowski
Sr. Applications Specialist
E.A. Fischione Instruments, Inc.
SEM sample preparation and analyses, semiconductor devices are typically prepared in two ways: a cross-section view or plan view. The cross-section view gives information about the device layers: total number, thickness, and chemical composition. Cross-section view is very helpful in identifying failures such as delamination, voids, discontinuity of layers, contact problems, or contamination. It has many applications, such as electrical measurements (electron beam induced current/electron beam absorbed current [EBIC/EBAC], scanning capacitance microscopy [SCM], and nanoprobing) and integrated circuit morphology visualizations for critical dimension measurement. The accuracy of these analyses is critical for semiconductor industry applications and are dependent on the quality of the investigated surface: the dimensions of the surface area available for investigation (the bigger the better), surface flatness, surface uniformity, and surface cleanliness (devoid of contamination).
The sample preparation for those measurements is often done by delayering process. The delayering process removes each device layer, layer-by-layer, and exposes the desired level of the device for future examination. A device delayering process can consist of many different steps and is often very complex. Currently, numerous techniques are used, such as mechanical polishing, chemical etching, Ga FIB and broad Ar ion beam milling.
In this tutorial, sample preparation methods for SEM characterizations of devices will be presented and discussed, as will advantages and disadvantages of the various methods. Selecting the appropriate sample preparation method and various imaging and microanalysis techniques will be illustrated through case studies.
Dr. Pawel Nowakowski is a Senior Application Scientist at Fischione Instruments, where he has worked since 2015. He earned his PhD in Materials Science and Engineering from the University of Toulon in 2008. With over 20 years of experience, Dr. Nowakowski has expertise in EBSD techniques, sample preparation (including delayering, BIB, and FIB), failure analyses and materials deformation. He previously worked at Nantes University and Oxford Instruments. In 2022, he won the Best Paper award at ISTFA. He currently serves as Co-Chair of the ISTFA Sample Preparation User Group.