Year: 2025
Type: conference-paper
Abstract: The growing interest in using Si/SiGe as a foundational material for 3D stackable DRAM and logic devices presents a significant challenge for inspection strategies, given the defect length scales, density and relative positions.1,2 Ensuring the quality of these templates is crucial to minimize current leakage and achieve high electrical efficiency. In this study, we explored various types of Si/SiGe-specific crystalline defects (e.g., misfits, threading dislocations and crosshatch), their z-positions (through stack, surface, at interface) and established correlations using multiple measurement techniques across a wide range of defect-specific interactions with various spectroscopic and microscopic techniques. High-throughput techniques like optical inspection and x-ray topography (XRT) were examined in their effectiveness in identifying misfits based on various physical characteristics. Additionally, high-resolution review techniques such as ebeam and atomic force microscopy (AFM) were tested to assess their ability to detect individual surface misfits and validate inspection results. The balance between throughput, sensitivity, and defect density was also analysed to optimize the detection capabilities of these techniques. Detecting threading dislocations (TDs) as a key objective was investigated using Electron Channelling Contrast Imaging (ECCI). While ECCI is a benchmark reference technique for TD detection, it faces significant throughput challenges. Despite these limitations, the presence of threading dislocations at the ends of misfits on 300mm wafers was identified. In summary, examining Si/SiGe-specific crystalline defects with a blend of high-throughput and high-resolution techniques is essential for optimizing the quality of Si/SiGe superlattices on 3D-DRAM and logic devices. This comprehensive approach can facilitate the development of more efficient inspection strategies, resulting in improved device reliability and electrical efficiency.
DOI: 10.1117/12.3052524
Authors: Matteo Beggiato, Roger Loo, Sun Wei, Alain Moussa, Gerhard Bast, Kaoru Fukaya, Dorin Cerbu, Nachiketa Janardan, Konstantin Chirko, Han Han, Masoud Dialameh, Gaetano Santoro, Gian F. Lorusso, Miki Isawa, Paul Wimmer, Christian Kranert, Christian Reimann, Markus Kuhn, Assunta Vigliante, Johan Meersschaut, Attilio Belmonte, Andrew Cross, Andrew Cockburn, Christophe Beral, Anne-Laure Charley, Gouri Sankar Kar, Janusz Bogdanowicz
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4410117878