Alternative FIB TEM Sample Preparation Method for Cross-Sections of Thin Metal Films Deposited on Polymer Substrates

2013 ◽  
Vol 19 (4) ◽  
pp. 1080-1091 ◽  
Author(s):  
Felipe Rivera ◽  
Robert Davis ◽  
Richard Vanfleet

AbstractTransmission electron microscopy (TEM) and focused ion beam (FIB) are proven tools to produce site-specific samples in which to study devices from initial processing to causes for failure, as well as investigating the quality, defects, interface layers, etc. However, the use of polymer substrates presents new challenges, in the preparation of suitable site-specific TEM samples, which include sample warping, heating, charging, and melting. In addition to current options that address some of these problems such as cryo FIB, we add an alternative method and FIB sample geometry that address these challenges and produce viable samples suitable for TEM elemental analysis. The key feature to this approach is a larger than usual lift-out block into which small viewing windows are thinned. Significant largely unthinned regions of the block are left between and at the base of the thinned windows. These large unthinned regions supply structural support and thermal reservoirs during the thinning process. As proof-of-concept of this sample preparation method, we also present TEM elemental analysis of various thin metallic films deposited on patterned polycarbonate, lacquer, and poly-di-methyl-siloxane substrates where the pattern (from low- to high-aspect ratio) is preserved.

Author(s):  
Jian-Shing Luo ◽  
Hsiu Ting Lee

Abstract Several methods are used to invert samples 180 deg in a dual beam focused ion beam (FIB) system for backside milling by a specific in-situ lift out system or stages. However, most of those methods occupied too much time on FIB systems or requires a specific in-situ lift out system. This paper provides a novel transmission electron microscopy (TEM) sample preparation method to eliminate the curtain effect completely by a combination of backside milling and sample dicing with low cost and less FIB time. The procedures of the TEM pre-thinned sample preparation method using a combination of sample dicing and backside milling are described step by step. From the analysis results, the method has applied successfully to eliminate the curtain effect of dual beam FIB TEM samples for both random and site specific addresses.


Author(s):  
Chuan Zhang ◽  
Jane Y. Li ◽  
John Aguada ◽  
Howard Marks

Abstract This paper introduces a novel sample preparation method using plasma focused ion-beam (pFIB) milling at low grazing angle. Efficient and high precision preparation of site-specific cross-sectional samples with minimal alternation of device parameters can be achieved with this method. It offers the capability of acquiring a range of electrical characteristic signals from specific sites on the cross-section of devices, including imaging of junctions, Fins in the FinFETs and electrical probing of interconnect metal traces.


Author(s):  
Hagit Barda ◽  
Irina Geppert ◽  
Avraham Raz ◽  
Rémy Berthier

Abstract An experimental setup is presented, that allows in-situ Transition Electron Microscopy (TEM) investigation of void formation and growth within fully embedded interconnect structure, as a response to an external bias. A special TEM holder is employed to perform in-situ I-V measurements across the Via, simultaneously monitoring the morphological and chemical changes surrounding the void. This work presents in detail a Focused Ion Beam (FIB) based sample preparation method that allows the analysis of a Cu single Via structure found in the advanced microelectronic 14nm FinFET technology, as well as preliminary TEM observations.


Author(s):  
Roger Alvis ◽  
Jeff Blackwood ◽  
Sang-Hoon Lee ◽  
Matthew Bray

Abstract Semiconductor devices with critical dimensions less than 20nm are now being manufactured in volume. A challenge facing the failure analysis and process-monitoring community is two-fold. The first challenge of TEM sample prep of such small devices is that the basic need to end-point on a feature-of-interest pushes the imaging limit of the instrument being used to prepare the lamella. The second challenge posed by advanced devices is to prepare an artifact-free lamella from non-planar devices such as finFETs as well as from structures incorporating ‘non-traditional’ materials. These challenges are presently overcome in many advanced logic and memory devices in the focused ion beam-based TEM sample preparation processes by inverting the specimen prior to thinning to electron transparency. This paper reports a highthroughput method for the routine preparation of artifact-free TEM lamella of 20nm thickness, or less.


2000 ◽  
Vol 8 (2) ◽  
pp. 36-39
Author(s):  
Clive Chandler

Control of layer thickness is critically important in the manufacture of semiconductor devices. Cross-sectioning exposes device structures for direct examination but conventional sample preparation procedures are difficult, time consuming, and grossly destructive. Cross sections created by focused ion beam (FIB) milling are easier, faster, and less destructive but have not offered the clear layer delineation provided by etching in the conventional sample preparation process. A new gas etch capability (Delineation Etch™ from FEI Company) offers results that are equivalent to conventional wet-etch preparations in a fraction of the time from a single, automated system in the fab without destroying the wafer. The new etch process also has application in milling high-aspect-ratio holes to create contacts to buried metal layers, and in deprocessing devices to reveal silicon and polysilicon structures.


Author(s):  
Woo Jun Kwon ◽  
Jisu Ryu ◽  
Christopher H. Kang ◽  
Michael B. Schmidt ◽  
Nicholas Croy

Abstract Focused ion beam (FIB) microscopy is an essential technique for the site-specific sample preparation of atom probe tomography (APT). The site specific APT and automated APT sample preparation by FIB have allowed increased APT sample volume. In the workflow of APT sampling, it is very critical to control depth of the sample where exact region of interest (ROI) for accurate APT analysis. Very precise depth control is required at low kV cleaning process in order to remove the damaged layer by previous high kV FIB process steps. We found low kV cleaning process with 5 kV and followed by 2kV beam conditions delivers better control to reached exact ROI on Z direction. This understanding is key to make APT sample with fully automated fashion.


2016 ◽  
Vol 850 ◽  
pp. 722-727 ◽  
Author(s):  
Hui Wang ◽  
Shang Gang Xiao ◽  
Qiang Xu ◽  
Tao Zhang ◽  
Henny Zandbergen

The preparation of thin lamellas by focused ion beam (FIB) for MEMS-based in situ TEM experiments is time consuming. Typically, the lamellas are of ~5μm*10μm and have a thickness less than 100nm. Here we demonstrate a fast lamellas’ preparation method using special fast cutting by FIB of samples prepared by conventional TEM sample preparation by argon ion milling or electrochemical polishing methods. This method has been applied successfully on various materials, such as ductile metallic alloy Ti68Ta27Al5, brittle ceramics K0.5Na0.5NbO3-6%LiNbO3 and semiconductor Si. The thickness of the lamellas depends on the original TEM sample.


2021 ◽  
Author(s):  
Tony Colpaert ◽  
Stefaan Verleye

Abstract Frontside die inspection by Scanning Electron Microscopy (SEM) is critical to investigate failures that appear dispersed over the GaN die surface and that will be very difficult to localize by the typical Focus Ion Beam (FIB) or Transmission Electron Microscopy (TEM) analysis. Frontside sample preparation is; however, extremely challenging if the device was already subjected to sample preparation for backside Photo Emission Microscopy (PEM). In this paper, a novel sample preparation method is presented where all front side layers are removed and only the 5μm GaN die is left for inspection.


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