Improved sample preparation for cross-sectional transmission electron microscopy of layered structures using rocking-angle ion-milling techniques

Author(s):  
Jeong Soo Lee ◽  
Young Woo Jeong ◽  
Sung Tae Kim
1999 ◽  
Vol 5 (S2) ◽  
pp. 916-917
Author(s):  
Salvatore Pannitteri

I present details of novel sample preparation techniques used for delineating two-dimensional dopant profiles in silicon devices. These techniques are based on selective chemical etch of doped silicon in a mixture of hydrofluoric and nitric acid, or simply in buffered HF. The altered topography of the etched surface is imaged by transmission electron microscopy (TEM). Two different strategies will be presented by focusing on their sensitive, resolution, and field of application.In the first case the silicon device is subjected to the conventional thinning procedure for TEM observations in cross-sectional configuration. The final thickness is obtained by Ar ion milling and it can vary between 50 to 500 nm. Sample is then immersed in a chemical solution containing HF (40%), HN03 (65%), and CH3COOH (95%) in the ratio 1:10:10. In presence of an intense illumination this mixture preferentially etches those device regions which are doped with boron, while in order to delineate n-type regions, the etching procedure must be performed in the dark.


Author(s):  
F. Shaapur

Non-uniform ion-thinning of heterogenous material structures has constituted a fundamental difficulty in preparation of specimens for transmission electron microscopy (TEM). A variety of corrective procedures have been developed and reported for reducing or eliminating the effect. Some of these techniques are applicable to any non-homogeneous material system and others only to unidirectionalfy heterogeneous samples. Recently, a procedure of the latter type has been developed which is mainly based on a new motion profile for the specimen rotation during ion-milling. This motion profile consists of reversing partial revolutions (RPR) within a fixed sector which is centered around a direction perpendicular to the specimen heterogeneity axis. The ion-milling results obtained through this technique, as studied on a number of thin film cross-sectional TEM (XTEM) specimens, have proved to be superior to those produced via other procedures.XTEM specimens from integrated circuit (IC) devices essentially form a complex unidirectional nonhomogeneous structure. The presence of a variety of mostly lateral features at different levels along the substrate surface (consisting of conductors, semiconductors, and insulators) generally cause non-uniform results if ion-thinned conventionally.


Author(s):  
Ching Shan Sung ◽  
Hsiu Ting Lee ◽  
Jian Shing Luo

Abstract Transmission electron microscopy (TEM) plays an important role in the structural analysis and characterization of materials for process evaluation and failure analysis in the integrated circuit (IC) industry as device shrinkage continues. It is well known that a high quality TEM sample is one of the keys which enables to facilitate successful TEM analysis. This paper demonstrates a few examples to show the tricks on positioning, protection deposition, sample dicing, and focused ion beam milling of the TEM sample preparation for advanced DRAMs. The micro-structures of the devices and samples architectures were observed by using cross sectional transmission electron microscopy, scanning electron microscopy, and optical microscopy. Following these tricks can help readers to prepare TEM samples with higher quality and efficiency.


1992 ◽  
Vol 7 (8) ◽  
pp. 2225-2229 ◽  
Author(s):  
Z.G. Li ◽  
P.F. Carcia ◽  
P.C. Donohue

The microstructure of LaB6-base thick film resistors was investigated by cross-sectional transmission electron microscopy. The specimens were prepared by a technique that polished them to a thin wedge, thus avoiding ion-milling and permitting imaging over a distance of tens of microns. The resistor microstructure contained a finely divided electrically conductive phase of TaB2 and nonconducting crystals of CaTa4O11, formed during high temperature processing of glass and LaB6 ingredients of the thick film ink. Using higher surface area ingredients virtually suppressed the formation of CaTa4O11 crystals, and the microstructure became more uniform. Resistors made with higher surface area intermediates also had better voltage withstanding properties.


2021 ◽  
Author(s):  
JungSik Park ◽  
Yoon-Jung Kang ◽  
SunEui Choi ◽  
YongNam Jo

Abstract The main purpose in this paper is a sample preparation of transmission electron microscopy (TEM) for the lithium-ion secondary battery in the form of micro-sized powders. To avoid artefacts of the TEM sample preparation, the use of ion slicer milling for thinning and maintaining the intrinsic structure is described. Argon-ion milling techniques have been widely examined to make the optimized specimen, which makes TEM analysis more reliable. In the past few years, the correction of spherical aberration (Cs) in scanning transmission electron microscopy (STEM) has been developing rapidly, that results in the direct observation with the atomic level resolution not only for the high acceleration voltage but also its deaccelerated voltage as well. Especially, low-kV application has been markedly increased that needs the sufficient-transparent specimen without the structural distortion during the process of the sample preparation. In this study, the sample preparation for the high-resolution STEM observation has been greatly accomplished and investigations of its crystal integrity are carried out by Cs-corrected STEM.


1998 ◽  
Vol 523 ◽  
Author(s):  
C. Amy Hunt ◽  
Yuhong Zhang ◽  
David Su

AbstractTransmission electron microscopy (TEM) is a useful tool in process evaluation and failure analysis for semiconductor industries. A common focus of semiconductor TEM analyses is metalization vias (plugs) and it is often desirable to cross-section through a particular one. If the cross-sectional plane deviates away from the center of the plug, then the thin adhesion layer around the plug will be blurred by surrounding materials such as the inter-layer dielectric and the plug material. The importance of these constraints, along with the difficulty of precision sample preparation, has risen sharply as feature sizes have fallen to 0.25 μm and below. The suitability of common sample preparation techniques for these samples is evaluated.


1990 ◽  
Vol 199 ◽  
Author(s):  
Jeffrey T. Wetzel ◽  
K. L. Kavanagh

ABSTRACTThis paper summarizes methods used to create cross-sectional samples for transmission electron microscopy and introduces another variant of the technique all of which rely upon some combination of lithographic patterning and reactive ion etching. The basic idea pursued in using these techniques was to form, from a preselected location, samples that had a large transparent area without use of mechanical polishing or ion milling. Samples were successfully prepared in this manner, but room for improvement remains due to the limited range of diffraction conditions available for imaging or diffraction pattern formation.


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