Ion thinning of integrated circuit transverse specimens for transmission electron microscopy

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.


2008 ◽  
Vol 381-382 ◽  
pp. 525-528 ◽  
Author(s):  
B.L. Wang ◽  
Han Huang ◽  
Jin Zou ◽  
Li Bo Zhou

Silicon (100) substrates machined by chemo-mechanical-grinding (CMG) and chemicalmechanical- polishing (CMP) were investigated using atomic force microscopy, cross-sectional transmission electron microscopy and nanoindentation. It was found that the substrate surface after CMG was slightly better than machined by CMP in terms of roughness. The transmission electron microscopy analysis showed that the CMG-generated subsurface was defect-free, but the CMP specimen had a crystalline layer of about 4 nm in thickness on the top of the silicon lattice as evidenced by the extra diffraction spots. Nanoindentation results indicated that there exists a slight difference in mechanical properties between the CMG and CMP machined substrates.


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.


1989 ◽  
Vol 169 ◽  
Author(s):  
M. Grant Norton ◽  
Lisa A. Tietz ◽  
Scott R. Summerfelt ◽  
C. Barry Carter

AbstractThe fabrication of high quality thin films often depends on the early stages of the growth process during which epitaxy is established. The substrate surface structure generally plays a critical role at this stage. Many observations of the high‐Tc superconductor film‐substrate interface structure and chemistry have been made by transmission electron microscopy (TEM) of cross‐section samples. Ion‐milling induced damage, however, can be severe in these specimens. In the present study, the early stages of the growth of high Tc superconducting thin films of YBa2Cu3O7δ have been studied by TEM using a technique which requires no post‐deposition specimen preparation.


1997 ◽  
Vol 480 ◽  
Author(s):  
Jeong Soo Lee ◽  
Hyun Ha Kim ◽  
Young Woo Jeong

AbstractThe cross-sectional transmission electron microscopy (TEM) specimens of Pt/Ti/SiO2/Si, RuO2/SiO2/Si, W/TiN/SiO2/Si, (Pb,La)TiO3/Pt/MgO, Bi4Ti3O12/Lal-xCaxMnO3/MgO, and GaN/Al2O3 were successfully made by the rocking-angle ion-milling technique. The differential thinning problems could be effectively mitigated when the rocking-angle and the ion-beam incidence angle were optimized for each heterostructure. It was found that the sputtering yield ratio between the layer milled most quickly and the layer milled most slowly is one of the important factors which determine the optimum rocking-angle ion-milling condition. The atomic force microscopy study on the surface topography of the cross-sectional Pt/Ti/SiO2/Si TEM sample after ion-milling provided quantitative information about the effects of the rocking-angle variation. A parameter which is the ratio between the layer with a minimum electron transparency and the layer with a maximum electron transparency was suggested.


1992 ◽  
Vol 275 ◽  
Author(s):  
K. Uehara ◽  
H. Sakai ◽  
H. Hayashi ◽  
Y. Shiohara ◽  
S. Tanaka

ABSTRACTHigh-resolution transmission electron microscopy (HREM) has been used to study the microstructures of Y-Ba-Cu-0 superconducting thin films in which the YBa2Cu4O8 phase was the main phase. From cross-sectional observations, the c-normal 123 phase predominated in the film near the substrate surface, while the c-normal 124 phase occupied the region near the film surface. Another remarkable microstructure was that a-normal 123 variants overcame the c-normal 123 region, but the c-normal 124 phase surpassed the a-normal 123 phase in the upper part of the film.


2014 ◽  
Vol 20 (5) ◽  
pp. 1471-1478 ◽  
Author(s):  
Esperanza Luna ◽  
Javier Grandal ◽  
Eva Gallardo ◽  
José M. Calleja ◽  
Miguel Á. Sánchez-García ◽  
...  

AbstractWe discuss observations of InN nanowires (NWs) by plan-view high-resolution transmission electron microscopy (TEM). The main difficulties arise from suitable methods available for plan-view specimen preparation. We explore different approaches and find that the best results are obtained using a refined preparation method based on the conventional procedure for plan-view TEM of thin films, specifically modified for the NW morphology. The fundamental aspects of such a preparation are the initial mechanical stabilization of the NWs and the minimization of the ion-milling process after dimpling the samples until perforation. The combined analysis by plan-view and cross-sectional TEM of the NWs allows determination of the degree of strain relaxation and reveals the formation of an unintentional shell layer (2–3-nm thick) around the InN NWs. The shell layer is composed of bcc In2O3 nanocrystals with a preferred orientation with respect to the wurtzite InN: In2O3 [111] || InN [0001] and In2O3 <110> || InN< $$ 11\bar 20 $$ >.


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