Links Between Etching Grooves Of Partial Dislocations And Their Characteristics Determined By TEM In 4H SiC

2008 ◽  
Vol 1069 ◽  
Author(s):  
Jean-Pierre Ayoub ◽  
Michael Texier ◽  
Gabrielle Regula ◽  
Bernard Pichaud ◽  
Maryse Lancin

ABSTRACTWe introduce defects into (1120) oriented highly N-doped 4H-SiC by surface scratching, bending and annealing in the brittle regime. Emerging defects at the sample surface are revealed by chemical etching of the deformed samples. The etch patterns are constituted of straight bulges and grooves exhibiting various topographical features. These etch figures correspond to the emergence of double stacking faults dragged by a pair of partial dislocations. In this paper, we discuss the links between the etch figure characteristics and the defect nature. Results obtained by optical and atomic force microscopy are completed by structural analysis of defects performed by transmission electron microscopy. Mobility of partial dislocations in 4H-SiC is discussed and correlated to their core composition and to the effect of the applied mechanical stress.

2005 ◽  
Vol 483-485 ◽  
pp. 299-302 ◽  
Author(s):  
Hosni Idrissi ◽  
Maryse Lancin ◽  
Joel Douin ◽  
G. Regula ◽  
Bernard Pichaud

4H-SiC samples were bent in compression mode at temperature ranging from 400°C to 700°C. The introduced-defects were identified by Weak Beam (WB) and High Resolution Transmission Electron Microscopy (HRTEM) techniques. They consist of double stacking faults bound by 30° Si(g) partial dislocations whose glide locally transforms the material in its cubic phase. The velocity of partial dislocations was measured after chemical etching of the sample surface. The formation and the expansion of the double stacking faults are discussed.


1995 ◽  
Vol 399 ◽  
Author(s):  
J. Tanimura ◽  
O. Wada ◽  
Y. Endoh ◽  
M. Imaizumi ◽  
T. Ogama

ABSTRACTStructure of stacking faults in a ZnSe epitaxial layer grown on a GaAs(001) buffer layer was determined with transmission electron microscopy. Two stacking faults were formed in pairs on (111) and (111) planes with the same polarity and met at a point which is a few atomic layers away from the interface between ZnSe and GaAs. Partial dislocations were found to be the Shockley type ones with a Burgers vector of 1/6<211>. Atomic force microscopy showed that hillocks were formed in pairs at a surface where the pair of stacking faults existed in the layer. Moreover, it was observed that the pair of stacking faults elongated along the <110> direction by gliding on the {111} faulted planes under annealing at 200°C for 30min. Formation mechanisms of the pair of stacking faults have been discussed.


2021 ◽  
Vol 53 (2) ◽  
pp. 187-198
Author(s):  
Milos Nenadovic ◽  
Danilo Kisic ◽  
Miljana Mirkovic ◽  
Snezana Nenadovic ◽  
Ljiljana Kljajevic

The implantation of high-density polyethylene (HDPE) has been conducted using Ag+ ions with energy of 60 keV, achieved fluences 1.5 and 10?1015 ions/cm2. Transmission electron microscopy (STEM) and field emission gun - scanning electron microscopy (FEG-SEM) showed the existence of nanoparticle clusters. X ray photoelectron spectroscopy (XPS) revealed the presence of silver in the sample surface region. The surface topography was studied by atomic force microscopy (AFM), while the surface composition uniformity was analyzed using phase imaging AFM. Optical characterization obtained by spectroscopic ellipsometry (SE) showed changes in refractive index, extinction coefficient and the optical band gap with the fluence of implanted ions.


2020 ◽  
Vol 1004 ◽  
pp. 421-426
Author(s):  
Hideki Sako ◽  
Kentaro Ohira ◽  
Kenji Kobayashi ◽  
Toshiyuki Isshiki

Two types of carrot defects with and without a shallow pit were found by mirror projection electron microscopy (MPJ) inspection in 4H-SiC epi wafer. Surface morphology and cross-sectional structure of prismatic stacking faults (PSFs) were investigated using MPJ and atomic force microscopy (AFM), transmission electron microscopy (TEM) and high-resolution scanning transmission electron microscopy (STEM). The depths of the surface grooves due to the PSFs, the stacking sequences around the PSFs and the structure of the Frank-type stacking faults which were connected to the PSFs were different. We discuss the difference between the two types of carrot defects.


1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.


1995 ◽  
Vol 403 ◽  
Author(s):  
G. Bai ◽  
S. Wittenbrock ◽  
V. Ochoa ◽  
R. Villasol ◽  
C. Chiang ◽  
...  

AbstractCu has two advantages over Al for sub-quarter micron interconnect application: (1) higher conductivity and (2) improved electromigration reliability. However, Cu diffuses quickly in SiO2and Si, and must be encapsulated. Polycrystalline films of Physical Vapor Deposition (PVD) Ta, W, Mo, TiN, and Metal-Organo Chemical Vapor Deposition (MOCVD) TiN and Ti-Si-N have been evaluated as Cu diffusion barriers using electrically biased-thermal-stressing tests. Barrier effectiveness of these thin films were correlated with their physical properties from Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Secondary Electron Microscopy (SEM), and Auger Electron Spectroscopy (AES) analysis. The barrier failure is dominated by “micro-defects” in the barrier film that serve as easy pathways for Cu diffusion. An ideal barrier system should be free of such micro-defects (e.g., amorphous Ti-Si-N and annealed Ta). The median-time-to-failure (MTTF) of a Ta barrier (30 nm) has been measured at different bias electrical fields and stressing temperatures, and the extrapolated MTTF of such a barrier is > 100 year at an operating condition of 200C and 0.1 MV/cm.


2008 ◽  
Vol 8 (8) ◽  
pp. 4081-4085 ◽  
Author(s):  
Y. Batra ◽  
D. Kabiraj ◽  
D. Kanjilal

Germanium (Ge) nanoparticles have attracted a lot of attention due to their excellent optical properties. In this paper, we report on the formation of Ge nanoparticles embedded in GeO2 matrix prepared by electron beam evaporation and subsequent annealing. Transmission electron microscopy (TEM) studies clearly indicate the formation of Ge nanocrystals in the films annealed at 500 °C. Fourier transform infrared (FTIR) spectroscopic studies are carried out to verify the evolution of the structure after annealingat each stage. Micro-Raman analysis also confirms the formation of Ge nanoparticles in the annealed films. Development of Ge nanoparticles is also established by photoluminescence (PL) analysis. Surface morphology study is carried out by atomic force microscopy (AFM). It shows the evolution of granular structure of the films with increasing annealing temperature.


2017 ◽  
Vol 23 (3) ◽  
pp. 661-667 ◽  
Author(s):  
Yue Li ◽  
Di Zhang ◽  
Ilker Capoglu ◽  
Karl A. Hujsak ◽  
Dhwanil Damania ◽  
...  

AbstractEssentially all biological processes are highly dependent on the nanoscale architecture of the cellular components where these processes take place. Statistical measures, such as the autocorrelation function (ACF) of the three-dimensional (3D) mass–density distribution, are widely used to characterize cellular nanostructure. However, conventional methods of reconstruction of the deterministic 3D mass–density distribution, from which these statistical measures can be calculated, have been inadequate for thick biological structures, such as whole cells, due to the conflict between the need for nanoscale resolution and its inverse relationship with thickness after conventional tomographic reconstruction. To tackle the problem, we have developed a robust method to calculate the ACF of the 3D mass–density distribution without tomography. Assuming the biological mass distribution is isotropic, our method allows for accurate statistical characterization of the 3D mass–density distribution by ACF with two data sets: a single projection image by scanning transmission electron microscopy and a thickness map by atomic force microscopy. Here we present validation of the ACF reconstruction algorithm, as well as its application to calculate the statistics of the 3D distribution of mass–density in a region containing the nucleus of an entire mammalian cell. This method may provide important insights into architectural changes that accompany cellular processes.


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