In-situ and ex-situ AFM imaging of μN load indents on silicate glass/alumina interfaces

1996 ◽  
Vol 54 ◽  
pp. 660-661
Author(s):  
A. V. Zagrebelny ◽  
E. T. Lilleodden ◽  
J. C. Nelson ◽  
S. Ramamurthy ◽  
C. B. Carter
Keyword(s):  
Single Crystal ◽  
Silicate Glass ◽  
Small Volume ◽  
Ex Situ ◽  
Surface Roughening ◽  
Mechanistic Approach ◽  
Afm Imaging ◽  
Indentation Analysis ◽  
Single Crystal Sapphire

Contact which only involves a small volume of material is becoming increasingly important to many industries including micromachines, microelectronics, and magnetic recording. The ability to characterize surface roughening on the micro- and nanoscopic scale is invaluable in understanding microplasticity due to indentation, scratches, wear, fatigue and epitactic mismatch. It has been demonstrated that AFM studies are appropriate for developing a mechanistic approach to μN load indentation analysis since they allow deformation volumes and residual depths to be measured and characterized directly and unambiguously.In the present study, interfaces between silicate glass and single-crystal α-Al2O3 have been studied using AFM and nanoindentation. The interfaces between the glass and the crystalline grains were prepared by growing films of anorthite (CaAl2Si2O8) composition with thickness ranging 100-200 nm on single-crystal sapphire substrates of {1120} (A-plane) and {1102} (R-plane) crystallographic orientations by pulsed-laser deposition (PLD). Some specimens were subjected to heat treatments in a conventional box furnace causing films to dewet the substrates. Fig. 1 shows schematically the morphology of the dewetted film which has resulted in the formation of distinctive islands, 0.5-2 μm in size. Both types of specimens were tested with two different micro/nanomechanical testers.

Effect of Glass Composition on Mechanical Properties of Interfaces Between Alumina and Silicate Glass

1996 ◽  
Vol 458 ◽  
Author(s):  
Andrey V. Zagrebelny ◽  
Erica T. Lilleodden ◽  
C. Barry Carter
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Silicate Glass ◽  
Glass Composition ◽  
Depth Sensing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Imaging ◽  
Force Displacement

ABSTRACTInterfaces between glass and crystalline grains have been examined using a thin-film geometry which allows the use of newly developed experimental methods for micromechanical testing of interfaces. In this approach, continuous films of thicknesses ranging 100–200 nm of anorthite (CaAl2Si2O8), celsian (BaAl2Si2O8), and monticellite (CaMgSiO4) are deposited onto single-crystal Al2O3 (α-structure) surfaces of different crystallographic orientations by pulsed-laser deposition (PLD).Mechanical properties such as hardness, stiffness, and reduced Young's modulus were probed with a newly developed high-resolution depth-sensing indentation instrument. Emphasis has been placed on examining how changes in the glass composition will affect the mechanical properties of the single-crystal Al2O3/silicate-glass interfaces. The indentation data obtained from these experiments correlate directly to the morphology of the deformed regions imaged with atomic force microscopy (AFM). Nanomechanical tests combined with AFM imaging of the deformed regions allow force-displacement measurements and in-situ imaging of the same regions of the specimen before and immediately after indentation. This new technique eliminates the uncertainty of locating the indenter after unloading.

On The Optimized Nucleation of Near-Single-Crystal Cvd Diamond Film

1995 ◽  
Vol 416 ◽  
Author(s):  
L. C. Chen ◽  
C. C. Juan ◽  
J. Y. Wu ◽  
K. H. Chen ◽  
J. W. Teng
Keyword(s):  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Morphological Evolution ◽  
Present Report ◽  
Ex Situ ◽  
Nucleation Density ◽  
Induced Current ◽  
Current Time ◽  
Single Crystal Diamond

ABSTRACTNear-single-crystal diamond films have been obtained in a number of laboratories recently. The optimization of nucleation density by using a bias-enhanced nucleation (BEN) method is believed to be a critical step. However, the condition of optimized nucleation has never been clearly delineated. In the present report, a novel quantitative technique was established to monitor the nucleation of diamond in-situ. Specifically, the induced current was measured as a function of nucleation time during BEN. The timedependence of induced current was studied under various methane concentrations as well as substrate temperatures. The optimized nucleation condition can be unambiguously determined from the current-time plot. Besides the in-situ current probe, ex-situ x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were also used to investigate the chemical and morphological evolution. Characteristic XPS and AFM features of optimized nucleation is discussed.

Tuning the Terrace and Step Stability of 6H-SiC (0001) for Graphene Film Deposition

2015 ◽  
Vol 821-823 ◽  
pp. 953-956
Author(s):  
Gemma Rius ◽  
Narcis Mestres ◽  
Osamu Eryu ◽  
Philippe Godignon
Keyword(s):  
Crystal Surface ◽  
Graphene Film ◽  
Film Deposition ◽  
Ex Situ ◽  
Surface Roughening ◽  
Single Crystal Surface ◽  
Planar Technology ◽  
Graphene Films ◽  
And Control

Graphene is a 2D material with potential for almost any purpose, thanks to a combination of excellent characteristics, e.g. high electrical conductivity. Graphene grown on SiC wafers is one of the promising routes for graphene integration into planar technology electronic applications. Synthesis is based on the decomposition of a SiC single crystal surface at high temperature, where Si-terminated SiC substrates require the formation of the C buffer layer. In spite of numerous experimental and theoretical works the understanding and control upon crucial factors such as step and terrace stability or surface roughening is far from been fully comprehended and then technologically optimized. We present experimental results on the deposition of graphene onto Si-terminated 6H-SiC. We analyze the effect of ex situ and in situ conditionings of the SiC surface in the thermal decomposition and reconstruction of the SiC terraces, toward higher control upon the growth process of graphene films.

In-situ AFM study of the crystallization and pH-dependent stability of ZnO(0001)-Zn surfaces

2007 ◽  
Vol 1035 ◽  
Author(s):  
Markus Valtiner ◽  
Guido Grundmeier
Keyword(s):  
Electrolyte Solutions ◽  
Ex Situ ◽  
Chemical Cleaning ◽  
Single Crystalline ◽  
Afm Imaging ◽  
Wide Range ◽  
Wet Chemical ◽  
Ph Dependent ◽  
Crystalline Surfaces

AbstractPolar ZnO(0001)-Zn surfaces can be prepared as very well defined and single crystalline surfaces by hydroxide stabilization simply by introducing hydroxides via a wet chemical cleaning step. Within this proceeding we present an in-situ AFM imaging of the crystallization process. The pH dependent stability of the resulting hydroxide-stabilized surfaces was further investigated by means of an ex-situ LEED approach. These investigations show, that it is possible to obtain high quality single crystalline ZnO(0001)-Zn surfaces in a simple way. Moreover, these surfaces turned out to be very stable within a wide range of pH values between 11 and 3 of NaClO4 based 1mM electrolyte solutions.

Ion Thinning of Electron Transparent Single Crystal Sapphire Substrates

1974 ◽  
Vol 32 ◽  
pp. 468-469
Author(s):  
J. L. Kenty ◽  
R. E. Johnson
Keyword(s):  
Thin Film ◽  
Single Crystal ◽  
Film Growth ◽  
Ion Beam ◽  
Thin Film Growth ◽  
Sapphire Substrates ◽  
Single Crystal Sapphire ◽  
Growth Experiments

Samples of single crystal sapphire (α-Al2O3) have been ion-beam thinned to yield electron transparent regions suitable for use as substrates for in situ thin film growth experiments. Routine fabrication of 1 mm dia. samples containing one or more thin (∼200Å) regions ∼10μm2 in area was possible. The samples were surprisingly robust, many surviving post-thinning subdivision, mounting into a TEM environment cell, and heating to ∼1200°C.

Dependence of Crystallographic Texture of C54 Tisi2 on Thickness and Linewidth In Submicron Cmos Structures

1996 ◽  
Vol 427 ◽  
Author(s):  
V. Svilan ◽  
K. P. Rodbell ◽  
L. A. Clevenger ◽  
C. Cabral ◽  
R. A. Roy ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Crystal Silicon ◽  
The One ◽  
Oriented Parallel ◽  
Preferential Crystal Orientation ◽  
Line Direction

AbstractPreferential crystal orientation of low-resistance C54 TiSi2 formed in the reaction of polycrystalline and single crystal silicon with titanium was investigated for Ti thicknesses ranging from 15 to 44 nm. Using in situ synchrotron x-ray diffraction during heating of 15 nm of Ti on single crystal Si, we observed that the C54 TiSi2 silicide film showed predominantly <040> grains oriented normal to the sample. In thicker silicide films the <311> orientation dominated or film was randomly oriented. An ex situ four circle diffractometer was used to investigate the strong <040> texture in narrow line arrays of C54-TiSi2 formed on polycrystalline silicon with linewidths from 0.2 to 1.1 μm. We observed that the angular distribution of <040> Ti Si2 grains is dependent on the line direction, where the majority of grains had their (100) planes oriented parallel with the line direction. These findings support a model of the C49 to C54 TiSi2 transformation involving rapid growth of certain orientations favored by the one-dimensional geometry imposed by narrow lines.

Gadolinium Oxide Gate Dielectrics for GaN MOSFETs

2001 ◽  
Vol 680 ◽  
Author(s):  
B.P. Gila ◽  
J.W. Johnson ◽  
K. N. Lee ◽  
V. Krishnamoorthy ◽  
S. Bates ◽  
...  
Keyword(s):  
Single Crystal ◽  
Oxide Films ◽  
Gadolinium Oxide ◽  
Ex Situ ◽  
Native Oxide ◽  
Breakdown Field ◽  
Thermally Stable ◽  
Amorphous Films ◽  
Substrate Temperatures

ABSTRACTSubstrate preparation of GaN, both in-situ and ex-situ, and the growth of gadolinium oxide, Gd2O3, by Gas source molecular beam epitaxy (GSMBE) have been investigated. Ex-situ cleaning techniques included wet chemical etching and UV-ozone treatments to remove surface contaminants and the native oxide. In-situ cleaning consisted of thermal treatment with and without exposure to an electron cyclotron resonance (ECR) oxygen plasma. A GaN (1x3) streaky RHEED pattern was the final product of this surface treatment study. Various growth initiation techniques were explored to produce Gd2O3 films with different microstructures as evidenced by RHEED, TEM, and XRD. Gd2O3 films planarized the initial GaN surface and stoichiometry was maintained over a range of substrate temperatures (300° to 650°C). Single crystal gadolinium oxide films were grown at substrate temperatures of 600-650°C. These films exhibited a breakdown field strength (EBD) of ∼1MV/cm, and showed high leakage current at high forward bias due to defects within the oxide. Single crystal oxide films were found to be thermally stable at annealing temperatures up to 1000°C. Quasi-amorphous films were grown at a substrate temperature of 100°C. These films exhibited a higher E BD of ∼3MV/cm and an interface state density of 3 × 1011 cm−2eV−1. However, the quasi-amorphous films were not thermally stable at 1000°C, showing evidence of re-crystallization in x-ray diffraction (XRD) scans.

Sign in / Sign up

Export Citation Format

Share Document