In-Situ TEM Observations of Surface Roughening and Defect Formation in Lattice Mismatched Heteroepitaxial Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Cengiz S. Ozkan ◽  
William D. Nix ◽  
Huajian Gao
Keyword(s):  
Thin Films ◽  
Defect Formation ◽  
High Vacuum ◽  
Surface Roughening ◽  
In Situ Tem ◽  
Thick Sample ◽  
Transmission Electron ◽  
Sample Preparation Procedure ◽  
Kinetics Of

ABSTRACTThis paper focuses on in-situ transmission electron microscopy observations of surface roughening and defect formation in heteroepitaxial Sil−xGex thin films. Annealing experiments have been carried out in-situ in the microscope under a high vacuum environment. We comment on the sample preparation procedure for in-situ TEM experiments and explain the importance of having a sufficiently thick sample to have the stress state in the film unaltered. Experimental results of in-situ surface roughening are presented for suberitically and supercritically thick Sil−xGex films. We found that, in a vacuum environment, the kinetics of surface roughening and the resulting surface morphology are much different than in a hydrogen environment.

Kinetics of Copper Grain Growth During Nitridation of Cu-Cr and Cu-Ti Thin Films by In Situ Tem

1994 ◽  
Vol 337 ◽  
Author(s):  
Z. Atzmon ◽  
R. Sharma ◽  
S. W. Russell ◽  
J.W. Mayer
Keyword(s):  
Thin Films ◽  
Growth Stages ◽  
In Situ Tem ◽  
Initial Growth ◽  
Transmission Electron ◽  
Diffusion Controlled ◽  
Cr System ◽  
Rate Limiting ◽  
Kinetics Of

ABSTRACTCo-deposited Cu-Cr and Cu-Ti thin films were heated at various temperatures in an ammonia ambient in an environmental cell placed into the column of a transmission electron microscope (TEM). The reaction dynamics were observed in situ and recorded on a videotape using a TV camera with 1/30 second time resolution. Nitridation of chromium and titanium was accompanied by the nucleation and growth of copper particles starting at 370 and 580°C, respectively. It was found that in the Cu-Ti system at a temperatures regime of 370-400°C the growth rate behaves under a parabolic law; namely, the process is controlled by diffusion of Cu through the nitride matrix. However, for the Cu-Cr system at temperatures of 610-630°C two growth regimes were observed. In the initial growth stages, the surface reaction is rate-limiting, while for longer nitridation times, growth is diffusion-controlled.

Growth kinetics of Al2Cu in an Al-1.5Cu thin film by in Situ TEM

1993 ◽  
Vol 51 ◽  
pp. 1172-1173
Author(s):  
M. Park ◽  
S.J. Krause ◽  
S.R. Wilson
Keyword(s):  
Thin Film ◽  
In Situ Tem ◽  
Collector Plate ◽  
Transmission Electron ◽  
Device Processing ◽  
Corrosion Susceptibility ◽  
Precipitation Phenomena ◽  
Semiconductor Chips ◽  
Kinetics Of

Cu alloying in Al interconnection lines on semiconductor chips improves their resistance to electromigration and hillock growth. Excess Cu in Al can result in the formation of Cu-rich Al2Cu (θ) precipitates. These precipitates can significantly increase corrosion susceptibility due to the galvanic action between the θ-phase and the adjacent Cu-depleted matrix. The size and distribution of the θ-phase are also closely related to the film susceptibility to electromigration voiding. Thus, an important issue is the precipitation phenomena which occur during thermal device processing steps. In bulk alloys, it was found that the θ precipitates can grow via the grain boundary “collector plate mechanism” at rates far greater than allowed by volume diffusion. In a thin film, however, one might expect that the growth rate of a θ precipitate might be altered by interfacial diffusion. In this work, we report on the growth (lengthening) kinetics of the θ-phase in Al-Cu thin films as examined by in-situ isothermal aging in transmission electron microscopy (TEM).

Oxidation Kinetics of Cu-Ni Alloy Observed by in situ UHV-TEM

2007 ◽  
Vol 1026 ◽  
Author(s):  
Li Sun ◽  
John E. Pearson ◽  
Judith C. Yang
Keyword(s):  
High Vacuum ◽  
Alloy Film ◽  
Ultra High Vacuum ◽  
Cross Sectional ◽  
Primary Mechanism ◽  
Transmission Electron ◽  
Ni Alloy ◽  
Cu Oxidation ◽  
Kinetics Of

AbstractThe nucleation and growth of Cu2O and NiO islands due to oxidation of Cu-24%Ni(001) films were monitored at various temperatures by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM). In remarkable contrast to our previous observations of Cu and Cu-Au oxidation, irregular-shaped polycrystalline oxide islands were observed to form with respect to the Cu-Ni alloy film, and an unusual second oxide nucleation stage was noted. Similar to Cu oxidation, the cross-sectional area growth rate of the oxide island is linear indicating oxygen surface diffusion is the primary mechanism of oxide growth.

In-Situ UHV TEM Investigations of the Initial Stages of Cu(001) Oxidation

1997 ◽  
Vol 3 (S2) ◽  
pp. 583-584
Author(s):  
J. C. Yang ◽  
M. Yeadon ◽  
B. Kolasa ◽  
J. M. Gibson
Keyword(s):  
High Vacuum ◽  
Copper Film ◽  
Ultra High Vacuum ◽  
Native Oxide ◽  
In Situ Tem ◽  
Face Centered Cubic ◽  
Free Standing ◽  
Transmission Electron ◽  
Face Centered

We studied the beginning oxidation stage of a model metal system by in-situ transmission electron microscopy (TEM) in order to gain insights into the initial kinetics of oxidation. In-situ TEM experiments can distinguish between nucleation and growth since individual oxide islands are imaged. We chose to investigate Cu, since it is a simple face-centered cubic metal. Also, Cu is a highly promising metal interconnect material because of its low resistivity and good electromigration properties as compared to Al.Single crystal -1000Å 99.999% purity copper films were grown on irradiated NaCl in an UHV e-beam evaporator system. The free-standing copper film was placed on a specially designed holder, which permits resistive heating of the sample. The microscope used for this experiment is a modified ultra-high vacuum, with base pressure of 10−9 torr, JEOL200CX, operated at l00kV. To remove the native oxide formed during exposure in air, the Cu film was annealed at ∼350°C

In situ TEM crystallization of sol-gel derived BaTiO3 thin films

1994 ◽  
Vol 52 ◽  
pp. 588-589
Author(s):  
Martha L. Mecartney ◽  
M. C. Gust ◽  
N. D. Evans
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
In Situ Tem ◽  
Lattice Match ◽  
Gel Layer ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Good Lattice ◽  
Thick Layers

BaTiO3 thin films made by the sol-gel process require a crystallization heat treatment to transform the amorphous gel into a crystalline material. This work used a Ba-Ti methoxypropoxide precursor in a 0.25M solution of methoxypropanol which was spin coated as 5 (each -600 nm thick) layers on (100) Si (FIG. 1). The {100} planes of perovskite BaTiO3 have a good lattice match with {110} Si; d110 of Si = 0.38 nm, and d100 of BaTiO3 = 0.4 nm. Consequently, it should be possible to grow heteroepitaxial films of (100) BaTiO3 on (100) Si. Such samples pyrolized at 350.C and then annealed in a conventional furnace at 750°C for one hour, however, did not crystallize heteroepitaxially with the substrate. Rather, crystallization occurred by a nucleation and growth process from within the gel. Furthermore, the gel layer at the Si/BaTiO3 interface remained amorphous. In-situ hot stage experiments were conducted in a transmission electron microscope (TEM) to determine the nucleation and crystallization behavior.

In-Situ TEM Observations of Different Growth Modes of Small Iron Particles on Sapphire

1980 ◽  
Vol 38 ◽  
pp. 402-403
Author(s):  
R. Anton ◽  
K. Heinemann
Keyword(s):  
Electron Beam ◽  
Width Ratio ◽  
In Situ Tem ◽  
Video Tape ◽  
Growth Modes ◽  
Transmission Electron ◽  
Special Direction ◽  
Substrate Temperatures ◽  
Kinetics Of

An in-situ study was performed of the growth kinetics of individual crystallites during the deposition of iron onto electron-transparent singlecrystalline α-Al2O3 (sapphire) substrates. Clean sapphire films were produced in-situ under UHV conditions by electron-beam induced crystallization of amorphous Al2O3 (1). Iron was electron-beam vapor-deposited at constant rates (0.2-0.5 nm/min) and elevated substrate temperatures (750 – 900°C) immediately following the crystallization. The nucleation, growth, and eventual coalescence of the metal particles were observed in-situ by transmission electron microscopy and recorded on video tape at 30 frames per second. In fig. 1, a growth and coalescence sequence of several Fe-particles on [100]-α-Al2O3 is shown. The images were selected and photographed from the TV monitor during video playback. The particles marked with letters were analyzed in detail. Noteworthy is that particle A (after about 30 min. of growth) started a rapid increase of its length-to-width ratio. Particle H, formed in a coalescence event, exhibited a preferred growth in a special direction, presumably in order to develop a certain crystallographic habit. Particle K developed a fast lateral growth ab-initio and remained a thin platelet until it coalesced with a neighboring particle about 25 min. after the beginning of the deposition.

Initial Oxidation Kinetics of Copper (110) Thin Films As Investigated By IN SITU UHV-TEM

2001 ◽  
Vol 7 (S2) ◽  
pp. 1274-1275
Author(s):  
Guang-Wen Zhou ◽  
Mridula D.Bharadwaj ◽  
Judith C.Yang
Keyword(s):  
Surface Science ◽  
Room Temperature ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Science Methods ◽  
Metal Oxidation ◽  
Initial Oxidation ◽  
Transmission Electron ◽  
Kinetics Of

In the study of metal oxidation, there is a wide gap between information provided by surface science methods and that provided by bulk oxidation studies. The former have mostly examined the adsorption of up to ∽1 monolayer (ML) of oxygen on the metal surface, where as both low and high temperature bulk oxidation studies have mainly focused on the growth of an oxide layer at the later stages of oxidation. Hence, we are visualizing the initial oxidation stages of a model metal system by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM), where the surfaces are atomically clean, in order to gain new understanding of these ambiguous stages of oxidation. We have previously studied the growth of Cu2O islands during initial oxidation of Cu(100) film. We are presently investigating the initial stages of Cu(110) oxidation, from 10−4 Torr O2 to atmospheric pressures and temperature range from room temperature to 700 °C.

Compositional Effects on the Crystallization Kinetics of Nickel Titanium Thin Films

2005 ◽  
Vol 20 (7) ◽  
pp. 1728-1734 ◽  
Author(s):  
Hai Ni ◽  
Hoo-Jeong Lee ◽  
Ainissa G. Ramirez
Keyword(s):  
Thin Films ◽  
Kinetic Parameters ◽  
Nickel Titanium ◽  
Heating And Cooling ◽  
Cooling Conditions ◽  
Transmission Electron ◽  
Titanium Thin Films ◽  
Sputter Deposited ◽  
Kinetics Of

The crystallization and phase transformations of amorphous NiTi thin films were studied using in situ transmission electron microscopy (TEM). These films were sputter-deposited onto micromachined silicon-nitride membranes and subjected to heating and cooling conditions. The microstructural evolution was monitored and recorded. Kinetic parameters such as the nucleation rate, growth rate, and area-fraction transformed were independently determined by noting the number of grains per frame and their change in size. Using the Johnson–Mehl–Avrami–Kolmogorov analysis, fitted kinetic parameters were determined and found to be consistent with TEM observations. To explore the compositional sensitivity of crystallization, samples near-equiatomic and slightly Ti-rich were studied with these methods. TEM micrographs show that equiatomic films exhibit polymorphic crystallization while samples that are slightly off-stoichiometry showed more complicated behavior.

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