In Situ Investigation of the a-Si:H/C-Si Interface

1996 ◽  
Vol 420 ◽  
Author(s):  
H. Feist ◽  
C. Swiatkowski ◽  
J. R. Elmiger ◽  
M. Zipfel ◽  
M. Kunst
Keyword(s):  
Crystalline Silicon ◽  
Microwave Frequency ◽  
Ex Situ ◽  
Silicon Substrates ◽  
Si Substrates ◽  
In Situ Investigation ◽  
Drastic Increase ◽  
Interface Recombination Velocity ◽  
Recombination Velocity

AbstractThe deposition of a-Si:H films on crystalline silicon substrates was monitored in situ by transient photoconductivity measurements in the microwave frequency range. At the start of the deposition a drastic increase of the interface recombination velocity was observed, followed by a rapid decrease. The implications of these results for the structure of the interface are discussed. Changes of the interface after deposition were detected without a change of the temperature, even at 250'C: The long relaxation time of the structure of the interface will be discussed. Ex situ results on the samples produced will be compared to the in situ results in view of the passivation properties of a-Si:H films on c-Si substrates.

Low Interface State Density Oxide-GaAs Structures Fabricated by In-Situ Molecular Beam Epitaxy

1996 ◽  
Vol 421 ◽  
Author(s):  
M. Passlack ◽  
M. Hong
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Molecular Beams ◽  
Interface State ◽  
State Density ◽  
Interface State Density ◽  
In Situ Deposition ◽  
Interface Recombination Velocity ◽  
Recombination Velocity

AbstractWe have extended the spectrum of molecular-beam epitaxy (MBE) related techniques by introducing in-situ deposition of oxides. The oxide films have been deposited on clean, atomically ordered (100) GaAs wafer surfaces using molecular beams of gallium-, magnesium-, silicon-, or aluminum oxide. Among the fabricated oxide-GaAs heterostructures, Ga2O3-GaAs interfaces exhibit unique electronic properties including an interface state density Dit in the low 1010 cm−2eV−1 range and an interface recombination velocity S of 4000 cm/s. The formation of inversion layers in both n- and p-type GaAs has been clearly established. Further, thermodynamic and photochemical stability of excellent electronic interface properties of Ga2O3-GaAs structures has been demonstrated.

Kinetics of Pt Silicide Formation Studied by Spectral Ellipsometry

1997 ◽  
Vol 470 ◽  
Author(s):  
R. Schwarz ◽  
A. Dittrich ◽  
S. M. Zhou ◽  
M. Hundhausen ◽  
L. Ley ◽  
...  
Keyword(s):  
Activation Energy ◽  
Crystalline Silicon ◽  
Silicon Substrates ◽  
Silicide Formation ◽  
Spectral Ellipsometry ◽  
Step Process ◽  
Depth Profiles ◽  
Ellipsometric Angle ◽  
Kinetics Of

ABSTRACTSuicide formation during thermal annealing of thin Pt layers deposited by evaporation onto crystalline silicon substrates was studied by in-situ spectral ellipsometry. As was shown in an earlier study, Pt suicide is formed in a two-step process with intermediate stages of Pt2Si and PtSi at temperatures of about 190 and 240 °C, respectively. We observed a shift of about 15 °C of the di- and monosilicide formation, when the anneal rate was lowered from 3 to 1 K/min. The analysis of the reaction kinetics using the normalized ellipsometric angle δ yields a good fit to the data for different anneal rates with an activation energy of (1.6 ± 0.2) eV. The underlying model of suicide formation through a multilayer system was checked with depth profiles and compositional information obtained from Rutherford Backscattering.

In‐Situ Fabrication of YBa2Cu3O7‐x Superconducting Thin Films Directly on Silicon Substrates with Tc0 > 77K

1989 ◽  
Vol 169 ◽  
Author(s):  
C. B. Lee ◽  
R. K. Singh ◽  
S. Sharan ◽  
A. K. Singh ◽  
P. Tiwari ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Pulses ◽  
Superconducting Film ◽  
Laser Evaporation ◽  
Silicon Substrates ◽  
Superconducting Thin Films ◽  
Si Substrates ◽  
In Situ Fabrication ◽  
Substrate Temperatures

AbstractWe report in‐situ fabrication of c‐axis textured YBa2Cu3O7‐x superconducting thin films with Tco > 77K on unbuffered silicon substrates by the biased pulsed laser evaporation (PLE) technique in the temperature range of 550‐650°C. At substrate temperatures below 550°C, no c‐axis texturing of the superconducting film was observed. The YBa2Cu3O7‐x superconducting films were fabricated by ablating a bulk YBa2Cu3O7 target by a XeCl excimer laser (λ = 308 nm, τ = 45 × 10‐9 sec) in a chamber maintained at an oxygen pressure of 0.2 torr . The thickness of the films was varied from 0.3 to 0.5 nm depending on the number of laser pulses. Extensive diffusion was observed in thin films deposited at substrate temperatures above 550°C. However, microstructurally, with increase in the substrate temperature the films exhibited larger grain size and greater degree of c‐axis texturing (measured by the ratio of the (005) and (110) X‐ray diffraction peaks). This was found to give rise to better superconducting properties with Tco exceeding 77 K for YBa2Cu3O7‐x films deposited on Si substrates at 650°C.

Investigation of an in-situ probe for phase transformations during RTP silicidation

1992 ◽  
Vol 260 ◽  
Author(s):  
R. J. Schreutelkamp ◽  
P. Vandenabeele ◽  
B. Deweerdt ◽  
W. Coppye ◽  
C. Vermeiren ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Thermal Degradation ◽  
Phase Transformations ◽  
Doping Level ◽  
Polycrystalline Silicon ◽  
Silicon Substrates ◽  
Si Substrates ◽  
Background Doping ◽  
Emissivity Measurements

ABSTRACTIn-situ emissivity measurements at a wavelength of 2.4 μα were used to monitor RTP Co silicidation on crystalline and polycrystalline silicon substrates. The influence of various parameters influencing the silicidation reaction was extensively studied. It is shown that particularly the phase transformation from CoSi to the final suicide phase, COSi2, strongly depends on parameters such as background doping level and type of substrate. This is illustrated for As-doped substrates. The method is extremely sensitive for the in-situ detection of the thermal degradation of thin COSi2 films at high temperatures, which is demonstrated for 25 nm COSi2 layers on highly As-doped c-Si substrates.

In situ fabricated Ga2O3–GaAs structures with low interface recombination velocity

1995 ◽  
Vol 66 (5) ◽  
pp. 625-627 ◽  
Author(s):  
M. Passlack ◽  
M. Hong ◽  
E. F. Schubert ◽  
J. R. Kwo ◽  
J. P. Mannaerts ◽  
...  
Keyword(s):  
Interface Recombination ◽  
Interface Recombination Velocity ◽  
Recombination Velocity

Growth and study of BaZrO3 thin films by pulsed excimer laser ablation

2003 ◽  
Vol 784 ◽  
Author(s):  
V. Rajasekarakumar ◽  
P. Victor ◽  
R. Ranjith ◽  
S. Saha ◽  
S. Rajagopalan ◽  
...  
Keyword(s):  
Thin Films ◽  
Secondary Ion Mass Spectrometry ◽  
Ex Situ ◽  
Silicon Substrates ◽  
Frequency Regime ◽  
Different Temperatures ◽  
The Right ◽  
Limiting Case ◽  
Secondary Ion

ABSTRACTThin films of BaZrO3 (BZ) were grown using a pulsed laser deposition technique on platinum coated silicon substrates. Films showed a polycrystalline perovskite structure upon different annealing procedures of in-situ and ex-situ crystallization. The composition analyses were done using Energy dispersive X-ray analysis (EDAX) and Secondary ion mass spectrometry (SIMS). The SIMS analysis revealed that the ZrO2 formation at the right interface of substrate and the film leads the degradation of the device on the electrical properties in the case of ex-situ crystallized films. But the in-situ films exhibited no interfacial formation. The dielectric properties have been studied for the different temperatures in the frequency regime of 40 Hz to 100kHz. The response of the film to external ac stimuli was studied at different temperatures, and it showed that ac conductivity values in the limiting case are correspond to oxygen vacancy motion. The electrical modulus is fitted to a stretched exponential function and the results clearly indicate the presence of the non-Debye type of dielectric relaxation in these materials.

In-Situ Investigation of Cu-In-Se Reactions by Thin Film Calorimetry

1997 ◽  
Vol 485 ◽  
Author(s):  
D. Wolf ◽  
G. Müller
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Equilibrium Phase ◽  
Reaction Times ◽  
Practical Interest ◽  
Ex Situ ◽  
In Situ Observation ◽  
Flux Agent ◽  
In Situ Investigation

AbstractStudies of the reaction path during annealing of Cu-In-Se thin films for solar cell absorbers have been limited up to now to ex-situ analyses of the phase composition by X-Ray Diffraction (XRD) after processing by a specific temperature-time program. As an indirect method, the application of ex-situ XRD is not sufficient for the determination of reaction temperatures and reaction times for setting up a general model of CIS-formation.We show in this paper that the use of a calorimetric method (Thin Film Calorimetry, TFC) offers the advantage of a direct (in-situ) observation of thin film reactions. Special care is taken to use film thicknesses of practical interest for industrial application (1.5 – 3 μm). In a first step we show results of binary reactions in the Cu-In, In-Se and Cu-Se systems. Their knowledge is necessary for understanding the processes involved in the ternary CIS-layers. It turned out that thin Cu-In and Cu-Se films react already at room temperature and behave as predicted by the bulk equilibrium phase diagrams during heating. In-Se thin films show prominent exothermic reactions starting with the melting of In. The first phase to be formed is generally In2Se which is then converted to more Se-rich compounds. In ternary Cu-In-Se films (Cu/In = 1.00) we observe transitions of the Cu-Se-system which can be attributed to the decomposition of CuSe2 and CuSe. Consequences for the model of improved CIS-growth by a Cu-Se flux agent are discussed.

In Situ Investigation of Nanoabrasive Wear of Silicon

2006 ◽  
Vol 129 (1) ◽  
pp. 11-16 ◽  
Author(s):  
S. Ingole ◽  
A. Schwartzman ◽  
H. Liang
Keyword(s):  
Abrasive Wear ◽  
Amorphous Silicon ◽  
Surface Characterization ◽  
Ex Situ ◽  
Normal Displacement ◽  
Length Scale ◽  
Crystal Silicon ◽  
In Situ Investigation ◽  
Nanometer Length Scale

Investigation of abrasive wear at the nanometer-length scale is presented on single crystalline (001) and amorphous silicon. Experiments were performed using nanoindentation and nanoscratch approaches. Surface characterization was carried out using an atomic force microscope. Results show that both materials behave quite differently from each other during indentation and scratch. Specifically, amorphous silicon is proven to be more unstable during scratching than single crystal silicon. The comparison of in situ and ex situ normal displacement was made. Evidence was found on the hysteretic and viscoplastic behavior of amorphous silicon in nanoscratch that is also seen in indentation. Furthermore, it is found that this material is unstable under stress within small scales. Indications of phase transformation, (reverse) densification, and transition of elastic-plastic deformation are seen. These observations, enabled on silicon using an in situ and nanometer length scale process, are fundamentally different from the understanding of conventional abrasive wear.

Suppression of the Phase Transition and Agglomeration of TiSi2 by Addition of Zr Element

1998 ◽  
Vol 514 ◽  
Author(s):  
Sanghyun Yoon ◽  
Hyeongtag Jeon
Keyword(s):  
Phase Transition ◽  
High Temperatures ◽  
Lower Surface ◽  
Ex Situ ◽  
Vacuum Furnace ◽  
Ion Pump ◽  
Cross Sectional ◽  
Surface And Interface ◽  
Si Substrates

ABSTRACTThe formation of C49 TiSi2 phase at high temperatures was investigated by adding the Zr contents in Ti-silicide film. Stabilizing the C49 TiSi2 phase which exhibits lower surface and interface energies than those of the C54 TiSi2 phase at high temperatures was expected to suppress the problems of Tisilicide, such as the phase transition and the film agglomeration. The thin films of Ti and Zr were codeposited (40 nm) on Si substrates in the dual e-beam evaporation system equipped with an ion pump and its base pressure of ∼5 × 10−9 torr. The amounts of Zr contents (5 and 10 atomic %) added on Tisilicide were monitored by in-situ quartz crystal monitor. Immediately after the deposition, this film was annealed by ex-situ vacuum furnace at temperatures between 600 °C and 900 °C in 100 °C increments. The identification of the phase and the chemical composition were investigated by XRD and AES, respectively. The surface and interface morphologies were examined using cross-sectional TEM. The phase transition temperature of TiSi2 was raised with increasing Zr contents. The agglomeration of TiSi2 film was also suppressed by adding Zr element and much improved interface morphologies were observed.

Ultrathin sputtered silver films protected by ALD alumina: Comparison of in-situ investigation with ex-situ resistance and ellipsometric measurements

Vacuum ◽  
2021 ◽  
pp. 110669
Author(s):  
Alexandr Belosludtsev ◽  
Anna Sytchkova ◽  
Naglis Kyžas ◽  
Ignas Bitinaitis ◽  
Rimantas Simniškis ◽  
...  
Keyword(s):  
Ex Situ ◽  
Silver Films ◽  
In Situ Investigation
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