Ion-Surface Interactions During Epitaxy

1990 ◽  
Vol 201 ◽  
Author(s):  
S. A. Barnett ◽  
C.-H. Choi ◽  
R. Kaspi
Keyword(s):  
High Vacuum ◽  
Surface Interactions ◽  
Epitaxial Films ◽  
Ultra High Vacuum ◽  
Semiconductor Materials ◽  
Layer By Layer ◽  
Crystalline Perfection ◽  
Ion Energies ◽  
Miscibility Gaps ◽  
Deposition Techniques

AbstractRecent work on low-energy ion-assisted deposition of epitaxial films is reviewed. Much of the interest in this area has centered on the use of very low ion energies (∼ 25 eV) and high fluxes (> 1 ion per deposited atom) obtained using novel ion-assisted deposition techniques. These methods have been applied in ultra-high vacuum, allowing the preparation of high-purity semiconductor materials. The following ion-surface interaction effects during epitaxy are discussed: improvements in crystalline perfection during low temperature epitaxy, ion damage effects, improved homogeneity and properties in III-V alloys grown within miscibility gaps, and changes in nucleation mechanism from Stranski-Krastanov to layer-by-layer.

scholarly journals Impact of Surface Roughness on Ion-Surface Interactions Studied with Energetic Carbon Ions 13C+ on Tungsten Surfaces

2019 ◽  
Vol 4 (1) ◽  
pp. 29 ◽  
Author(s):  
Maren Hellwig ◽  
Martin Köppen ◽  
Albert Hiller ◽  
Hans Koslowski ◽  
Andrey Litnovsky ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Angular Distribution ◽  
Surface Morphology ◽  
High Vacuum ◽  
Surface Interactions ◽  
Surface Interaction ◽  
Ultra High Vacuum ◽  
Nuclear Reaction Analysis ◽  
Angle Of Incidence ◽  
Carbon Ions

The effect of surface roughness on angular distributions of reflected and physically sputtered particles is investigated by ultra-high vacuum (UHV) ion-surface interaction experiments. For this purpose, a smooth (R a = 5.9 nm) and a rough (R a = 20.5 nm) tungsten (W) surface were bombarded with carbon ions 13C+ under incidence angles of 30 ∘ and 80 ∘ . Reflected and sputtered particles were collected on foils to measure the resulting angular distribution as a function of surface morphology. For the qualitative and quantitative analysis, secondary ion mass spectrometry (SIMS) and nuclear reaction analysis (NRA) were performed. Simulations of ion-surface interactions were carried out with the SDTrimSP (Static Dynamic Transport of Ions in Matter Sputtering) code. For rough surfaces, a special routine was derived and implemented. Experimental as well as calculated results prove a significant impact of surface roughness on the angular distribution of reflected and sputtered particles. It is demonstrated that the effective sticking of C on W is a function of the angle of incidence and surface morphology. It is found that the predominant ion-surface interaction process changes with fluence.

A compact UHV X-ray diffractometer for studying surfaces and interfaces

1998 ◽  
Vol 5 (3) ◽  
pp. 887-889
Author(s):  
Yoshikazu Fujii ◽  
Takeshi Nakamura ◽  
Mutsumi Kai ◽  
Kentaroh Yoshida
Keyword(s):  
High Vacuum ◽  
Layer Growth ◽  
Ultra High Vacuum ◽  
Layer By Layer ◽  
Crystal Surfaces ◽  
X Ray ◽  
Surfaces And Interfaces ◽  
Optical Table ◽  
Specimen Orientation

A compact ultra-high-vacuum (UHV) X-ray diffractometer for surface glancing X-ray scattering has been constructed. All the equipment, including a rotating-anode source of 18 kW and a UHV specimen chamber, is arranged on one optical table of dimensions 70 × 90 cm. The specimen chamber is 14 cm in diameter and 20 cm high and can be evacuated up to 3 × 10−8 Pa. It is equipped with two Be windows of thicknesses 0.2 and 0.4 mm. Specimen orientation in the vacuum is controlled from the outside. The specimen can be heated up to 773 K. The chamber has two evaporation cells and can be used for in situ observations of growing crystal surfaces. Using this instrument, we observed a mechanically polished Ag surface and successfully made an in situ observation of the layer-by-layer growth of a PbSe(111) surface. The instrument will be useful for preliminary experiments using laboratory sources, prior to final measurements at synchrotron radiation facilities.

Properties of Metal / Polyphenylquinoxaline Interfaces

1994 ◽  
Vol 337 ◽  
Author(s):  
L. Bellard ◽  
J.M. Themlin ◽  
F. Palmino ◽  
A. Cros
Keyword(s):  
Metal Layer ◽  
High Vacuum ◽  
Polymer Surface ◽  
Pure Metal ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Layer By Layer ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTWe have investigated the microscopic properties of copper and chromium layers deposited on polyphenylquinoxaline (PPQ). PPQ is a thermostable polymer used for multichip module applications. The metal is deposited under ultra-high vacuum conditions and analysed in-situ by X-ray photoemission (XPS) and atomic force microscopy (ex situ). Copper does not react significantly with the PPQ and tends to diffuse into the polymer matrix upon annealing. On the contrary, chromium strongly reacts with the polymer surface at room temperature. With increasing metal coverage, chromium grows in a layer-by-layer mode and the reacted interface is progressively burried under the pure metal layer.

Thermal Stability of Ir-Silicide/SiGe Layers Grown in a Dual Electron Gun Chamber at Ultra-High Vacuum (Extended Abstract)

1994 ◽  
Vol 299 ◽  
Author(s):  
C. K. Chung ◽  
J. Hwang
Keyword(s):  
Thermal Stability ◽  
Thermal Instability ◽  
High Vacuum ◽  
Epitaxial Films ◽  
Ultra High Vacuum ◽  
Electron Gun ◽  
Guard Ring ◽  
X Ray ◽  
Silicide Layer ◽  
Thermal Stability Of

AbstractHeteroepitaxial Ir-silicide/SiGe layers on the top of p-Si(100) have been achieved at a substrate temperature of 450 °C. The co-deposited Ir-silicide layer was determined to be Ir3Si4 with four types of epitaxial modes. Thermal stability of the film was examined by using Auger electron spectroscopy and X-ray diffractometer. The Ir3Si4/SiGe layers were stable as annealed at 550 °C for 20 sec in a rapid thermal annealing furnace, while interdiffusion between Ir3Si4 and SiGe occurs at a temperature of 750 deg;C or higher for 20 sec. The traditional guard-ring fabrication process should be performed before epitaxial films deposition due to this thermal instability.

Raman scattering and x-ray diffraction characterization of amorphous semiconductor multilayer interfaces

1986 ◽  
Vol 1 (3) ◽  
pp. 468-475 ◽  
Author(s):  
D.D. Allred ◽  
J. Gonzalez-Hernandez ◽  
O.V. Nguyen ◽  
D. Martin ◽  
D. Pawlik
Keyword(s):  
Raman Spectra ◽  
High Vacuum ◽  
Amorphous Semiconductor ◽  
Ultra High Vacuum ◽  
Chemical Bonds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sharp Interfaces ◽  
Deposition Techniques

Raman spectroscopy (RS) and low-angle x-ray diffraction (LAXRD) have been used to characterize semiconductor multilayer interfaces. In the present study a model for Raman spectra of multilayers is developed and applied to the specific case of the interfaces of a-Si/a-Ge multilayers. Quantification of the “blurring” of interfaces is possible because peak heights in the Raman spectra of thin films are proportional to the number of scatterers, thus RS is capable of directly “counting” the total number of chemical bonds of a given type in the film. Multilayers, prepared by various deposition techniques, are compared. The relative roles of LAXRD and RS in investigating interfaces are contrasted. Several a-Si/a-Ge multilayers deposited by ultra-high vacuum (UHV) evaporation (MBD) are found to exhibit very regular periodicities and exceptionally sharp interfaces (<1.0 Å intermixing).

Characterization of the a-SN/CDTE(110) Interface by Angle-Resolved X-Ray Photoemission

1986 ◽  
Vol 77 ◽  
Author(s):  
Tzer-Shen Lin ◽  
William J. Partin ◽  
Yip-Wah Chung
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Layer By Layer ◽  
Tungsten Filament ◽  
X Ray ◽  
Semiconductor Heterostructure ◽  
Argon Sputtering ◽  
Abrupt Junction

ABSTRACTStoichiometric and atomically clean CdTe(110) surfaces have been prepared by suitable chemical etching, followed by argon sputtering, and sample annealing in ultra-high vacuum. Cubic (α) -tin was grown on CdTe(110) by tin evaporation from a tungsten filament at a substrate temperature of 30 °C. Angle-resolved X-ray photoelectron spectroscopy (ARXPS) was used to determine the a-Sn growth mechanism and the composition profile of this semiconductor heterostructure nondestructively. From our analyses, we conclude that a-Sn grows on CdTe(110) at 30 °C by a layer by layer mechanism and forms an abrupt junction with CdTe(110).

Progression of the Surface Roughness of N+ Silicon Epitaxial Films as Analyzed by AFM

1995 ◽  
Vol 399 ◽  
Author(s):  
S. John ◽  
E. J. Quinones ◽  
B. Ferguson ◽  
K. Pacheco ◽  
C. B. Mullins ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Vacuum ◽  
Film Surface ◽  
Chemical Vapor ◽  
Epitaxial Films ◽  
Ultra High Vacuum ◽  
Phosphorus Segregation ◽  
Surface Mobility ◽  
Partial Pressures ◽  
Effects Of Ph

ABSTRACTWe report on the morphology of heavily phosphorous doped silicon films grown by ultra high vacuum chemical vapor deposition at temperatures of ∼550° C. The effects of PH3 on epitaxial films have been examined for silicon deposited using SiH4 and Si2H6. It is found that films grown using silane experience an increase in surface roughness with increasing phosphine partial pressure. AFM and RHEED studies indicate 3-D growth. As epitaxy progresses, it is believed that phosphorus segregation on the growing film surface greatly diminishes the adsorption and surface mobility of the silicon bearing species. Initial Si deposition results in a pitted surface, but as growth advances and the phosphorus coverage increases, growth within the pits decreases the surface roughness. In contrast to SiH4, it is found that Si2H6 provides excellent quality, smooth films even at high PH3 partial pressures.

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