Si surface preparation and passivation by vapor phase of heavy water

2008 ◽  
Author(s):  
Andrea Edit Pap ◽  
Peter Petrik ◽  
Bela Pecz ◽  
Gabor Battistig ◽  
Istvan Barsony ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Heavy Water ◽  
Surface Preparation

Characterization of Oxide Etching and Wafer Cleaning using Vapor-Phase Anhydrous HF and Ozone

1997 ◽  
Vol 470 ◽  
Author(s):  
Barbara Froeschle ◽  
Lutz Deutschmann ◽  
Anton J. Bauer ◽  
Edmund P. Burte
Keyword(s):  
Vapor Phase ◽  
Gate Dielectric ◽  
Dielectric Breakdown ◽  
Uv Light ◽  
Reference Sample ◽  
Surface Preparation ◽  
Time Dependent Dielectric Breakdown ◽  
Wafer Cleaning ◽  
Phase Surface ◽  
Cluster Tool

ABSTRACTA cleaning process using anhydrous HF (AHF)/methanol and ozone is carried out in a STEAG-AST Vapor Phase Cleaning module (VPC). This module is integrated in a state-of-the-art cluster tool also consisting of a STEAG-AST Rapid Thermal Oxidation module (RTO). The dependence of AHF vapor phase etch rate of thermally grown silicon dioxide on different process parameters, such as etch time, AHF-flow, and temperature is evaluated. The optimized etch process is found to be at a temperature of 40°C and at a pressure of 50 mbar for this VPC module. Using the above etch parameters various combinations of vapor phase surface preparation chemistries combining AHF etching and ozone/UV cleaning are evaluated.To demonstrate the feasibility of this cluster tool for advanced gate dielectric formation, 4.0 nm thin oxide is grown directly after the cleaning in the RTO module without breaking the vacuum. Time dependent dielectric breakdown results for oxides pre-oxidation-cleaned in AHF, and in AHF followed by ozone are compared to a reference sample without any dry pre-oxidation cleaning. It can be shown, that the cleaning in AHF with a subsequent ozone step at 200°C under UV light leads to improved breakdown characteristics compared to AHF/methanol cleanings without such subsequent ozone/UV step or conventional wet cleaning using HF-Dip.

Surface Preparation and Growth Condition Dependence of Cubic GaN Layer on (001) GaAs by Hydride Vapor Phase Epitaxy

1997 ◽  
Vol 468 ◽  
Author(s):  
H. Tsuchiya ◽  
K. Sunaba ◽  
S. Yonemura ◽  
T. Suemasu ◽  
F. Hasegawa
Keyword(s):  
Vapor Phase ◽  
Surface Preparation ◽  
Growth Conditions ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Buffer Layers ◽  
Condition Dependence ◽  
X Ray Diffraction ◽  
Cubic Gan ◽  
The Will

ABSTRACTGaN buffer layers and thick GaN layers were grown on (001) GaAs substrates by hydride vapor phase epitaxy. The ratio of cubic to hexagonal components in the grown layer was estimated from the ratio of the integrated X-ray diffraction intensities of the cubic (002) plane and hexagonal (1011) planes measured by w scan. The optimum growth conditions were thermal cleaning at 600°C, growth temperature of 500°C and thickness of 30 nm for the buffer layer, and the Will ratio of 300 for thick GaN growth at 800°C. Cubic component in the layer grown with those conditions was more than 85% and strong cubic photoluminescence emission was observed at 377 nm (3.28 eV).

Planar defects in ordered (Ga,In)P

1988 ◽  
Vol 46 ◽  
pp. 902-903
Author(s):  
S. McKernan ◽  
C. B. Carter ◽  
D. Bour ◽  
J. R. Shealy
Keyword(s):  
Electron Diffraction ◽  
Vapor Phase ◽  
Growth Direction ◽  
High Density ◽  
Ordered Structure ◽  
Planar Defects ◽  
Diffraction Patterns ◽  
Ternary Semiconductors ◽  
Anion Species ◽  
Metallic Vapor

The growth of ternary III-V semiconductors by organo-metallic vapor phase epitaxy (OMVPE) is widely practiced. It has been generally assumed that the resulting structure is the same as that of the corresponding binary semiconductors, but with the two different cation or anion species randomly distributed on their appropriate sublattice sites. Recently several different ternary semiconductors including AlxGa1-xAs, Gaxln-1-xAs and Gaxln1-xP1-6 have been observed in ordered states. A common feature of these ordered compounds is that they contain a relatively high density of defects. This is evident in electron diffraction patterns from these materials where streaks, which are typically parallel to the growth direction, are associated with the extra reflections arising from the ordering. However, where the (Ga,ln)P epilayer is reasonably well ordered the streaking is extremely faint, and the intensity of the ordered spot at 1/2(111) is much greater than that at 1/2(111). In these cases it is possible to image relatively clearly many of the defects found in the ordered structure.

EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

1995 ◽  
Vol 53 ◽  
pp. 538-539
Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher
Keyword(s):  
Steel Surface ◽  
Surface Preparation ◽  
Treatment Method ◽  
Chrome Plating ◽  
Transmission Electron ◽  
Alloy Steels ◽  
Pre Treatment ◽  
Hard Chrome ◽  
Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

Selective Corrosion of brazed joint between BNi-2 filler metal and stainless steel 316

1996 ◽  
Vol 54 ◽  
pp. 218-219
Author(s):  
H. S. Kim ◽  
R. U. Lee
Keyword(s):  
Stainless Steel ◽  
Filler Metal ◽  
Surface Preparation ◽  
Optical Microscope ◽  
Heating Element ◽  
Incomplete Fusion ◽  
Atmospheric Conditions ◽  
Leak Test ◽  
High Temperature Side ◽  
Inconel 600

A heating element/electrical conduit assembly used in the Orbiter Maneuvering System failed a leak test during a routine refurbishment inspection. The conduit, approximately 100 mm in length and 12 mm in diameter, was fabricated from two tubes and braze-joined with a sleeve. The tube on the high temperature side (heating element side) and the sleeve were made of Inconel 600 and the other tube was stainless steel (SS) 316. For the filler metal, a Ni-Cr-B brazing alloy per AWS BNi-2, was used. A Helium leak test spotted the leak located at the joint between the sleeve and SS 316 tubing. This joint was dissected, mounted in a plastic mold, polished, and examined with an optical microscope. Debonding of the brazed surfaces was noticed, more pronounced toward the sleeve end which was exposed to uncontrolled atmospheric conditions intermittently. Initially, lack of wetting was suspected, presumably caused by inadequate surface preparation or incomplete fusion of the filler metal. However, this postulation was later discarded based upon the following observations: (1) The angle of wetting between the fillet and tube was small, an indication of adequate wetting, (2) the fillet did not exhibit a globular microstructure which would be an indication of insufficient melting of the filler metal, and (3) debonding was intermittent toward the midsection of the sleeve.

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