X-ray Photoelectron Spectroscopic Studies of Cu-AI alloy/SiO2 Interfaces

1999 ◽  
Vol 564 ◽  
Author(s):  
Pei-I Wang ◽  
G. -R. Yang ◽  
S. P. Murarka ◽  
T. -M. Lu

AbstractCu-Al alloys have been recommended for application as the diffusion barriers/adhesion promoters for advanced copper based metallization schemes. In this study interfacial reaction between Cu-Al alloy/SiO2 is investigated by x-ray photoelectron spectroscopy (XPS). A set of thin Cu-Al alloy films, about 30Å in thickness, are deposited on SiO2 substrates. These were directly examined by XPS. This is followed by a study of the interface formation during bias temperature stressing (BTS) of metal/dielectric interfaces in Cu/Cu-5at.%AI/SiO2 subjected to the electrical testing. Core-level spectra of silicon and aluminum obtained indicate that the reduction of silicon dioxide initiates at room temperature when the aluminum concentration in the copper alloys reaches about 5 atomic percent. The silicon diffusion into metal or vice versa is found to be suppressed during the low temperature anneal (300°C) by the Al2O3 interfacial layer. Also, a difference is present in the observed chemical states and interfacial reaction progressing between sputter and electron-beam deposited films. The films of Cu doped with Al appear to act as a suitable diffusion barrier and adhesion promoter between SiO2 and Cu.

1989 ◽  
Vol 43 (7) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yaoming Xie ◽  
Peter M. A. Sherwood

X-ray photoelectron spectroscopy has been used to monitor the surface chemical changes occurring on type II carbon fibers exposed to air, oxygen, and nitrogen plasmas. In all cases the plasmas caused changes in surface functionality, in terms of both C-O and C-N functionality. Prolonged exposure to the plasmas caused loss of surface functionality for air and oxygen plasmas, and extended treatment caused fiber damage. Plasma treatment of fibers promises to be an effective method of fiber treatment.


BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8134-8159
Author(s):  
Rico John ◽  
Katja Trommler ◽  
Katja Schreiter ◽  
Carolin Siegel ◽  
Frank Simon ◽  
...  

Wood veneer/biopolyethylene (bio-PE) biocomposite materials were produced by using poly(N-vinylformamide-co-vinylamine) (PVFA-co-PVAm) copolymers as a phase-mediating reagent. In a preliminary step, PVFA-co-PVAm was adsorbed onto the wood veneer component from aqueous solution. In its adsorbed form, it served as an adhesion promoter and improved the compatibility between both the highly polar wood veneer and weakly polar bio-PE surface. Structural parameters and their effect on the adsorption process, such as the degree of hydrolysis (DH) of poly(N-vinylformamide) (PVFA) (30, 50, and > 90%), the molecular weight of PVFA-co-PVAm (Mw 10,000, 45,000, or 340,000 g/mol), and the pH value (4, 7, and 11) influenced the resulting wetting behavior of the PVFA-co-PVAm-modified wood veneer surface. Thus, the hydrophobizing effect of the PVFA-co-PVAm was clearly detectable because the contact angle with water was considerably increased up to 116° by adsorption of PVFA-co-PVAm 9095 at pH 11. The adsorbed amount of PVFA-co-PVAm was determined by energy-dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS). The PVFA-co-PVAm-coated wood veneers were consolidated with bio-PE in a hot press process. The modified composite materials showed remarkably improved Young’s moduli (552 MPa) and tensile strengths (4.5 MPa) compared to former composite materials produced without PVFA-co-PVAm modification.


1988 ◽  
Vol 58 (11) ◽  
pp. 640-645 ◽  
Author(s):  
Lyndsay M. Dowling ◽  
Leslie N. Jones ◽  
Ian H. Leaver ◽  
Anthony E. Hughes

A method is described for cleanly separating the cortex and cuticle of wool fibers using water or an aqueous buffered solution as the immersion medium. Nearly complete removal of cuticle cells can be achieved in 2–3 hours when snippets of wool are vortex-mixed with a suspension containing both glass fiber snippets and glass beads. Examination of treated fibers (transverse sections) by transmission electron microscopy indicates removal of cuticle cell layers (endo- and exocuticle), together with associated membrane intracellular bands ( i-layers). The surface elemental composition of the fiber (determined using x-ray photoelectron spectroscopy) changes appreciably with cuticle removal. The sulfur content of the intracellular cortical proteins at the exposed surface is estimated to be 2%, compared to 9% for the epicuticle proteins at the surface of untreated wool.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 48 ◽  
Author(s):  
C.G. Nava-Dino ◽  
A. Martinez-Villafañe

Ni-Al alloys create a cone- shaped figure when there is internal oxide. This behavior was studied by TEM, SEM, X-Ray (XRD), Optical Microscopy and Image Processing. The internal oxide precipitates and its results indicate that this precipitation forms continuous rods in a cone-shaped configuration extending from the surface to the internal oxide front for Ni-Al alloys, whereas for Ni-X (X = Cr, Mo, V, W and Mn) alloys the precipitation is discrete and more irregularly-shaped. Furthermore, in a high atomic percentage (5.18% to 8.67%), the precipitation was rod-like and continuous from the surface to the internal oxide front for all temperature\time conditions. For the Ni-2.47% Al alloy at 800 °C, observations showed a mixture of rod-like and fork like precipitates, whereas after oxidation at 1000 and 1100 °C the precipitation was rod-like and continuous. For the Ni-1.18% Al alloy the aluminum concentration was insufficient for fully continuous precipitation to develop, and the internal oxides were generally acicular-shaped and discontinuous. Images obtained by TEM and, after that, analyzed by image processing allowed us to understand their behavior and the internal oxide patterns.


2007 ◽  
Vol 29-30 ◽  
pp. 67-70
Author(s):  
Wei Zhang ◽  
Jim Metson ◽  
C.L. Nguyen ◽  
S. Chen

The surface characteristics of an extruded 6060 aluminium alloy were investigated with X-ray Photoelectron Spectroscopy (XPS). The results revealed that the extruded surface was covered by oxides of aluminium and magnesium. The thickness of aluminium oxide was found to change along the extrusion direction with the thinnest and thickest oxide at the beginning and end of the extrudate, respectively. Magnesium segregation was found on the surface of the extrusion with the highest and lowest Mg concentration at the beginning and end of the extrudate, respectively. This is the inverse result of that expected where increasing Mg content was believed to be associated with film instability and thicker films.


1995 ◽  
Vol 60 (3) ◽  
pp. 383-392 ◽  
Author(s):  
Zdeněk Bastl

The effects of ion bombardment and r.f. plasma oxidation of graphite surfaces on subsequent growth and electronic properties of vacuum deposited palladium clusters have been investigated by methods of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy with X-ray excitation (XAES). Due to the significantly increased density of surface defects on which the nucleation process occurs the bulk value of the Pd 3d core level binding energy is achieved at higher surface coverage by palladium on bombarded surfaces than on ordered graphite. Angle resolved photoelectron spectra of oxidized graphite surfaces reveal significant embedding of oxygen in graphite surface layers. The C 1s and O 1s photoelectron spectra are consistent with presence of two major oxygen species involving C-O and C=O type linkages which are not homogeneously distributed within the graphite surface layers. Two effects were observed on oxidized surfaces: an increase of palladium dispersion and interaction of the metal clusters with surface oxygen groups. Using the simple interpretation of the modified Auger parameter the relaxation and chemical shift contributions to the measured Pd core level shifts are estimated. In the region of low surface coverage by palladium the effect of palladium-oxygen interaction on Pd core level binding energy exceeds the effects of increased dispersity.


RSC Advances ◽  
2014 ◽  
Vol 4 (108) ◽  
pp. 62935-62939 ◽  
Author(s):  
Parthasarathi Bera ◽  
Chinnasamy Anandan

X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) investigations of interfacial reactions between Ce and Si have been carried out on as-deposited and 15 month aged CeO2/Si and CeO2/Si3N4 thin films.


2000 ◽  
Vol 615 ◽  
Author(s):  
Pei-I Wang ◽  
S. P. Murarka ◽  
G.-R. Yang ◽  
E. Barnat ◽  
T.-M. Lu ◽  
...  

ABSTRACTCu-Al alloys have been recommended for application as the diffusion barriers/adhesion promoters for advanced copper based metallization schemes. This approach to barrier formation is to generate an ultra-thin interfacial layer through Cu alloying without significantly affecting the resistivity of Cu. In this paper the microstructure of the bilayers of Cu/Cu-5 at%Al and Cu-5 at%Al/Cu sputter deposited on SiO2 before and after thermal annealing is investigated by transmission electron microscopy (TEM). Interfacial layer is observed in both cases. The variation of the resistance of the Cu-Al alloy film is consistent with its microstructure. The x-ray diffraction (XRD) spectra of Cu-5 at%Al on SiO2 shows that the addition of Al into Cu intends to favor the Cu (111) texture. These results will be presented and discussed showing that films of Cu doped with Al appear to act as a suitable barrier and adhesion promoter between SiO2 and Cu.


2003 ◽  
Vol 57 (6) ◽  
pp. 628-635 ◽  
Author(s):  
Georgia Kandilioti ◽  
Angeliki Siokou ◽  
Vasiliki Papaefthimiou ◽  
Stella Kennou ◽  
Vasilis G. Gregoriou

This work represents a characterization study of silicon oxide on Si(111) and Si(100) surfaces intended for use as substrates in organic light-emitting diodes (OLEDs) on chip devices. Samples have been prepared using either native oxide formation or thermal oxidation, and they have also been treated for activation of hydroxyl groups on their surface. Both Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) have been used in order to understand the molecular orientation as well as the chemical composition of the various oxide types formed during these different oxidation processes. These spectroscopic studies reveal the formation of two different types of oxides on these substrates. The first type is a thin oxide layer on the surface, whereas the second type, called interstitial, is found deeper in the substrate. Specifically, it was found that the Si(100) substrate forms a randomly oriented interstitial oxide, whereas the presence of a lower quantity but more oriented interstitial oxide was found for the Si(111) substrate. In addition, we report for the first time the position of the impurity oxygen for Si(111) substrates at 1122 cm−1. Finally, in both Si(100) and Si(111) substrates, the thin (<15 Å) silicon oxide layers are oriented and appear to contain silicon atoms of similar oxidation states. In contrast, both the thicker surface film (100 Å) as well as the interstitial oxide produced by the thermal oxidation procedure show random orientation and relative uniformity. Overall these orientation studies clearly show that the formation process of surface oxides in different substrates clearly creates species that are oriented differently with respect to the surface.


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