| 1. |
- Petersson, L.-G., et al.
(författare)
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A Pd-MOS structure as a hydrogen sensor in catalytic reactions
- 1984
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Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; A2, s. 1032-
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Tidskriftsartikel (refereegranskat)abstract
- By letting a catalytic reaction involving hydrogen occur on the Pd gate metal of a Pd–MOS structure the amount of hydrogen atoms on the surface can be monitored without any external probes by measuring the dipole induced by the hydrogen atoms that have diffused to the Pd–SiO2 interface. The ability to work over a wide pressure range (10-11 Torr to atm) makes the Pd–MOS structure an interesting device in the study of catalytic reactions. In this article, we will give a short review of some of the many applications of this component. We have combined this technique with other surface sensitive techniques such as UPS, XPS, work function measurements and mass spectrometry and, e.g., studied how the hydrogen adsorption–desorption processes are influenced by alloying the Pd surface with various amounts of Ag, thereby also changing the distribution of d states close to Fermi energy. We have also studied the H2+O→H2O reaction on Pd. It, e.g., turns out that the water reaction rate reaches a maximum when the oxygen coverage approaches zero and that the hydrogen atoms on the surface have a larger lateral mobility.
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| 2. |
- Axelsson, O., et al.
(författare)
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Reactive evaporation of potassium in CO2 and the formation of bulk intermediates
- 1994
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 12:1, s. 158-160
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Tidskriftsartikel (refereegranskat)abstract
- Potassium vapor condensed in CO2 has been studied by transmission infrared spectroscopy and by total pressure thermal desorption spectroscopy. The results are compared with surface spectroscopic data for CO2 adsorbed on alkali metal overlayers. Both systems show the formation of bulk coordinated oxalate species at cryogenic temperatures and the conversion to carbonate intermediates upon annealing.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Berg, Sören, et al.
(författare)
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Atom assisted sputtering yield amplification
- 1992
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - 0734-2101 .- 1520-8559. ; 10:4, s. 1592-1596
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Berg, Sören, et al.
(författare)
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Ion assisted selective thin film deposition
- 1986
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - 0734-2101 .- 1520-8559. ; 4:3, s. 448-
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Tidskriftsartikel (refereegranskat)
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| 9. |
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| 10. |
- Berg, Sören, et al.
(författare)
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Process modelling of reactive sputtering
- 1989
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - 0734-2101 .- 1520-8559. ; 7:3, s. 1225-1229
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Tidskriftsartikel (refereegranskat)
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Blom, Hans-Olof, et al.
(författare)
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Reactively sputtered titanium boride thin films
- 1989
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - 0734-2101 .- 1520-8559. ; 7:2, s. 162-165
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Tidskriftsartikel (refereegranskat)
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| 16. |
- Blom, Hans-Olof, et al.
(författare)
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Removal of RSE induced damages in silicon
- 1986
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - 0734-2101 .- 1520-8559. ; 4:3, s. 752-
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Tidskriftsartikel (refereegranskat)
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Hedlund, C, et al.
(författare)
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Microloading effect in reactive etching
- 1994
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - 0734-2101 .- 1520-8559. ; 12:4, s. 1962-1965
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Tidskriftsartikel (refereegranskat)
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| 21. |
- Hedlund, Christer, 1964-, et al.
(författare)
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Microloading effect in reactive ion etching
- 1994
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 12:4, s. 1962-1965
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Tidskriftsartikel (refereegranskat)abstract
- The etch rate of silicon, during reactive ion etching (RIE), depends on the total exposed area. This is called the loading effect. However, local variations in the pattern density will, in a similar way, cause local variations in the etch rate. This effect is caused by a local depletion of reactive species and is called the microloading effect. Silicon wafers patterned with silicon dioxide have been etched in order to study the microloading effect. The pattern consists of a large exposed area and narrow lines at different distances from the edge of the large area. This arrangement makes it possible to study how the distance from the large area, which depletes the etchants, influences the etch rate. The influence of different processing parameters like, e.g., pressure, gas flow rate, and flow direction on the microloading effect have been investigated. It has been found that the microloading effect is small (<10%) compared to other pattern dependent nonuniformities. It is also shown that the nonuniformities caused by the microloading effect can be decreased by, e.g., decreasing the pressure or increasing the gas flow rate.
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| 22. |
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| 23. |
- Hultman, L., et al.
(författare)
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Formation of polyhedral voids at surface cusps during growth of epitaxial TiN/NbN superlattice and alloy films
- 1992
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Ingår i: Journal of Vacuum Science and Technology A. - : American Vacuum Society. - 0734-2101. ; 10:4, s. 1618-1624
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial TiN/NbN(001) superiattice thin films with periods A between 0 (alloy) and 9.6 nm have been grown by ultrahigh vacuum reactive magnetron sputter deposition on MgO(OOl) substrates in mixed Ar/N2 discharges. Cross-sectional transmission electron microscopy was used for characterizing layer and defect structure. Coherency strain relaxation close to the film/substrate interface resulted in nonplanar growth with surface cusps and the creation of apparent column boundaries at which TiN and NbN layers curved towards the substrate, but across which the basic lattice was ordered. Also, a fraction of the boundaries were associated with threading defects along the growth direction. The column boundaries and threading defects were decorated by voids that exhibited an orthorhombohedral shape, were elongated in the growth direction, and typically had flat surfaces on {100} planes. The origin of voids is suggested to be through self-shadowing at surface cusps in combination with limited adatom mobility. The voids subsequently attained equilibrium shape as the result of surface and bulk diffusion. The void density varied withλ and the void length in the growth direction was generally an integer number of periods, indicating that the void formation was influenced by the superiattice layers. The formation of limited voids is suggested to be characteristic of thin film growth close to the epitaxial temperature.
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| 24. |
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| 25. |
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| 26. |
- LARSSON, CUS, et al.
(författare)
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CORE-LEVEL SHIFTS ON THE H2O EXPOSED GE(100)2X1 SURFACE
- 1989
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 7:3, s. 2044-2048
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Tidskriftsartikel (refereegranskat)
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Nender, C, et al.
(författare)
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Selective deposition of Ti - an interface study
- 1987
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - 0734-2101 .- 1520-8559. ; 5:4, s. 1073-
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Tidskriftsartikel (refereegranskat)
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| 31. |
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| 32. |
- Paul, Jan
(författare)
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Alkali overlayers on aluminum, alumina, and aluminum carbide
- 1987
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 5:4, s. 664-670
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Tidskriftsartikel (refereegranskat)abstract
- Adsorption data for potassium and sodium atoms on the surfaces of aluminum metal, aluminum oxide, and aluminum carbide are presented. Low coverage adsorption of K(Na) on Al(100) is characterized by a 4.6(3.2) D surface dipole and desorption around 620(590) K. Increasing the alkali coverage lowers the desorption temperature as well as the effective surface dipole per alkali atom. Clustering on aluminum metal is activated by annealing to around room temperature. The adsorption of K and Na monomers on dehydrogenated Al2O3 is characterized by desorption around 350 K and, for sodium, by cluster formation even at submonolayer coverage. Finally, potassium but not sodium atoms bind strongly to Al4C3 (Id>700 K). This explains a previous observation of potassium at a promoted aluminum surface after exposure to carbon monoxide and annealing to 700 K.
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| 33. |
- WIGREN, C, et al.
(författare)
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GROWTH AND EPITAXY OF YB SILICIDES ON SI(111)
- 1991
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 9:3, s. 1942-1945
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Tidskriftsartikel (refereegranskat)abstract
- Yb silicides have been grown epitaxially on the Si(111) surface using solid-state epitaxy with annealing to 400-degrees-C. The amount of deposited Yb was varied from parts of a monolayer to films being about 40 monolayer thick. Auger- and photoelectron spectroscopy showed that Si segregates into the Yb overlayer at room temperature and that a strong reaction occurs during annealing to 400-degrees-C leading to the formation of thick silicides. The epitaxial silicides showed a 1 x 1 or a unroofed-radical 3 x unroofed-radical 3 low-energy electron diffraction pattern depending on the detailed preparation procedure. The composition of the silicide was found to be YbSi2-x.
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| 34. |
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