Surface and interface properties of PdCr/SiC Schottky diode gas sensor annealed at 425 degrees C

Citation
Ly. Chen et al., Surface and interface properties of PdCr/SiC Schottky diode gas sensor annealed at 425 degrees C, SOL ST ELEC, 42(12), 1998, pp. 2209-2214
Citations number
6
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Eletrical & Eletronics Engineeing
Journal title
SOLID-STATE ELECTRONICS
ISSN journal
00381101 → ACNP
Volume
42
Issue
12
Year of publication
1998
Pages
2209 - 2214
Database
ISI
SICI code
0038-1101(199812)42:12<2209:SAIPOP>2.0.ZU;2-8
Abstract
The surface and interface properties of Pd0.9Cr0.1/SiC Schottky diode gas s ensors both before and after annealing are investigated using Anger electro n spectroscopy (AES), scanning electron microscopy (SEM), and energy disper sive spectroscopy (EDS). At room temperature the alloy reacted with SIC and formed PdxSi only in a very narrow interfacial region. After annealing for 250 h at 425 degrees C, the surface of the Schottky contact area has much less silicon and carbon contamination than that found on the surface of an annealed Pd/SiC structure. Palladium silicides (PdxSi) formed at a broadene d interface after annealing, but a significant layer of alloy film is still free of silicon and carbon. The chromium concentration with respect to pal ladium is quite uniform down to the deep interface region. A stable catalyt ic surface and a clean layer of Pd0.9Cr0.1 film are likely responsible for significantly improved device sensitivity. (C) 1998 Published by Elsevier S cience Ltd. All rights reserved.