4174. New sputtering system for manufacturing ZnO thin-film SAW devices. (USA)
- Publisher
- Elsevier Science
- Year
- 1979
- Tongue
- English
- Weight
- 134 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0042-207X
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✦ Synopsis
Classified abstracts 4170-4178 30 4170. Ge-GaAs (110) interface formation. (USA) The heterojunction chemistry for Ge grown by molecular beam epitaxy (MBE) on in situ cleaved GaAs exhibits significant interdiffusion in short times at growth temperatures T~ of 430°C (significantly lower critical TG than that reported for moderate-vacuum physical vapour deposition). This results in profound changes in the electronic properties of the interface as probed by synchrotonradiation-excited 3d core electron photoemission. Even when there is significant alloying of the two lattice-matched semiconductors, there is nearly equal probability for Ge to bond to either a Ga or an As atom at the initial stage. As Ge becomes the dominant species, we find As preferentially diffusing toward the Ge side of the junction. This As is distributed throughout the overlayer in contrast to metalsemiconductor interface formation where the diffusing constituent resides only on the free, growing surface. We show that these behaviours are consistent with the kinetic and thermodynamic properties of the atomic species. The valence band discontinuity is negligible over atomic dimensions, while for an abrupt interface (T~ : 350C) we measure AE~. : 0.7 5= °°SeV. The photoemission changes