Band alignment of zinc oxide as a channel layer in a gate stack structure grown by plasma enhanced atomic layer deposition
| Autor: | Chiyu Zhu, Robert J. Nemanich, David J. Smith |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Materials science
Photoemission spectroscopy Process Chemistry and Technology Analytical chemistry Wide-bandgap semiconductor Band offset Surfaces Coatings and Films Electronic Optical and Magnetic Materials Amorphous solid Atomic layer deposition chemistry.chemical_compound Lanthanum oxide chemistry Materials Chemistry Electrical and Electronic Engineering Thin film Instrumentation Layer (electronics) |
| Zdroj: | Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena. 30:051807 |
| ISSN: | 2166-2754 2166-2746 |
| DOI: | 10.1116/1.4752089 |
| Popis: | A gate stack structure with a thin ZnO layer between an oxidized Si(100) surface and an alloyed hafnium and lanthanum oxide (HfO2-La2O3) layer was prepared by plasma enhanced atomic layer deposition at ∼175 °C. High resolution electron microscopy indicated an amorphous structure of the deposited layers. The electronic properties were characterized with x-ray and ultraviolet photoemission spectroscopy. A significant amount of excess oxygen was observed in the as-deposited ZnO and (HfO2-La2O3) layers. A helium plasma postdeposition treatment can partially remove the excess oxygen in both layers. The band alignment of this structure was established for an n-type Si substrate. A valence band offset of 1.5 ± 0.1 eV was measured between a thin ZnO layer and a SiO2 layer. The valence band offset between HfO2-La2O3 (11% HfO2 and 89% La2O3) and ZnO was almost negligible. The band relationship developed from these results demonstrates confinement of electrons in the ZnO film as a channel layer for thin film transis... |
| Databáze: | OpenAIRE |
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