CVD-SiO2 and plasma-SiNx films as Zn diffusion masks for GaAs
| Autor: | B. Emmerstorfer, C. Blaauw, A.J. Springthorpe, S. Dzioba |
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| Rok vydání: | 1984 |
| Předmět: |
Materials science
Scanning electron microscope Analytical chemistry Plasma Condensed Matter Physics Electronic Optical and Magnetic Materials Etching (microfabrication) Materials Chemistry Electrical and Electronic Engineering Reactive-ion etching Diffusion (business) Thin film p–n junction Buffered oxide etch |
| Zdroj: | Journal of Electronic Materials. 13:251-262 |
| ISSN: | 1543-186X 0361-5235 |
| Popis: | The effectiveness of plasma-deposited SiNx and chemical-vapor-deposited SiO2 as masks for localized diffusion at 600°C of Zn in GaAs has been investigated. Variables included the diffusion time (0.25-16 hrs), and the mask thickness (0.1-0.5 Μm) for both SiO2 and SiNx films, and the deposition temperature (300-500°C) and the phosphorous content (0-8 wt.%) for SiO2 films. Diffusion windows were defined photolithographically and opened by etching in buffered HF or by reactive ion etching of CF4. Profiles of p-n junctions associated with the Zn diffusion were determined by scanning electron microscopy of an etched cleaved section. Films of SiNx formed effective diffusion masks, but for masks of SiO2, enhanced diffusion of Zn took place along the substrate-mask interface, with sideways-to-depth diffusion ratios up to 10. The Inclusion of P in SiO2 masks reduced, but did not eliminate, this effect. Mechanisms which may contribute to the enhanced sideways diffusion include strain, diffusion through the mask, and degradation of the masksubstrate interface. It is shown that the first of these mechanisms has only a minor effect. |
| Databáze: | OpenAIRE |
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