| Authors: |
Dagata, J. A., Glembocki, O. , Tuchman, J. , Ko, K. , Pang, S. |
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| Title: |
Photoreflectance Study of the Chemically Modified (100) GaAs Surface |
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| Published: |
May 01, 1994 |
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| Abstract: |
Photoreflectance (PR) spectroscopy has been used to study the Fermi-level pinning position of chemically modified (100) GaAs surfaces. It is shown that there are two pinning positions for the unmodified (100) GaAs surface. For n-GaAs, the Fermi level pins near midgap, while for p-GaAs the Fermi level pins near the valence band. We used an Ar/Cl(2) plasma generated by an electron-cyclotron resonance (ECR) source and P2S5 chemical passivation to change the stoichiometry of the surface. We show that ECR etching makes the surface oxide As rich and that the Fermi-level position for this circumstance is near midgap. The P(2)S(5) passivation produces a thin Ga rich oxide which is observed to pin the Fermi-level near the valence band. These results allow us to relate the Fermi-level pinning position to the stoichiometry of the GaAs/oxide interface. |
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| Conference: |
Spectroscopic Characterization Techniques for Semiconductor Technology V, Orest J. Glembocki, Editor May 1994, Semiconductor Device Characterization I |
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| Proceedings: |
Proceedings of SPIE |
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| Volume: |
2141 |
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| Pages: |
pp. 96-102 |
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| Location: |
Los Angeles, CA |
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| Dates: |
January 26, 1994 |
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| Research Area: |
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