| AVS 55th International Symposium & Exhibition | |
| Surface Science | Thursday Sessions |
| Session SS-ThP |
| Session: | Poster Session |
| Presenter: | W. Melitz, University of California, San Diego |
| Authors: | J. Shen, University of California, San Diego W. Melitz, University of California, San Diego A.C. Kummel, University of California, San Diego |
| Correspondent: | Click to Email |
The Si based MOS field effect transistors (MOSFETs) technology is rapidly approaching its theoretical physical limits. III-V compound semiconductors are known as a potential additional technology platform to silicon. The key to fabricating a practical III-V MOSFET is forming an unpinned oxide-semiconductor interface with low fixed charge. The correlation between the atomic bonding structure and the electronic structure at oxide-semiconductor interfaces is critical to understanding how atomic scale changes in electronic structure can cause localization of electrons or holes at these interfaces. We have used atomically resolved scanning tunneling microscopy (STM) images and scanning tunneling spectra (STS) to determine the atomic and electronic structure of clean InGaAs surface structure and gate-oxide/InGaAs semiconductor interface. Using a low temperature preparation we can get an InGaAs(001)-(2×4) surface reconstruction that is mostly β2(2×4) with some α2(2×4) regions. However these surfaces are very oxygen sensitive and reconstruction is not pure. Then increasing preparation temperature, we can get mixed surface reconstruction structure of InGaAs(001)-(2×4) and (4×2). For even high temperature, we can get pure InGaAs(001)-(4×2) surface reconstruction. Then oxides are deposited on InGaAs surface and STS measurements are being performed to determine the electronic properties of the interface and whether Fermi level is pinning or unpinning.