
Anders Mikkelsen
Professor

InAs-oxide interface composition and stability upon thermal oxidation and high-k atomic layer deposition
Author
Summary, in English
Defects at the interface between InAs and a native or high permittivity oxide layer are one of the main challenges for realizing III-V semiconductor based metal oxide semiconductor structures with superior device performance. Here we passivate the InAs(100) substrate by removing the native oxide via annealing in ultra-high vacuum (UHV) under a flux of atomic hydrogen and growing a stoichiometry controlled oxide (thermal oxide) in UHV, prior to atomic layer deposition (ALD) of an Al2O3 high-k layer. The semiconductor-oxide interfacial stoichiometry and surface morphology are investigated by synchrotron based X-ray photoemission spectroscopy, scanning tunneling microscopy, and low energy electron diffraction. After thermal oxide growth, we find a thin non-crystalline layer with a flat surface structure. Importantly, the InAs-oxide interface shows a significantly decreased amount of In3+, As5+, and As0 components, which can be correlated to electrically detrimental defects. Capacitance-voltage measurements confirm a decrease of the interface trap density in gate stacks including the thermal oxide as compared to reference samples. This makes the concept of a thermal oxide layer prior to ALD promising for improving device performance if this thermal oxide layer can be stabilized upon exposure to ambient air.
Department/s
- Synchrotron Radiation Research
- NanoLund: Centre for Nanoscience
- Solid State Physics
- Nano Electronics
Publishing year
2018-12-01
Language
English
Publication/Series
AIP Advances
Volume
8
Issue
12
Document type
Journal article
Publisher
American Institute of Physics (AIP)
Topic
- Materials Engineering
- Condensed Matter Physics (including Material Physics, Nano Physics)
Status
Published
Research group
- Nano Electronics
ISBN/ISSN/Other
- ISSN: 2158-3226