In-situ photoemission analyses of ALD-oxide/InxGa1-xAs (001) interfaces
Abstract
High-κ dielectrics on high carrier mobility channels, such as InxGa1-xAs, are now being considered for CMOS technology beyond 15 nm node. The initial bonding of high-κ/InGaAs determines the value and the distribution of interfacial density of states (Dit) within the InxGa1-xAs band gap, key to the device performance. In this work, atomic layer deposited (ALD) HfO2 and Al2O3 on MBE-grown InxGa1-xAs (001) have been in-situ and ex-situ carried out to investigate the initial stage of interfacial reactions by high resolution photoemission spectroscopy using synchrotron radiation and monochromatic Al Ka x-ray sources. Comparing the results with the corresponding electrical measurements (C-V and G-V at various temperatures), Fermi level unpinning in the oxide/InxGa1-xAs hetero-structure may be attributed to the exclusion of the As-As and the As-O bonding during the initial interfacial formation.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- February 2012
- Bibcode:
- 2012APS..MARQ28005H