InAs MOS capacitors;Fabrication & Characterization

Abstract: The down scaling of metal-oxide-semiconductor based devices has been halted by the shortcomings of silicon. To enable further miniaturization new materials are required. The proposed replacements include compound III-V semiconductors and high-k oxides, the implementation of which has been difficult. This work investigates metal-oxide-semiconductor capacitors fabricated on InAs substrate. The oxide layer was formed by atomic layer deposition of high permittivity materials, ZrO_2 and Al_2O_3. The quality of the InAs-oxide interface was to be investigated after in situ surface treatment method including cyclic nitrogen plasma and trimethylaluminum pulses. The measurements showed a large dispersion in capacitance-voltage (C-V) data and a high leakage current through the oxide layer. Possible sources of the defects leading to poor C-V behavior of the MOS capacitors are subsequently investigated.