Abstract
We report that depositing Al 2 O 3 on InGaAs in an H-containing ambient (e.g., in forming gas) results in significant reduction of interface-trap density and significantly suppressed frequency dispersion of accumulation capacitance. The results of the inelastic electron tunneling spectroscopy study reveal that strong trap features at the Al 2 O 3 /InGaAs interface in the InGaAs band gap are largely removed by depositing Al 2 O 3 in an H-containing ambient. Transmission electron microscopy images and x-ray photoelectron spectroscopy data shed some light on the role of hydrogen in improving interface properties of the Al 2 O 3 /In 0.53 Ga 0.47 As gate stack. © 2011 American Institute of Physics.