Influences of surface treatment on In0.53Ga0.47As epitaxial layer grown on silicon substrate using trimethylaluminum.

A development of high quality In x Ga 1 − x As epitaxial layers on Si substrates is essential for high-performance logic transistors due to the low fabrication cost and high compatibility with a conventional Si technology. We investigate the surface of In 0.53 Ga 0.47 As epitaxial layers grown by metal-organic chemical vapor deposition on a Si substrate (with InP/GaAs buffer layers) to obtain a high capacitance using high-k films (HfO 2 /Al 2 O 3 bilayer). The high-k films were grown on In 0.53 Ga 0.47 As epitaxial layers by atomic layer deposition (ALD). The interface between the high-k bilayer and the In 0.53 Ga 0.47 As epitaxial layer was analyzed depending on a surface treatment of the In 0.53 Ga 0.47 As epitaxial layer, and the surface treatment of the In 0.53 Ga 0.47 As epitaxial layer using trimethylaluminum (TMA) enhanced the electrical performances of Pt/high-k film/In 0.53 Ga 0.47 As capacitors. The TMA was introduced on the In 0.53 Ga 0.47 As epitaxial layer in the ALD chamber, which reduced native oxides (such as gallium and arsenic oxides) of the In 0.53 Ga 0.47 As surface and minimized a formation of interfacial layers between the high-k film and In 0.53 Ga 0.47 As layer. A capacitance equivalent thickness (CET) of ~ 1.5 nm was achieved with a low leakage current (~ 10 − 4 A/cm 2 at 1 V). A CET as low as ~ 1.3 nm and a capacitance > 2.5 μF/cm 2 was attained by optimizing the high-k/In 0.53 Ga 0.47 As interface. The TMA treatment on the In 0.53 Ga 0.47 As epitaxial layer is compatible with the conventional Si technology and provides promising opportunities for the development of state-of-the-art field-effect transistor technology using In x Ga 1 − x As epitaxial layers. [ABSTRACT FROM AUTHOR]