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

Publication date: 31 January 2018
Source:Thin Solid Films, Volume 646
Author(s): Soo Bin Kim, Seung Hyun Lee, Hae Jun Jung, Myung Su Seo, Sung Min Kim, Soonil Lee, Ji-Yong Park, Tae Joo Park, Hae-Yong Jeong, Dong-Hwan Jun, Kyung Ho Park, Won-Kyu Park, Sang Woon Lee
A development of high quality InxGa1−xAs 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 In0.53Ga0.47As 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 (HfO2/Al2O3 bilayer). The high-k films were grown on In0.53Ga0.47As epitaxial layers by atomic layer deposition (ALD). The interface between the high-k bilayer and the In0.53Ga0.47As epitaxial layer was analyzed depending on a surface treatment of the In0.53Ga0.47As epitaxial layer, and the surface treatment of the In0.53Ga0.47As epitaxial layer using trimethylaluminum (TMA) enhanced the electrical performances of Pt/high-k film/In0.53Ga0.47As capacitors. The TMA was introduced on the In0.53Ga0.47As epitaxial layer in the ALD chamber, which reduced native oxides (such as gallium and arsenic oxides) of the In0.53Ga0.47As surface and minimized a formation of interfacial layers between the high-k film and In0.53Ga0.47As layer. A capacitance equivalent thickness (CET) of ~1.5nm was achieved with a low leakage current (~10⁻⁴ A/cm² at 1V). A CET as low as ~1.3nm and a capacitance >2.5μF/cm² was attained by optimizing the high-k/In0.53Ga0.47As interface. The TMA treatment on the In0.53Ga0.47As 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 InxGa1−xAs epitaxial layers.