Selective-Area Growth of Vertical InGaAs/GaSb Core-Shell Nanowires on Silicon and Dual Switching Properties

The epitaxy of the Sb-related quantum well structure has been extensively investigated. However, the GaSb facet growth in selective-area growth (SAG) and GaSb nanostructures has not been investigated because of the surface diffusion complexity and surfactant effect of Sb adatoms. Here, the growth morphology of GaSb structures in SAG was characterized via InGaAs nanowires (NWs) monolithically grown on a Si template. SAG of GaSb using NWs included four growth processes: lateral-over growth along the ⟨1̅10⟩ directions, axial growth along the vertical ⟨111⟩ B direction, downward step-flow growth, and desorption of Sb adatoms from the NW sidewalls. The dominant processes could be controlled by the GaSb growth temperature and could form smooth GaSb shell layers. The vertical diode of InGaAs/GaSb core-shell NWs on Si exhibited moderate rectifying properties because of the InGaAs/GaSb heterojunction band alignment. In the vertical transistor application, specific dual-carrier modulation behaviors, such as p-channel field-effect transistor and n-channel tunnel field-effect transistor modes, occurred in the same transistor architecture. This was because the carrier transport changed with respect to the bias polarity. This specific transistor behavior in the InGaAs/GaSb core-shell NW on Si would expand possibilities for integrated circuit technologies using only a single transistor structure.