Performance enhancement of n-channel inversion type InxGa1−xAs metal-oxide-semiconductor field effect transistor using ex situ deposited thin amorphous silicon layer

Significant enhancement in metal-oxide-semiconductor field effect transistor (MOSFET) transport characteristics is achieved with InxGa1−xAs (x=0.53, x=0.20) channel material using ex situ plasma enhanced chemical vapor deposited amorphous Si layer. InxGa1−xAs MOSFETs (L=2 μm, Vgs-Vt=2.0 V) with Si interlayer show a maximum drain current of 290 mA/mm (x=0.53) and 2 μA/mm (x=0.20), which are much higher compared to devices without a Si interlayer. However, charge pumping measurements show a lower average interface state density near the intrinsic Fermi level for devices without the silicon interlayer indicating that a reduction in the midgap interface state density is not responsible for the improved transport characteristics.