We investigated the effects of quantum confinement in determining the interface traps (Dit) and border traps (Nbt) of ALD deposited Al2O3 with temperature variations onto InxGa1-xAs on a 300-mm Si (001) substrate. We also analysed the impact of these effects on the total gate capacitance of high- $k$ /Si and high- $k$ /InxGa1-xAs structures using 1D Poisson-Schrodinger solver simulation tool (Nextnano). While quantum confinement has no or very little impact on the gate capacitance of high- $k$ /Si structure, it has a considerably high amount of impact on the high- $k$ /InxGa1-xAs structures and substantially lowers the total gate capacitance. To reflect the actual thickness between the insulator-semiconductor interface and charge centroid, capacitance-equivalent-thickness was used to reflect the effects of quantum confinement in the InxGa1-xAs layer. The Dit and Nbt values extracted using capacitance-equivalent-thickness were observed to be around 10% and 25%, respectively, higher than the values of extraction with equivalent-oxide-thickness.
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