A large-scale quantum computer based on the electron/hole spin degree of freedom in Metal Oxide Semiconductor (MOS) silicon quantum dots relies on building reliable and reproducible quantum dot arrays [1]. Hence, it is of great importance to fabricate MOS stacks with a high quality silicon-oxide interface. Therefore, in this work, we investigate the $Si-SiO_2$ interface in two-dimensional hole and electron gases in silicon MOSFET Hall bars and capacitance structures. We explore how diffusion barriers reduce oxygen scavenging and characterize the influence of $SiO_2$ thickness on percolation density $n_p$, peak mobility $\mu_{peak}$ and density of interface traps $D_{it}$. Furthermore, we show the effect of annealing on the characteristic parameters.
[1] Vandersypen, Lieven MK, and Mark A. Eriksson. "Quantum computing with semiconductor spins." Physics Today 72 (2019): 8-38.