Surface charge effects on the resistivity and Hall coefficient of thin silicon-on-sapphire films

Abstract

Surface depletion due to surface charges was observed on thin films of silicon on sapphire spinel. A gated metal-oxide-semiconductor (MOS) Hall bar structure with a deposited silicon dioxide dielectric was used to determine the true average properties of the films. It is shown that these charges can cause very serious errors in the interpretation of resistivity, Hall coefficient, and mobility data. A decreasing mobility into the films is directly observed.