Wide-bandgap semiconductor layer characterization

A method of characterizing a compound semiconductor material, comprising;

• providing a substrate including a layer stack of a conductive material layer, a dielectric material layer, and a compound semiconductor material layer;
• disposing a tip of a mercury probe on a top surface of the compound semiconductor material layer;
• generating a set of multiple alternating-current (AC) capacitance curves of the layer stack at multiple values of a direct-current (DC) bias voltage across the conductive material layer and the compound semiconductor material layer for different values of frequencies for a sinusoidal alternating-current (AC) perturbation voltage;
• and
• extracting a material property of the compound semiconductor material layer from profiles of the set of multiple AC capacitance curves as a function of the DC bias voltage.

A method of characterizing a compound semiconductor material, comprising;

• depositing a dielectric metal oxide layer over a doped silicon substrate;
• depositing a compound semiconductor material layer on the dielectric metal oxide layer, whereby a capacitive structure including a vertical stack of a conductive material layer, the dielectric metal oxide layer, and the compound semiconductor material layer is formed;
• disposing a tip of a mercury probe on a top surface of the compound semiconductor material layer;
• measuring an alternating-current (AC) capacitance as a function of a variable direct-current (DC) bias voltage by applying a combination of the variable DC bias voltage and an alternating-current (AC) perturbation voltage across the mercury probe and the doped silicon substrate at multiple values of the variable DC bias voltage;
• and
• determining a charge carrier concentration within the compound semiconductor material layer based on a profile of the AC capacitance as the function of the variable DC bias voltage.