Multiparameter Admittance Spectroscopy as a Diagnostic Tool for Interface States at Oxide/Semiconductor Interfaces

Multiparameter admittance spectroscopy (MPAS) measurements have been performed on Al/HfO_2/SiO_x/Si structures before and after postmetallization annealing. Contour plots of conductance data as a function of the logarithm of inverted signal frequency and applied voltage as obtained by MPAS are compared with standard capacitance versus voltage ( C-V) data demonstrating the advantage of MPAS as a diagnostic tool. MPAS reveals more detailed properties of oxide/semiconductor interface states and renders measured data for better perceptiveness.