Electrical Methods for Characterizing Directly Bonded Silicon/Silicon Interfaces

Abstract

Measurement methods for characterizing the electrical properties of directly bonded Si/Si n-type/n-type or p-type/p-type interfaces are presented. The density of interface states in the bandgap of the semiconductor and the density of interface charge at the bonded interface are determined from measurements of current and capacitance vs applied voltage. The density of interface charge is thus obtained from two different measurements. The two measurement methods are compared and the limitations of the methods are discussed. Also, a high density of interface states at the bonded interface gives rise to a current transient when a voltage step is applied. This can be used as a qualitative estimate of the interface properties.