ELECTRICAL CHARACTERIZATION OF BONDING INTERFACES

An overview is given on measurement techniques and results obtained for the characterization of bonded Si-Si, Si-SiO2, and SiO2-SiO2 interfaces. The electrical properties of Si-Si interfaces are similar to those of grain boundaries, which suggests a model where the current across the interface is limited by a potential barrier determined by charge carriers captured into electron states at the bonded interface. From current-voltage and capacitance-voltage measurements, the interface charge and its energy distribution can be determined. For bonded Si-SiO2 interfaces, energy distributions. of interface states are obtained by capacitance-voltage technique with midgap densities in the region at or above 5 x 10(10) eV-1 cm-2. Interfaces between two bonded SiO2 layers exhibit charge trapping phenomena.