Electrostatic force microscopy study about the hole trap in thin nitride/oxide/semiconductor structure

The stoichiometric nitride (SiN1.33) and Si-rich nitride (SiN1.1) are characterized by the conductive atomic force microscopy (c-AFM) and electrostatic force microscopy (EFM). Only in SiN1.1, EFM is capable of resolving the domains of positive charges with similar to 10 nm radius. However, the phase dependence on the bias elsewhere is similar to that of SiN1.33, supporting electron tunneling. The following c-AFM image also exhibits that the local leakage is found exclusively on SiN1.1. We suggest that the hole injection which breaks the Si - Si bond occur in the structure with the voltage, increasing the overall conductance.