RF Dielectric Loss Due to MOCVD Aluminum Nitride on High Resistivity Silicon

The contribution of high-frequency losses from an aluminum nitride (AlN) layer on high resistivity silicon (Si) is reported. The AlN, deposited on silicon via metalorganic chemical vapor phase deposition as a nucleation layer for subsequent gallium nitride growth, is analyzed for its contribution to the dielectric losses from 6-20 GHz and differentiated from the loss due to the p-type layer formed in the silicon substrate. It is found that AlN is a stronger contributor to overall dielectric loss in comparison with the silicon substrate.