A MOSFET fabrication process comprises nitridation of the dielectric silicon interface so that silicon-dangling bonds are connected with nitrogen atoms creating silicon—nitrogen bonds, which are stronger than silicon-hydrogen bonds. A tunnel dielectric is formed on the substrate. A nitride layer is then formed over the tunnel dielectric layer. The top of the nitride layer is then converted to an oxide and the interface between the substrate and the tunnel dielectric is nitrided simultaneously with conversion of the nitride layer to oxide.