present inventors believe that the phenomenon of the increased leakage current is affected in part by the quality of silicon dioxide formed on the substrate the interface state of silicon and silicon dioxide and mobile ions the pevcd oxide grown in a plasma environment provides more positive charge therefore these charges provide a counter balance during htrb and humidity tests providing the device with more consistent characteristics in one embodiment the diode 200 may be a fast recovery diode in which case platinum is provided in the substrate the platinum dopants are provided within the substrate typically between the step 8 photomask for contact opening and step 9 metallization above alternatively the substrate may be doped with gold au fig3 illustrates a diode 300 designed for high blocking voltage i e above 400v the diode 300 includes an n u2212 region 301 and n substrate 302 an emitter region 303 is formed on an upper portion of the n u2212 region 301 an anode 306 contacts the emitter region 303 a plurality of guard rings 311 surrounding the emitter region alternatively or in combination one or more field plates 307 may be provided an n region 304 or channel stopper is provided at an edge of the n u2212 region 301 a first passivation layer 308 covers the surface between the emitter region 303 and the n region 304 the first passivation layer is made of thermally grown oxide as with the diode 100 a second passivation layer 309 is formed on.