Method of making schottky diode with guard ring

A method of fabricating a Schottky diode on a semiconductor layer comprising:

• forming a field insulator in the semiconductor layer;
• forming an insulator layer over the semiconductor layer and adjacent the field insulator;
• forming a resistive layer over a portion of the field insulator and over a portion of the insulator layer;
• forming a guard ring in the semiconductor layer;
• forming a patterned insulator over the insulator layer, over the field insulator, and over the resistive layer;
• removing a portion of the insulator layer;
• forming a first conductive contact over a surface of the semiconductor layer where the portion of the insulator layer has been removed and over a first portion of the patterned insulator to form a Schottky barrier at the junction of the first conductive contact and the semiconductor layer, the guard ring being adjacent the Schottky barrier and separated from the first conductive contact by the patterned insulator;
• forming a second conductive contact over the patterned insulator and in electrical contact with a first portion of the resistive layer;
• forming a conductive extension connecting the second conductive contact to the first conductive contact;
• and
• forming a third conductive contact over the insulator and in electrical contact with a second portion of the resistive layer and in electrical contact with the guard ring.