A silicon carbide self-aligned and ion implanted static induction transistor (SAI-SIT) for 150 watt S-Band operation

The Static Induction Transistor (SIT) has proven itself as an appropriate device to take full advantage of the high breakdown field strength, thermal conductivity, and electron velocity characteristics of silicon carbide. Microwave SITs using metal Schottky gates have been fabricated by several groups. For example, L-Band Schottky SITs with over 900 W of output power and 60% efficiency have been demonstrated. However, in order to achieve power gain at 3.0 GHz, more stringent geometric and alignment tolerances are required. At the same time, reaching 150 Watts at S-Band requires that the tight dimensional constraints be maintained across the expanse of large devices. A novel type of Static Induction Transistor fabricated in 4H-silicon carbide, described here for the first time, relies on self-aligned oxide isolation spacers between the source and an implanted gate.