High-power parallel-array IMPATT diodes

Fabrication of parallel arrays of silicon IMPATT diodes in which the arrays are formed in a single diode chip is described. The technique includes formation of an integral heatsink for the diode arrays during wafer processing. For a given total active device area, the use of a parallel array of smaller diodes, rather than one large diode, allows a significant reduction in thermal impedance and consequently larger power-dissipation capability. The contribution shown in the letter is the ease and economy with which parallel arrays on an integral heatsink can be fabricated and handled as a single entity. In a diode operated at 6.4 GHz, 3.5 W of c.w. output power has been achieved with a room-temperature copper heatsink and a junction temperature of about 280°C.