Texas Instruments Incorporated
HEMT having conduction barrier between drain fingertip and source

Abstract:

A High Electron Mobility Transistor (HEMT) includes an active layer on a substrate, and a Group IIIA-N barrier layer on the active layer. An isolation region is through the barrier layer to provide at least one isolated active area including the barrier layer on the active layer. A gate is over the barrier layer. A drain includes at least one drain finger including a fingertip having a drain contact extending into the barrier layer to contact to the active layer and a source having a source contact extending into the barrier layer to contact to the active layer. The source forms a loop that encircles the drain. The isolation region includes a portion positioned between the source and drain contact so that there is a conduction barrier in a length direction between the drain contact of the fingertip and the source.