Microwave power transistor with double recess and its fabrication process

摘要

The transistor is formed in a substrate (1) and includes at least two active semiconductor layers (2). A contact layer (3) is etched to provide two hollows or recesses (24,25), between the source (15) and drain (16) metallisation. There is a barrier (32) is formed between the recesses, over 100nm in length. Pref. the barrier is sufficiently long for the space charge regions, formed under the recess, to remain separated with a drain source voltage of 9 volts, in the band 0 to 100 GHz. One recess, the gate recess, may be situated closer to source than drain and is contacted by the gate metallisation (30). The second recess, located between the gate and the first recess, may include a voltage divider between gate and drain.