Self-Aligned GaAs Power Mesfet's for X-Band

More than 1 W att output power has been achieved at 10 GHz with GaAs MESFETs which are produced using a self-alignment technique. Principal improvements in performances are due to an increased maximum operating voltage of the Schottky diodes. This is obtained with a graded doping profile and there is in addition an improved linearity of the MESFET's. A technique of interconnection of the sources by metallic columns through the substrate has been used and a similar structure using N+ columns instead of the metal will be proposed. These techniques simplify the mounting of the transistor and reduces the parasitic inductances in series with the sources.