Retardation of Impatt diode aging by use of tungsten in the electrodes

Stable rf performance of Pt-GaAs Schottky barrier Impatt diodes may be affected by the platinum reacting with the GaAs, thereby producing junction movement during aging. This paper presents data which monitor the junction movement and then demonstrates the effect of using a tungsten layer to limit the Pt-GaAs reaction. The tungsten layer does not alter the rf performance. The platinum ’’chew in ’’ is controlled and the tendency of the reverse I-V characteristics to soften with age is slowed.