~l~.4~s Tunnel Diodes Grown on GaAs

We demonstrate, for the first time, functional metamorphic Iq,53G~.47As/lnaszA&,.& tunnel diodes on GaAs(100). Two types of tunnel diodes are presented. Type-A tunnel diodes show a peak current density of 50,OOO A/cmz, a peak to valley current ratio of 10 and af- of 2.5 GHz. Type-B tunnel diode shows a peak current density of 9,OOO A/cmz, and PVCR of 25. AFM images of the as grown tunnel diodes show a surface RMS roughness of approximately 35 A. TEM micrographs and x- ray diffraction of ~.~~G~.~~AS/I~O. ~~A~O.~~AS metamorphic test structures indicate smooth abrupt interfaces that are comparable to lattice matched structures.