Suppression of drain conductance frequency dispersion in InP-based HEMTs by eliminating hole accumulation

InP-based HEMTs are promising devices for large-capacity optical fiber communication systems. To enable higher bit rate systems, though, drain conductance (g/sub d/) frequency dispersion must be suppressed as it causes jitter, which reduces the size of eye pattern openings in integrated circuits. We propose a planar structure device to remarkably suppress g/sub d/ frequency dispersion by eliminating hole accumulation at the extrinsic source. The band-discontinuity between the source contact and the channel was eliminated by direct ohmic contact, which increased the flow of holes to the source contact.