Bulk unipolar diodes formed in GaAs by ion implantation

In an attempt to emulate epitaxially manufactured semiconductor multilayers for microwave device applications, we have produced a camel diode structur e in GaAs for the first time, using the tail of a Mg implant into a molecul ar beam epitaxially grown n(+)-n -n(+) structure. Using a range of ion ener gies and doses, samples are observed to exhibit bulk unipolar diode charact eristics. With low dose and energy, a diode with barrier height of similar to 0.8 V and ideality factor similar to 1.25 is achieved. 'Punch through' d iode characteristics are obtained at high ion dose and energy. some with kn ee voltages in excess of 7 V. (C) 1999 Elsevier Science B.V. All rights res erved.