In situ Ga+ focused ion beam definition of high current density resonant tunneling diodes

Abstract

Articles you may be interested inSystematic studies of SiGe ∕ Si islands nucleated via separate in situ or ex situ Ga + focused ion beam-guided growth techniques Annealing of defect density and excess currents in Si-based tunnel diodes grown by low-temperature molecularbeam epitaxy J. Appl. Phys. 96, 747 (2004); 10.1063/1.1755436 151 kA/cm 2 peak current densities in Si/SiGe resonant interband tunneling diodes for high-power mixed-signal applications Appl.Results are presented for small embedded tunnel area ͑Ͻ100 m 2 ͒, high current density resonant tunneling diodes ͑RTDs͒ fabricated using a combination of in situ Ga ϩ focused ion beam ͑FIB͒ implantation with molecular beam epitaxial regrowth. In such devices, the tunnel current path is defined by the highly resistive disordered lattice ͑from the Ga ϩ FIB lithography͒ and confined to the undamaged regions. Postgrowth optical processing is then straightforward to perform. The success of this novel technique is demonstrated by systematically varying the wet etched mesa dimensions, the FIB defined tunneling area, and the ion implantation dose, with experimental data discussed in each case. Furthermore, it is shown that this approach allows a common and easy connection to an array of individual RTDs, which is of considerable interest for microwave and millimeter wave power combining applications.