IMPROVING THE OHMIC PROPERTIES OF Au/Ni-Mg/p-GaN CONTACTS BY ADDING SWCNT METALLIZATION INTERLAYER BETWEEN METAL AND p-GaN LAYERS

We have examined electrical properties and concentration depth profiles of contact structures Au/Ni-Mg-(O)/SWCNT/pGaN and Au/Ni-Mg-O/p-GaN, thus with and without an interlaying layer of single-walled carbon nanotubes (SWCNT). The metallization layers were deposited on p-GaN by DC reactive magnetron sputtering in an atmosphere with and without a low concentration of oxygen (cca 0.2 at%). The contacts were annealed in N2. We have found that the structure containing the SWCNT interlayer exhibits lower values of contact resistivity in comparison with an otherwise identical contact without the SWCNT interlayer. K e y w o r d s: p-GaN, Au/Ni-Mg-O/p-GaN, Au/Ni-Mg-(O)/SWCNT/p-GaN, single-walled carbon nanotubes (SWCNT), ohmic contact, specific contact resistance, circular transmission line method (CTLM)