文摘
The microstructure of Ti–GaSb junctions in samples annealed at 300°C, 400°C, 500°C, and 600°C in N2 atmosphere has been characterized using transmission electron microscopy in combination with energy-dispersive spectrometry, nanobeam electron diffraction, and selected-area diffraction patterns. Only Ga3Ti phase formed at the Ti/GaSb interface at annealing temperature of 400°C. Upon increasing the temperature to 500°C, in addition to Ga3Ti phase, Sb from GaSb diffused toward Ti and accumulated at the interface to form a Sb-rich layer. Moreover, three phases, namely TiSb(Ga), Sb2Ti, and Ga3Ti, formed simultaneously at the Ti/GaSb interface when the annealing temperature was increased to 600°C, causing a significant increase in the sheet resistance, RS, of the Ti–GaSb alloy. These results indicate that the annealing temperature of the Ti/GaSb structure should be maintained below 500°C for successful formation of low-resistance metal Ti/GaSb contacts in GaSb-based p-type metal–oxide–semiconductor field-effect transistors.
