Characteristics of ultrashallow hetero indium-gallium-zinc-oxide/germanium junction

In this letter, we demonstrate an n-indium-gallium-zinc-oxide (IGZO)/i-germanium (Ge) heterojunction diode with an ultrashallow junction depth of \sim 37 nm. X-ray diffraction, atomic force microscopy, and secondary ion mass spectrometry analyses are performed to precisely investigate the n-IGZO and n-IGZO/i-Ge junctions. When the junction diodes are annealed at between 400 \circC and 600 \circC, a very high on-current density (\hbox180-320\ \hboxA/cm2), which is comparable to that of a Ti/i-Ge reference junction, is obtained. In particular, after the 600 \circC anneal, a fairly high on/off-current ratio (\hbox7 \times \hbox102) is also observed.