High performance n+/p and p+/n germanium diodes at low-temperature activation annealing
In this work we demonstrate the fabrication and characterization of high performance junction diodes using annealing temperatures within the temperature range of 300350C. The low temperature dopant activation was assisted by a 50nm platinum layer which transforms into platinum germanide during annealing. The fabricated diodes exhibited high forward currents, in excess of 400A/cm2 at ?|0.7|V for both p+/n and n+/p diodes, with forward to reverse ratio IF/IR greater than 104. Best results for the n+/p junctions were obtained at the lower annealing temperature of 300C. These characteristics compare favorably with the results of either conventional or with Ni or Co assisted dopant activation annealing. The low-temperature annealing in combination with the high forward currents at low bias makes this method suitable for high performance/low operating power applications, utilizing thus high mobility germanium substrates.
germanium junction diodes platinum germanide low temperature phosphorus activation