Observation of pn-junction depth in Mg₂Si diodes fabricated by short period thermal annealing

Abstract

We have fabricated Mg2Si pn-junction diodes by short-period (30 sec and 1 min) annealing between 400 ℃ and 480 ℃ and evaluated the pn-junction depth by EBIC and VC observations. The pn-junction depth of approximately 6 and 30 µm was formed for the annealing conditions of 400 ℃, 30sec and 480 ℃, 1min, respectively. By comparing the Ag depth profiles determined by SIMS, we estimated the activation ratio at the pn-junction of approximately 8 and 10 % for annealing at 450 ℃ and 480 ℃, respectively. All diodes showed clear rectifying behavior in J-V characteristic and the spectral photosensitivity below approximately 1.8 µm under zero bias condition.