Removing the transients electron trapping in P-N junction diode by using soft X-ray annealing method

摘要

This paper describes a transient phenomenon in the reverse current of P-N junctions giving rise to a hump at a specific reverse bias. P-N diode as been fabricated by a deep boron ion implantation (120 keV) and a junction depth around 4 um is expected. Ion implantation can cause defect in silicon substrate even if the device was cured by annealing process, the defect or its effect is still remained. I-V characteristic has been acquired from -10 V to 0 V in temperature variation of 30-80℃. At the specific condition of -3 V, 80℃ humps occurred on the curve and when the device was exposed to X-ray at energy of 40, 55 and 70 keV. The humps were then shifted toward 0 V. Activation energy has been calculated in order to give an insight into the device characteristics. It revealed the presence of a non-uniform density of electron traps corresponding to a broad range of energy levels from about 0.65-0.67 eV above the intrinsic band. This report shows an interesting phenomenon of the deep P-N junction diode modified by X-ray irradiation.