Significant improvement in characteristics of SOS/MOSFETs by CW-Ar laser-recrystallization

Generally in SOS (silicon on sapphire) films, the density of Si defects such as twins and stacking faults is quite high, especially near the Si/sapphire interface, mainly due to the lattice mismatch between Si and sapphire. This leads to inferior electrical properties compared to their bulk counterparts. Although it has been reported that the characteristics of SOS devices can be improved by a pulse laser irradiation, the quality of laser-irradiated SOS films has not been investigated in detail. It is demonstrated that the SOS films have been significantly improved by CW-Ar laser recrystallization, resulting in almost defect-free SOS films. The defect-free SOS films reduce back-channel leakage currents in both n- and p-MOSFETs, while at the same time improving carrier mobilities by 30-50%.<
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