Microwave Effects on Metal-Semiconductor Contact of Heavily Nitrogen-Implanted Silicon

Nitrogen-implanted (N-implanted) silicon was employed to examine the microwave effects because of the dipole-like defects formed by implanted ions. The defects spread through an insulator-to-conductor transition depending on annealing conditions. Rapid thermal annealing (RTA) and microwave annealing (MWA) are investigated. MWA unexpectedly improved insulating ability of implanted nitrogen impurities in silicon, while RTA made metal-semiconductor (MS) contact ohmic-like. The sheet resistance ( $\textit{R}_{\text{s}}\text{)}$ , Hall measurement, $\textit{I}$ - $\textit{V}$ curve of metal-semiconductor-metal (MSM) junction, Fourier-transform infrared spectroscopy (FTIR), grazing incidence X-ray diffraction (GIXRD), and secondary ion mass spectrometry (SIMS) were used to characterize the microwave effects in electrical and IR spectrum. The results showed that the MS contact behavior of the titanium/silicon junction could be tuned, which is ideal for fabricating selector-like devices due to the similar MSM structure. Enhancement in turn-on voltage of MSM back-to-back Schottky diode implied that MWA could be a potential technology for device optimization.