Effects of post-annealing on the microstructural and electrical properties of amorphous LaAlO _3 film grown on Si

摘要

10-nm-thick amorphous LaAlO _3 film was deposited on n-type Si (001) substrate at 600°C by magnetron sputtering and then annealed in N _2 ambience at 300°C for 2 min using a rapid thermal annealing furnace. Grazing incidence X-ray diffraction analyses indicated that the post-annealed LaAlO _3 film was still amorphous. The root-mean-square roughness of the post-annealed sample is a little smaller than that of the as-grown sample, which could stem from the densification of LaAlO _3 film after post-annealing. No obvious hysteretic behavior was observed in the capacitancevoltage measurement and the dielectric constant of LaAlO 3 film was estimated to be 16.7. Due to the deficiency of oxygen vacancy after post-annealing, the low leakage current density of the post-annealed film with EOT of 2.33 nm is about 5.52 × 10 ~(-5) A/cm ~2 at +1 MV/cm. Moreover, it is found that both the as-grown and post-annealed capacitors satisfy Ohmic conduction behavior at the whole positive measured electric fields.