Downscaling of defect-passivated Gd_2O_3 thin films on p-Si(001) wafers grown by H_2O-assisted atomic layer deposition

摘要

Crystalline thin films of Gd_2O_3 of varying thicknesses were grown on 2 inch p-Si(100) wafers by H_2O-assisted atomic layer deposition (ALD) using a homoleptic gadolinium tris-guanidinate precursor [Gd(~iPr-Me_2N-Guan)_3]. The Gd_2O_3 layers grown at 225 ℃ were polycrystalline with columnar growth morphology. The as-grown films were electrically characterized as a metal oxide semiconductor (MOS) capacitor and exhibited instability in the flat-band voltage. Upon subjection to post-deposition defect-passivation treatment, they exhibited promising electrical characteristics. More importantly, the vertical downscaling of Gd_2O_3 thin films through the H_2O-assisted ALD process could be realized through the capacitance equivalent thickness versus physical thickness studies.