Correlation between structure and properties of Er2O3 nanocrystalline thin films

Er2O3 thin films have been deposited by low-pressure metalorganic chemical vapor deposition (MOCVD) also plasma assisted (RP-MOCVD), using tris(isopropylcyclopentadienyl)erbium and O-2 on Si(100), Si(111) and corning glass substrates. The RP-MOCVD approach produced highly (100)-oriented, dense and mechanically stable Er2O3 films with columnar structure, while films with (111) texture are deposited by MOCVD. A high refractive index of 2.1 at 589.3 nm comparable to that of bulk single crystalline Er2O3, a high transparency in the vis-near UV range and an optical band-gap of 6.5 eV have been found, which make Er2O3 interesting as antireflective and protective coating. A static dielectric constant k similar to 12, a density of interface traps as low as 4.2 x 1010 cm(2) eV(-1), for 5-10 nm thick Er2O3 layers grown on Si(100), render the present Er2O3 films interesting also as high-k dielectric in CMOS devices. (C) 2008 Elsevier B.V. All rights reserved.