Atomic Layer Deposition of Hafnium Dioxide Films Using Hafnium Bis(2-butanolate)bis(1-methoxy-2-methyl-2-propanolate) and Water

• Published in: Advanced materials (Weinheim) 2003-12, Vol.9 (6), p.315-320
• Main Authors: Kukli, K., Ritala, M., Leskelä, M., Sajavaara, T., Keinonen, J., Jones, A.C., Roberts, J.L.
• Format: Article
• Language: English
• Subjects: Atomic layer deposition; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Dielectric properties of solids and liquids; Dielectrics; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Hafnium dioxide; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Permittivity (dielectric function); Physics
• ISSN: 0948-1907; 0935-9648; 1521-3862
• DOI: 10.1002/cvde.200306263

HfO2 films were grown by atomic layer deposition (ALD) from a mononuclear Hf(OtBu)2(OCMe2CH2OMe)2 complex and H2O at temperatures in the range 275–400 °C on borosilicate glass and Si(100) substrates. The growth of the densest films was achieved at temperatures above 300 °C. The growth rate was influenced by the thermal decomposition of the Hf precursor. The as‐deposited films were oxides with an O:Hf ratio of 2.0 ± 0.2, although containing large amounts of impurities. Crystalline monoclinic films were grown at temperatures exceeding 325 °C, whereas at lower temperatures the films mostly remained amorphous. On the whole, the refractive index of the films varied between 1.95 and 2.00. The effective permittivities of the dielectrics in Al/HfO2/p‐Si(100) capacitor structures varied between 12 and 14, slightly increasing with growth temperature. HfO2 films are grown by ALD from a mononuclear Hf(OBut)2‐(OCMe2CH2OMe)2 complex and H2O at 273–400 °C on borosilicate glass and Si(100) substrates. The growth of the densest films is achieved at temperatures above 300 °C with refractive index between 1.95 and 2.00 and O/Hf ratio of 2.0 ± 0.2. Films deposited at temperatures above 325 °C are found to be monoclinic, whereas at lower temperatures the deposited films are amorphous. The effective permittivities of the dielectrics in a Al/HfO2/p‐Si(100) capacitor structure is found to vary between 12 and 14, slightly increasing with growth temperature.