Comparison of hafnium oxide films grown by atomic layer deposition from iodide and chloride precursors

• Published in: Thin solid films 2002-09, Vol.416 (1), p.72-79
• Main Authors: Kukli, Kaupo, Ritala, Mikko, Sajavaara, Timo, Keinonen, Juhani, Leskelä, Markku
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Crystallization; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Elements, oxides, nitrides, borides, carbides, chalcogenides, etc; Exact sciences and technology; Materials science; Metal-oxide-semiconductor structure; Methods of deposition of films and coatings; film growth and epitaxy; Oxides; Physics
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(02)00612-0

Stoichiometric HfO 2 films were atomic layer deposited from HfI 4 and HfCl 4 at 300 °C on p-Si(1 0 0) substrates. Water was in both cases used as an oxygen precursor. The films consisted dominantly of monoclinic HfO 2 phase. Additional tetragonal HfO 2 could be detected only in the films grown from HfCl 4. Effective permittivities were frequency-independent and varied in the range of 12–14, without clear dependence on the precursor used. Oxide rechargeable trap densities were relatively high for the films grown from HfCl 4. The films grown from HfI 4 were more resistant against breakdown. The films grown from either precursor contained 0.4 at.% of halide residues and 1.0–1.5 at.% hydrogen. Annealing in forming gas at 400 °C did not affect the film composition. The growth rate was somewhat more stable in the HfI 4 based process.