Structure and electrical properties of pure and yttrium-doped HfO2 films by chemical solution deposition through layer by layer crystallization process

Publication date: 15 April 2017
Source:Materials & Design, Volume 120
Author(s): Hailong Liang, Jin Xu, Dayu Zhou, Xuexia Wang, Xiaohua Liu, Shichao Chu, Xiaoying Liu
Pure and yttrium doped HfO2 thin films were fabricated on Si (100) substrates by chemical solution deposition through a layer by layer crystallization process. We systematically investigated the effects of thickness and Y doped concentration on structure and electrical properties of the HfO2 films. Results revealed that 4nm thick undoped HfO2 was crystallized into a t/c-phase due to the surface energy effect, and this higher symmetry phase could be retained up to a film thickness of 16nm through the layer by layer crystallization process. This layer by layer crystallization process also required less Y doping to stabilize t/c-HfO2 in thick films. The films showed a high dielectric constant about 42, low leakage current density of about 10⁻⁷A/cm² (at 1MV/cm) and a breakdown field up to 5MV/cm. Considering the cost-effective deposition technique and good electrical properties, these films would be suitable for insulator applications in microelectronic devices.

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