Epitaxial growth of yttrium-stabilized HfO2 high-k gate dielectric thin films on Si

Abstract

Epitaxial yttrium-stabilized HfO 2 thin films were deposited on p-type ͑100͒ Si substrates by pulsed laser deposition at a relatively lower substrate temperature of 550°C. Transmission electron microscopy observation revealed a fixed orientation relationship between the epitaxial film and Si; that is, (100)Si//(100)HfO 2 and ͓001͔Si//͓001͔HfO 2 . The film/Si interface is not atomically flat, suggesting possible interfacial reaction and diffusion. X-ray photoelectron spectrum analysis also revealed the interfacial reaction and diffusion evidenced by Hf silicate and Hf-Si bond formation at the interface. The epitaxial growth of the yttrium stabilized HfO 2 thin film on bare Si is via a direct growth mechanism without involving the reaction between Hf atoms and SiO 2 layer. High-frequency capacitance-voltage measurement on an as-grown 40-Å yttrium-stabilized HfO 2 epitaxial film yielded an effective dielectric constant of about 14 and equivalent oxide thickness to SiO 2 of 12 Å. The leakage current density is 7.0ϫ10 Ϫ2 A/cm 2 at 1 V gate bias voltage.

Electric characterization of HfO2 thin films prepared by chemical solution deposition

“…3 show the C-V behavior of a typical MOS device, with three distinct regimes of accumulation, inversion and depletion. A relative dielectric constant (K) of about 13.5 was obtained from the MOS structure with 65 nm HfO 2 film, which is comparable with the previous results obtained with HfO 2 films prepared by more complex techniques, e.g., K = 14 by pulsed laser deposition (PLD) [8], K = 10-12 by atomic layer deposition (ALD) [9], and K = 10-11 by ALD [10].…”

Low Leakage Current Transport and High Breakdown Strength of Pulsed Laser Deposited HfO2/SiC Metal-Insulator-Semiconductor Device Structures

“…23 The formation of SiO 2 seems to be dependent on the deposition process as observed in the ALD technique, where there is a distinct peak appearing at $103 eV. 24,25 The C-V measurements, as shown in Fig. 4, were carried out for the MIS devices in a frequency range of 10-400 MHz.…”

Improved interfacial properties of HfGdON gate dielectric Ge MOS capacitor by optimizing Gd content*

“…[24] Figure 4 demonstrates the core-level spectra of Hf 4f, and all of them are deconvoluted into two peaks of Hf 4f 5/2 and Hf 4f 7/2 , which are in accordance with spin-orbit splitting energy of about 1.7 eV. [25][26][27] From the above XPS results, it can be suggested that the HfGdON dielectric film is formed. By calculating the peak-area ratio of Gd 4d to Hf 4f for each of the three Gd-doped samples, their Gd content values [Gd/(Gd+Hf)] are obtained to be 13.16%, 29.86%, and 45.47%, respectively.…”