Structural and dielectric properties of Ti and Er co-doped HfO2 gate dielectrics grown by RF sputtering

This work reports on the structural and dielectric properties of high-k Ti and Er co-doped HfO2 (HfTiErOx) gate dielectrics deposited on Si(1 0 0) substrates by RF sputtering. Results indicate that the capacitance value of HfTiErOx gate dielectric at 100 °C substrate temperature is higher and exhibits a lower hysteresis voltage as well as interface trap density compared to HfO2, HfErOx and HfTiOx films at the same conditions in capacitance-voltage (C-V) curves. Furthermore, the structural, chemical compositions and photonics properties of these films have been explored by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Photo luminous (PL) measurements. The results are well attributed to crystalline HfTiErOx microstructure thus new chemical bonding of HfTiErO may exit. PL spectra of all the prepared samples exhibit peaks in range of ∼2.82 to ∼3.03 eV which is attributed to oxygen vacancies.

► HfTiErOx gate dielectrics were prepared by employing growth parameters on Si(1 0 0) using RF sputtering at 100 °C substrate temperature. ► XRD pattern confirms the crystalline structure and XPS results showed that HfTiErO chemical bond may be existed. ► C-V measurements reveal that improved flatband voltage shift, hysteresis voltage and interface-state density (Dit) in contrast of other samples.