Characterization of Sol–Gel Derived and Crystallized ZrO₂Thin Films

Abstract

LETTERSlosses. Assuming an average density of 2 X 10 13 cm 3 , T e = 8 eV and Tj= 15 eV, we estimate an MHD flow time enhanced by the mirror ratio of 200 /us [12] and an ideal multiple-mirror axial diffusive time of about 1 ms [ 1 ]. These have to be compared with radial losses due both to electron-ion collisions and higherorder ion-ion collisions, both enhanced by the nonuniform cross-section [13]. The classical radial losses alone are estimated to give a decay time of 100 /xs, which is about equal to that observed.

Characterization of Sol-Gel-Derived and Crystallized HfO2, ZrO2, ZrO2-Y2O3 Thin Films on Si(001) Wafers with High Dielectric Constant

“…XPS spectra of sol-gel-derived ZrO 2 thin films: (a) XPS Zr 3d spectrum and (b) XPS O 1s spectrum. Solid lines are the observed XPS spectra and dashed lines are for Zr 3d and O 1s spectra, which have two Gaussian peaks fitted by the nonlinear least-squares algorithm (Shimizu et al, 2009 …”

“…To clarify whether the small peaks (small protrusions) between 100 and 200 °C in the TPD curves were due to physisorbed H 2 O (mere adsorption of H 2 O) on the surface of the ZrO 2 thin films and/or chemisorbed Zr-OH in the bulk at the surface area (Figure 11), the following three experiments were carried out (Shimizu et al, 2009). First (process ), a sample immediately after firing at 350 °C for 30 min was measured by TPD until 350 °C and then (process ) successively measured by TPD again from room temperature to 350 °C; finally (process ), the sample was exposed to air for 59 h and then measured by TPD from room temperature to 700 °C.…”

“…TPD curves for processes (1), (2), and (3). In process (1), a sample immediately after firing at 350 °C for 30 min was measured by TPD until 350 °C, followed by process (2) in which the sample was successively measured by TPD again from room temperature to 350 °C; finally, process (3) in which the sample was exposed to air for 59 h and then measured by TPD from room temperature to 700 °C (Shimizu et al, 2009). until 350 °C in the first TPD measurement.…”

“…Sol-gel-derived ZrO 2 thin films fired in air at 350 and 450 °C on Si(001) wafers are reported to be amorphous and around 9-10 nm in thickness. Crystallization occurs first at 550 °C as amorphous/tetragonal (011), and finally at 700°C, the ZrO 2 film crystallizes into tetragonal (011)/monoclinic (11 1 ) and (111) structures (Shimizu et al, 2009). Electrical characteristics have been evaluated using capacitors with an Al/ZrO 2 and/or HfO 2 /Si sandwich structure.…”

“…The leakage current and dielectric constant of the films have been examined using current-voltage (I-V) and capacitance-voltage (C-V) methods. On the basis of C-V characteristics, the dielectric constant (relative permittivity: ε ZrO2 and ε HfO2 ) of sol-gel derived ZrO 2 and HfO 2 thin films fired in air were shown to be far higher than that of silicon dioxide (SiO 2 : 3.9) (Shimizu et al, 2009(Shimizu et al, , 2010. This chapter summarizes the characterizations of sol-gel-derived HfO 2 , ZrO 2 and ZrO 2 -Y 2 O 3 thin films on Si(001) wafers with the aim of showing their suitability as alternative gate insulator materials in advanced CMOS devices.…”