The sol–gel solution used ethanol as the solvent, and the molar ratio of the mixture for ZrCl4/SiCl4/TiCl4/ethanol was 1:1:1:1,000. After the sol–gel film was coated, a rapid

thermal annealing (RTA) process was conducted at 600°C for 60 s in an oxygen ambience. During the RTA process, a compound layer of metal-oxide-silicate containing titanium and zirconium was formed. A 10-nm blocking oxide film selleckchem and 200-nm amorphous Si film were then deposited subsequently. The blocking oxide was grown by plasma-enhanced chemical vapor deposition, using silane (SiH4) and nitrous oxide (N2O) as the precursors to form a 10-nm SiO2. The 200-nm amorphous Si film, used as the gate electrode, was deposited in the same system using the

SiH4 precursor. After gate patterning, As+ ions were implanted at 20 keV with a dosage of 5E15 cm−2 and annealed at 600°C for 24 h to define the source and drain. Finally, a NVP-HSP990 mw 500-nm tetraethyl orthosilicate oxide was formed as the passivation layer, AZD9291 chemical structure and the subsequent processes were used to fabricate the memory. The schematic structure of the Ti x Zr y Si z O flash memory is shown in Figure 1. The channel width and length of the memory were 10 and 0.35 μm, respectively. Figure 1 Schematic structure of the Ti x Zr y Si z O flash memory. The Ti x Zr y Si z O thin film was used here as the charge trapping layer. Results and discussion Figure 2 shows the cross-sectional transmission electron microscopy (TEM) image of the sol–gel-derived Ti x Zr y Si z O film annealed at 600°C. A continuous and smooth film of 2 nm in thickness was observed, suggesting that no obvious film morphology occurred in the sample annealed at 600°C. The composition Ureohydrolase of the sol–gel-derived Ti x Zr y Si z O film was analyzed by X-ray photoelectron spectroscopy (XPS), and the Si 2p, O 1s, Zr 3d, and Ti 2p spectra of the Ti x Zr y Si z O film are shown in Figure 3a,b,c,d, respectively. The peaks in the figures indicate the component formation of the Ti x Zr y Si z O film. Figure

2 Cross-sectional TEM image of the sol–gel-derived Ti x Zr y Si z O film. The thickness of the Ti x Zr y Si z O film is calculated to be 2 nm after 600°C annealing. Figure 3 XPS spectra of the sol–gel-derived Ti x Zr y Si z O film. (a) Si 2p, (b) O 1s, (c) Zr 3d, and (d) Ti 2p spectra. Figure 4 shows the I d-V g curves of the Ti x Zr y Si z O memory in fresh, program, and erase states. The measured condition for the program operation was V g = −8 V, V d = 8 V, and 1 ms, and that for the erase operation was V g = 8 V, V d = 8 V, and 1 ms. The characteristic curve shows a 3.7-V leftward shift after the program operation and then a shift back to the original, fresh state after the erase operation.