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3 stacks la12/6/2023 A higher D it of sample S1 than S2 can be attributed to the more recombination of dangling bonds at the high- k/Si interface for a higher annealing temperature. Where G max is the maximum value of conductance, and C c is the corresponding capacitance of the gate voltage at which the G max is obtained. C1s peak from adventitious carbon at 284.6 eV was used as an internal energy reference during the analysis. X-ray photoelectron spectroscopy (XPS) was used to examine the bonding structures and chemical quantitative composition of the films. In the end, the electrical properties including capacitance-voltage ( C- V), conductance-voltage ( G- V), and leakage current-voltage ( I- V) characteristics were evaluated using an Agilent B1500A semiconductor parameter analyzer at the frequency of 100 kHz. A metal electrode with a diameter of 300 μm was fabricated by depositing 150 nm Al by the electron-beam evaporation through a shadow mask. The rapid thermal annealing (RTA) process was carried out at 600 and 800 ☌ in N 2 ambient for 1 min after the deposition. Besides, ultra-high purity nitrogen (N 2, 99.999%) was employed as purge gas and carrier. La(i-PrCp) 3 and trinethyluminium (TMA) were used as precursors of La and Al, and O 3 was used as oxidant. Then La 2O 3/Al 2O 3 high- k stacks were deposited on Si wafers by ALD reactor (Picosun R-150, Espoo, Finland) in 300 ☌. P-type Si (100) wafers with resistivity of 3–8 Ω cm were dipped in deionized water and diluted HF for 3 min, respectively, to remove the native oxide before deposition. After the deposition of metal gate, the interfacial issues and electrical properties of the fabricated MIS structures were studied. In this paper, multilayer La 2O 3/Al 2O 3 stacks and LaAlO 3 dielectric film were prepared by ALD reactor, and then, post-deposition annealing (PDA) was carried out at different temperatures. However, the electrical property difference between the La 2O 3/Al 2O 3 dielectric stacks and LaAlO 3 have not been fully studied. And compared with La 2O 3 and Al 2O 3 dielectric stacks (ALO or LAO structure), the lanthanum aluminate (LaAlO 3) meets the thermal processing requirement better, since the added Al 2O 3 greatly improves the chemical stability and crystallization temperature. Researchers also revealed that the ultra-thin 0.5-nm Al 2O 3 inserted layer under the 4 nm LaAlO 3 can reduce the EOT to 1.2 nm with optimized interface trap density. Lee found that the hydration of La 2O 3 can be blocked by the Al 2O 3 in Al 2O 3/La 2O 3/Si (ALO structure) after the annealing treatment at 700 ☌. Srikant Jayanti pointed out that significant improvement about charge trapping and leakage characteristics was obtained by using a La 2O 3 interface scavenging layer for Al 2O 3 interpoly dielectric. The electrical properties of La 2O 3 and Al 2O 3 dielectric stacks have been studied by many researchers. Simultaneously, the accompanying problems also draw great attentions. Among them, La 2O 3 is regarded as a promising candidate due to the high dielectric constant ( k ~ 27) and large band gap. Lanthanum oxide (La 2O 3), aluminum oxide (Al 2O 3), yttrium oxide (Y 2O 3), hafnium oxide (HfO 2), and zirconium oxides (ZrO 2) have been tried to use as alternative gate dielectric materials. With the continuous development of integrated circuit, high- k materials have been extensively studied to substitute traditional SiO 2 gate dielectrics in CMOS devices as a solution for the saturation of the leakage current and power consumption. We also noticed that a better breakdown behavior for multilayer La 2O 3/Al 2O 3 stack is achieved after annealing at a higher temperature for its less defects. In addition, a significant improvement about leakage current property is observed for LaAlO 3 dielectric film compared with multilayer La 2O 3/Al 2O 3 stacks at the same annealing condition. For LaAlO 3 dielectric film, compared with multilayer La 2O 3/Al 2O 3 dielectric stacks, a clear promotion of trapped charges density ( N ot) and a degradation of interface trap density ( D it) can be obtained simultaneously. A clear promotion of capacitance properties is observed for multilayer La 2O 3/Al 2O 3 stacks after post-deposition annealing (PDA) at 800 ☌ compared with PDA at 600 ☌, which indicated the recombination of defects and dangling bonds performs better at the high- k/Si substrate interface for a higher annealing temperature. The capacitance and leakage current properties of multilayer La 2O 3/Al 2O 3 dielectric stacks and LaAlO 3 dielectric film are investigated in this paper.
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