Properties of high κ gate dielectrics Gd2O3 and Y2O3 for Si

Abstract

We present the materials growth and properties of both epitaxial and amorphous films of Gd2O3 (κ=14) and Y2O3 (κ=18) as the alternative gate dielectrics for Si. The rare earth oxide films were prepared by ultrahigh vacuum vapor deposition from an oxide source. The use of vicinal Si (100) substrates is key to the growth of (110) oriented, single domain films in the Mn2O3 structure. Compared to SiO2 gate oxide, the crystalline Gd2O3 and Y2O3 oxide films show a reduction of electrical leakage at 1 V by four orders of magnitude over an equivalent oxide thickness range of 10–20 Å. The leakage of amorphous Y2O3 films is about six orders of magnitude better than SiO2 due to a smooth morphology and abrupt interface with Si. The absence of SiO2 segregation at the dielectric/Si interface is established from infrared absorption spectroscopy and scanning transmission electron microscopy. The amorphous Gd2O3 and Y2O3 films withstand the high temperature anneals to 850 °C and remain electrically and chemically intact.

Surface termination and hydrogen bubble adhesion on Si(100) surfaces during anisotropic dissolution in aqueous KOH

“…The dissolution of Si(1 0 0) in aqueous KOH is a complex process in which two mechanisms are involved [23][24][25]. In the chemical mechanism silicon is dissolved in a hydroxide-catalysed, thermally activated chemical reaction, in which water is the reactive species.…”

Deposition temperature effect of the memory characteristics for Al₂O₃/Y₂O₃/SiO₂ (AYO) multi-stacked film

“…The cross-sectional structure of the AYO multi-stacked film deposited at 500°C is shown in Fig. 2 11) thus it was hard to crystallize. In a thin film clamped by a substrate, volume expansion is restricted and nucleation may be completely suppressed.…”

“…In the current densityvoltage (JV) measurements, the AYO multilayer deposited at 500, 550°C had better leakage current (a) (b) (c) Journal of the Ceramic Society of Japan 120 [11] 525-529 2012…”

LaTiON/LaON as band-engineered charge-trapping layer for nonvolatile memory applications

“…In addition, the nitrogen content in the LaTiON and LaON films was determined to be 3.3 % and 2.7 %, respectively, by XPS analysis. Then 14-nm Al 2 O 3 as blocking layer was deposited by means of atomic layer deposition using trimethylaluminum (Al(CH 3 ) 3 ) and H 2 O as precursors at 300°C. Next, the samples went through a post-deposition annealing (PDA) in N 2 ambient at 850°C for 30 s. Finally, Al was evaporated and patterned as gate electrode, followed by a forming-gas annealing at 300°C for 20 min.…”

“…Recently, extensive researches have been carried out to study high-k dielectrics instead of Si 3 N 4 for further scaling down the device dimensions and improving its charge-trapping efficiency. Among various high-k dielectrics, rare-earth metal oxides, such as La 2 O 3 (k ∼ 25) [1], Gd 2 O 3 (k ∼ 14) [2,3], Pr 2 O 3 (k ∼ 15) [4], Nd 2 O 3 (k ∼ 16) [4], Er 2 O 3 (k ∼ 13) [4], have received much interest as charge-trapping layer, mainly due to their relatively high dielectric constants, appropriate conductionband offsets with respect to Si and good electrical properties [4,5]. Moreover, nitrogen incorporated into the chargetrapping dielectrics has also been widely investigated to induce deep-level traps and enhance the reliability of the memory devices [6][7][8].…”