Superior electrical properties of crystalline Er2O3 films epitaxially grown on Si substrates

Abstract

Crystalline Er2O3 thin films were epitaxially grown on Si (001) substrates. The dielectric constant of the film with an equivalent oxide thickness of 2.0nm is 14.4. The leakage current density as small as 1.6×10−4A∕cm2 at a reversed bias voltage of −1V has been measured. Atomically sharp Er2O3∕Si interface, superior electrical properties, and good time stability of the Er2O3 thin film indicate that crystalline Er2O3 thin film can be an ideal candidate of future electronic devices.

Thermal stability of Er2O3 thin films grown epitaxially on Si substrates

“…16 These results indicate that as-grown Er 2 O 3 films on Si͑001͒ have a single crystal structure and a good interface with Si, which allows us to easily clarify the interface reactions that occur in thermal processes. Figures 1͑a͒ and 1͑b͒ show the XRD patterns of the Er 2 O 3 thin films annealed at 450°C for 30 min in O 2 and N 2 ambiences, respectively.…”

“…6 Because the theoretical studies show that they have high dielectric constant and good thermal stability, rare earth ͑RE͒ oxides such as Pr 2 [13][14][15] Among them, the Er 2 O 3 films grown epitaxially on Si substrate with an equivalent oxide thickness of 2 nm have been realized, which reveals a good electrical property. 16 To check whether epitaxially grown Er 2 O 3 is an ideal high-k material, the knowledge on its thermal stability is needed. Ten years ago, Hubbard and Schlom 17 gave a theoretical analysis on the thermal stability of the majority of binary oxides.…”

Fowler-Nordheim hole tunneling in metal-Er2O3-silicon structures

“…2 and 3 implies that the film has a very smooth surface as well as a very smooth interface, which is well consistent with our RHEED, AFM, and XRD results. 6 In the XRD curves of the film, many interference fringes are clearly observed, it means that both surfaces and interfaces of Er 2 O 3 films are smooth. The RHEED patterns for this Er 2 O 3 film look streaklike, indicative of smooth surface.…”

“…This has prompted search for alternative ͑or high-͒ dielectrics. [5][6][7] For Si based metal-oxide-semiconductor ͑MOS͒ diode, the gate leakage currents are mainly due to Fowler-Nordheim ͑FN͒ tunneling and direct tunneling shown in Fig. 1.…”

Monoclinic B-phase erbium sesquioxide (Er2O3) thin films by filtered cathodic arc deposition

“…Due to the high dielectric constant (≈14) it is a candidate material to replace the gate dielectric SiO 2 in the next generation of complementary metal oxide semiconductor devices (CMOS) with an oxide layer thickness below 2 nm [1,2]. Recent research also comprised optoelectronic applications [3,4] and antireflective coatings [5].…”