Layered tantalum-aluminum oxide films deposited by atomic layer epitaxy

Current-transport properties of atomic-layer-deposited ultrathin Al2O3 on GaAs

“…integration or digital applications, which requires not only much better and reliable oxide/semiconductor interface properties, but also high-k gate dielectric materials with further scalability to sub-0.7-nm effective inversion gateoxide thickness. For above reasons, the current-transport studies of ultrathin high-k oxides on GaAs are of great importance for ultimate CMOS technology, although the electrical properties of ALD Al 2 O 3 films on the order of $1000 Å have been investigated by several research groups already [7][8][9][10][11][12][13][14][15]. In this paper, we report detailed currenttransport studies of ultrathin Al 2 O 3 dielectrics on GaAs grown by ALD.…”

Atomic Layer Epitaxy in Deposition of Various Oxide and Nitride Thin Films

“…Other important properties of the insulator layer are of course good adhesion, chemical stability, small number of pinholes, high charge storage density and small dielectric loss [38,73]. ALE deposited Al O3 films fulfil the demands of TFEL devices: dielectric constant = 8.3, breakdown voltage > 10 V/cm and they are pinhole free [71].…”

“…by composite films. So far the systems Ta20,-A1203, Ta205-Hf02 and Ta205-Zr02 have been studied and they show how the ALE method enables, besides decreasing the leakage current, also tailoring of dielectric constant and refractive index with the aid of multilayer structures [71,76,77].…”

“…Ta205 has higher dielectric constant (23)(24)(25) than M2O3 but when the dielectric constant increases the leakage current tends to increase simultaneously [71]. Dielectric losses in ALE grown Ta205 films are in the order of 10-~ but the leakage current is significant in oxides prepared from chloride and still 2.3-4.0 &cm2 at l MVIcm in those prepared from ethoxide [70,71].…”

“…When deposited on glass some of the ALE oxides (A1203 [51,56], Ta205 [70,71]) are completely amorphous to XRD while some others (e.g. Hf02 [67], In203 [68]) possess highly oriented crystalline structures.…”