Liquid Injection MOCVD of Dysprosium Scandate Films

Abstract

Crystalline Dy 2 O 3 , Sc 2 O 3 , and amorphous high-k DyScO 3 thin films have been deposited on Si͑100͒ substrates by metallorganic chemical vapor deposition ͑MOCVD͒ using two metal precursors M͑EDMDD͒ 3 ͓MϭDy, Sc; EDMDDϭ6-Ethyl-2,2-Di Methyl -3,5-Decane Dionato͔. The precursors were evaluated in terms of efficiency and growth rate under various conditions, viz. vaporizer and susceptor temperatures, reactor pressure, injection rate, and injection delay between the two precursors. Amorphous DyScO 3 films with nearly correct stoichiometry were deposited within the temperature range of 560-700°C. These amorphous films were smoother than the crystalline binary oxides and reached a density of around 85% of the bulk crystalline density. Amorphous structure and surface smoothness retained up to an annealing temperature as high as 950°C. The thickness of the SiO x interlayer did not vary with deposition temperature, but annealing at temperatures above 900°C increased the interlayer thickness. Electrical properties are promising; the dielectric constant of DyScO 3 ͑k Ϸ 22͒ is much higher than that of the binary oxides Dy 2 O 3 and Sc 2 O 3 ͑k Ϸ 10͒, and the leakage currents are very low compared to SiO 2 .

Atomic layer deposition of scandium‐based oxides

“…For Sc 2 O 3 , one peak is well defined and its position corresponds to the (222) reflection of the cubic structure. This crystalline structure is typically observed for Sc 2 O 3 , irrespective of the deposition technique . Layers of only ∼10 nm already show this c(222) peak, although with lower intensity.…”

Si-compatible candidates for high-κdielectrics with thePbnmperovskite structure

“…These compounds are at the focus of the present work. Some of them have been studied in thin-film form, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] but the full dielectric tensor of these materials has not yet been established, making the selection of materials best suited for high-applications difficult.…”

Dielectric properties and electrical conduction of high-k LaGdO3 ceramics

“…3,4 In this regard, rare-earth based multicomponent oxides in the amorphous state are found to be promising candidates for the next generation dielectrics after the silicates. [5][6][7][8][9] Among binary rare earth oxides, interlanthanide oxides have been reported to have thermodynamically stable interfaces with Si and higher k-value. 10,11 To this end, we have identified lanthanide compound LGO in the ceramic form as a promising high-k dielectric material in terms of its linear, highk value with low leakage current.…”