Atomic Layer Deposition of Gadolinium Oxide Films

Abstract

Thin cubic Gd 2 O 3 films are grown by atomic layer deposition (ALD), in the temperature range 300-400°C, using a novel tris(2,3-dimethyl-2-butoxy)gadolinium(III) precursor, Gd[OC(CH 3 ) 2 CH(CH 3 ) 2 ] 3 , and water. The films are crystalline in their as-deposited state. The films contain some residual hydrogen and carbon, and are probably oxygen-deficient in the as-deposited state, causing flat-band shifts in Gd 2 O 3 -based metal-oxide-semiconductor (MOS) capacitor structures. On the other hand, the permittivity of Gd 2 O 3 dielectric layers reaches 16, approximately, when calculated from the relationship between equivalent and physical oxide thicknesses, and breakdown fields as high as 8 MV cm -1 .

Atomic Layer Deposition of Gadolinium Aluminate using Gd(iPrCp)3, TMA, and O3 or H2O

“…Capacitance/voltage (C-V) data of metal-insulator-semiconductor (MIS) capacitors with 12.5 AE 0.5 nm thick Gd x Al 2- The permittivity was found to increase with Gd content, in keeping with the permittivity values reported for Al 2 O 3 (k $ 8) [42] and Gd 2 O 3 (typically 14-16, [18,19,25,43,44] although higher values up to 24 have also been reported for epitaxial layers [45] [12,13,46] where no large decrease of Full Paper the permittivity with respect to La 2 O 3 was also observed, neither due to Al 2 O 3 incorporation [47] nor due to amorphization. [48] 3.…”

“…Several papers have been published on the deposition and characterization of Gd 2 O 3 using, e.g., e-beam evaporation [18][19][20][21] or radio frequency (RF) sputtering. [22] In addition, ALD was reported using Gd(thd) 3 (thd ¼ 2,2,6,6-tetramethyl-3,5-heptanedionato) in combination with O 3 , [23] or, alternatively, using Gd(CpCH 3 ) 3 (Cp ¼ cyclopentadieentadienyl), [23] Gd(mmp) 3 (mmp ¼ 1-methoxy-2-methyl-2-propoxide), [24] or tris(2,3-dimethyl-2-butoxy)Gd [25,26] in combination with H 2 O. On the other hand, a very limited number of papers report on the deposition of Gd x Al 2-x O 3 thin films, and then only by non-standard techniques, for example, sol-gel deposition.…”

Characteristics of Gadolinium Oxide Nanocrystal Memory with Optimized Rapid Thermal Annealing

“…It is performed by the crystal growth at the nucleation site after RTA, where the crystallization temperature is about 250°C. 20 From Figure 1a and b we can observe that the Gd 2 O 3 -NC dot size is increased with temperature. To find the NC density, top-view transmission electron microscopy ͑TEM͒ images of Gd 2 O 3 -NC memories were analyzed.…”

Mixed oxide growth on combinatorial aluminium–gadolinium alloys — a thermodynamic and first-principles approach

“…Gadolinium orthoaluminate (GdAlO 3 ) mixed oxide possesses excellent magnetic and antiferromagnetic properties [20][21][22]. The pure oxide Gd 2 O 3 is a wide bandgap material (5.37-6.37 eV) [23] and meets the low leakage current requirement in CMOS applications [24]. The superior optical properties of Gd 2 O 3 thin films make them efficient for use in optical applications [23,25,26].…”

“…The pure oxide Gd 2 O 3 is a wide bandgap material (5.37-6.37 eV) [23] and meets the low leakage current requirement in CMOS applications [24]. The superior optical properties of Gd 2 O 3 thin films make them efficient for use in optical applications [23,25,26]. Hong et al reported that Gd 2 O 3 is an excellent dielectric material to passivate GaAs surface, with a dielectric constant of 10 for epitaxial cubic phase and a low leakage current density of 10 −9 -10 −10 A cm −2 at zero bias [27], while Zhou et al have found out a value of 20 for Gd 2 O 3 thin-film [28].…”