Deposition of Pr- and Nd-aluminate by Liquid Injection MOCVD and ALD Using Single-Source Heterometallic Alkoxide Precursors

Abstract

Thin films of praseodymium aluminate (PrAlO x ) and neodymium aluminate (NdAlO x ) have been deposited by liquid injection metalorganic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD) using the bimetallic alkoxide precursors [PrAl(OPri)6(PriOH)]2 and [NdAl(OPri)6(PriOH)]2. Auger electron spectroscopy showed that all the films were high purity, with no carbon detectable (est. detection limit ≈ 0.5 at %). X-ray diffraction showed that the PrAlO x and NdAlO x films remained amorphous up to temperatures of 900 °C. Films grown by ALD were all Pr- or Nd-deficient (Pr/Al = 0.54−0.71; Nd/Al = 0.30−0.42), but near-stoichiometric films of PrAlO x (Pr/Al = 0.76) and NdAlO x (Nd/Al = 0.87) were obtained by MOCVD at deposition temperatures of 500 and 450 °C, respectively. The electrical properties of the films were assessed using C − V and I − V on MOS capacitors. Post-metalization annealing (PMA) in forming gas was effective in reducing charge levels in all films. Following PMA, the dielectric properties of NdAlO x were superior to those of PrAlOx, MOSCs fabricated with NdAl x O y (Nd/Al = 0.87) and PrAlO x (Pr/Al = 0.76) showed leakage current densities below 7.5 × 10-10 A cm-2 (κ ∼ 14) and 1 × 10-6 A cm-2 (κ ≈ 12), respectively.

Unusual stoichiometry control in the atomic layer deposition of manganese borate films from manganese bis(tris(pyrazolyl)borate) and ozone

“…36 PrAlO x and NdAlO x films were grown by ALD with 1:1 neodymium/praseodymium to aluminum bimetallic isopropoxide precursors, but nonstoichiometric praseodymium to aluminum and neodymium to aluminum ratios (0.30-0.71) resulted. 37 Bi(CH 2 SiMe 3 ) 3 and ozone were used for the ALD growth of Bi-Si-O films, 38 but the silicon to bismuth ratio increased from 1.5 to 5.0 between 200 and 450 C.…”

“…34 ALD growth from various bimetallic precursors does not generally replicate the precursor element stoichiometries in the resultant thin films. [35][36][37][38] Given the increasing importance of first row transition metal borates, [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] proposed to arise from the strong oxidizing properties of higher valent manganese oxide layers that are formed upon ozonolysis of surface manganese sites.…”

Advanced CMOS Gate Stack: Present Research Progress

“…Furthermore, they remain amorphous up to high temperatures, leading to a large reduction in leakage current relative to polycrystalline M 2 O 3 films and to inhibition of the growth of a SiO 2 interfacial layer during CMOS processing. AES shows that all the praseodymium aluminate (PrAlO x ) and neodymium aluminate (NdAlO x ) films [46] are high pure, with no carbon detectable. XRD shows that the PrAlO x and NdAlO x films remained amorphous up to temperatures of 900…”

“…• C), leading to a large reduction in leakage current relative to polycrystalline M 2 O 3 films and to inhibition of the growth of a SiO 2 interfacial layer during CMOS processing [46]. The electrical properties of the praseodymium aluminate (PrAlO x ) and neodymium aluminate (NdAlO x ) films are assessed using C-V and I-V on MOS capacitors.…”

The Atomic Layer Deposition of SrB2O4 Films Using the Thermally Stable Precursor Bis(tris(pyrazolyl)borate)strontium

“…The liquid injection ALD growth of PrAlO x and NdAlO x films was performed using 1:1 neodymium/aluminum and praseodymium/aluminum isopropoxide-based precursors with water as the oxygen source. [48] The neodymium/aluminum and praseodymium/ aluminum ratios varied from 0.30 to 0.71 and self-limiting film growth was only observed up to 300 8C. [48] The ALD growth of bismuth silicate films from Bi(CH 2 SiMe 3 ) 3 and ozone was reported, and the bismuth/silicon ratios were close to 2:1 throughout the ALD window (250-350 8C).…”