Selective atomic layer deposition ͑ALD͒ was performed on copper patterned silicon substrates to selectively deposit HfO 2 film on silicon. The selectivity is based on differences of surface physics/ chemistry rather than use of any molecular masking such as self-assembled monolayers. On silicon, the growth rate of HfO 2 is 0.11 nm /cycle with no initial inhibition of film growth, while on copper no HfO 2 deposition was observed up to at least 25 ALD cycles. The selective growth on silicon over copper at 25 ALD cycles provides a patterned film deposition at thicknesses of 2.8 nm HfO 2 which is relevant to semiconductor nanofabrication.

Thin stoichiometric erbium oxide films were atomic layer deposited on p-type Si(100) substrates using tris(methylcyclopentadienyl)erbium and ozone. The film growth rate was found to be 0.12 ± 0.01 nm/cycle with an atomic layer deposition temperature window of 170-330 ºC. X-ray photoelectron spectral (XPS) analysis of the resulting Er 2 O 3 films indicated the as-deposited films to be stoichiometric with no evidence of carbon contamination. Studies of post deposition annealing effects on resulting films and interfaces were done using Fourier transforms infrared spectroscopy, XPS, glancing incidence X-ray diffraction, and optical surface profilometry.As-deposited Er 2 O 3 films were found to crystallize in the cubic structure with dominant (222) orientation; no erbium silicate was found at the interface. After annealing at 800 ºC in N 2 for 5 min, a new XPS feature was found and it was assigned to the formation of erbium silicate. As the annealing temperature was increased, the interfacial erbium silicate content was found to increase in the temperature range studied.

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Tetrakis ͑diethylamino͒ hafnium ͑TDEAH͒, tetrakis ͑diethylamino͒ titanium ͑TDEAT͒, and H 2 O were used for the atomic layer deposition ͑ALD͒ of HfO 2 , TiO 2 , and Hf x Ti 1−x O 2 films on silicon substrates. The ALD temperature windows were found to be 175-250°C for HfO 2 ͑0.12 nm/cycle͒ and 150-250°C for TiO 2 ͑ ϳ0.06 nm/cycle͒. The 175-250°C overlap region is ideal for the ALD of the Hf x Ti 1−x O 2 films. Different compositions of Hf x Ti 1−x O 2 were obtained by varying the ͓TDEAH/H 2 O͔/͓TDEAT/H 2 O͔ cycle ratios, and excellent tunability of film composition was found using X-ray photoelectron spectroscopy ͑XPS͒. The Hf x Ti 1−x O 2 deposition rate was found to be the superposition of the two individual growth rates. Both as-deposited and postdeposition annealed films were studied with XPS, phase shift interferometry, and grazing incidence X-ray diffraction. As-deposited HfO 2 and TiO 2 films were found to be amorphous, and they began to crystallize after annealing at 600°C in the monoclinic phase ͑HfO 2 ͒ and in weak anatase phase ͑TiO 2 ͒. The Hf x Ti 1−x O 2 films remained amorphous after annealing up to about 1000°C in N 2 for 5 min.Structural and interfacial studies of ultrathin, high dielectric constant ͑͒ films during high temperature fabrication processes are critical to the continuous scaling of microelectronic devices. In particular, these materials are of great importance for the gate insulator of metal oxide semiconductor field effect transistors and the capacitor dielectric of dynamic random access memories. 1,2 So far, many candidate materials such as have been studied for the replacement of SiO 2 . 3 From all these materials, HfO 2 and TiO 2 seem to be promising candidates due to their favorable properties. HfO 2 is known to have relatively good thermal stability and compatibility with the Si substrate, and it has a dielectric constant of 15-30 with a large bandgap ͑5.7 eV͒. 4-6 TiO 2 is even more favorable in terms of its dielectric constant which is 80 or higher; 7 however, it has a rather small bandgap ͑3.1 eV͒, 8 which could result in more leakage current than that of HfO 2 . The reported crystallization temperature of each of these two materials has been reported to be as low as ϳ550°C. 9,10The earliest atomic layer deposition ͑ALD͒ of HfO 2 from tetrakis ͑diethylamino͒ hafnium ͑TDEAH͒ and H 2 O was published by Deshpande et al. with a growth rate of ϳ0.13 nm/cycle at 300°C. 11 Titanium tetrachloride ͑TiCl 4 ͒ and titanium isopropoxide ͑TTIP͒ have typically been used as metal precursors in the ALD of TiO 2 films, with water being the oxidant. 12-16 Growth rates of 0.03 nm/cycle or lower in these systems were reported. Our earlier ALD studies with other homoleptic metal precursors having the diethylamino ligand, such as TDEAH and tris ͑diethylamino͒ aluminum, have resulted in broad ALD temperature windows and rather high growth rates. 9,11,17,18 Such results have prompted interest in examining the suitability of tetrakis ͑diethylamino͒ titanium ͑TDEAT͒ as a precursor for the ALD of TiO 2 ...

This work introduces the fabrication of nano scale magnetostrictive NiFe2O4 (NFO) thin films using reduced pressure metallorganic chemical vapor deposition (MOCVD) with programmable cyclic pulsing of novel precursor combination — n-butylferrocene and nickelocene. Using a custom-designed CVD system, different rate-limiting steps and Ea in the CVD of iron oxide and nickel oxide depositions are discussed. Both cyclic-deposition and co-deposition modes were investigated through NFO depositions on silicon substrates at 17 Torr and 500°C. Growth rates of NFO films obtained by co-deposition and cyclic-deposition were 3 and 1.6 nm/min, respectively. Material characterizations were conducted on NFO films fabricated at optimized process conditions and annealed samples. Rutherford backscattering spectroscopic results showed better stoichiometric control for cyclic-deposited films. As-deposited NFO films showed homogeneous stoichiometric chemical composition without carbon contamination in the bulk film; a saturation magnetization of 25 emu/g was observed from its trevorite crystalline phase upon annealing at 700°C in argon ambience for one hour.