CVD of Titanium Oxide Thin Films from the Reaction of Tetrakis(dimethylamido)‐ titanium with Oxygen

Abstract

CVD of thin films with high dielectric constants (k) is of intense current interest.[1±4] New generations of ULSI technology require the insulating layer to be less than 20 thick. SiO 2 (k = 3.9), the current gate insulating material, is not effective at this thickness. CVD of thin films of metal oxides, such as MO 2 (M = Zr, Hf) and Ta 2 O 5 , and mixed oxides MO x -SiO x with large dielectric constants have been actively studied. [1±4] In addition, these oxides are of current interest as replacements for SiO 2 in the new generation of dynamic random access memories (DRAM).[1c] Metal alkoxides, amides and imides have been studied as precursors to give metal oxide and silicate thin films.

Investigation of New 2,5‐Dimethylpyrrolyl Titanium Alkylamide and Alkoxide Complexes as Precursors for the Liquid Injection MOCVD of TiO2

“…[45] The TiO x films deposited from (1) and [(MeCp)-Ti(NMe 2 ) 3 ] show a high level of carbon contamination (C ¼ 12.7 at.-%). Significantly, carbon was reportedly absent in TiO 2 films grown by MOCVD using [Ti(NMe 2 ) 4 ], [29] suggesting that the major route to carbon incorporation is the decomposition of the [2,5-dimethylpyrrolyl] 3 (dmae)] (C ¼ 2.9 À 7.7 at.-%), [31] …”

“…[27] The anhydrous metal nitrate precursor [Ti(NO 3 ) 4 ] [28] and the alkylamide complex [Ti(NMe 2 ) 4 ] [29] have also been used for the deposition of high-purity TiO 2 by MOCVD. The rapidly growing use of liquid injection techniques for the MOCVD of multi-component metal oxides [30] has led to the requirement for precursors with reduced air/moisture sensitivity, and for co-precursors with similar thermal [30]…”

Reactivities of d0 transition metal complexes toward oxygen: Synthetic and mechanistic studies

“…2 Chemical vapor deposition of TiO 2 thin films from the reaction of d 0 Ti(NMe 2 ) 4 (1) with O 2 [10] We have found that Ti(NMe 2 ) 4 (1) in hexanes is inert to 1 atm O 2 at 23℃. It, however, reacts with O 2 at 250-300℃, yielding TiO 2 thin films of ca.…”

“…Our work is focused on the reactions of O 2 with metal amide complexes such as M(NMe 2 ) 4 (M = Ti, 1; Zr, 2; Hf, 3) and Ta(NMe 2 ) 5 (6). Though Ti(NMe 2 ) 4 (1) is inert to oxygen at room temperature, it reacts fast with oxygen in a CVD process to give a TiO 2 thin film [10] . Reactions of M(NMe 2 ) 4 (M = Zr, 2; Hf, 3) with O 2 give trinuclear oxo aminoxy complexes M 3 (NMe 2 ) 6 (μ-NMe 2 ) 3 (μ 3 -O)(μ 3 -ONMe 2 ) (M = Zr, 4; Hf, 5) [11] .…”

Controlled deposition of new organic ultrathin film as a gate dielectric layer for advanced flexible capacitor devices

“…Among various methods to prepare semiconductor or insulator films, atomic layer deposition (ALD), physical vapor deposition (PVD), and chemical vapor deposition (CVD) appear to be the most useful new technologies [9][10][11]. However, above methods require ultrahigh vacuum condition and expensive tools.…”