Bis(tert‐butylimido)‐bis(dialkylamido) Complexes of Molybdenum as Atomic Layer Deposition (ALD) Precursors for Molybdenum Nitride: the Effect of the Alkyl Group

Abstract

Bis(tert-butylimido)-bis(diethylamido)molybdenum [(, possible precursors for atomic layer deposition (ALD) of molybdenum nitride, are synthesized and characterized. Calorimetric studies are carried out to examine the thermal stability of the new precursor candidates. For the diethylamido complex, sufficient thermal stability is found, ALD tests are performed, and satisfactory parameters for controlled growth are identified. Films grown from bis(tert-butylimido)-bis(diethylamido)molybdenum and ammonia are amorphous, smooth, and conformal. The di-isopropylamido complex shows thermal instability and a very low synthetic yield, hence it is not tested in ALD. Possible decomposition reactions of the precursors are studied by density functional theory (DFT) calculations. The computational results support the low thermal stability of di-isopropylamido complex found through calorimetric studies.

Rapid Wafer-Scale Growth of Polycrystalline 2H-MoS2 by Pulsed Metal–Organic Chemical Vapor Deposition

“…In this model, the anchor points at which the MoS 2 originates out of the substrate could be the initial nucleation sites. Surface-limited reaction of (N t Bu) 2 (NMe 2 ) 2 Mo with hydroxyl groups was reported for ALD of MoO 3 49 and MoN 50,51 at <325 °C. Assuming a similar interaction with surface hydroxyls, the initial formation of Si-O-Mo bonds may also play a role in MoS 2 nucleation.…”

A Quantum Chemical Descriptor for CVD Precursor Design: Predicting Decomposition Rates of TBP and TBAs Isomers and Derivatives

“…Ab initio quantum chemical approaches are an established tool for the prediction of precursor chemistry, or even describing all steps of CVD processes . They are also often used to complement experimental investigations, however, for the prediction of decomposition channels, tedious computation of reaction barriers and transition states for every compound accessible is necessary . Establishing reliable predictors for the quick assessment of relative barriers, and thus decomposition rates, is highly desirable.…”

Ligand-Assisted Volatilization and Thermal Stability of Bis(imido)dichloromolybdenum(VI) ([(t-BuN═)2MoCl2]2) and Its Adducts

“…Bis(tert-butylimido)-bis(dimethylamido)molybdenum(VI) is a volatile compound (reaching a vapor pressure of 1 Torr at 79 ºC). 7 It has been used as a precursor for the ALD of MoNx, [8][9][10][11] MoO3, 7,[12][13][14][15][16][17] MoS2, 18,19 and MoCxNy, 20 but it has not yet been reduced to molybdenum metal. This precursor is typically prepared from (t-BuN=)2MoCl2, 8 which is often isolated as the hexacoordinate 1,2-dimethoxyethane (dme) complex 1.…”