Mn ALKYLAMIDINATES | mocvd-precursor-encyclopedia.de

MANGANESE ALKYLAMIDINATES (N,N'-DIALKYL-2-ALKYL-AMIDINATES)

Manganese amidinates were proposed by group of R. Gordon as ALD precursors for Mn containing films.[613]

Manganese bis(N,N’-diisopropylacetamidinate) [Mn2(iPr-MeAMD)4]

Manganese bis(N,N’-diisopropylacetamidinate) [Mn2(µ-iPr-MeAMD)2(η2-iPr-MeAMD)2]

Manganese bis(N,N’-diisopropylacetamidinate) [Mn2(µ-iPr-MeAMD)2(η2-iPr-MeAMD)2] is volatile (sublimation temperature 65°C / 50 mTorr) and applicable for ALD of Mn-containing thin films with precursor temperatures <120 °C.

Although X-ray structure determination was not done for [Mn2(µ-iPr-MeAMD)2(η2-iPr-MeAMD)2] its similar sublimation temperature to that of the corresponding iron compound suggests that is also a dimer containing two nonbridging and two bridging acetamidinate ligands. This can be explained by greater ionic size of Mn(II), compared to f.e. Co(II) and Ni(II) in corresponding monomeric Co and Ni amidinates, therefore in Mn compound the isopropyl substituents are insufficient to provide monomeric structures, and generate dinuclear compound.

Mn(iPr2amd)2 for metal Mn by MOCVD

Bis(N,N′-diisopropylpentylamidinato)Mn(II) Mn(iPr2amd)2 (and for comparison Mn(MeCp)(CO)3 ) was applied as Mn precursor for the growth of manganese-based films on silicon oxide substrates by thermal MOCVD; the grown layers were characterized without exposure to air in the coupled XPS analytical chamber. The Mn acetamidinate complex proved to be highly reactive manganese precursor (in contrast to unreactive Mn(MeCp)(CO)3 ), allowing the deposition of Mn at reasonable growth rates, increasing at higher temperatures, but also leading to the incorporation of approximately 15% of N and additional C in the grown Mn(0) films. A nonstoichiometric mixture of MnOx + SiOx and Mn silicate is formed first, possibly followed by the formation of a thin subsurface Mn silicide layer. The combined Mn silicate/Mn silicide structure acts as an effective diffusion barrier, allowing further growth of Mn(0) metallic films.[[i]]

[i] Huaxing Sun and Francisco Zaera, J. Phys. Chem. C, 2012, 116 (44), pp 23585–23595, DOI: 10.1021/jp309083a, http://pubs.acs.org/doi/abs/10.1021/jp309083a , “Chemical Vapor Deposition of Manganese Metallic Films on Silicon Oxide Substrates”

Mn(iPr2amd)2 for Mn-doped GaN by MOCVD

Dimeric Mn(II) diisopropylacetamidinate M2(η2-iPrNC(CH3)NiPr)2(μ2-iPrNC(CH3)NiPr)2 was synthesized and characterized Mn(iPr2amd)2 and similar dimeric complexes of other metals sublime at ~80-100 ºC / 10-3 torr. The higher sublimation temperatures for the dimeric complexes, compared to the monomeric complexes, suggest that the dimeric complexes sublime as intact dimers.

Mn(iPr2amd)2 was proposed as potential MOCVD precursor for the growth of Mn-doped GaN thin films, which are of considerable interest for spintronics applications. [[i]]

[i] Winter, Charles H., “New Lanthanide Precursors for Doping Semiconductor Films”, ADA429770, Final rept. 2001- 2004, WAYNE STATE UNIV DETROIT http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA429770

Manganese bis(N,N’-di-tert-butylacetamidinate) [Mn(tBu-MeAMD)2]

Manganese bis(N,N’-di-tert-butylacetamidinate) [Mn(tBu-MeAMD)2] is volatile (sublimation temperature 55°C/ 60 mTorr) and are applicable for ALD of Mn-containing thin films with precursor temperatures <120 °C.

TGA/DSC measurements of [Mn(tBu-MeAMD)2] at atmospheric pressure presented clean one step evaporation with low residual mass (4%), showing its thermal stability during vaporization even at 1 atm pressure. Thermal stability for short times (≤1 s) at higher temperatures was determined by flowing the precursor vapor by N2 carrier through a tube furnace; the lowest temperature at which material deposited on a heated substrate in the tube was 300 °C (decomposition onset temperature).

X-Ray structure: tert-butyl groups in [Mn(tBu-MeAMD)2], result in monomeric complex having lower sublimation temperature.

Mn(tBu2amd)2 for Mn-doped GaN by MOCVD

A series of volatile alkylamidinate complexes including Mn(tBuNC(CH3)NtBu)2, was synthesized and characterized. Due to presence of bulky tert-butyl group, the complex was found to be monomeric, four-coordinate complex, contain all-nitrogen coordination sphere and subliming rapidly without decomposition at 50-60 ºC / 10-3 torr.

Mn(tBuNC(CH3)NtBu)2 was proposed as an excellent dopant source candidates the growth of Mn-doped GaN films by MOCVD for their use for spintronic applications.[[i]]

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