A new N‐heterocyclic carbene (NHC)‐based silver amide compound, 1,3‐di‐tert‐butyl‐imidazolin‐2‐ylidene silver(I) 1,1,1‐trimethyl‐N‐(trimethylsilyl)silanaminide [(NHC)Ag(hmds)] was synthesized and analyzed by single‐crystal X‐ray diffraction, 1H and 13C NMR spectroscopy, as well as EI mass spectrometry, and subsequently evaluated for its thermal characteristics. This new halogen‐ and phosphine‐free Ag atomic layer deposition (ALD) precursor was tested successfully for silver thin film growth in atmospheric pressure plasma enhanced spatial (APP‐ALD). High‐purity conductive Ag thin films with a low sheet resistance of 0.9 Ω/sq (resistivity: 10−5 Ωcm) were deposited at 100 °C and characterized by X‐ray photoelectron spectroscopy, scanning electron microscopy, optical transmittance, and Rutherford back‐scattering techniques. The carbene‐based Ag precursor and the new APP‐ALD process are significant developments in the field of precursor chemistry as well as metal ALD processing.

Volatile metal complexes are important for chemical vapour deposition (CVD) and atomic layer deposition (ALD) to deliver metal components to growing thin films. Compounds that are thermally stable enough to volatilize but that can also react with a specific substrate are uncommon and remain unknown for many metal centres. Guanidinate ligands, as discussed in this review, have proven their utility for CVD and ALD precursors for a broad range of metal centres. Guanidinate complexes have been used to deposit metal oxides, metal nitrides and pure metal films by tuning process parameters. Our review highlights use of guanidinate ligands for CVD and ALD of thin films over the past five years, design trends for precursors, promising precursor candidates and discusses the future outlook of these ligands.

No abstract

Thin films of Y 2 O 3 are deposited on Si(100) and Al 2 O 3 (0001) substrates via metal-organic (MO)CVD for the first time using two closely related yttrium tris-amidinate compounds as precursors in the presence of oxygen in the temperature range 400-700 8C. The structural, morphological, and compositional features of the films are investigated in detail. At deposition temperatures of 500 8C and higher both the precursors yield polycrystalline Y 2 O 3 thin films in the cubic phase. The compositional analysis revealed the formation of nearly stoichiometric Y 2 O 3 . The optical band gaps are estimated using UVVis spectroscopy. Preliminary electrical measurements are performed in the form of a metal oxide semiconductor (MOS) structure of Al/Y 2 O 3 /p-Si/Ag. Leakage currents and dielectric constants are also determined.

Ein Silberamidkomplex eines N‐heterocyclischen Carbens, (1,3‐Di‐tert‐butyl‐imidazolin‐2‐yliden)silber(I)‐1,1,1‐trimethyl‐N‐(trimethylsilyl)silanamid [(NHC)Ag(hmds)], wurde synthetisiert, mittels Einkristall‐Röntgenstrukturanalyse, 1H‐ und 13C‐NMR‐Spektroskopie und EI‐Massenspektrometrie analysiert, sowie bezüglich seiner thermischen Eigenschaften untersucht. Diese neue halogen‐ und phosphorfreie Vorstufe für die Atomlagenabscheidung (ALD) wurde in einem plasmaunterstützten räumlich getrennten (APP‐)ALD‐Prozess unter Atmosphärendruck für die Abscheidung dünner Silberschichten genutzt. Besonders reine und elektrisch leitende dünne Silberschichten mit einem geringen Flächenwiderstand von 0.9 Ω/sq (10−5 Ωcm) wurden bei 100 °C abgeschieden und mittels Röntgenphotoelektronenspektroskopie, Rasterelektronenmikroskopie, optischer Transmissionsspektroskopie und Rutherford‐Rückstreuspektrometrie untersucht. Die Carben‐basierte ALD‐Vorstufe und der zugehörige APP‐ALD‐Prozess ermöglichen zukünftige Anwendungen solcher Silberschichten.