Synthesis and Characterization of Allyl(β-ketoiminato)palladium(II) Complexes:  New Precursors for Chemical Vapor Deposition of Palladium Thin Films

Abstract

Treatment of -ketoiminates with [(allyl)Pd(µ-Cl)] 2 affords volatile, air-stable allyl( -ketoiminato)palladium(II) complexes. The structure of [(methallyl)Pd(Phacac)] (Phacac ) MeCOCHCMeNPh) was determined by single-crystal X-ray diffraction. In solution 1 H NMR analyses indicate either a direct rotation of a planar allyl ligand about the allyl-palladium axis or a solvent-assisted exchange process involving the transient formation of a monodentate ketoiminato ligand. The physical properties of the complexes were modified by altering the -ketoiminato or the η 3 -allyl ligands. Some derivatives are liquid at room temperature and were known to be suitable for chemical vapor deposition of Pd thin films.The preparation of thin films of palladium by metal organic chemical vapor deposition (CVD) is becoming increasingly attractive for the fabrication of electronic devices 1 because such films have potentially useful applications in replacing gold as electrical contacts in integrated circuits and in making gas sensors, magnetooptical data storage devices, etc. 2 The largest obstacle to CVD of Pd films has been the lack of suitable precursors, as most volatile Pd complexes suffer from poor stability in air and moisture. 3 Recently, this problem was partially overcome by Puddephatt, who reported the preparation of volatile allyl( -diketonato)-palladium(II) complexes, which are liquid and stable at room temperature and are excellent CVD precursors for Pd films. 4 In view of these results, we felt it desirable to investigate analogous complexes having -ketoiminate ligands, which allow for organic functional group variation on the imine nitrogen as a possible way to finetune physical and chemical properties. In this article, we report the synthesis and characterization of such -ketoiminato complexes and a preliminary investigation of their application in the generation of Pd films. Experimental SectionGeneral Information and Materials. Infrared spectra were recorded on a Perkin-Elmer 2000 FT-IR spectrometer. 1 H and 13 C NMR spectra were recorded on a Bruker AM-400 or AMX-300 instrument. Mass spectra were obtained on a JEOL SX-102A instrument operating in fast atom bombardment (FAB) mode. Thermogravimetric analyses were made with a Seiko TG/DTA 300 instrument. Melting points were determined using Seiko SSC 5000 differential scanning calorimetry. Elemental analyses were performed at the NSC

Synthesis and Characterization of Tris(β‐ketoiminato)ruthenium(III) Complexes: Potential Precursors for CVD of Ru and RuO2 Thin Films

“…1 the NSC Regional Instrumentation Center at National Cheng Kung University, Tainan, Taiwan. The ketoimine ligands HOC(CF 3 )=CHCR=NMe, (keim1)H with R = Me and (keim2)H with R = CF 3 , were obtained via condensation of b-diketone with amine RNH 2 in the presence of montmorillonite K10 [32], while the Ru source reagent [Ru(COD)Cl 2 ] x was prepared according to the literature method [33]. All reactions were performed under nitrogen using anhydrous solvents or solvents treated with appropriate drying reagents.…”

Bis(β-diketonato)- and allyl-(β-diketonato)-palladium(ii) complexes: synthesis, characterization and MOCVD application

“…Based on these results, similar types of CVD palladium compounds were developed, including a series of Pd-b-diketoiminate-and -imino-alcoholate species. 23,25 It was found that the usage of asymmetrical bdiketonate ligands provides the possibility to increase the volatility and decrease the melting point. 26 Despite the so far investigated precursors, there is still need for palladium compounds containing an asymmetrical bdiketonate ligand without having halogenated groups such as CF 3 , which is, however, challenging since the respective metalorganic complexes only possess low vapor pressures, i.e.…”

Synthesis of pure and bimetallic Pd films supported in anodic alumina membranes by Solid State Reduction

“…Pure and multimetallic films for these applications are commonly obtained by vacuum processes such as sputtering [12][13][14], electron beam evaporation [4,15], chemical vapor deposition [16,17], and atomic layer deposition [18]. Through these techniques the film thickness, deposition rates, and microstructure can be controlled.…”