Evaluation of precursors for chemical vapor deposition of ruthenium

MOCVD of [(1,5-cyclooctadiene)(toluene)Ru 0 ] on copper and silicon substrates in a vertical cold-wall reactor led to the formation of thin metallic ruthenium films with low carbon content. The deposition was carried out by varying the substrate temperature (150±450 C), total pressure (100±500 mbar) and mean residence time (0.17±0.50 s). It was found that Ru films could be deposited at temperatures as low as 150 C. The exhaust gas was analyzed by gas chromatography (GC) and the deposited films were characterized by energy dispersive analysis of X-rays (EDX) and elastic recoil detection analysis (ERDA). A correlation was found between the carbon content of the films and the presence of chemically modified ligands in the MOCVD exhaust gas. 1,5-Cyclooctadiene was identified as the main source for carbon incorporated into the deposited Ru films. C±H activation at the metallic ruthenium surface was regarded as the primary process of ligand degradation, which led to final carbon contamination.

Section: Introductionmentioning

confidence: 99%

[(1,5‐Cyclooctadiene)(toluene)ruthenium(0)]: A Novel Precursor for the MOCVD of Thin Ruthenium Films

Schneider¹,

Popovska

Holzmann

et al. 2005

“…We estimated the carbon concentration by taking the area ratio of the Ru 3d 3/2 and Ru 3d 5/2 XPS peaks, assuming that the Ru 3d 5/2 peak arises only from Ru and that the C signal overlaps only the Ru 3d 3/2 signal. [14,19] For pure ruthenium, the ratio of the Ru 3d 3/2 to Ru 3d 5/2 XPS peak areas is about 3:2, which corresponds to the theoretical value due to spin-orbit interactions of d-electrons [19,20] . The excess of carbon present in the Ru film would show the variation of the observed 3d 3/2 /3d 5/2 peak ratio from the ideal value.…”

Section: Film Compositionmentioning

confidence: 68%

Ruthenium Films Deposited by Liquid‐Delivery MOCVD Using Bis(ethylcyclopentadienyl)ruthenium with Toluene as the Solvent

Hur'yeva

Lisker

Burte

2006

Pure ruthenium thin films are prepared by liquid-delivery metal-organic (MO)CVD using bis(ethylcyclopentadienyl)ruthenium (Ru(EtCp) 2 ) with toluene as the solvent. The deposition of Ru thin films is carried out on various substrates at temperatures in the range 330-460°C via the oxygen-assisted pyrolysis of Ru(EtCp) 2 . Ru in a single phase can be obtained under all growth conditions. The reaction kinetics, film composition, film morphology, mechanical properties, and electrical properties of deposited Ru films were investigated. The films obtained have a low resistivity value of 20 lX cm, low stress values of about 70 MPa, and a preferred crystalline orientation (002), offering potential application in storage-capacitor electrodes.

“…Moreover, the observed growth behavior is somewhat different to that reported in the literature, where growth of the RuO 2 film decreased at temperatures above 400 C due to the formation of volatile oxide compounds RuO 3 (g) and RuO 4 (g). [10,18] This discrepancy is caused by the natural characteristics of complex 1, as it seems to be highly effective in giving off its organic ligands. Formation of both volatile oxide compounds and adsorbed oxygen and carbon atoms that may block the precursor adsorption sites would be significantly suppressed for our experiments conducted using low O 2 flow rate and reduced system pressure.…”

Section: Deposition Of Ruo 2 Thin Filmsmentioning

confidence: 99%

“…[9] Most recently, even the considerably less volatile cyclopentadienyl dimer complex [(C 5 H 5 )Ru(CO) 2 ] 2 has proven useful for depositing Ru thin films employing a bench-scale CVD facility. [10] In the latter study, the main goal was to develop a generalized screening method for new CVD source reagents. Recently, we have established a new program designed to tailor and synthesize novel precursors that may be suitable for the growth of ruthenium and ruthenium oxide thin films.…”

Section: Introductionmentioning

confidence: 99%

Deposition of Conductive Ru and RuO₂ Thin Films Employing a Pyrazolate Complex [Ru(CO)₃(3,5‐(CF₃)₂‐pz)]₂ as the CVD Source Reagent

Song

Chen

Chi³

et al. 2003

The reaction of Ru 3 (CO) 12 with three equivalent of 3,5-bis(trifluoromethyl) pyrazole [(3, ) 2 -pz)H] at 180 C produces the double pyrazolate-bridged ruthenium complex [Ru(CO) 3 (3,5-(CF 3 ) 2 -pz)] 2 , (1), in high yield. This ruthenium complex has been characterized by spectroscopic methods, revealing a molecular structure similar to that of the diosmium analogue [Os(CO) 3 (3,5-(CF 3 ) 2 -pz)] 2 . Thermogravimetric analysis (TGA) of complex 1 showed an enhanced volatility compared to the parent carbonyl compound Ru 3 (CO) 12 and the closely related, unsaturated 3,5-di-tert-butyl pyrazole complex (2) [Ru 2 (CO) 5 (3,5-t-Bu 2 -pz) 2 ]. Using complex 1 as the CVD source reagent, ruthenium metal with a preferred (002) orientation can be deposited at 400 C using H 2 as the carrier gas. If, however, O 2 is used as the carrier gas, RuO 2 thin films with a (101) orientation are obtained. The as-deposited metal thin films were characterized by various surface techniques, as well as by electrical resistivity measurements.