Vapor Deposition of Ruthenium from an Amidinate Precursor

Abstract

Atomic layer deposition ͑ALD͒ and pulsed chemical vapor deposition ͑CVD͒ were used to make ruthenium ͑Ru͒ thin films from a volatile Ru amidinate precursor, bis͑N,NЈ-di-tert-butylacetamidinato͒ruthenium͑II͒ dicarbonyl. The CVD films were grown without any coreactant, while the ALD films used ammonia as a coreactant. The films are fine-grained polycrystalline ruthenium with high purity ͑Ͻ0.2% impurities͒. Ru grew as a continuous, electrically conductive, pinhole-free film on tungsten nitride ͑WN͒ films even for films as thin as 2 nm. The resistivities of the films match those of pure sputtered ruthenium of the same thickness. Roughness is Ͻ2% of the film thickness. The films are very conformal, with 80% step coverage over holes with high aspect ratios ͑40:1͒. This thermal process does not use any oxidant or plasma as a second reagent, thereby avoiding damage to sensitive substrates. The ALD growth rate can reach 1.5 Å/cycle at a substrate temperature of 300°C.

Atomic Layer Deposition of Ruthenium Thin Films from an Amidinate Precursor

“…The ruthenium amidinate precursor, bis(N,N'-di-tert-butylacetamidinato)ruthenium(II) dicarbonyl, has been synthesized in our group and used to deposit ruthenium thin films with or without NH 3 as co-reactant. [7,8] Highly pure and conductive films have been conformally deposited in holes with aspect ratio 40:1. [8] In this research, we report an ALD process for ruthenium thin films using this amidinate precursor and O 2 .…”

“…[7,8] Highly pure and conductive films have been conformally deposited in holes with aspect ratio 40:1. [8] In this research, we report an ALD process for ruthenium thin films using this amidinate precursor and O 2 . We found that the growth mechanism is quite different from the process using NH 3 as a co-reactant.…”

In Situ Infrared Characterization during Atomic Layer Deposition of Lanthanum Oxide

“…9,10 Some transition metals, such as Cu, Co, Fe, Ru, Mn, and Ni, as well as their nitrides and oxides and rare earth oxides have been successfully grown by ALD from the corresponding amidinate precursors. 7,[11][12][13][14][15][16] However, the surface chemistry of these relatively new precursors has not yet been investigated in situ, because most studies to-date have focused on ex situ film characterization by electrical, physical, or chemical measurements.…”

Synthesis, structure, properties, volatility, and thermal stability of molybdenum(II) and tungsten(II) complexes containing allyl, carbonyl, and pyrazolate or amidinate ligands

“…2.286(2) W(1)-C (12) 1.964(2) W(1)-C(13) 1.940(2) W(1)-C (14) 2.292(2) W(1)-C (15) 2.202(3) W(1)-C (16) 2.326(2) N(1)-W(1)-N(2) 37.12 ( 148.65 (14) characterized molybdenum(II) and tungsten(II) complexes containing the fac-M(allyl)(CO) 2 fragment [1][2][3][4][5]. The structural features of the the fac-M(allyl)(CO) 2 moieties are very similar in 1a, 2b, 3a, and 4b.…”