Effects of Adsorbed Moisture in SiO₂ Substrates on the Formation of a Mn Oxide Layer by Chemical Vapor Deposition

Self-Formed Mn Oxide Barrier on SiOCH for Nanoscale Copper Interconnect by Metal Organic Chemical Vapor Deposition of Mn

“…The hydrophobicity also indicates the lack of hydroxyl groups on the dielectric layer, which can react chemically with Mn MO precursor molecules. 6 This rough Mn oxide film is expected to cause Cu migration into the insulating layer after Cu deposition.…”

“…The enhanced hydroxyl group changed the surface from hydrophobic to hydrophilic. 6 The low-k surface was exposed to O 2 plasma for 5 s to 30 s at the working pressure of 0.8 Torr O 2 and flow rate of 200 sccm. Maximum power of 50 W (13.56 MHz) without a bottom bias was applied.…”

“…The water vapor absorbed on the dielectrics or the oxygen within the Cu layer enhances to the formation of an SFB layer. 6 It is known that the SFB layer formed by annealing Cu-Al alloy film on SiO 2 has the dielectric constant of 11, composed of MnO [k = 18 1] and MnSiO 3 [k = 7 1] bilayers, which can be considered as a series capacitor. 7 The physical vapor deposition (PVD) process for metal deposition, however, can damage vulnerable, porous, low dielectric constant (low-k) dielectric materials such as SiOCH.…”

What can we do about barrier layer scaling to 5 nm node technology ?

“…Since the Mn oxide layer is formed below the precursor pyrolysis temperature of ~500 o C, precursor decomposition is considered to be driven by preferential reaction with moisture adsorbed on or absorbed in the dielectric substrate. This surface reaction has a tendency to limit the barrier growth, but the amount and type of moisture have substantial influence on the thickness and chemical composition of the Mn oxide layer [11,12]. Careful pre-annealing of the substrate is required to obtain a reproducible and desirable barrier layer.…”

Deposition behavior and substrate dependency of ALD MnO<inf>x</inf> diffusion barrier layer

“…However, we reported previously that the presence of absorbed water in dielectrics has notable effects on the structure, composition, and thickness of the CVD-grown MnO x layer [8][9][10]. Since the amount of the absorbed water is difficult to control, a new MnO x forming process should be developed so as not to be influenced by the absorbed water in the dielectric substrates.…”