Diffusion Barriers

Damage to OSG low‐k films during IPVD deposition of the Ta barrier layer

“…[ 59,60 ] Using Al–SiO 2 –Si structure, the formation of protons through the interaction of photogenerated holes with atomic hydrogen released from the top gate electrode [ 61 ] was suggested. The VUV‐induced damage of SiO 2 can be represented as the proton‐assisted electrochemical reduction of the oxide resulting in the formation of surface silanol and trivalent Si center [ 10 ] : $$${{\rm{O}}}_{3}\equiv \text{Si}-{\left(\begin{array}{c}{\rm{H}}\\ \text{\unicode{x022EE}}\\ {\rm{O}}\end{array}\right)}^{+}-\text{Si}\equiv {{\rm{O}}}_{3}+{{\rm{e}}}^{-}\to {{\rm{O}}}_{3}\equiv \text{Si}-\text{OH}+\bullet \text{Si}\equiv {{\rm{O}}}_{3}.$$$…”

“…The Cu diffusion would otherwise lead to low‐ k degradation. [ 10 ] The specific resistivity of the barrier material is usually higher than that of copper, so its thickness should be minimal. An increase in low‐ k porosity not only reduces the k ‐value but also worsens the mechanical strength and makes it difficult to deposit defect‐free thin barrier layers since their thickness becomes comparable to the pore size.…”

Examination of Salicylaldehyde as a Surface Modifier of Manganese for Application in Chemical Mechanical Planarization

“…1 A number of nontraditional barrier materials have been proposed to address this demand, among which the Mn based liners have received considerable attention in recent years. 2 These latter materials include self-aligned MnSi x O y , [3][4][5] as well as Mn and Mn-oxide 6 layers of <5 nm thickness, fabricated by vapor deposition techniques. These diffusion barriers have been shown to provide ultrathin conformal layers on densely patterned wafers with satisfactory adhesion as well as effective blockage of copper.…”

“…These diffusion barriers have been shown to provide ultrathin conformal layers on densely patterned wafers with satisfactory adhesion as well as effective blockage of copper. [2][3][4][5][6] However, the Mn component of such self-aligned barriers is electro-active with respect to Cu, and hence becomes prone to strong galvanic corrosion when interfaced with Cu and exposed to a wet chemical environment. 7 This situation typically arises during damascene fabrication of Cu interconnects where both the Cu lines and the Mn-based barrier films are sequentially processed by chemical mechanical planarization (CMP).…”

Advanced Interconnects: Materials, Processing, and Reliability

“…Some materials like Ta/TaN were developed for microporous films like PECVD low-k materials with k ≥ 2.5. 13 Their application to more porous materials is very challenging. Several new candidates have been considered including MnN-like compounds.…”